WorldWideScience

Sample records for range sheep flocks

  1. Prevalence of and risk factors associated with ovine progressive pneumonia in Wyoming sheep flocks.

    Science.gov (United States)

    Gerstner, Shelley; Adamovicz, Jeffrey J; Duncan, John V; Laegreid, William W; Marshall, Katherine L; Logan, James R; Schumaker, Brant A

    2015-10-15

    To determine the prevalence of antibodies against small ruminant lentivirus (SRLV), the causative agent of ovine progressive pneumonia (OPP), and to identify risk factors associated with OPP in Wyoming sheep flocks. Cross-sectional study. 1,415 sheep from 54 flocks in Wyoming. Flocks were surveyed as part of the National Animal Health Monitoring System (NAHMS) 2011 sheep study. Serum samples obtained from sheep in Wyoming were analyzed for anti-SRLV antibodies by use of a competitive-inhibition ELISA. The prevalence of seropositive animals overall and within each flock was calculated. Respective associations between flock OPP status and various demographic and management variables were assessed. The estimated prevalence of sheep seropositive for anti-SRLV antibodies and OPP-infected flocks in Wyoming was 18.0% and 47.5%, respectively. Within OPP-infected flocks, the prevalence of seropositive sheep ranged from 3.9% to 96%. Flocks maintained on nonfenced range were more likely to be infected with OPP than were flocks maintained on fenced range (OR, 3.4; 95% confidence interval, 1.1 to 10.7). The estimated prevalence of OPP-infected flocks in Wyoming did not vary substantially from that at the regional or national level reported in the NAHMS 2001 sheep study. Compared with results of the NAHMS 2011 sheep study, Wyoming producers were more familiar with OPP than were other US sheep producers, but only 61% of Wyoming producers surveyed reported being very or somewhat familiar with the disease. Results indicated that OPP is prevalent in many Wyoming sheep flocks, which suggested that continued efforts are necessary to increase producer knowledge about the disease and investigate practices to minimize economic losses associated with OPP.

  2. High frequency of chlamydial co-infections in clinically healthy sheep flocks

    Directory of Open Access Journals (Sweden)

    Sachse Konrad

    2011-06-01

    Full Text Available Abstract Background The epidemiological situation of ovine chlamydial infections in continental Europe, especially Germany is poorly characterised. Using the German state of Thuringia as a model example, the chlamydial sero- and antigen prevalence was estimated in thirty-two randomly selected sheep flocks with an average abortion rate lower than 1%. Seven vaccinated flocks were reviewed separately. Results A wide range of samples from 32 flocks were examined. Assumption of a seroprevalence of 10% (CI 95% at flock level, revealed that 94% of the tested flocks were serologically positive with ongoing infection (i.e. animals with seroconversion in nearly half (47% of the flocks. On the basis of an estimated 25% antigen prevalence (CI 95%, PCR and DNA microarray testing, together with sequencing revealed the presence of chlamydiae in 78% of the flocks. The species most frequently found was Chlamydophila (C. abortus (50% followed by C. pecorum (47% and C. psittaci genotype A (25%. Mixed infections occurred in 25% of the tested flocks. Samples obtained from the vaccinated flocks revealed the presence of C. abortus field samples in 4/7 flocks. C. pecorum was isolated from 2/7 flocks and the presence of seroconversion was determined in 3/7 flocks. Conclusions The results imply that chlamydial infections occur frequently in German sheep flocks, even in the absence of elevated abortion rates. The fact that C. pecorum and the potentially zoonotic C. psittaci were found alongside the classical abortifacient agent C. abortus, raise questions about the significance of this reservoir for animal and human health and underline the necessity for regular monitoring. Further studies are needed to identify the possible role of C. psittaci infections in sheep.

  3. Development of pneumonia in desert bighorn sheep after exposure to a flock of exotic wild and domestic sheep.

    Science.gov (United States)

    Callan, R J; Bunch, T D; Workman, G W; Mock, R E

    1991-03-15

    From 1986 to 1989, 5 desert bighorn sheep (3 Ovis canadensis mexicana and 2 O c nelsoni), ranging in age from 2 to 3 years, were exposed to a flock of exotic wild and domestic sheep to potentially achieve naturally acquired pneumonia. Pasteurella multocida was isolated from nasal samples from 4 of 6 sheep randomly sampled from the flock. Bighorn sheep were exposed individually and each exposure period was a trial. Treatment before and after exposure varied and included combinations of alpha interferon, antibiotics, anti-inflammatory drugs, and vaccines. Treatments were chosen on the basis of recommendations of others for treating pneumonia in desert bighorn sheep as well as our own experience in sheep and cattle. Regardless of treatment used, bighorn sheep in trials 1 to 4 developed signs of pneumonia within 10 to 14 days of exposure. Bighorn sheep in trials 1 to 3 died within 11 to 17 days of initial exposure. In trial 4, the bighorn sheep was isolated from the carrier sheep for treatment of pneumonia on day 14 and died on day 30. Pasteurella multocida was isolated from lung tissue in 3 of the 4 bighorn sheep. On the basis of results of trials 1 to 4, a more in depth clinical study was conducted in trial 5. Nasal and blood specimens were collected prior to and during trial 5 for bacteriologic culturing and serologic testing for bovine viral diarrhea virus, infectious bovine rhinotracheitis, parainfluenza-3 virus, and respiratory syncytial virus.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Prevalence of Coxiella burnetii in clinically healthy German sheep flocks

    Directory of Open Access Journals (Sweden)

    Hilbert Angela

    2012-03-01

    Full Text Available Abstract Background Current epidemiological data on the situation of Coxiella (C. burnetii infections in sheep are missing, making risk assessment and the implementation of counteractive measures difficult. Using the German state of Thuringia as a model example, the estimated sero-, and antigen prevalence of C. burnetii (10% and 25%, respectively was assessed at flock level in 39/252 randomly selected clinically healthy sheep flocks with more than 100 ewes and unknown abortion rate. Results The CHECKIT™ Q-fever Test Kit identified 11 (28% antibody positive herds, whereas real-time PCR revealed the presence of C. burnetii DNA in 2 (5% of the flocks. Multiple-locus variable number of tandem repeats analysis of 9 isolates obtained from one flock revealed identical profiles. All isolates contained the plasmid QpH1. Conclusions The results demonstrate that C. burnetii is present in clinically inconspicuous sheep flocks and sporadic flare-ups do occur as the notifications to the German animal disease reporting system show. Although C. burnetii infections are not a primary veterinary concern due to the lack of significant clinical impact on animal health (with the exception of goats, the eminent zoonotic risk for humans should not be underestimated. Therefore, strategies combining the interests of public and veterinary public health should include monitoring of flocks, the identification and culling of shedders as well as the administration of protective vaccines.

  5. The first survey for antibody against Bluetongue virus in sheep flocks in Southeast of Iran

    Institute of Scientific and Technical Information of China (English)

    Ali Asghar Mozaffari; Mohammad Khalili

    2012-01-01

    Objective: Bluetongue virus is an arthropod-borne Orbivirus in the family Reoviridae which infects both domestic and wild ruminants. Bluetongue disease is a "List A" disease of the Office of International Epizootics. To the best of our knowledge, no report has been published on bluetongue disease of sheep flocks of Southeast of Iran. The objective of this study was to describe the seroprevalence rates of BTV in sheep flocks in southeast of Iran. Methods: The blood samples were collected randomly from herds of Southeast of Iran. A total of 188 sera samples (94 male, 94 female) collected between 2009 and 2010, were available. Antibodies to BTV in sera were detected by using a commercial competitive ELISA (Institute Pourquier, Montpellier, France) according to manufacturer’s instructions. Results: The seroprevalence rates were 6.57 %for sheep herds. Within a herd, prevalence of BTV seropositive animals ranged from 0% to 42.85%. 33.3% sheep flocks were positive to BTV antibodies. Sex didn't affect the rate of seropositivity, but the rate of seropositivity was significantly changed in different age groups. Conclusion: This study describes the seroprevalence rates of Bluetongue virus (BTV) in sheep flocks in southeast of Iran for the first time.

  6. Fatal systemic cladosporiosis in a merino sheep flock.

    Science.gov (United States)

    Haligur, Mehmet; Ozmen, Ozlem; Dorrestein, Gerry M

    2010-12-01

    Systemic cladosporiosis is described in 25 merino sheep from a flock consisting 250 animals. The fungal pneumonia appeared after an intensive antibiotic treatment, because of a respiratory system disorder. The pen of the flock was humid and crowded, and animals had signs of respiratory distress, coughing, fever and anorexia. All of the ill animals died, and necropsy was performed on 10 sheep. The lesions were characterized by a multifocal pyogranulomatous pneumonia and an abomasitis. Severe hemorrhages were observed in the lungs. At the histopathological examination, severe vasculitis with thrombosis was observed in various organs, especially in the lungs and abomasums, suggestive for a hematogenous dissemination of the infection in these organs. Numerous PAS-positive fungal elements were seen in the pyogranulomatous foci. Dark green fungal colonies were seen in the blood agar and Sabouraud dextrose agar that were identified as Cladosporium cladosporioides. This report highlights that phaeohyphomycosis can cause a severe systemic and fatal disease in merino sheep under insufficient management conditions.

  7. Transmission and control implications of seroconversion to Maedi-Visna virus in Basque dairy-sheep flocks.

    Science.gov (United States)

    Berriatua, Eduardo; Alvarez, Vega; Extramiana, Belén; González, Lorenzo; Daltabuit, Mara; Juste, Ramón

    2003-09-12

    A retrospective analysis of seroconversion to Maedi-Visna virus (MVV) was carried out for 10 infected semi-intensively reared dairy-sheep flocks that were tested annually between 1994 and 1999. Four of the flocks raised replacement lambs artificially with bovine colostrum and milk replacement to avoid lactogenic MVV infection but did not prevent aerosol contact between replacements and other sheep in the flock. Flock culling percentages ranged between 14 and 25% and in eight flocks the number of sheep that seroconverted was similar to or lower than the number of sheep culled--suggesting that incidence could be reduced by culling seropositive sheep without increasing average culling percentages. Random-effects logistic regression indicated that seroconversion was associated positively with increasing contact with infected sheep and with lifetime MV-serological status of the dam (used as a proxy measure of genetic susceptibility), but not with mode of rearing pre-weaning (artificially or with a seropositive or seronegative dam). Our results indicate that when conditions allow efficient horizontal transmission, there is no evidence that lactogenic infection increases the risk of MV infection and that there is an important inheritable component of disease resistance or susceptibility.

  8. A case-control study on scrapie in Norwegian sheep flocks.

    Science.gov (United States)

    Hopp, P; Ulvund, M J; Jarp, J

    2001-10-11

    Scrapie first was detected in indigenous sheep in Norway in 1981, and from 1995 to 1997 an increase in the number of flocks with scrapie cases was recorded. These flocks were mainly in one geographical region. A study to identify risk factors for scrapie was conducted. The study had three frequency-matched controls selected for every case within the same Veterinary District. A questionnaire was submitted to 176 sheep flocks (42 had been scrapie flocks). The data obtained by the questionnaire were linked to data collected from governmental and industry registers. After imputing missing data using single random imputation, the statistical analysis was performed using multivariable conditional logistic regression. Purchase of female sheep from scrapie flocks, sharing of rams, or sharing of pastures between different flocks were the risk factors associated with the occurrence of scrapie. Of factors potentially sustaining and promoting the infection in the flock, number of winter-fed sheep, number of buildings for housing sheep, rams and ewes shared room during mating period and increase in the flock size were associated with scrapie. We interpret these findings to show that factors involving transfer of sheep between flocks or direct contact between sheep of different flocks are important for the spread of scrapie. Management factors are important for the development of scrapie. However, it was not possible to discriminate between the different management factors in this study at the flock level. Also, factors indicating awareness and interest of the farmer (as well as willingness to contact a veterinarian for diseased sheep) were related to the detection of scrapie in the flock.

  9. Epidemiological characteristics of classical scrapie outbreaks in 30 sheep flocks in the United Kingdom.

    Directory of Open Access Journals (Sweden)

    K Marie McIntyre

    Full Text Available Most previous analyses of scrapie outbreaks have focused on flocks run by research institutes, which may not reflect the field situation. Within this study, we attempt to rectify this deficit by describing the epidemiological characteristics of 30 sheep flocks naturally-infected with classical scrapie, and by exploring possible underlying causes of variation in the characteristics between flocks, including flock-level prion protein (PrP genotype profile. In total, the study involved PrP genotype data for nearly 8600 animals and over 400 scrapie cases.We found that most scrapie cases were restricted to just two PrP genotypes (ARQ/VRQ and VRQ/VRQ, though two flocks had markedly different affected genotypes, despite having similar underlying genotype profiles to other flocks of the same breed; we identified differences amongst flocks in the age of cases of certain PrP genotypes; we found that the age-at-onset of clinical signs depended on peak incidence and flock type; we found evidence that purchasing infected animals is an important means of introducing scrapie to a flock; we found some evidence that flock-level PrP genotype profile and flock size account for variation in outbreak characteristics; identified seasonality in cases associated with lambing time in certain flocks; and we identified one case that was homozygous for phenylalanine at codon 141, a polymorphism associated with a very high risk of atypical scrapie, and 28 cases that were heterozygous at this codon.This paper presents the largest study to date on commercially-run sheep flocks naturally-infected with classical scrapie, involving 30 study flocks, more than 400 scrapie cases and over 8500 PrP genotypes. We show that some of the observed variation in epidemiological characteristics between farms is related to differences in their PrP genotype profile; although much remains unexplained and may instead be attributed to the stochastic nature of scrapie dynamics.

  10. Effects of housing on the incidence of visna/maedi virus infection in sheep flocks.

    Science.gov (United States)

    Leginagoikoa, I; Minguijón, E; Juste, R A; Barandika, J; Amorena, B; de Andrés, D; Badiola, J J; Luján, L; Berriatua, E

    2010-06-01

    The incidence of seroconversion to visna/maedi virus (VMV) infection and its relationship with management and sheep building structure was investigated in 15 dairy sheep flocks in Spain during 3-7years. Incidence rates were 0.09 per sheep-year at risk in semi-intensive Latxa flocks and 0.44 per sheep-year at risk in intensive Assaf flocks and was greatest for the one year old Assaf replacement flock. Separate multivariable models developed for replacement and adult flocks indicated that in both cases seroconversion was strongly associated to direct contact exposure to infected sheep and to being born to a seropositive dam. The latter effect was independent of the mode of rearing preweaning and the risk of seroconversion was similar for sheep fed colostrum and milk from a seropositive or a seronegative dam. These results are further evidence of the efficiency of horizontal VMV transmission by close contact between sheep and also suggest a inheritable component of susceptibility and resistance to infection. In contrast, indirect aerogenous contact with seropositive sheep was not associated with seroconversion as evidenced in replacement sheep housed in separate pens in the same building as adult infected sheep for one year. Consequently, VMV may not be efficiently airborne over short distances and this is important for control of infection. Moreover, there was no relationship between seroconversion and shed open areas. The latter could be related to having examined few flocks in which high infection prevalence dominated the transmission process while ventilation, may depend on a variety of unrecorded factors whose relationship to infection needs to be further investigated.

  11. Worm control practice against gastro-intestinal parasites in Norwegian sheep and goat flocks

    Directory of Open Access Journals (Sweden)

    Vatn Synnøve

    2011-05-01

    Full Text Available Abstract Background Anthelmintic treatment is the most common way of controlling nematode infections in ruminants. However, several countries have reported anthelmintic resistance (AR, representing a limitation for sustainable small ruminant production. The knowledge regarding worm control management represents a baseline to develop a guideline for preventing AR. The aim of the present study was therefore to improve our knowledge about the worm control practices in small ruminant flocks in Norway. Methods A questionnaire survey regarding worm control practices was performed in small ruminant flocks in Norway. Flocks were selected from the three main areas of small ruminant farming, i.e. the coastal, inland and northern areas. A total of 825 questionnaires, comprising 587 sheep flocks (return rate of 51.3% and 238 goat flocks (52.6% were included. Results The results indicated that visual appraisal of individual weight was the most common means of estimating the anthelmintic dose used in sheep (78.6% and goat (85.1% flocks. The mean yearly drenching rate in lambs and ewes were 2.5 ± 1.7 and 1.9 ± 1.1, respectively, whereas it was 1.0 (once a year in goats. However, these figures were higher in sheep in the coastal area with a rate of 3.4 and 2.2 in lambs and ewes, respectively. Benzimidazoles were the predominant anthelmintic class used in sheep flocks (64.9% in 2007, whereas benzimidazoles and macrocyclic lactones were both equally used in dairy goat flocks. In the period of 2005-2007, 46.3% of the sheep flocks never changed the anthelmintic class. The dose and move strategy was practiced in 33.2% of the sheep flocks. Conclusions The present study showed that inaccurate weight calculation gives a risk of under-dosing in over 90% of the sheep and goat flocks in Norway. Taken together with a high treatment frequency in lambs, a lack of anthelmintic class rotation and the common use of a dose-and-move strategy, a real danger for development of

  12. Housing conditions and management practices associated with neonatal lamb mortality in sheep flocks in Norway.

    Science.gov (United States)

    Holmøy, Ingrid H; Kielland, Camilla; Stubsjøen, Solveig Marie; Hektoen, Lisbeth; Waage, Steinar

    2012-12-01

    A study was conducted in order to obtain information about sheep farms in Norway and to identify housing and management characteristics that were risk factors for neonatal mortality of lambs 0-5 days of age. A questionnaire was submitted to sheep farmers, who provided demographic data and information on sheep housing conditions and feeding and management practices. Our description of farms is based on the questionnaire responses received from 2260 farmers. Data on lamb mortality during the preceding lambing season were available for those flocks that were enrolled in the Norwegian Sheep Recording System. Some flocks where the number of lambing ewes was less than 20 or greater than 400 were excluded. The total number of flocks included in the analysis of neonatal mortality was 1125. An increase in the mean number of live-born lambs per ewe per flock was associated with increasing neonatal mortality. Factors independently associated with increased neonatal survival were continuous monitoring of the ewes during the lambing season, active support to ensure sufficient colostrum intake of the lambs, feeding a combination of grass silage and hay compared with grass silage alone, and supplying roughage at least twice per day versus only once. Increased survival was also observed in flocks where the farmer had at least 15 years of experience in sheep farming. Flocks in which the Spæl breed predominated had lower odds for neonatal deaths compared to flocks in which the Norwegian White breed predominated. In conclusion, measures in sheep flocks targeted at feeding practices during the indoor feeding period and management practice during lambing season would be expected to reduce neonatal lamb mortality.

  13. Temperament, age and weather predict social interaction in the sheep flock.

    Science.gov (United States)

    Doyle, Rebecca E; Broster, John C; Barnes, Kirsty; Browne, William J

    2016-10-01

    The aim of the current study was to investigate the social relationships between individual sheep, and factors that influence this, through the novel application of the statistical multiple membership multiple classification (MMMC) model. In study one 49 ewes (ranging between 1 and 8 years old) were fitted with data loggers, which recorded when pairs of sheep were within 4m or less of each other, within a social group, for a total of 6days. In study two proximity data were collected from 45 ewes over 17days, as were measures of ewe temperament, weight and weather. In study 1 age difference significantly influenced daily contact time, with sheep of the same age spending an average of 20min 43s together per day, whereas pairs with the greatest difference in age spent 16min 33s together. Maximum daily temperature also significantly affected contact time, being longer on hotter days (34min 40s hottest day vs. 18min 17s coolest day), as did precipitation (29min 33s wettest day vs. 10min 32s no rain). Vocalisation in isolation, as a measure of temperament, also affected contacts, with sheep with the same frequency of vocalisations spending more time together (27min 16s) than those with the greatest difference in vocalisations (19min 36s). Sheep behaviour in the isolation box test (IBT) was also correlated over time, but vocalisations and movement were not correlated. Influences of age, temperature and rain on social contact are all well-established and so indicate that MMMC modelling is a useful way to analyse social structures of the flock. While it has been demonstrated that personality factors affect social relationships in non-human animals, the finding that vocalisation in isolation influences pair social contact in sheep is a novel one. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Feasibility of pedigree recording and genetic selection in village sheep flocks of smallholder farmers.

    Science.gov (United States)

    Gizaw, Solomon; Goshme, Shenkute; Getachew, Tesfaye; Haile, Aynalem; Rischkowsky, Barbara; van Arendonk, Johan; Valle-Zárate, Anne; Dessie, Tadelle; Mwai, Ally Okeyo

    2014-06-01

    Pedigree recording and genetic selection in village flocks of smallholder farmers have been deemed infeasible by researchers and development workers. This is mainly due to the difficulty of sire identification under uncontrolled village breeding practices. A cooperative village sheep-breeding scheme was designed to achieve controlled breeding and implemented for Menz sheep of Ethiopia in 2009. In this paper, we evaluated the reliability of pedigree recording in village flocks by comparing genetic parameters estimated from data sets collected in the cooperative village and in a nucleus flock maintained under controlled breeding. Effectiveness of selection in the cooperative village was evaluated based on trends in breeding values over generations. Heritability estimates for 6-month weight recorded in the village and the nucleus flock were very similar. There was an increasing trend over generations in average estimated breeding values for 6-month weight in the village flocks. These results have a number of implications: the pedigree recorded in the village flocks was reliable; genetic parameters, which have so far been estimated based on nucleus data sets, can be estimated based on village recording; and appreciable genetic improvement could be achieved in village sheep selection programs under low-input smallholder farming systems.

  15. Preliminary survey on the impact of Schmallenberg virus on sheep flocks in South of Belgium.

    Science.gov (United States)

    Saegerman, C; Martinelle, L; Dal Pozzo, F; Kirschvink, N

    2014-10-01

    Between late February and May 2012, a preliminary anonym survey was conducted among sheep farmers in south of Belgium in order to contribute to future estimations of the economic losses caused by Schmallenberg virus (SBV). Based on clinical signs consistent with SBV infection, this survey involved 13 meat sheep flocks considered as positive flocks with subsequent SBV detection by RT-qPCR [SBV-positive flocks (PF); total of 961 animals], and 13 meat sheep flocks considered as negative flocks (NF; total of 331 animals). These preliminary results indicated several significant characteristics that were more present in PF than in NF. These include an increased rate of abortions (6.7% in PF versus 3.2% in NF), of lambs born at term but presenting malformations (10.1% in PF versus 2.0% in NF) and of dystocia (10.1% in PF versus 3.4% in NF). Lamb mortality during the first week of life was reported more frequently in PF (8 of 13 PF, 61.5%) than in NF (1 of 13 NF, 7.7%). In PF, the observed prolificacy rate was 2-fold lower (93%) than expected (186%). The implementation of a survey at larger scale, including a high number of breeders, is necessary to allow a more detailed analysis of the SBV impact in the sheep sector.

  16. Prevalence of Clostridium perfringens toxin genotypes in enterotoxemia suspected sheep flocks of Andhra Pradesh

    Directory of Open Access Journals (Sweden)

    N. Vinod Kumar

    2014-12-01

    Full Text Available Aim: To identify the Clostridium perfringens toxin genotypes prevailing in enterotoxemia suspected sheep flocks in Andhra Pradesh by using multiplex PCR. Materials and Methods: Intestinal scrapings were collected from lambs below three months of age from flocks with similar management from different Districts of Andhra Pradesh, in India. A total of 208 samples were collected with 140 from enterotoxemia suspected flocks and 68 from healthy flocks. Following processing and culture of the samples, colonies were identified by morphological and biochemical tests. All the clostridial isolates were analyzed by multiplex PCR. Results: C. pefringens were isolated from 97 out of 140 enterotoxemia suspected flocks (69.29% and 27 out of 68 healthy flocks (39.71 %. Genotyping of the 97 iolates by multiplex PCR from enterotoxemia suspected flocks indicated C. perfringens type A, C and D 67.01% (65 out of 97; 11.34% (11 out of 97 and 21.65% (21 out of 97 respectively. Isolates from healthy flocks indicated the presence of type A and D 92.59% (25 out of 27 and 7.40% (2 out of 27 respectively. Number of isolates from enterotoxaemia suspected flocks were significantly high (P<0.001 than healthy flocks. Type A is found to be predominant in both enterotoxemia suspected and healthy flocks (67.01% and 92.59%. Conclusions: Prevalence of C. perfringens type C was reported for the first time in India. Clostridium perfringens type D and type C were found to be the major causative types for enterotoxemia.

  17. Detection of antibodies against Chlamydophila abortus in Costa Rican sheep flocks

    Directory of Open Access Journals (Sweden)

    R. Villagra-Blanco

    2015-09-01

    Full Text Available A total of 359 sheep samples from 15 flocks were analyzed for the presence of antibodies against Chlamydophila abortus using a commercial Enzyme linked Immunosorbent Assay (ELISA. Antibodies were detected in 19 (5.29% sheep from 12 (80% flocks. Seropositive animals were found in all analyzed regions (Central, Chorotega, Atlantic Huetar, North Huetar and Central Pacific determining prevalence between 0.28% and 4.4%, and intra-flock positivity between 3.7% and 25.0%. The survey revealed two risk factors associated with seropositivity; introducing animals (males and females, embryos, or semen from other farms or from abroad without any sanitary certification, and flocks not having quarantine areas or separated boxes for diseased animals. No clinical signs of disease were observed in positive seroreactors. C. abortus seems to be present in Costa Rica in a very low prevalence in sheep flocks. Further studies, to isolate the bacteria are required. Finally, implementation of control measures to prevent the spread of C. abortus is recommended.

  18. Seroepidemiological survey of sheep flocks from Northern Japan for Mycoplasma ovipneumoniae and Mycoplasma agalactiae.

    Science.gov (United States)

    Giangaspero, Massimo; Nicholas, Robin A J; Hlusek, Miroslav; Bonfini, Barbara; Osawa, Takeshi; Orusa, Riccardo; Tatami, Shingo; Takagi, Eishu; Moriya, Hiroaki; Okura, Norimoto; Kato, Kazuo; Kimura, Atsushi; Harasawa, Ryô; Ayling, Roger D

    2012-03-01

    Sheep flocks from Hokkaido, Iwate and Aomori, three northern prefectures of Japan, were screened for antibodies to Mycoplasma ovipneumoniae and Mycoplasma agalactiae by ELISA. Sixty four animals out of 246 (26%) were seropositive to M. ovipneumoniae, with positive results obtained from all three prefectures. None of the sera tested were serologically positive to M. agalactiae.

  19. A serological investigation of caseous lymphadenitis in four flocks of sheep

    NARCIS (Netherlands)

    Malone, F.E.; Fee, S.A.; Kamp, E.M.; King, D.C.; Baird, G.J.; O'Reilly, K.M.; Murdock, F.E.A.

    2006-01-01

    A double antibody sandwich ELISA developed by ID-DLO, Lelystad to detect Corynebacterium pseudotuberculosis infection was used on 329 sheep from four pedigree Suffolk flocks in which clinical cases of caseous lymphadenitis (CLA) had occurred. At subsequent necropsy, typical CLA lesions were seen in

  20. Artificial immune system and sheep flock algorithms for two-stage fixed-charge transportation problem

    DEFF Research Database (Denmark)

    Kannan, Devika; Govindan, Kannan; Soleimani, Hamed

    2014-01-01

    approaches are unable to solve real-world instances of such NP-hard problems in a reasonable time. These approaches involve cumbersome computational steps in real-size cases. In order to solve the mixed integer linear programming model, we develop an artificial immune system and a sheep flock algorithm...

  1. Comparison of strategies for substantiating freedom from scrapie in a sheep flock

    Directory of Open Access Journals (Sweden)

    Ducrot Christian

    2009-04-01

    Full Text Available Abstract Background The public health threat represented by a potential circulation of bovine spongiform encephalopathy agent in sheep population has led European animal health authorities to launch large screening and genetic selection programmes. If demonstrated, such a circulation would have dramatic economic consequences for sheep breeding sector. In this context, it is important to evaluate the feasibility of qualification procedures that would allow sheep breeders demonstrating their flock is free from scrapie. Classical approaches, based on surveys designed to detect disease presence, do not account for scrapie specificities: the genetic variations of susceptibility and the absence of live diagnostic test routinely available. Adapting these approaches leads to a paradoxical situation in which a greater amount of testing is needed to substantiate disease freedom in genetically resistant flocks than in susceptible flocks, whereas probability of disease freedom is a priori higher in the former than in the latter. The goal of this study was to propose, evaluate and compare several qualification strategies for demonstrating a flock is free from scrapie. Results A probabilistic framework was defined that accounts for scrapie specificities and allows solving the preceding paradox. Six qualification strategies were defined that combine genotyping data, diagnostic tests results and flock pedigree. These were compared in two types of simulated flocks: resistant and susceptible flocks. Two strategies allowed demonstrating disease freedom in several years, for the majority of simulated flocks: a strategy in which all the flock animals are genotyped, and a strategy in which only founders animals are genotyped, the flock pedigree being known. In both cases, diagnostic tests are performed on culled animals. The less costly strategy varied according to the genetic context (resistant or susceptible and to the relative costs of a genotyping exam and of a

  2. The Effects of Good Breeding Practices on Brucellosis Incidence in Kangal Akkaraman Sheep Flocks

    Directory of Open Access Journals (Sweden)

    Yusuf Ziya Oğrak

    2014-03-01

    Full Text Available The aim of the present study was to compare the incidence of brucellosis in groups of Kangal Akkaraman sheep flocks raised in farm conditions in Sivas province. The first and second groups of the sheep flocks were part of the 8 sub-projects which belong to The Project entitled “Nationwide Genetic Improvement of Small Ruminants in Farm Condition” continued for 7 and 1-3 years, respectively. The third group of the sheep flocks was not part of this nationwide project. The study material consisted of 1491 units of blood serum (n=278, 1166 and 47 for the first, second and third groups, respectively. Brucella antibodies were looked for in blood serum using tube and slide agglutination tests. The incidences of brucellosis were 4% and 7.5% in flocks which were part of the nationwide project continued for 7 and 3 years, respectively and 25.5% for the flocks not part of the nationwide project. The differences between groups were found statistically significant. Even though there was no brucella vaccination programs in the flocks of the nationwide project, practices such as regular controls of the flocks by veterinary technicians, drug/vaccination applications for parasites and some other diseases, removal of rams positive for brucella before breeding season significantly reduced the incidence of brucella. As a result, promoting good breeding practices along with the brucella vaccination program applied by the related Ministry can be very beneficial for the eradication of brucella disease that is a big problem for the country.

  3. Mutations in Ovis aries TMEM154 are associated with lower small ruminant lentivirus proviral concentration in one sheep flock.

    Science.gov (United States)

    Alshanbari, F A; Mousel, M R; Reynolds, J O; Herrmann-Hoesing, L M; Highland, M A; Lewis, G S; White, S N

    2014-08-01

    Small ruminant lentivirus (SRLV), also called ovine progressive pneumonia virus or maedi-visna, is present in 24% of US sheep. Like human immunodeficiency virus, SRLV is a macrophage-tropic lentivirus that causes lifelong infection. The production impacts from SRLV are due to a range of disease symptoms, including pneumonia, arthritis, mastitis, body condition wasting and encephalitis. There is no cure and no effective vaccine for preventing SRLV infection. However, breed differences in prevalence and proviral concentration indicate a genetic basis for susceptibility to SRLV. Animals with high blood proviral concentration show increased tissue lesion severity, so proviral concentration represents a live animal test for control post-infection in terms of proviral replication and disease severity. Recently, it was found that sheep with two copies of TMEM154 haplotype 1 (encoding lysine at position 35) had lower odds of SRLV infection. In this study, we examined the relationship between SRLV control post-infection and variants in two genes, TMEM154 and CCR5, in four flocks containing 1403 SRLV-positive sheep. We found two copies of TMEM154 haplotype 1 were associated with lower SRLV proviral concentration in one flock (P < 0.02). This identified the same favorable diplotype for SRLV control post-infection as for odds of infection. However, frequencies of haplotypes 2 and 3 were too low in the other three flocks to test. The CCR5 promoter deletion did not have consistent association with SRLV proviral concentration. Future work in flocks with more balanced allele frequencies is needed to confirm or refute TMEM154 association with control of SRLV post-infection. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Animal Genetics published by John Wiley & Sons Ltd on behalf of Stichting International Foundation for Animal Genetics.

  4. Flock-level seroprevalence of, and risk factors for, Neospora caninum among sheep and goats in northern Jordan.

    Science.gov (United States)

    Abo-Shehada, Mahmoud N; Abu-Halaweh, Marwan M

    2010-01-01

    During the period January 2002 to December 2003, serum samples were collected from 104 small ruminant flocks consisting of 18 sheep flocks, 27 goat flocks and 59 mixed flocks containing both sheep and goats in northern Jordan. Only female animals were sampled. At least 5 females aged over 2 years per flock per species were sampled and examined for anti-Neospora caninum antibodies using ELISA. To increase the chances of detecting positive flocks, sick or older ewes were sampled. Also, N. caninum DNA was investigated in 7 sheep brains using PCR technique and 1 was found positive. The flock-level true seroprevalence in small ruminants was 53% (95% CI: 43,63). The true flock-level seroprevalence was higher in sheep (92%) than goats (12%) (OR=55; 95% CI: 17,197). Similarly, the individual-level seroprevalence in sheep and goat was 63% and 2% respectively (OR=25; 95% CI: 16,39). Out of 32 production and health management variables, the presence of dogs with the flock (OR=3.6, 95% CI: 1.2,10) enhanced seropositivity. Cold temperate climate (OR=0.1, 95% CI: 0.03,0.4), veterinary supervision (OR=0.2, 95% CI: 0.06,0.6) and buying healthy animals to replace those culled (OR=0.3, 95% CI: 0.1,0.97) reduced the risk of seropositivity. Both sheep and goats in Jordan are exposed to N. caninum infection with higher seroprevalence in sheep than goats. The contribution of N. caninum to abortion in small ruminant flock needs to be evaluated. Educating the farmers with regard to the role of dogs in transmitting N. caninum infection is expected to enhance small ruminant health in Jordan.

  5. A serological investigation of caseous lymphadenitis in four flocks of sheep

    Directory of Open Access Journals (Sweden)

    Malone Frank E

    2006-01-01

    Full Text Available Abstract A double antibody sandwich ELISA developed by ID-DLO, Lelystad to detect Corynebacterium pseudotuberculosis infection was used on 329 sheep from four pedigree Suffolk flocks in which clinical cases of caseous lymphadenitis (CLA had occurred. At subsequent necropsy, typical CLA lesions were seen in 133 sheep, and the diagnosis was confirmed on culture. Lesions were most commonly seen in lungs (n = 46, parotid lymph nodes (n = 44, prescapular lymph nodes (n = 38 and mediastinal lymph nodes (n = 31. The sensitivity of the ELISA test for detecting culture-positive sheep was 0.88, while the specificity of the test was 0.55. The antibody ELISA detected 87.5 per cent of sheep that had CLA lesions restricted to internal organs only. It was concluded that the ELISA test has a valuable role in detecting sheep with both clinical and subclinical CLA.

  6. Diversity of ectoparasites in sheep flocks in São Paulo, Brazil.

    Science.gov (United States)

    Madeira, N G; Amarante, A F; Padovani, C R

    2000-08-01

    The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of São Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the 'Associação Paulista de Criadores de Ovinos' (ASPACO; São Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.

  7. Ovine and Caprine Brucellosis (Brucella melitensis) in Aborted Animals in Jordanian Sheep and Goat Flocks

    OpenAIRE

    Assadullah Samadi; M. MK. Ababneh; Giadinis, N. D.; LAFI, S. Q.

    2010-01-01

    Two hundred and fifty five biological samples were collected from 188 animals (81 sheep and 107 goats) during the lambing season from September 2009 to April 2010 from the Mafraq region of Jordan. Sampled animals belonged to 93 sheep and goat flocks that had abortion cases in the region. One hundred and seven (41.9%) biological samples were positive for the omp2 primers that were able to identify all Brucella species in the collected samples which were obtained from 86 aborted animals (86/188...

  8. Deletion variant near ZNF389 is associated with control of ovine lentivirus in multiple sheep flocks

    Science.gov (United States)

    White, S N; Mousel, M R; Reynolds, J O; Herrmann-Hoesing, L M; Knowles, D P

    2014-01-01

    Ovine lentivirus (OvLV) is a macrophage-tropic lentivirus found in many countries that causes interstitial pneumonia, mastitis, arthritis and cachexia in sheep. There is no preventive vaccine and no cure, but breed differences suggest marker-assisted selective breeding might improve odds of infection and control of OvLV post-infection. Although variants in TMEM154 have consistent association with odds of infection, no variant in any gene has been associated with host control of OvLV post-infection in multiple animal sets. Proviral concentration is a live-animal diagnostic measure of OvLV control post-infection related to severity of OvLV-induced lesions. A recent genome-wide association study identified a region including four zinc finger genes associated with proviral concentration in one Rambouillet flock. To refine this region, we tested additional variants and identified a small insertion/deletion variant near ZNF389 that showed consistent association with proviral concentration in three animal sets (P sheep from multiple locations and management conditions. Strikingly, one flock had exceptionally high prevalence (>87%, including yearlings) and mean proviral concentration (>950 copies/μg), possibly due to needle sharing. The best estimate of proviral concentration by genotype, obtained from all 1310 OvLV-positive animals tested, showed insertion homozygotes had less than half the proviral concentration of other genotypes (P sheep flocks. PMID:24303974

  9. Dynamics of the natural transmission of bovine spongiform encephalopathy within an intensively managed sheep flock.

    Science.gov (United States)

    Jeffrey, Martin; Witz, Janey P; Martin, Stuart; Hawkins, Steve A C; Bellworthy, Sue J; Dexter, Glenda E; Thurston, Lisa; González, Lorenzo

    2015-10-28

    Sheep are susceptible to the bovine spongiform encephalopathy (BSE) agent and in the UK they may have been exposed to BSE via contaminated meat and bone meal. An experimental sheep flock was established to determine whether ovine BSE could be naturally transmitted under conditions of intensive husbandry. The flock consisted of 113 sheep of different breeds and susceptible PRNP genotypes orally dosed with BSE, 159 sheep subsequently born to them and 125 unchallenged sentinel controls. BSE was confirmed in 104 (92%) orally dosed sheep and natural transmission was recorded for 14 of 79 (18%) lambs born to BSE infected dams, with rates varying according to PRNP genotype. The likelihood of natural BSE transmission was linked to stage of incubation period of the dam: the attack rate for lambs born within 100 days of the death of BSE infected dams was significantly higher (9/22, 41%) than for the rest (5/57, 9%). Within the group of ewes lambing close to death, those rearing infected progeny (n = 8, for 9/12 infected lambs) showed a significantly greater involvement of lymphoid tissues than those rearing non-infected offspring (n = 8, for 0/10 infected lambs). Horizontal transmission to the progeny of non-infected mothers was recorded only once (1/205, 0.5%). This low rate of lateral transmission was attributed, at least partly, to an almost complete absence of infected placentas. We conclude that, although BSE can be naturally transmitted through dam-lamb close contact, the infection in this study flock would not have persisted due to low-efficiency maternal and lateral transmissions.

  10. Ovine and Caprine Brucellosis (Brucella melitensis in Aborted Animals in Jordanian Sheep and Goat Flocks

    Directory of Open Access Journals (Sweden)

    Assadullah Samadi

    2010-01-01

    Full Text Available Two hundred and fifty five biological samples were collected from 188 animals (81 sheep and 107 goats during the lambing season from September 2009 to April 2010 from the Mafraq region of Jordan. Sampled animals belonged to 93 sheep and goat flocks that had abortion cases in the region. One hundred and seven (41.9% biological samples were positive for the omp2 primers that were able to identify all Brucella species in the collected samples which were obtained from 86 aborted animals (86/188=45.7%. Using the B. melitensis insertion sequence 711 (IS711 primers on the 107 omp2 positive samples, only 61 confirmed to be positive for B. melitensis. These positive samples were obtained from 28 sheep and 33 goats. The prevalence rate of B. melitensis was 27.1% (51/188 among aborted animals. For differentiation between vaccine strain and field strain infection, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP method using PstI endonuclease enzyme was used. Vaccination with Rev-1 in the last year (OR=2.92, CI: 1.1–7.7 and grazing at common pasture (OR=2.78, CI: 1.05–7.36 were statistically significant (P≤.05 risk factors positively associated with the occurrence of brucellosis in sheep and goat flocks.

  11. Ovine and Caprine Brucellosis (Brucella melitensis) in Aborted Animals in Jordanian Sheep and Goat Flocks.

    Science.gov (United States)

    Samadi, Assadullah; Ababneh, M Mk; Giadinis, N D; Lafi, S Q

    2010-10-28

    Two hundred and fifty five biological samples were collected from 188 animals (81 sheep and 107 goats) during the lambing season from September 2009 to April 2010 from the Mafraq region of Jordan. Sampled animals belonged to 93 sheep and goat flocks that had abortion cases in the region. One hundred and seven (41.9%) biological samples were positive for the omp2 primers that were able to identify all Brucella species in the collected samples which were obtained from 86 aborted animals (86/188 = 45.7%). Using the B. melitensis insertion sequence 711 (IS711) primers on the 107 omp2 positive samples, only 61 confirmed to be positive for B. melitensis. These positive samples were obtained from 28 sheep and 33 goats. The prevalence rate of B. melitensis was 27.1% (51/188) among aborted animals. For differentiation between vaccine strain and field strain infection, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method using PstI endonuclease enzyme was used. Vaccination with Rev-1 in the last year (OR = 2.92, CI: 1.1-7.7) and grazing at common pasture (OR = 2.78, CI: 1.05-7.36) were statistically significant (P ≤ .05) risk factors positively associated with the occurrence of brucellosis in sheep and goat flocks.

  12. Problems with readings of electronic tagged sheep in dairy flocks

    Directory of Open Access Journals (Sweden)

    Antun Kostelić

    2010-01-01

    Full Text Available Reliable traceability system in animal production is a crucial part for protection of animal and human health. Small ruminants are usually ear’ tagged but this tagging system especially in extensive production systems is not reliable. The use of Radio Frequency Indentifying Devices (RFID, or electronic identification is more suitable. Ruminal boluses (Rumitag 20 gr, hdx are first chosen for ruminant tagging because they are easy and early applicable, easy to read and fraud resistant but they encounter some problems, mainly reading failure. In our trial we investigated reading failure on one sheep dairy farm. Six hundred and eight sheep have been milked during the trial and read for four times during milking. In all four readings we had quite high reading failure in comparison to other author findings. Probable cause for this very high failure could be the use of hand held readers in crowded environment which caused lot of double reading. This means that reading protocol should be improved. Unfortunately we did not have fixed reader so we could not compare readings.

  13. Report of outbreaks of classical scrapie in Dorper sheep and associated prion protein gene polymorphisms in affected flocks.

    Science.gov (United States)

    de Andrade, Caroline Pinto; de Oliveira, Eduardo Conceição; Leal, Juliano Souza; de Almeida, Laura Lopes; de Castro, Luiza Amaral; da Silva, Sergio Ceroni; Driemeier, David

    2015-08-01

    Scrapie is an infectious neurodegenerative disease affecting sheep and goats, related with conformational alteration of an isoform of the prion protein that leads to deposition and aggregation in the host's central nervous system. Occurrence of the natural disease can be influenced by host genetic factors, such as a single nucleotide polymorphism of the prion protein gene. This study reports three scrapie-affected Dorper flocks located on three different farms in Brazil. The objective of this study was to analyze these three flocks using scrapie diagnostics, combining histology, immunohistochemistry, genotyping, and western blot assays. For immunohistochemistry, 192 sheep were selected and 308 sheep blood samples were taken for genotyping. A total of 22 sheep were scrapie positive by immunohistochemistry. Of these, four presented clinical signs and had scrapie immunoreactivity at the obex in western blot assays. The sheep without clinical signs were positive in lymphoid organs, such as the third eyelid and rectal mucosa. The major genotypes found on the flocks were ARQ/ARQ, ARQ/ARR, and ARQ/VRQ for codons 136, 154, and 171. Most of the sheep were considered to be at moderate to high risk, based on risk groups for developing scrapie. Some blood samples were sequenced, and polymorphisms were identified in other codons, such as 127, 142, and 143. Our data demonstrate the importance of preclinical scrapie diagnosis in Brazilian sheep, as most of the affected sheep showed no clinical signs, and emphasize the relevance of genotyping other Dorper sheep to determine the genotypic profile of the breed.

  14. Increased Toxoplasma gondii positivity relative to age in 125 Scottish sheep flocks; evidence of frequent acquired infection

    Directory of Open Access Journals (Sweden)

    Katzer Frank

    2011-12-01

    Full Text Available Abstract Toxoplasma gondii seroprevalence was determined in 3333 sheep sera from 125 distinct sheep flocks in Scotland, with the majority of flocks being represented by 27 samples, which were collected between July 2006 and August 2008. The selected farms give a representative sample of 14 400 sheep holdings identified in the Scottish Government census data from 2004. Overall T. gondii seroprevalence, at individual sheep level, was determined to be 56.6%; each flock tested, had at least a single positive animal and in four flocks all ewes tested positive. The seroprevalence of sheep increased from 37.7% in one year old stock to 73.8% in ewes that were older than six years, showing that acquired infections during the life of the animals is frequent and that environmental contamination by T. gondii oocysts must be significant. The median within-flock seroprevalence varied significantly across Scotland, with the lowest seroprevalence of 42.3% in the South and the highest seroprevalence of 69.2% in the far North of Scotland and the Scottish Islands, while the central part of Scotland had a seroprevalence of 57.7%. This distribution disequilibrium may be due to the spread and survival of oocysts on pasture and lambing areas. A questionnaire accompanying sampling of flocks identified farms that used Toxovax®, a commercial vaccine that protects sheep from abortion due to T. gondii infection. Only 24.7% of farmers used the vaccine and the vaccine did not significantly affect the within flock seroprevalence for T. gondii. The implications for food safety and human infection are discussed.

  15. Serosurvey of Schmallenberg Virus Infections in Sheep and Goat Flocks in Lower Saxony, Germany.

    Science.gov (United States)

    Helmer, C; Eibach, R; Tegtmeyer, P C; Humann-Ziehank, E; Runge, M; Ganter, M

    2015-08-01

    Schmallenberg virus (SBV) infections can cause congenital musculoskeletal and vertebral malformations as well as neurological failures in foetuses of several ruminant species if susceptible mother animals were infected during early gestation. Blood samples gained from 17 goat and 64 sheep flocks in Lower Saxony (LS), Germany (January-May 2012), which is located in the core region of the 2011/2012 epidemic were tested for antibodies against SBV by ELISA to detect past exposure to SBV. A SBV-specific questionnaire was raised in all flocks. The calculated median within-herd prevalence was 43.8% (min-max: 5.6-93.3%) for goats and 58.7% (min-max: 6.5-100%) for sheep, showing that small ruminants in LS, especially goats, are still at risk of novel SBV infections in the following lambing seasons as not all animals have seroconverted yet. Statistical analysis revealed that goats have a significantly lower risk of SBV infections than sheep which might be explained by different host preferences of Culicoides ssp. as main vectors for SBV and different housing conditions.

  16. Factors influencing temporal variation of scrapie incidence within a closed Suffolk sheep flock.

    Science.gov (United States)

    González, Lorenzo; Dagleish, Mark P; Martin, Stuart; Finlayson, Jeanie; Sisó, Sílvia; Eaton, Samantha L; Goldmann, Wilfred; Witz, Janey; Hamilton, Scott; Stewart, Paula; Pang, Yvonne; Steele, Philip; Reid, Hugh W; Chianini, Francesca; Jeffrey, Martin

    2012-01-01

    Several studies have shown that transmission of natural scrapie can occur vertically and horizontally, and that variations in scrapie incidence between and within infected flocks are mostly due to differences in the proportion of sheep with susceptible and resistant PRNP genotypes. This report presents the results of a 12-year period of scrapie monitoring in a closed flock of Suffolk sheep, in which only animals of the ARQ/ARQ genotype developed disease. Among a total of 120 of these, scrapie attack rates varied between birth cohorts from 62.5 % (5/8) to 100 % (9/9), and the incidence of clinical disease among infected sheep from 88.9 % (8/9) to 100 % (in five birth cohorts). Susceptible sheep born to scrapie-infected ewes showed a slightly higher risk of becoming infected (97.2 %), produced earlier biopsy-positive results (mean 354 days) and developed disease at a younger age (median 736 days) than those born to non-infected dams (80.3 %, 451 and 782 days, respectively). Taken together, this was interpreted as evidence of maternal transmission. However, it was also observed that, for the birth cohorts with the highest incidence of scrapie (90-100 %), sheep born to infected and non-infected dams had a similar risk of developing scrapie (97.1 and 95.3 %, respectively). Compared with moderate-attack-rate cohorts (62.5-66.7 %), high-incidence cohorts had greater numbers of susceptible lambs born to infected ewes, suggesting that increased rates of horizontal transmission in these cohorts could have been due to high levels of environmental contamination caused by infected placentas.

  17. Sheep farmer opinions on the current and future role of veterinarians in flock health management on sheep farms: a qualitative study.

    Science.gov (United States)

    Kaler, Jasmeet; Green, L E

    2013-11-01

    A 2009 UK Government report on veterinary expertise in food animal production highlighted that there was insufficient herd health expertise among veterinarians and lack of appropriate business models to deliver veterinary services to the livestock sector. Approximately two thirds of sheep farmers only contact their veterinarian for emergencies and one fifth have all year round contact. The aim of the current study was to understand sheep farmers' perception, the current and future role of veterinarians in flock health management using qualitative methodology. The eligibility criteria were male farmers with a flock size of at least 200 adult sheep. Seven focus groups of farmers (n=45) stratified by three regions and two age groups (≤50 and >50) were conducted. Thematic analysis of the discussions indicated that most farmers considered and used their veterinarian as a fire-fighter, whilst other advice was gathered free of charge when the veterinarian was on the farm for other reasons (typically seeing cattle) or by telephone. A small group of farmers were using their veterinarian or a sheep consultant proactively with regular contact and found this financially beneficial. Farmers indicated that the key barriers to using a veterinarian proactively were inconsistent service, high turnover of veterinarians, lack of expertise of sheep farming among veterinarians and concern about independence of advice. Although economics was also mentioned as a key barrier to using veterinarians more proactively, most farmers did not know where they gained and lost income from their flock; there was heavy reliance on the single farm payment scheme (SPS) and very few farmers kept records from which they could investigate where there were inefficiencies in production. Overall sheep farmers considered sheep farming complex and that each farm was unique and that they themselves were the experts to manage their flock. We conclude that there is an impasse: veterinarians might need to

  18. Outbreak of subclinical mastitis in a flock of dairy sheep associated with Burkholderia cepacia complex infection.

    Science.gov (United States)

    Berriatua, E; Ziluaga, I; Miguel-Virto, C; Uribarren, P; Juste, R; Laevens, S; Vandamme, P; Govan, J R

    2001-03-01

    An outbreak of subclinical mastitis in a flock of 620 milking sheep was investigated. Microbiological and epidemiological analyses identified the causative agent as belonging to the Burkholderia cepacia complex (formerly Pseudomonas cepacia). Every ewe in the milking flock was individually tested for subclinical mastitis on two separate occasions, 6 weeks apart, by the California (rapid) mastitis test (CMT). The proportion of CMT-positive ewes was 69 of 393 (17.6%) on the first sampling and 27 of 490 (5.5%) on the second sampling. Pure B. cepacia cultures identified with the API 20 NE system were grown from 64 of 96 (66.7%) CMT-positive ewes and from 1 of 33 (3.0%) CMT-negative ewes. Statistical analysis confirmed the significant association between a positive CMT result and a positive culture result for B. cepacia complex. Additional polyphasic taxonomic analyses of eight isolates showed that seven belonged to B. cepacia genomovar III; the remaining isolate was identified as Burkholderia vietnamiensis (formerly B. cepacia genomovar V). Bacteriological investigation of samples from milking equipment and other environmental sites failed to identify "B. cepacia" in any of the samples taken. To our knowledge, this is the first report of an outbreak of natural infection in animals caused by B. cepacia complex and the first description of B. cepacia complex infection in sheep.

  19. Detection of Salmonella Carriers in Sheep and Goat Flocks of Bushehr and Lorestan Provinces, Iran

    Directory of Open Access Journals (Sweden)

    Hossein Esmaeili

    2017-01-01

    Full Text Available Background:    Salmonellosis is an infectious and a food-borne disease of humans and animals. The initial source of the infection is the intestinal tracts of birds and other animals. Apparently healthy animals can become subclinical carriers and persistently shed Salmonella in their feces which can act as a reservoir for the pathogen. The aim of this study is to detect the carriers of Salmonella among apparently healthy sheep and goat flocks of Bushehr and Lorestan provinces, Iran.Methods:    A total of 389 fecal samples were aseptically collected from the rectum of apparently healthy sheep and goat flocks of Bushehr and Lorestan provinces. Bacteriological culture was conducted using selenite cystine, Rappaport–Vassiliadis, brilliant green and xylose lysine deoxycholate agar. Suspected colonies were inoculated in to TSI, peptone water, Simmon’s Citrate, Urea medium and MRVP. Sero-groups were detected by antisera.              Results:    Two samples from 189 samples (1.05% were positive for Salmonella in Bushehr province. Salmonella abortusovis and Salmonella typhimurium were detected following serotyping. No Salmonella carriers were detected in Lorestan province.Conclusion:    As the rate of carriers of Salmonella was low, the risk of food-borne salmonellosis due to consumption of small ruminant's meat is low, especially in the condition of well cooked meat. Since S. abortusovis was detected, strategies of prevention and control of abortion due to this agent must be taken to reduce the economic losses. Moreover, the presence of S. typhimurium is a hazard to public health and people who have close contact to sheep and goats.

  20. Discrepant epidemiological patterns between classical and atypical scrapie in sheep flocks under French TSE control measures.

    Science.gov (United States)

    Fediaevsky, Alexandre; Gasqui, Patrick; Calavas, Didier; Ducrot, Christian

    2010-09-01

    The occurrence of secondary cases of atypical and classical scrapie was examined in 340 outbreaks of atypical and 296 of classical sheep scrapie detected in France during active surveillance programmes between 2002 and 2007. The prevalence of atypical scrapie in these flocks was 0.05% under selective culling and 0.07% under intensified monitoring i.e. not significantly different from that detected during active surveillance of the general population (P>0.5), whereas these figures were much higher for classical scrapie (3.67% and 0.25%, respectively, P<10(-5)). In addition the number of atypical scrapie cases per outbreak did not indicate clustering. The results suggest that atypical scrapie occurs spontaneously or is not particularly contagious, and that the control measures in force allowed appropriate control of classical scrapie but were not more efficient than active surveillance in detecting cases of atypical scrapie.

  1. Anthelmintic-resistant nematodes in Irish commercial sheep flocks- the state of play

    Directory of Open Access Journals (Sweden)

    Good Barbara

    2012-12-01

    Full Text Available Abstract Anthelmintic resistance has been reported in most sheep producing countries. Prior to the mid 1990s, reports of anthelmintic resistance in Ireland were sparse and focused on benzimidazole, one of the three classes of anthelmintic available during this period. This evidence for efficacy issues on Irish farms combined with awareness that anthelmintic resistance was increasingly being reported in other countries prompted the need for more comprehensive investigations on Irish farms. Faecal egg count reduction and micro-agar larval development tests were employed to investigate resistance to benzimidazole, levamisole and macrocyclic lactone. There is compelling evidence for resistance to both benzimidazole (>88% of flocks and levamisole (>39% of flocks. Resistance of nematode populations to macrocyclic lactone was suspected on a small number of farms (11% but needs to be confirmed. The recent introduction of two new classes of anthelmintics, after over a 25 year interval, together with the evidence that anthelmintic resistance is reported within a relatively short time following the introduction of a new anthelmintic compound means that the challenge to the industry is immediate. Actions are urgently required to manage anthelmintic resistance so as to prolong the lifespan of anthelmintics.

  2. Ranging Behaviour of Commercial Free-Range Broiler Chickens 1: Factors Related to Flock Variability

    Science.gov (United States)

    Hemsworth, Paul H.; Groves, Peter J.; Rault, Jean-Loup

    2017-01-01

    Simple Summary Free-range chicken meat consumption has increased. However, little is known about how meat chickens use the outdoor range. Understanding ranging behaviour could help improve management and shed and range design to ensure optimal ranging opportunities. We tracked 1200 individual broiler chickens in four mixed sex flocks on one commercial farm across two seasons. More chickens accessed the range in summer than winter. Chickens that accessed the range in winter did so less frequently and for a shorter period of time daily than chickens ranging in summer. The number of chickens ranging and the frequency and duration of range visits increased over the first two weeks of range access and stabilised thereafter. More chickens entered and exited the range through particular doors in the shed. More chickens ranged in the morning and evening compared to the middle of the day. Ranging behaviour decreased with increased rainfall and shed dew point. This study provides knowledge regarding ranging behaviour in commercial conditions that may guide improvements on farm to provide chickens with optimal ranging opportunities. Abstract Little is known about the ranging behaviour of chickens. Understanding ranging behaviour is required to improve management and shed and range design to ensure optimal ranging opportunities. Using Radio Frequency Identification technology, we tracked 300 individual broiler chickens in each of four mixed sex ROSS 308 flocks on one commercial farm across two seasons. Ranging behaviour was tracked from the first day of range access (21 days of age) until 35 days of age in winter and 44 days of age in summer. Range use was higher than previously reported from scan sampling studies. More chickens accessed the range in summer (81%) than winter (32%; p < 0.05). On average, daily frequency and duration of range use was greater in summer flocks (4.4 ± 0.1 visits for a total of 26.3 ± 0.8 min/day) than winter flocks (3.2 ± 0.2 visits for a total

  3. Target selected treatment with levamisole to control the development of anthelmintic resistance in a sheep flock.

    Science.gov (United States)

    Chagas, Ana Carolina de Souza; Domingues, Luciana Ferreira; Gaínza, Yousmel Alemán; Barioni-Júnior, Waldomiro; Esteves, Sérgio Novita; Niciura, Simone Cristina Méo

    2016-03-01

    Levamisole phosphate, chosen based on its 100 % efficacy demonstrated by a previous fecal egg count reduction test (FECRT), was used as the exclusive anthelmintic treatment in the Embrapa Southeast Livestock sheep flock from 2009 to 2014 in a target selected treatment scheme. In the present study, the effectiveness of this nematode control scheme was evaluated after 5 years by FECRT, larval development test (LDT), and a molecular test to assess the development of levamisole resistance in Haemonchus contortus. Animals were submitted to treatments with albendazole, levamisole, closantel, ivermectin, moxidectin, and monepantel. Eggs per gram of feces (EPG) counts and fecal cultures were performed, and anthelmintic efficacy was calculated by the RESO 4.0 program. The helminths of the flock (GIN Embrapa2014) were compared to susceptible (McMaster) and resistant (Embrapa2010) H. contortus isolates in the LDT to estimate the LC50 and LC90 of levamisole and in a molecular test to evaluate the 63-bp indel in the acr8 gene associated with levamisole resistance. In the FECRT, parasites were susceptible to monepantel (99.6 %) and closantel (98.3 %), but resistant to moxidectin (93.8 %), levamisole (70.4 %), ivermectin (48.1 %), and albendazole (0 %). In the coproculture on D14, and the control group presented 80 % H. contortus and 20 % Trichostrongylus sp., while in the monepantel group L1 were observed as well as Oesophagostomum sp. L3. LDT and resistance factors provided good separation between susceptible and resistant parasites. The genotypic frequencies of the 63-bp insertion in the acr8 gene in H. contortus were 11.9, 6.7, and 0 % in GIN Embrapa2014, Embrapa2010, and McMaster isolates, respectively. After 5 years of exclusive use, the nematodes developed resistance to levamisole, detected by FECRT and by increase in LC50 and LC90 for levamisole in the LDT. The 63-bp indel was not confirmed as a molecular marker of levamisole resistance in our isolates. The target

  4. Neospora caninum infection as a cause of reproductive failure in a sheep flock.

    Science.gov (United States)

    González-Warleta, Marta; Castro-Hermida, José Antonio; Regidor-Cerrillo, Javier; Benavides, Julio; Álvarez-García, Gema; Fuertes, Miguel; Ortega-Mora, Luis Miguel; Mezo, Mercedes

    2014-08-26

    Neospora caninum has been detected only sporadically in cases of ovine abortion, and it has therefore traditionally been considered as an unimportant parasite in small ruminants. This study was carried out with the aim of identifying the pathogen causing serious reproductive problems on a commercial sheep farm. Sera from all rams and ewes tested negative for antibodies against Border disease virus, Schmallenberg virus and Coxiella burnetii, and infections by these agents were therefore ruled out. Nevertheless, seropositivity to N. caninum and/or Toxoplasma gondii was detected, although the seroprevalence was higher in the case of N. caninum. The percentage of lambings and the number of lambs per dam were significantly lower in ewes that were seropositive to N. caninum while no effect on these parameters was detected in ewes that were seropositive to T. gondii. There was also no evidence of infection by T. gondii in the foetal/lamb tissues analyzed by PCR and/or immunohistopathological techniques. On the contrary, the DNA of N. caninum was detected in 13 out of 14 foetuses/lambs descendant from dams seropositive to this parasite. Characteristic lesions caused by N. caninum and/or its antigen were also detected. Genotyping of the N. caninum DNA revealed only two closely related microsatellite multilocus genotypes. The results clearly demonstrate that infection by N. caninum was the cause of the low reproductive performance of this sheep flock.

  5. [The resistance status of gastrointestinal strongyles against anthelmintics in three Estonian sheep flocks].

    Science.gov (United States)

    Anupöld, Ann Mari; Hinney, Barbara; Joachim, Anja

    2014-01-01

    Poor efficacy of anthelmintic drugs in sheep due to infections with resistant gastrointestinal strongyles is reported worldwide. The aim of this pilot study was to gain an insight into the current situation of anthelmintic efficacy in Estonian sheep flocks. From September to November 2012, faecal egg count reduction tests (FECRT) were carried out in three Estonian sheep farms, evaluating the efficacy of albendazole and ivermectin. Individual faecal samples were taken at the day of treatment and 10 to 14 days later and examined by a modified McMaster technique. Anthelmintic treatment was carried out with ivermectin (Bimectin 10 mg/ml, Bimeda Chemicals Export) subcutaneously with a dose rate of 0.2 mg/kg of body weight in the IVM group (n = 20 animals/farms 1 and 2; n = 5 for farm 3) or albendazol (Endospec 10%, Bimeda Chemicals Export) orally in the dose of 5 mg/kg of body weight in the ALB group (n = 20 animals/ farm); animals in the control group (n = 20 animals for farms 1 and 3, n = 18 for farm 2) were left untreated. The FECRT was carried out according to the WAAVP guidelines. On farm 1 the efficacy of albendazole and ivermectin was reduced with 66% and 65% FECR, respectively. With a FECR of 26% the results of farm 2 showed a pronounced albendazole resistance while ivermectin was still sufficiently efficient (99% reduction). Farm 3 showed nearly 100% efficacy of albendazole and ivermectin, but earlier problems with high endoparasite burden and mortality may indicate a possible developing albendazole resistance which could not be detected with the FECRT yet. The results of this study show that in Estonia resistance against benzimidazoles and macrocyclic lactones does occur, indicating that close countrywide monitoring is advisable.

  6. Case study of a commercial sheep flock under extensive mountain grazing: Pasture derived lipid compounds in milk and cheese.

    Science.gov (United States)

    Valdivielso, I; Bustamante, M A; Aldezabal, A; Amores, G; Virto, M; Ruiz de Gordoa, J C; de Renobales, M; Barron, L J R

    2016-04-15

    Terpenoid, fat-soluble antioxidant and fatty acid (FA) composition of pasture as well as those of milk and cheese from a commercial sheep flock managed under extensive mountain grazing in the east region of the Cantabrian mountain (Northern Spain) was investigated. The grazing period lasted for 2 months and ewes were at late lactation stage. Plants, feces, bulk milk and cheese samples were collected on two sampling dates. The abundance of the dominating botanical families in the mountain pasture prevailed in the sheep diet of the commercial flock. Major terpenoids and tocols in the pasture appeared as major ones in milk and cheese, whereas C18 unsaturated FAs in milk and cheese were derived from the intake of C18 polyunsaturated FAs which were prevalent in the pasture. No carotene was detected in the dairy samples but retinol (free or esterified), derived from the intake of β-carotene present in pasture plants, was found in milk and cheese.

  7. Outbreak of foot and mouth disease and peste des petits ruminants in sheep flock imported for immediate slaughter in Riyadh

    Directory of Open Access Journals (Sweden)

    M. A. Mahmoud

    2017-02-01

    Full Text Available Aim: To detect and identify the causative agent or agents of the following clinical symptoms which were fever, lack of appetite, salivation, vesiculation, erosions of the buccal mucosa, nose, and feet. The signs vary from mild to severe. The mortality rate of the disease is high. The morbidity rate reaches up to 100%. Sheep also show bloody diarrhea and rapid respiration. Sheep flock resident in El-Kharje Governorate. Materials and Methods: A total of 50 serum samples and 50 buffy coat samples were collected from Marino sheep flock suffered from high mortalities, fever, lameness, diarrhea, stomatitis, and respiratory distress. PrioCHECK® foot and mouth disease virus (FMDV nonstructural (NS (marketable enzyme-linked immunosorbent assay [ELISA] kit was used for revealing of the NS antibodies and liquid phase blocking enzyme immunoassay (LPBE for identifying the FMD serotype and examined by competitive ELISA (cELISA for detection of peste des petits ruminants (PPR antibodies. The buffy coat samples were examined by immunocapture ELISA (Ic ELISA for detection of PPR antigen. Results: Using PrioCHECK® FMDV NS: Commercial ELISA kit: 38/50 (76% of the serum samples were positive for the presence of FMD NS viral proteins. In addition, using LPBE the positive samples were identified as FMD serotype O. Examination of the serum sample by cELISA for detection of PPR antibodies gave positive results in 32/50 (64%. While the Ic ELISA identified 32 (64% positive reactors for PPR antigen. Conclusion: This study reflected high susceptibility of the imported sheep flocks to the infection with FMD and PPR viruses, which are endemic in the Kingdom of Saudi Arabia (KSA. Hence, the imported flocks that prepared for slaughter must be vaccinated with the used vaccine in KSA in the quarantine for the control of FMD especially when importation occurs from counters that are free from these diseases.

  8. Outbreak of foot and mouth disease and peste des petits ruminants in sheep flock imported for immediate slaughter in Riyadh

    Science.gov (United States)

    Mahmoud, M. A.; Galbat, S. A.

    2017-01-01

    Aim: To detect and identify the causative agent or agents of the following clinical symptoms which were fever, lack of appetite, salivation, vesiculation, erosions of the buccal mucosa, nose, and feet. The signs vary from mild to severe. The mortality rate of the disease is high. The morbidity rate reaches up to 100%. Sheep also show bloody diarrhea and rapid respiration. Sheep flock resident in El-Kharje Governorate. Materials and Methods: A total of 50 serum samples and 50 buffy coat samples were collected from Marino sheep flock suffered from high mortalities, fever, lameness, diarrhea, stomatitis, and respiratory distress. PrioCHECK® foot and mouth disease virus (FMDV) nonstructural (NS) (marketable enzyme-linked immunosorbent assay [ELISA] kit) was used for revealing of the NS antibodies and liquid phase blocking enzyme immunoassay (LPBE) for identifying the FMD serotype and examined by competitive ELISA (cELISA) for detection of peste des petits ruminants (PPR) antibodies. The buffy coat samples were examined by immunocapture ELISA (Ic ELISA) for detection of PPR antigen. Results: Using PrioCHECK® FMDV NS: Commercial ELISA kit: 38/50 (76%) of the serum samples were positive for the presence of FMD NS viral proteins. In addition, using LPBE the positive samples were identified as FMD serotype O. Examination of the serum sample by cELISA for detection of PPR antibodies gave positive results in 32/50 (64%). While the Ic ELISA identified 32 (64%) positive reactors for PPR antigen. Conclusion: This study reflected high susceptibility of the imported sheep flocks to the infection with FMD and PPR viruses, which are endemic in the Kingdom of Saudi Arabia (KSA). Hence, the imported flocks that prepared for slaughter must be vaccinated with the used vaccine in KSA in the quarantine for the control of FMD especially when importation occurs from counters that are free from these diseases. PMID:28344409

  9. Ovine progressive pneumonia provirus levels are unaffected by the prion 171R allele in an Idaho sheep flock.

    Science.gov (United States)

    Harrington, Robert D; Herrmann-Hoesing, Lynn M; White, Stephen N; O'Rourke, Katherine I; Knowles, Donald P

    2009-01-22

    Selective breeding of sheep for arginine (R) at prion gene (PRNP) codon 171 confers resistance to classical scrapie. However, other effects of 171R selection are uncertain. Ovine progressive pneumonia/Maedi-Visna virus (OPPV) may infect up to 66% of a flock thus any affect of 171R selection on OPPV susceptibility or disease progression could have major impact on the sheep industry. Hypotheses that the PRNP 171R allele is 1) associated with the presence of OPPV provirus and 2) associated with higher provirus levels were tested in an Idaho ewe flock. OPPV provirus was found in 226 of 358 ewes by quantitative PCR. The frequency of ewes with detectable provirus did not differ significantly among the 171QQ, 171QR, and 171RR genotypes (p > 0.05). Also, OPPV provirus levels in infected ewes were not significantly different among codon 171 genotypes (p > 0.05). These results show that, in the flock examined, the presence of OPPV provirus and provirus levels are not related to the PRNP 171R allele. Therefore, a genetic approach to scrapie control is not expected to increase or decrease the number of OPPV infected sheep or the progression of disease. This study provides further support to the adoption of PRNP 171R selection as a scrapie control measure.

  10. Ovine progressive pneumonia provirus levels are unaffected by the prion 171R allele in an Idaho sheep flock

    Directory of Open Access Journals (Sweden)

    Herrmann-Hoesing Lynn M

    2009-01-01

    Full Text Available Abstract Selective breeding of sheep for arginine (R at prion gene (PRNP codon 171 confers resistance to classical scrapie. However, other effects of 171R selection are uncertain. Ovine progressive pneumonia/Maedi-Visna virus (OPPV may infect up to 66% of a flock thus any affect of 171R selection on OPPV susceptibility or disease progression could have major impact on the sheep industry. Hypotheses that the PRNP 171R allele is 1 associated with the presence of OPPV provirus and 2 associated with higher provirus levels were tested in an Idaho ewe flock. OPPV provirus was found in 226 of 358 ewes by quantitative PCR. The frequency of ewes with detectable provirus did not differ significantly among the 171QQ, 171QR, and 171RR genotypes (p > 0.05. Also, OPPV provirus levels in infected ewes were not significantly different among codon 171 genotypes (p > 0.05. These results show that, in the flock examined, the presence of OPPV provirus and provirus levels are not related to the PRNP 171R allele. Therefore, a genetic approach to scrapie control is not expected to increase or decrease the number of OPPV infected sheep or the progression of disease. This study provides further support to the adoption of PRNP 171R selection as a scrapie control measure.

  11. Risk factors and impacts of clinical and subclinical mastitis in commercial meat-producing sheep flocks in Quebec, Canada.

    Science.gov (United States)

    Arsenault, Julie; Dubreuil, Pascal; Higgins, Robert; Bélanger, Denise

    2008-11-17

    We conducted a prospective observational study on clinical and subclinical mastitis in 30 commercial meat-producing sheep flocks from 2 regions of the province of Quebec, Canada. A total of 2,792 ewes selected in late gestation were followed from lambing to weaning of lambs. The incidence of clinical mastitis for the total lactation period (average of 58 days) ranged among flocks from 0 to 6.6%, with a median of 1.2%. The most frequently isolated bacteria from the cases of clinical mastitis, in pure or mixed culture, were Mannheimia haemolytica (26%), Staphylococcus aureus (23%), and coagulase-negative staphylococci (17%). Incidence of clinical mastitis was higher in ewes that gave birth to 3 or more lambs and from the Estrie region, and was associated with an increase in ewe mortality, an increase in lamb mortality at the litter level, and a decrease in lamb's weaning weight for lambs born in multiple litter size or from ewes >or=4 years old. Among 354 selected ewes with clinically normal udder at the end of lactation, 28.8% had potentially pathogenic bacteria isolated from milk. The most prevalent bacteria were S. aureus (9.3%) and coagulase-negative staphylococci (9.3%). The risk of having a positive culture in at least one half was different between the two regions. Prevalence of ewes (n=261) with California Mastitis Test (CMT) positive result in at least one half was 24.1 and 14.9% using a cut-off of >or=1+ and >or=2+, respectively. Prevalence of culture-positive udder halves was 11.7% for CMT-negative compared with 53.6% for CMT 3+ halves. CMT status was positively associated with the isolation of coagulase-negative staphylococci, M. haemolytica, S. aureus, and various Streptococcus species, but not with other isolated bacteria. Additionally, prevalence of CMT-positive halves was higher in ewes from the Estrie region, aged of >or=4 years versus 1 year, having clinical mastitis previously detected in the lactation and/or with low body condition score. Lamb

  12. Genetic factors controlling wool shedding in a composite Easycare sheep flock.

    Science.gov (United States)

    Matika, O; Bishop, S C; Pong-Wong, R; Riggio, V; Headon, D J

    2013-12-01

    Historically, sheep have been selectively bred for desirable traits including wool characteristics. However, recent moves towards extensive farming and reduced farm labour have seen a renewed interest in Easycare breeds. The aim of this study was to quantify the underlying genetic architecture of wool shedding in an Easycare flock. Wool shedding scores were collected from 565 pedigreed commercial Easycare sheep from 2002 to 2010. The wool scoring system was based on a 10-point (0-9) scale, with score 0 for animals retaining full fleece and 9 for those completely shedding. DNA was sampled from 200 animals of which 48 with extreme phenotypes were genotyped using a 50-k SNP chip. Three genetic analyses were performed: heritability analysis, complex segregation analysis to test for a major gene hypothesis and a genome-wide association study to map regions in the genome affecting the trait. Phenotypes were treated as a continuous or binary variable and categories. High estimates of heritability (0.80 when treated as a continuous, 0.65-0.75 as binary and 0.75 as categories) for shedding were obtained from linear mixed model analyses. Complex segregation analysis gave similar estimates (0.80 ± 0.06) to those above with additional evidence for a major gene with dominance effects. Mixed model association analyses identified four significant (P wool shedding, demonstrated the possibility of a single putative dominant gene controlling this trait and identified four SNPs that may be in partial linkage disequilibrium with gene(s) controlling shedding.

  13. Factors influencing variation of bulk milk antibiotic residue occurrence, somatic cell count, and total bacterial count in dairy sheep flocks.

    Science.gov (United States)

    Gonzalo, C; Carriedo, J A; García-Jimeno, M C; Pérez-Bilbao, M; de la Fuente, L F

    2010-04-01

    To study the variations of bulk tank milk variables in dairy ewe flocks and to identify the main target practices and flock groups to improve milk quality and safety, a total of 71,228 records of antibiotic residue (AR) and milk yield and 68,781 records of somatic cell count (SCC) and total bacterial count (TBC) were obtained over 5 yr from the same 209 dairy ewe flocks of the Assaf breed belonging to the Consortium for Ovine Promotion of Castilla-León (Spain). Based on a logistic regression model, year, month, semester, SCC, TBC, dry therapy, and milk yield significantly contributed to AR variation. High SCC was associated with increased AR violations. When antibiotic dry therapy was implemented, AR occurrence was higher than when this practice was not used. A polynomial monthly distribution throughout the year was observed for AR occurrence; the highest values were in autumn, coinciding with low milk yields per flock. Yearly occurrences drastically diminished from 2004 (1.36%) to 2008 (0.30%), probably as a result of effective educational programs. The mixed-model ANOVA of factors influencing variation in SCC and TBC indicated that year, month, AR, dry therapy group, milking type, and year interactions were significant variation factors for SCC and TBC; mathematical model accounted for 74.1 and 35.4% of total variance for each variable, respectively. Differences in management and hygiene practice caused significant SCC and TBC variations among flocks and within flocks throughout the 5-yr study. Over time, continuously dry treated flocks showed lower logSCC (5.80) and logTBC (4.92) than untreated (6.10 and 5.18, respectively) or discontinuously dry treated (6.01 and 5.05, respectively) flocks. Continuously dry treated flocks had lower AR occurrences than did discontinuously dry treated flocks. As a whole, AR occurrence and SCC and TBC bulk tank milk variables can be used for monitoring mammary health and milk hygiene and safety in dairy sheep throughout time.

  14. The signature of scrapie: differences in the PrP genotype profile of scrapie-affected and scrapie-free UK sheep flocks.

    OpenAIRE

    Baylis, M.; Houston, Fiona; Goldmann, W.; Hunter, N.; McLean, A.R.

    2000-01-01

    The amino-acid sequence of the PrP protein plays an important role in determining whether sheep are susceptible to scrapie. Although the genetics of scrapie susceptibility are now well understood, there have been few studies of the PrP gene at the population level, especially in commercially farmed sheep. Here we describe the PrP genetic profiles of the breeding stock of four UK sheep flocks, comprising nearly 650 animals in total. Two flocks had been scrapie affected for about eight years an...

  15. Vaccination delays maedi-visna lentivirus infection in a naturally-infected sheep flock

    Directory of Open Access Journals (Sweden)

    Gudnadóttir Margrét

    2013-01-01

    Full Text Available Abstract Background The Maedi-Visna (MV lentivirus causes two slowly progressive eventually fatal diseases of sheep, Maedi, a progressive interstitial pneumonia, and Visna, a progressive demyelinating disease of the central nervous system. Other lentiviruses also cause fatal slow infections in their natural hosts, e.g. the HIV virus in humans. Results of experimental vaccination against any lentivirus where vaccinees are challenged by natural routes, may therefore be of general interest. From 1991–1998 experiments with formalin-inactivated whole Maedi-Visna virus vaccine were carried out in the Department of Microbiology at the University of Iceland. Western Blot tests showed good immune response to all major proteins of the virus. When aluminium hydroxide was added to the vaccine all vaccinees developed neutralizing antibodies to the vaccine strain at titers 1/8 – 1/256. After housing 5 twin pairs, one twin in each pair vaccinated, the other unvaccinated, with infected sheep for 4 years, all the unvaccinated twins became infected, but only 2 of their vaccinated siblings as confirmed by virus cultivation experiments on tissues from their lungs spleens lymph nodes and choroid plexuses. Results One twin in each of 40 female twin pairs, born into a Maedi-Visna-infected sheep flock and kept under natural farming conditions in Cyprus, was vaccinated at birth, 3 weeks and 3 months, with formalin-inactivated whole Maedi-Visna lentivirus vaccine adjuvanted with aluminium hydroxide. 17 mothers of the twins were seronegative, 13 seroconverting and 10 had old infection. Of 17 vaccinees born to seronegative mothers 9 were uninfected at 28 months, but only 2 of their unvaccinated siblings. Of 13 unvaccinated twins born to seroconverting mothers, 12 caught infection during their first 10 weeks, but only 4 of their vaccinated siblings. Vaccination had no effects on 10 vaccinees born to mothers with long-standing Maedi-Visna infections and broad andibody

  16. A Bayesian framework to assess the potential for controlling classical scrapie in sheep flocks using a live diagnostic test.

    Science.gov (United States)

    Gryspeirt, Aiko; Gubbins, Simon

    2013-09-01

    Current strategies to control classical scrapie remove animals at risk of scrapie rather than those known to be infected with the scrapie agent. Advances in diagnostic tests, however, suggest that a more targeted approach involving the application of a rapid live test may be feasible in future. Here we consider the use of two diagnostic tests: recto-anal mucosa-associated lymphatic tissue (RAMALT) biopsies; and a blood-based assay. To assess their impact we developed a stochastic age- and prion protein (PrP) genotype-structured model for the dynamics of scrapie within a sheep flock. Parameters were estimated in a Bayesian framework to facilitate integration of a number of disparate datasets and to allow parameter uncertainty to be incorporated in model predictions. In small flocks a control strategy based on removal of clinical cases was sufficient to control disease and more stringent measures (including the use of a live diagnostic test) did not significantly reduce outbreak size or duration. In medium or large flocks strategies in which a large proportion of animals are tested with either live diagnostic test significantly reduced outbreak size, but not always duration, compared with removal of clinical cases. However, the current Compulsory Scrapie Flocks Scheme (CSFS) significantly reduced outbreak size and duration compared with both removal of clinical cases and all strategies using a live diagnostic test. Accordingly, under the assumptions made in the present study there is little benefit from implementing a control strategy which makes use of a live diagnostic test.

  17. Estimation of flock/herd-level true Mycobacterium avium subspecies paratuberculosis prevalence on sheep, beef cattle and deer farms in New Zealand using a novel Bayesian model.

    Science.gov (United States)

    Verdugo, Cristobal; Jones, Geoff; Johnson, Wes; Wilson, Peter; Stringer, Lesley; Heuer, Cord

    2014-12-01

    The study aimed to estimate the national- and island-level flock/herd true prevalence (HTP) of Mycobacterium avium subsp. paratuberculosis (MAP) infection in pastoral farmed sheep, beef cattle and deer in New Zealand. A random sample of 238 single- or multi-species farms was selected from a postal surveyed population of 1940 farms. The sample included 162 sheep flocks, 116 beef cattle and 99 deer herds from seven of 16 geographical regions. Twenty animals from each species present on farm were randomly selected for blood and faecal sampling. Pooled faecal culture testing was conducted using a single pool (sheep flocks) or two pools (beef cattle/deer herds) of 20 and 10 samples per pool, respectively. To increase flock/herd-level sensitivity, sera from all 20 animals from culture negative flocks/herds were individually tested by Pourquier(®) ELISA (sheep and cattle) or Paralisa™ (deer). Results were adjusted for sensitivity and specificity of diagnostic tests using a novel Bayesian latent class model. Outcomes were adjusted by their sampling fractions to obtain HTP estimates at national level. For each species, the posterior probability (POPR) of HTP differences between New Zealand North (NI) and South (SI) Islands was obtained. Across all species, 69% of farms had at least one species test positive. Sheep flocks had the highest HTP estimate (76%, posterior probability interval (PPI) 70-81%), followed by deer (46%, PPI 38-55%) and beef herds (42%, PPI 35-50%). Differences were observed between the two main islands of New Zealand, with higher HTP in sheep and beef cattle flocks/herds in the NI. Sheep flock HTP was 80% in the NI compared with 70% (POPR=0.96) in the SI, while the HTP for beef cattle was 44% in the NI and 38% in the SI (POPR=0.80). Conversely, deer HTP was higher in the SI (54%) than the NI (33%, POPR=0.99). Infection with MAP is endemic at high prevalence in sheep, beef cattle and deer flocks/herds across New Zealand.

  18. Evidence of co-infection with Mycobacterium bovis and tick-borne pathogens in a naturally infected sheep flock.

    Science.gov (United States)

    López, Vladimir; Alberdi, Pilar; Fernández de Mera, Isabel G; Barasona, José Angel; Vicente, Joaquín; Garrido, Joseba M; Torina, Alessandra; Caracappa, Santo; Lelli, Rossella Colomba; Gortázar, Christian; de la Fuente, José

    2016-03-01

    Ticks are responsible for the transmission of pathogens of veterinary importance, including those affecting sheep. The current study was designed to investigate co-infections with tick-borne and other pathogens in a naturally infected sheep flock with poor health condition using serology and PCR. Infection with Anaplasma ovis was detected by serology and PCR in 56% of the animals. The presence of Rickettsia spp. of the Spotted Fever Group (SFG) was detected by PCR and sequence analysis in 31% of the animals. All the animals were negative for Anaplasma phagocytophilum either by serology or PCR. Twelve sheep were randomly selected for anatomopathological studies. Five of these animals presented lesions consistent with Mycobacterium tuberculosis complex (MTBC) infection and spoligotyping confirmed infection with Mycobacterium bovis spoligotype SB0339. Co-infection with tick-borne pathogens and MTBC could contribute to the poor health condition observed in these animals but other uncontrolled factors may also be responsible. The differential expression of immune response genes supported previous findings in ruminants and suggested that infection with tick-borne pathogens and M. bovis may results in unique gene expression patterns in sheep. The results underline the need for further research into the possible role of sheep in the epidemiology of animal tuberculosis.

  19. Monitoring of parasitic cysts in the brains of a flock of sheep in Egypt

    Directory of Open Access Journals (Sweden)

    Shehata Anwar

    Full Text Available Cerebral parasitic cysts constitute a major problem for livestock. Among these, coenurosis and toxoplasmosis are predominant. Here, a total number of 60 sheep obtained from a private farm in Suez province, Egypt, were examined postmortem to detect visible parasitic cysts, and microscopically to detect small-sized entities. Necropsy revealed bladder-like cysts measuring 0.5-6.5 cm in diameter that were filled with a translucent fluid containing a large number of protoscolices. Accordingly, the cysts were identified as the metacestodeCoenurus cerebralis. Among the sheep examined, 11 animals (7 males and 4 females (18.3% were infected. Most of the cysts were located in the cerebral hemispheres, with numbers ranging from one to three per infected animal. The effect of the presence of cysts in the brain tissue was evaluated. Histopathologically, pseudocysts of the apicomplexan Toxoplasma gondii were found in two animals with no detectable inflammatory cell reactions. In conclusion, coenurosis and toxoplasmosis are serious parasitic problems that play a significant role in sheep management in Egypt, as a result of close contact between livestock and dogs and cats, which play a critical role in the life cycle of these parasites.

  20. The U.S. National Sheep Improvement Program: across-flock genetic evaluations and new trait development.

    Science.gov (United States)

    Notter, D R

    1998-09-01

    The U.S. National Sheep Improvement Program (NSIP) began in 1987 to provide within-flock genetic evaluations for the American sheep industry. An evaluation of operating procedures and methodology for NSIP began in 1993 and has resulted in across-flock, multiple-trait EPD for three breeds: Targhee, Suffolk, and Polypay. Traits reported in the across-flock analyses included direct and maternal effects on weaning weight in all breeds, postweaning weight at 120 d in Suffolk and Polypay and at 365 d in Targhee, greasy fleece weight in Targhee and Polypay, and wool fiber diameter in Targhee. Number born per ewe lambing was also evaluated in single-trait analyses for all breeds. Genetic parameters were derived separately for each breed. Important genetic antagonisms include an unfavorable genetic correlation of .51 between fleece weight and fiber diameter in Targhee and a genetic correlation of -.55 between direct and maternal effects on weaning weight in Polypay. Estimates of genetic trends between 1987 and 1995 were consistent with perceived breed roles. In Targhee, direct and maternal effects on body weights increased, fiber diameter declined, fleece weight was maintained, and number born declined. In Suffolk, direct effects on body weight increased, but number born and maternal effects on weaning weight did not change. In Polypay, number born and maternal contributions to weaning weight increased, but direct genetic merit for body weight declined. Prospective enhancements to NSIP include methods for genetic evaluation of performance in accelerated lambing and of carcass leanness and development of breeding objectives and selection aids for various production systems.

  1. Circulation of Coxiella burnetii in a Naturally Infected Flock of Dairy Sheep: Shedding Dynamics, Environmental Contamination, and Genotype Diversity.

    Science.gov (United States)

    Joulié, A; Laroucau, K; Bailly, X; Prigent, M; Gasqui, P; Lepetitcolin, E; Blanchard, B; Rousset, E; Sidi-Boumedine, K; Jourdain, E

    2015-10-01

    Q fever is a worldwide zoonosis caused by Coxiella burnetii. Domestic ruminants are considered to be the main reservoir. Sheep, in particular, may frequently cause outbreaks in humans. Because within-flock circulation data are essential to implementing optimal management strategies, we performed a follow-up study of a naturally infected flock of dairy sheep. We aimed to (i) describe C. burnetii shedding dynamics by sampling vaginal mucus, feces, and milk, (ii) assess circulating strain diversity, and (iii) quantify barn environmental contamination. For 8 months, we sampled vaginal mucus and feces every 3 weeks from aborting and nonaborting ewes (n=11 and n=26, respectively); for lactating females, milk was obtained as well. We also sampled vaginal mucus from nine ewe lambs. Dust and air samples were collected every 3 and 6 weeks, respectively. All samples were screened using real-time PCR, and strongly positive samples were further analyzed using quantitative PCR. Vaginal and fecal samples with sufficient bacterial burdens were then genotyped by multiple-locus variable-number tandem-repeat analysis (MLVA) using 17 markers. C. burnetii burdens were higher in vaginal mucus and feces than in milk, and they peaked in the first 3 weeks postabortion or postpartum. Primiparous females and aborting females tended to shed C. burnetii longer and have higher bacterial burdens than nonaborting and multiparous females. Six genotype clusters were identified; they were independent of abortion status, and within-individual genotype diversity was observed. C. burnetii was also detected in air and dust samples. Further studies should determine whether the within-flock circulation dynamics observed here are generalizable.

  2. Changes in terpenoid composition of milk and cheese from commercial sheep flocks associated with seasonal feeding regimens throughout lactation.

    Science.gov (United States)

    Valdivielso, Izaskun; de Renobales, Mertxe; Aldai, Noelia; Barron, Luis Javier R

    2017-01-01

    Changes in the terpenoid content of milk and cheese from commercial sheep flocks monitored throughout lactation in the Cantabrian area of northern Spain were investigated. The flocks followed the same seasonal feeding strategy during lactation: indoor feeding in winter (early lactation) based on concentrate and forage; part-time grazing in the valley in early spring (mid lactation); and from mid spring on (late lactation), flocks were managed under extensive mountain grazing. In the present study design, seasonal feeding and lactation stage were intrinsically linked and could not be considered in isolation, and a holistic approach was necessary to consider the whole production management of the commercial flocks studied. Furthermore, the study focused on the identification of sesquiterpenoid ratios to differentiate milks and cheeses produced under extensive mountain grazing from those produced under other seasonal feeding regimens. Total abundance of mono- and sesquiterpenoids and that of individual compounds such as α-pinene, β-caryophyllene, α-humulene, α-amorphene, and γ-cadinene significantly increased in milk and cheese from indoor feeding to mountain extensive grazing. Sesquiterpenoid ratios such as γ-cadinene/α-muurolene, γ-cadinene/δ-cadinene, β-caryophyllene/α-muurolene, and (β-caryophyllene + γ-cadinene)/α-muurolene were used to differentiate mountain milks and cheeses from those from indoor feeding and part-time grazing in the valley. Multivariate discriminant analysis applied to individual terpenoids and sesquiterpenoid ratios showed milk and cheese samples classified into 2 groups: samples from indoor feeding and part-time grazing in the valley were classified together, and clearly separated from mountain milks and cheeses. The results of the present study showed that the sesquiterpenoid ratios approach could help to differentiate mountain dairy products from others obtained under other specific feeding regimens in a local environment.

  3. Blowfly strike in sheep flocks as an example of the use of a time-space scan statistic to control confounding.

    Science.gov (United States)

    Ward, M P

    2001-04-13

    The use of a time-space scan statistic--defined by a cylindrical window with a circular geographic base and height corresponding to time--was investigated as a method of detecting clustering in veterinary epidemiology whilst controlling confounding. The example data set consisted of farmer-recorded occurrence of body strike and breech strike between August 1998 and May 1999 in 26 sheep flocks located in two local government areas of southeastern Queensland, Australia. This information was derived from a questionnaire survey mailed to farmers. Potentially confounding factors included in the investigation were flock size ( median), flock structure (proportion of lambs, wethers, ewes and rams), pesticide application for flystrike control (yes, no) and rainfall ( median). The total sheep population within selected flocks was 92,660; 1012 (1.09%) and 518 (0.56%) cases of body strike and breech strike were reported in 16 and 10 flocks, respectively.Clustering analyses of body strike and breech strike were undertaken separately, because different predisposing factors are associated with these diseases. Significant clustering of body strike (28.76 degrees S, 151.82 degrees E) during March 1999 and breech strike (28.73 degrees S, 151.16 degrees E) between February and May 1999 was detected. Adjusting for flock structure, flock size, pesticide use and rainfall did not alter the most likely cluster of body strike identified--although the relative risk changed (> 10%) after adjusting for flock structure. Adjustment for flock structure and rainfall resulted in different clusters of breech strike being identified.

  4. Risk factors for malformations and impact on reproductive performance and mortality rates of Schmallenberg virus in sheep flocks in the Netherlands.

    Science.gov (United States)

    Luttikholt, Saskia; Veldhuis, Anouk; van den Brom, René; Moll, Lammert; Lievaart-Peterson, Karianne; Peperkamp, Klaas; van Schaik, Gerdien; Vellema, Piet

    2014-01-01

    In Northwestern Europe, an epizootic outbreak of congenital malformations in newborn lambs due to infection with Schmallenberg virus (SBV) started at the end of 2011. The objectives of this study were to describe clinical symptoms of SBV infection, the effect of infection on mortality rates, and reproductive performance in sheep, as well as to identify and quantify flock level risk factors for SBV infections resulting in malformations in newborn lambs. A case-control study design was used, with 93 case flocks that had notified malformed lambs and 84 control flocks with no such lambs. Overall animal seroprevalence in case flocks was estimated at 82.0% (95% CI: 74.3-87.8), and was not significantly different from the prevalence in control flocks being 76.4% (95% CI: 67.2-83.6). The percentages of stillborn lambs or lambs that died before weaning, repeat breeders, and lambs with abnormal suckling behaviour were significantly higher in case flocks compared to control flocks. However, effect of SBV infection on mortality rates and reproductive performance seemed to be limited. Multivariable analysis showed that sheep flocks with an early start of the mating season, i.e. before August 2011 (OR = 33.1; 95% CI: 10.0-109.8) and in August 2011 (OR = 8.2; 95% CI: 2.7-24.6) had increased odds of malformations in newborn lambs caused by SBV compared to sheep flocks with a start of the mating season in October 2011. Other flock-level risk factors for malformations in newborn lambs were purchase of silage (OR 5.0; 95% CI: 1.7-15.0) and flocks with one or more dogs (OR = 3.3; 95% CI: 1.3-8.3). Delaying mating until October could be a potential preventive measure for naïve animals to reduce SBV induced losses. As duration of immunity after infection with SBV is expected to last for several years, future SBV induced congenital malformations are mainly expected in offspring of early mated seronegative animals.

  5. Risk factors for malformations and impact on reproductive performance and mortality rates of Schmallenberg virus in sheep flocks in the Netherlands.

    Directory of Open Access Journals (Sweden)

    Saskia Luttikholt

    Full Text Available In Northwestern Europe, an epizootic outbreak of congenital malformations in newborn lambs due to infection with Schmallenberg virus (SBV started at the end of 2011. The objectives of this study were to describe clinical symptoms of SBV infection, the effect of infection on mortality rates, and reproductive performance in sheep, as well as to identify and quantify flock level risk factors for SBV infections resulting in malformations in newborn lambs. A case-control study design was used, with 93 case flocks that had notified malformed lambs and 84 control flocks with no such lambs. Overall animal seroprevalence in case flocks was estimated at 82.0% (95% CI: 74.3-87.8, and was not significantly different from the prevalence in control flocks being 76.4% (95% CI: 67.2-83.6. The percentages of stillborn lambs or lambs that died before weaning, repeat breeders, and lambs with abnormal suckling behaviour were significantly higher in case flocks compared to control flocks. However, effect of SBV infection on mortality rates and reproductive performance seemed to be limited. Multivariable analysis showed that sheep flocks with an early start of the mating season, i.e. before August 2011 (OR = 33.1; 95% CI: 10.0-109.8 and in August 2011 (OR = 8.2; 95% CI: 2.7-24.6 had increased odds of malformations in newborn lambs caused by SBV compared to sheep flocks with a start of the mating season in October 2011. Other flock-level risk factors for malformations in newborn lambs were purchase of silage (OR 5.0; 95% CI: 1.7-15.0 and flocks with one or more dogs (OR = 3.3; 95% CI: 1.3-8.3. Delaying mating until October could be a potential preventive measure for naïve animals to reduce SBV induced losses. As duration of immunity after infection with SBV is expected to last for several years, future SBV induced congenital malformations are mainly expected in offspring of early mated seronegative animals.

  6. Preliminary serological study of Leptospira spp. in a sheep flock on the savannah of Bogotá

    Directory of Open Access Journals (Sweden)

    Jessica Alexandra Parra Solano

    2016-06-01

    Full Text Available The research aimed to conduct a serological study on leptospirosis in a sheep flock on the savannah of Bogotá, in order to detect the presence of this agent and to broaden knowledge on its tendency in our field. There were two visits to the farm, one during the dry season ( January and another one in the rainy season (May, to check 250 animals in each season, which were 100 males and 150 females of different races living on the farm. Microscopic agglutination test was used to determine the presence of antibodies to the six serovars that have been identified as the most frequent in Colombia in different domestic species. The results of the study indicated that the most common serovar in sheep was L. interrogans serovar Icterohaemorrhagiae, followed by L. interrogans serovar Bratislava, L. borgpetersenii serovar Hardjo, L. interrogans serovars Canicola, Pomona and Grippotyphosa. The research concluded that, even though there were no clinical cases reported during the study, leptospirosis associated with different serovars in sheep suggests the presence of the agent in the herd; new studies would be necessary to deepen our knowledge on the effect this would have on reproduction.

  7. Short communication: investigation of Coxiella burnetii occurrence in dairy sheep flocks by bulk-tank milk analysis and antibody level determination.

    Science.gov (United States)

    García-Pérez, A L; Astobiza, I; Barandika, J F; Atxaerandio, R; Hurtado, A; Juste, R A

    2009-04-01

    To estimate the prevalence of Coxiella burnetii in the dairy sheep population from the Basque Country (northern Spain), a study was carried out combining molecular and serological techniques. First, bulk-tank milk samples from 154 flocks belonging to the Latxa Breed Farmers Association were analyzed by PCR, with 22% of flocks testing positive for C. burnetii. Then, a selection of 34 flocks (7 PCR positive and 17 negative) was investigated for the presence of serum antibodies by ELISA test on 1,011 ewes (approximately 30 ewes per flock). A total of 8.9% of the animals were seropositive, 67.6% of the flocks had at least one seropositive animal, but only in 14.7% of them was seroprevalence greater than 25%. Older ewes showed a significantly greater prevalence (17.5%) compared with yearlings (7.5%) or replacement lambs (1.5%). A marginally significant association was found between seroprevalence and PCR detection of C. burnetii in bulk-tank milk. The widespread distribution of C. burnetii in the region advocates for the implementation of Q fever control strategies and highlights the potential risk of sheep as a reservoir and infection source for other domestic and wildlife species and the human population.

  8. A longitudinal study of factors associated with acute and chronic mastitis and their impact on lamb growth rate in 10 suckler sheep flocks in Great Britain.

    Science.gov (United States)

    Grant, Claire; Smith, Edward Mark; Green, Laura Elizabeth

    2016-05-01

    A 2-year prospective, longitudinal study of 10 suckler sheep flocks in Great Britain was run to identify factors associated with acute mastitis (AM) and chronic mastitis, and their impact on lamb growth rate. Data were collected on AM, intramammary masses (IMM; a marker for chronic mastitis), udder and teat conformation, teat lesions, body condition, ewe nutrition, litter size, lamb weight and general flock management. Each flock was visited twice each year, approximately 4 weeks before lambing and 9 weeks into lactation, for two years and all ewes present at a visit were examined. There were 7021 examinations in total. AM was reported in 2.1-3.0% of ewes/year; this ranged from 0.0% to 37.1% by flock. IMM were detected in 4.7% of ewes in pregnancy and 10.9% of ewes in lactation. Once an IMM had been detected there was an increased risk of future IMM although IMM were not consistently present. The majority of ewes had good udder conformation to suckle lambs. Factors associated with AM, IMM in pregnant and lactating ewes, udder conformation and lamb daily live weight gain were explored using mixed effect multivariable models. An increased risk of AM was associated with underfeeding protein in pregnancy (OR 4.05), forward pointing teats (OR 2.54), downward pointing teats (OR 4.68), rearing≥2 lambs (OR 2.65), non-traumatic teat lesions (OR 2.09); and marginally associated with the presence of IMM. An increased risk of IMM in lactation was associated with AM during lactation (OR 12.39), IMM in pregnancy (OR 4.79), IMM in the previous lactation (OR 4.77), underfeeding energy in pregnancy (OR 6.66) and traumatic teat lesions (OR 2.48). An increased risk of IMM in pregnancy was associated with IMM in the previous pregnancy, IMM in the previous lactation and underfeeding energy in the previous lactation (OR 2.95). Lower lamb daily live weight gain was associated with traumatic teat lesions, IMM in lactation (-0.01kg/day) and AM (-0.04kg/day). We conclude that inadequate

  9. Smothering in UK free-range flocks. Part 1: incidence, location, timing and management.

    Science.gov (United States)

    Barrett, J; Rayner, A C; Gill, R; Willings, T H; Bright, A

    2014-07-05

    Smothering in poultry is an economic and welfare-related concern. This study presents the first results from a questionnaire addressing the incidence, location, timing and management of smothering of free-range farm managers from two commercial egg companies (representing 35 per cent of the UK free-range egg supply). Overall, nearly 60 per cent of farm mangers experienced smothering in their last flock, with an average of 25.5 birds lost per incidence, although per cent mortality due to smothering was low (x̄=1.6 per cent). The majority of farm managers also reported that over 50 per cent of all their flocks placed had been affected by smothering. The location and timing of smothering (excluding smothering in nest boxes) tended to be unpredictable and varied between farms. Blocking off corners/nest boxes and walking birds more frequently were identified as popular smothering reduction measures, although there was a wide variety of reduction measures reported overall. The motivation to implement reduction measures was related to a farm manager's previous experience of smothering. To our knowledge, this is the first study to provide a representative industry estimate on the incidence, location, timing and management of smothering. The results suggest that smothering is a common problem, unpredictable between flocks with no clear, effective reduction strategies. A follow-up study will investigate the correlations among smothering, disease and other welfare problems and may shed further light on management solutions. British Veterinary Association.

  10. Estimating the human health risk from possible BSE infection of the British sheep flock.

    Science.gov (United States)

    Ferguson, N M; Ghani, A C; Donnelly, C A; Hagenaars, T J; Anderson, R M

    2002-01-24

    Following the controversial failure of a recent study and the small numbers of animals yet screened for infection, it remains uncertain whether bovine spongiform encephalopathy (BSE) was transmitted to sheep in the past via feed supplements and whether it is still present. Well grounded mathematical and statistical models are therefore essential to integrate the limited and disparate data, to explore uncertainty, and to define data-collection priorities. We analysed the implications of different scenarios of BSE spread in sheep for relative human exposure levels and variant Creutzfeldt-Jakob disease (vCJD) incidence. Here we show that, if BSE entered the sheep population and a degree of transmission occurred, then ongoing public health risks from ovine BSE are likely to be greater than those from cattle, but that any such risk could be reduced by up to 90% through additional restrictions on sheep products entering the food supply. Extending the analysis to consider absolute risk, we estimate the 95% confidence interval for future vCJD mortality to be 50 to 50,000 human deaths considering exposure to bovine BSE alone, with the upper bound increasing to 150,000 once we include exposure from the worst-case ovine BSE scenario examined.

  11. Risk Factors for Malformations and Impact on Reproductive Performance and Mortality Rates of Schmallenberg Virus in Sheep Flocks in the Netherlands

    OpenAIRE

    Luttikholt, Saskia; Veldhuis, Anouk; van den Brom, René; Moll, Lammert; Lievaart-Peterson, Karianne; Peperkamp, Klaas; Van Schaik, Gerdien; Vellema, Piet

    2014-01-01

    In Northwestern Europe, an epizootic outbreak of congenital malformations in newborn lambs due to infection with Schmallenberg virus (SBV) started at the end of 2011. The objectives of this study were to describe clinical symptoms of SBV infection, the effect of infection on mortality rates, and reproductive performance in sheep, as well as to identify and quantify flock level risk factors for SBV infections resulting in malformations in newborn lambs. A case-control study design was used, wi...

  12. Diversity and seasonal occurrence of Eimeria species in a mixed flock of communally reared sheep and goats in Mafikeng in the North West Province, South Africa

    Directory of Open Access Journals (Sweden)

    F.R. Bakunzi

    2010-05-01

    Full Text Available Diversity and seasonal occurrence of coccidia in a communally reared mixed flock of sheep and goats at Mafikeng, North West Province, South Africa, was determined between March 2008 and February 2009. Faecal specimens were collected directly from the rectum of the animals and the number of oocysts per gram of faeces (opg determined. The mean monthly opg for goats was significantly higher than that for sheep. Higher oocyst counts were observed during the hot, rainy season than during the cold, dry season. The highest mean values for both the sheep (862.5 opg and goats (1200 opg were recorded during March. Six species (Eimeria crandallis, E. bakuensis, E. weybridgensis, E. ahsata, E. intricata, and E. ovinoidalis were recovered from sheep, with E. crandallis and E. bakuensis occurring most frequently. The last 2 species, together with E. ahsata, are considered among the most pathogenic species in sheep. In goats, 7 species (E. arloingi, E. jolchijevi, E. caprina, E. alijevi, E. caprovina, E. christenseni and E. hirci were recovered, with E. arloingi and E. jolchijevi occurring most frequently. Up to 5 Eimeria species were recovered from individual specimens in goats while up to 4 were recovered in sheep. No cross-infections between goats and sheep were recorded and no clinical coccidiosis was noted during the study. It is increasingly becoming evident that the pathogenic E. arloingi is one of the most commonly occurring Eimeria species in goats in South Africa.

  13. An economic assessment of differently managed sheep flocks in eastern Turkey

    Directory of Open Access Journals (Sweden)

    Carlos Alcibiades Gimenez Diaz

    2010-01-01

    Full Text Available The aim of this study was to evaluate production and economic effects of feeding management and hormonal strategy on fat tailed sheep raised in eastern Anatolia. Animals were divided into six groups. Strategies were as follows: ewes were offered 1 1.0 of the estimated metabolizable energy (1.5kg dry grass hay/ewe/day (non flushed: NF, n=77 2 1.5kg dry grass hay/ewe/day and 300gr barley/ewe /day for 21 days prior to mating (flushing: F, n=100. Thereafter, nutritionally flushed ewes were subdivided: 3 supplemented with Vitamin A and E prior to mating (VIT, n=90, estrus of ewes were synchronized; 4 FGA (30mg impregnated sponge and 600 U PMSG (Sponge and Flushing: SF, n=113 or 5 PGF2α (125μg/mL Cloprostenol and 600 U PMSG (PGF, n=90, or 6 feed additive estrus synchronization treatment, Melengesterol Acetate (MGA, 0.25mg per head daily, n=90. Ewes in estrus were hand mated with rams of proven fertility. Reproductive performance was measured from fertility, percentage of animals in estrus within 6 days of ram introduction and the number of lambs born. Also, lamb birth and weaning weights, and survivability rate at weaning were recorded for prolonged productivity. Production data was subjected to gross margin calculating for economic evaluation. The use of MGA outperformed the other groups in fertility and survivability. Net returns per ewe were US$ 21.58/ewe. PGF2α hormone treatments (US$ 17.12/ewe was the most profitable source of extra revenue compared with vaginal sponge (US$ 12.69/ewe and supplementing vitamins (US$ 13.66/ewe. The economic viability and reproductive performance indicators demonstrate that steps should be taken to disseminate these new practices in the fat tailed sheep development program.

  14. The long-term dynamics of Campylobacter colonizing a free-range broiler breeder flock: an observational study.

    Science.gov (United States)

    Colles, Frances M; McCarthy, Noel D; Bliss, Carly M; Layton, Ruth; Maiden, Martin C J

    2015-04-01

    A free-range broiler breeder flock was studied in order to determine the natural patterns of Campylobacter colonization over a period of 63 weeks. Campylobacter sequence types (STs) were not mutually exclusive and on average colonized only 17.7% of the birds tested at any time. Campylobacter STs typically reached a peak in prevalence upon initial detection in the flock before tailing off, although the ST and antigenic flaA short variable region in combination were stable over a number of months. There was evidence that, with a couple of exceptions, the ecology of C. jejuni and C. coli differed, with the latter forming a more stable population. Despite being free range, no newly colonizing STs were detected over a 6-week period in autumn and a 10-week period in winter, towards the end of the study. There was limited evidence that those STs identified among broiler chicken flocks on the same farm site were likely to colonize the breeder flock earlier (R(2) 0.16, P 0.01). These results suggest that there is natural control of Campylobacter dynamics within a flock which could potentially be exploited in designing new intervention strategies, and that the two different species should perhaps be considered separately.

  15. Bacterial contamination of eggs and behaviour of poultry flocks in the free range environment.

    Science.gov (United States)

    Moyle, Talia; Drake, Kelly; Gole, Vaibhav; Chousalkar, Kapil; Hazel, Susan

    2016-12-01

    The free range production system is becoming more common in Australia and is expected to increase. Free range hens are exposed to more stressors in comparison to hens from barn and cage systems and it is suggested that stress can increase bacterial shedding on eggs. The aims of this study were to examine the level of total bacteria and Enterobacteriaceae populations, as well as the presence of Salmonella and Campylobacter, in eggs collected from two free range flocks on two different farms and to conduct longitudinal observations of the behaviour and welfare of hens in the free range production system. Hen age (weeks) was shown to have a significant effect (increase) on the level of total bacteria on the egg shell surface and in shell pores, as well as having an effect on feather condition score. As the hens aged, the frequency of external visual egg characteristics increased, as did feather condition score (where feather condition was poorer). These observations indicate areas which should be investigated further to improve the food safety of eggs and optimise the welfare of free range hens. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  16. Variation in the cervical range of motion over time measured by the "Flock of Birds" electromagnetic tracking system

    NARCIS (Netherlands)

    Bergman, GJD; Knoester, B; Assink, N; Dijkstra, PU; Winters, JC

    2005-01-01

    Study Design. Observational longitudinal study. Objective. To establish the normal variation over time for active and passive cervical range of motion ( ROM) measured with the Flock of Birds electromagnetic tracking system ( FOB). Summary of Background Data. Data about normal variation of cervical R

  17. F200Y polymorphism of the β-tubulin isotype 1 gene in Haemonchus contortus and sheep flock management practices related to anthelmintic resistance in eastern Amazon.

    Science.gov (United States)

    Chagas, Alexandre Moura; Sampaio Junior, Francisco Dantas; Pacheco, Adlilton; da Cunha, Amanda Batista; Cruz, Juliana Dos Santos; Scofield, Alessandra; Góes-Cavalcante, Gustavo

    2016-08-15

    The objective of the present study was to determine the frequency of the F200Y polymorphism in the β-tubulin isotype 1 gene of Haemonchus contortus from various sheep flocks in eastern Amazon, and to identify management practices that may favor the emergence of resistance to anthelmintic drugs in the same area. In total, 305 specimens of H. contortus were collected from sheep at 12 farms located in the state of Pará. An allele-specific PCR was performed to detect the F200Y polymorphism, and questionnaires were used to obtain information about the farms and flocks. All genotypes were detected as follows: 31% of the parasites were RR, 37% of the parasites were SR, and 32% were SS. The completed questionnaires revealed that all farms employed semi-intensive farming systems, performed suppressive anthelmintic treatment, and based their choice of drug on cost and availability rather than on any knowledge regarding drugs that remained effective on their property. It can thus be concluded that the SNP in codon 200 of the β-tubulin isotype 1 gene is present in the H. contortus populations from eastern Amazon, and that a series of management practices that favor the emergence of anthelmintic resistance are employed on these farms.

  18. Prevalence of Neospora caninum antibodies in sheep flocks of Uberlândia county, MG Prevalência de anticorpos anti-Neospora caninum em rebanhos de ovinos do município de Uberlândia, MG

    Directory of Open Access Journals (Sweden)

    Sandra Renata Sampaio Salaberry

    2010-09-01

    Full Text Available Neosporosis is a parasitic disease that occurs in sheep and is associated with reproductive failure. The aim of this study was to verify seroprevalence of Neospora caninum antibodies in 12 sheep flocks in Uberlândia county, Minas Gerais, Brazil, using Indirect Immunofluorescence Assay (IFA. A total of 334 sheep blood samples were analyzed and an epidemiologic questionnaire was applied for each farm in order to correlate with risk factors of neosporosis: gender, age, breed, abortion problems, contact with cattle and dogs, and presence of wild canids. The prevalence of Neospora caninum antibodies in sheep was 8.1%, with titers ranging from 50 to 3200 and 83.3% of farms detected at least one ovine reactive. There was statistically significant difference in flocks with abortion problems associated with the presence of Neospora caninum antibodies (p A neosporose é uma doença parasitária que acomete os ovinos e está associada a perdas reprodutivas. O objetivo deste estudo foi verificar a prevalência de anticorpos anti-Neospora caninum em 12 rebanhos de ovinos do município de Uberlândia, MG, utilizando a Técnica de Imunofluorescência Indireta (RIFI. Foram analisadas 334 amostras de sangue e, em cada propriedade, aplicou-se um questionário epidemiológico para avaliar os fatores de risco envolvidos na transmissão desse protozoário: sexo, idade, raça, problemas de aborto, contato com bovinos e caninos e presença de canídeos silvestres. A prevalência de anticorpos anti-Neospora caninum em ovinos foi de 8,1%, com títulos variando de 50 a 3200 e 83,3% das propriedades apresentaram pelo menos um ovino reagente. Houve diferença estatística significativa para rebanhos com problemas de aborto associados à presença de anticorpos anti-Neospora caninum (p < 0,05.

  19. Genetic trend for growth and wool performance in a closed flock of Bharat Merino sheep at sub temperate region of Kodai hills, Tamil Nadu

    Directory of Open Access Journals (Sweden)

    P. K. Mallick

    2016-03-01

    Full Text Available Aim: The study was conducted at Southern Regional Research Center, ICAR-Central Sheep and Wool Research Institute (CSWRI, Mannavanur, Kodaikanal, Tamil Nadu to estimate genetic trends for birth weight (BWT, weaning weight (3WT, 6 months weight (6WT, and greasy fleece weight (GFY in a Bharat Merino (BM flock, where selection was practiced for 6WT and GFY. Materials and Methods: The data for this study represents a total of 1652 BM lambs; progeny of 144 sires spread over 15 years starting from 2000 to 2014, obtained from the BM flock of ICAR-SRRC (CSWRI, Mannavanur, Kodaikanal, Tamil Nadu, India. The genetic trends were calculated by regression of average predicted breeding values using software WOMBAT for the traits BWT, 3WT, 6WT and GFY versus the animal’s birth year. Results: The least square means were 3.28±0.02 kg, 19.08±0.23 kg, 25.00±0.35 kg and 2.13±0.07 kg for BWT, 3WT, 6WT and GFY, respectively. Genetic trends were positive and highly significant (p<0.01 for BWT, while the values for 3WT, 6WT and GFY though positive, were not significant. The estimates of genetic trends in BWT, 3WT, 6WT and GFY were 5 g, 0.8 g, 7 g and 0.3 g/year gain and the fit of the regression shows 55%, 22%, 42% and 12% coefficient of determination with the regressed value, respectively. In this study, estimated mean predicted breeding value (kg in BWT and 3WT, 6WT and GFY were 0.067, 0.008, 0.036 and −0.003, respectively. Conclusion: Estimates of genetic trends indicated that there was a positive genetic improvement in all studied traits and selection would be effective for the improvement of body weight traits and GFY of BM sheep.

  20. Assessment of biosecurity measures against highly pathogenic avian influenza risks in small-scale commercial farms and free-range poultry flocks in the northcentral Nigeria.

    Science.gov (United States)

    Alhaji, N B; Odetokun, I A

    2011-04-01

    There is considerable global concern over the emergence of highly pathogenic avian influenza (HPAI) that has affected domestic poultry flocks in Nigeria and other parts of the world. There have been little investigations on the proposition that free-range flocks are potentially at higher risk of HPAI than confined small-scale commercial enterprises. The objective is to analyse the biosecurity measures instituted in the small-scale commercial poultry farms and established free-range bird flocks owned by households in the rural areas and qualitatively assess the risk status at the two levels of poultry management systems in northcentral Nigeria. We used data collected through questionnaire administration to farms and flock owners and subjected them to a traffic light system model to test for relative risks of HPAI infection based on the biosecurity measures put in place at the farm and flock levels. The results indicate that free-range flocks are at lower risk compared to small-scale commercial operations. These findings are plausible as birds from free-range flocks have more opportunities to contact wild bird reservoirs of low-pathogenic avian influenza (LPAI) strains than small-scale commercial poultry, thus providing them with constant challenge and maintenance of flock immunity. The development of efficient and effective biosecurity measures against poultry diseases on small-scale commercial farms requires adequate placement of barriers to provide segregation, cleaning and disinfection, while concerted community-led sanitary measures are required for free-range poultry flocks in the developing topical and subtropical economies.

  1. Density of wild prey modulates lynx kill rates on free-ranging domestic sheep.

    Directory of Open Access Journals (Sweden)

    John Odden

    Full Text Available Understanding the factors shaping the dynamics of carnivore-livestock conflicts is vital to facilitate large carnivore conservation in multi-use landscapes. We investigated how the density of their main wild prey, roe deer Capreolus capreolus, modulates individual Eurasian lynx Lynx lynx kill rates on free-ranging domestic sheep Ovis aries across a range of sheep and roe deer densities. Lynx kill rates on free-ranging domestic sheep were collected in south-eastern Norway from 1995 to 2011 along a gradient of different livestock and wild prey densities using VHF and GPS telemetry. We used zero-inflated negative binomial (ZINB models including lynx sex, sheep density and an index of roe deer density as explanatory variables to model observed kill rates on sheep, and ranked the models based on their AICc values. The model including the effects of lynx sex and sheep density in the zero-inflation model and the effect of lynx sex and roe deer density in the negative binomial part received most support. Irrespective of sheep density and sex, we found the lowest sheep kill rates in areas with high densities of roe deer. As roe deer density decreased, males killed sheep at higher rates, and this pattern held for both high and low sheep densities. Similarly, females killed sheep at higher rates in areas with high densities of sheep and low densities of roe deer. However, when sheep densities were low females rarely killed sheep irrespective of roe deer density. Our quantification of depredation rates can be the first step towards establishing fairer compensation systems based on more accurate and area specific estimation of losses. This study demonstrates how we can use ecological theory to predict where losses of sheep will be greatest, and can be used to identify areas where mitigation measures are most likely to be needed.

  2. Detection of Bovine Viral Diarrhoea Virus 2 as the Cause of Abortion Outbreaks on Commercial Sheep Flocks.

    Science.gov (United States)

    Elvira Partida, L; Fernández, M; Gutiérrez, J; Esnal, A; Benavides, J; Pérez, V; de la Torre, A; Álvarez, M; Esperón, F

    2017-02-01

    Outbreaks of abortions and lambs born with nervous clinical signs and/or congenital malformations affected different sheep farms in Spain. Initial diagnosis of 'border disease-like' was established, based on clinical signs, serology and/or RNA detection by a pan-pestivirus RT-PCR. However, further investigation using immunohistochemical and molecular techniques identified BVDV-2b as the aetiological agent.

  3. Comparative analysis of agr groups and virulence genes among subclinical and clinical mastitis Staphylococcus aureus isolates from sheep flocks of the Northeast of Brazil.

    Science.gov (United States)

    de Almeida, Lara M; de Almeida, Mayra Zilta P R B; de Mendonça, Carla L; Mamizuka, Elsa M

    2013-01-01

    Staphylococcus aureus is one of the most frequent mastitis causative agents in small ruminants. The expression of most virulence genes of S. aureus is controlled by an accessory gene regulator (agr) locus. This study aimed to ascertain the prevalence of the different agr groups and to evaluate the occurrence of encoding genes for cytotoxin, adhesins and toxins with superantigen activity in S. aureus isolates from milk of ewes with clinical and subclinical mastitis in sheep flocks raised for meat production The agr groups I and II were identified in both cases of clinical and subclinical mastitis. Neither the arg groups III and IV nor negative agr were found. The presence of cflA gene was identified in 100% of the isolates. The frequency of hla and lukE-D genes was high - 77.3 and 82.8%, respectively and all isolates from clinical mastitis presented these genes. The sec gene, either associated to tst gene or not, was identified only in isolates from subclinical mastitis. None of the following genes were identified: bbp, ebpS, cna, fnbB, icaA, icaD, bap, hlg, lukM-lukF-PV and se-a-b-d-e.

  4. The effect of vaccination on undetected persistence of foot-and-mouth disease virus in cattle herds and sheep flocks.

    Science.gov (United States)

    Schley, D; Paton, D J; Cox, S J; Parida, S; Gubbins, S

    2009-10-01

    The importance of carrier animals (those in whom virus persists after recovery from disease or acute infection) and their potential role in the spread of disease remain open questions within foot-and-mouth disease epidemiology. Using simple probabilistic models we attempt to quantify the effect of emergency vaccination--and especially the time of application--on the likely number of such animals, using data from challenge experiments on both cattle and sheep to determine the probability of persistence in diseased and subclinically infected animals. We show that the number of persistently infected animals in a group is predominantly determined by the number of animals initially infected on premises--the high variability of which ultimately limits the accuracy of any predictions of carrier numbers based upon transmission models. Furthermore, results suggest that, within a cattle herd, carrier numbers may be increased if challenge occurs shortly after vaccination. We show that the quality of inspection is the principal factor influencing whether or not carrier herds occur and that, by reducing clinical signs, the application of vaccination in regularly checked stock also results in an increase in undetected persistently infected animals. Where clinical detection would be poor regardless of the use of vaccination (i.e. particularly in sheep), vaccination will result in a reduction in the probability of a group containing undetected carriers: otherwise there is a benefit only if vaccination is applied sufficiently far in advance of any challenge. The implications of the results for serosurveillance are discussed, including the requisite test sensitivity and practices for successful implementation.

  5. Geospatial Database of Hydroclimate Variables, Spring Mountains and Sheep Range, Clark County, Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This point feature class contains 81,481 points arranged in a 270-meter spaced grid that covers the Spring Mountains and Sheep Range in Clark County, Nevada. Points...

  6. 78 FR 25943 - Changes to Scrapie Flock Certification Program

    Science.gov (United States)

    2013-05-03

    ... Animal and Plant Health Inspection Service Changes to Scrapie Flock Certification Program AGENCY: Animal... giving notice of changes to the Scrapie Flock Certification Program (SFCP), a voluntary program for sheep and goat flock owners who wish to reduce and/or eliminate the risk of introducing classical...

  7. Environmental conditions associated with lesions in introduced free-ranging sheep in Hawai‘i

    Science.gov (United States)

    Powers, Jenny G.; Duncan, Colleen G.; Spraker, Terry R.; Schuler, Bridget A.; Hess, Steven C.; Faford, Jonathan K.J.; Sin, Hans

    2014-01-01

    Wildlife species which have been translocated between temperate and tropical regions of the world provide unique opportunities to understand how disease processes may be affected by environmental conditions. European mouflon sheep (Ovis gmelini musimon) from the Mediterranean Islands were introduced to the Hawaiian Islands for sport hunting beginning in 1954 and were subsequently hybridized with feral domestic sheep (O. aries), which had been introduced in 1793. Three isolated mouflon populations have become established in the Hawaiian Islands but diseases in these populations have been little studied. The objective of this study was to evaluate and compare gross and histologic lesions in respiratory, renal, and hepatic systems of free-ranging sheep in two isolated volcanic environments on Hawai‘i Island. Tissue and fecal samples were collected in conjunction with population reductions during February 2011. We found gross or histologic evidence of lungworm infection in 44/49 sheep from Mauna Loa which were exposed to gaseous emissions from Kīlauea Volcano. In contrast, only 7/50 sheep from Mauna Kea had lesions consistent with lungworm, but Mauna Kea sheep had significantly more upper respiratory tract inflammation and hyperplasia consistent with chronic antigenic stimulation, possibly associated with exposure to fine airborne particulates during extended drought conditions. We hypothesize that gasses from Kīlauea Volcano contributed to severity of respiratory disease principally associated with chronic lungworm infections at Mauna Loa; however, there were numerous other potentially confounding environmental factors and interactions that merit further investigation.

  8. Seroprevalence and risk factors for Toxoplasma gondii in sheep in Grosseto district, Tuscany, Italy

    Directory of Open Access Journals (Sweden)

    Cenci-Goga Beniamino T

    2013-02-01

    Full Text Available Abstract Background Serum samples from 630 milk sheep, in 33 dairy flocks representative of the southern area of the Tuscany region, were tested for the presence of antibodies to Toxoplasma gondii using an indirect immunofluorescence antibody test (IFAT. Questionnaires exploring the management system were completed by the veterinarian in charge of the flocks. Results At least one seropositive animal was found in 32 of the 33 flocks tested (97.0%; 95% CI: 84.2%, 99.9%. In the positive flocks, median seroprevalence was 29.4% (interquartile range: 15.9%-46.1%. Overall animal-level seroprevalence, adjusted for sampling weights and test sensitivity and specificity, was 33.3% (95% CI: 24.8%, 42.7%. In a multivariable negative binomial regression model the number of seropositive animals in a flock decreased with increasing flock size (for >400 vs. CR = 0.62; 95% CI: 0.41, 0.95; P = 0.028 and was greater on farms where stray cats had access to animals’ water (CR = 1.54; 95% CI: 1.05, 2.26; P = 0.027. Conclusions Small flock size and access of cats to water are potential risk factors for Toxoplasma infection in sheep in the Grosseto district in Tuscany, Italy. Sheep could be an important source of T. gondii infection in humans, since we estimate that between 25% and 43% of sheep in the district were seropositive. Toxoplasmosis is also likely to be an important cause of abortion in sheep in the district. Control and prophylactic measures must be adopted to improve the rearing system and the implementation of health promoting programmes in a joint effort between sheep farmers, farmers’ associations and veterinarians to inform about the means of transmission of the infection and for a better understanding of the disease.

  9. Avian influenza epidemiology in semi-intensive free ranging duck flocks of the Moyingyi Wetland in Bago East District, Myanmar.

    Science.gov (United States)

    Cristalli, Alessandro; Morini, Matteo; Comin, Arianna; Capello, Katia; Sunn, Kyaw; Martini, Marco

    2017-09-27

    Highly pathogenic avian influenza virus subtype H5N1 first entered Myanmar in 2006 in the Mandalay District. Several H5N1 outbreaks followed and the one of Bago East District (2007) required post outbreak surveillance in the at-risk domestic duck population of the Moyingyi Wetland. A field epidemiological study based on a randomised prospective stratified study with five surveys provided the serological evidence that the avian influenza H5 subtype circulates in the domestic duck population and spreads to almost all the newly housed (and negative) flocks in the time span of a seasonal production cycle. Virological investigation was negative. The survival analysis showed that the probability of seroconversion increased rapidly over the study period, without significant difference among different agro-ecosystems. The analysis suggests that viral spread in the new cycle could be limited if control measures were adopted at the time new flocks are housed. The study recommends that future surveillance schemes for ducks are designed in a way to get as much information as possible from serological results which should drive virological sampling to determined farms.

  10. Ovine Enzootic Abortion (OEA: a comparison of antibody responses in vaccinated and naturally-infected swiss sheep over a two year period

    Directory of Open Access Journals (Sweden)

    Zimmermann Dieter R

    2007-09-01

    Full Text Available Abstract Background Prevention and control of ovine enzootic abortion (OEA can be achieved by application of a live vaccine. In this study, five sheep flocks with different vaccination and infection status were serologically tested using a competitive enzyme-linked immunosorbent assay (cELISA specific for Chlamydophila (Cp. abortus over a two-year time period. Results Sheep in Flock A with recent OEA history had high antibody values after vaccination similar to Flock C with natural Cp. abortus infections. In contrast, OEA serology negative sheep (Flock E showed individual animal-specific immunoreactions after vaccination. Antibody levels of vaccinated ewes in Flock B ranged from negative to positive two and three years after vaccination, respectively. Positive antibody values in the negative control Flock D (without OEA or vaccination are probably due to asymptomatic intestinal infections with Cp. abortus. Excretion of the attenuated strain of Cp. abortus used in the live vaccine through the eye was not observed in vaccinated animals of Flock E. Conclusion The findings of our study indicate that, using serology, no distinction can be made between vaccinated and naturally infected sheep. As a result, confirmation of a negative OEA status in vaccinated animals by serology cannot be determined.

  11. Hydroclimate of the Spring Mountains and Sheep Range, Clark County, Nevada

    Science.gov (United States)

    Moreo, Michael T.; Senay, Gabriel B.; Flint, Alan L.; Damar, Nancy A.; Laczniak, Randell J.; Hurja, James

    2014-01-01

    Precipitation, potential evapotranspiration, and actual evapotranspiration often are used to characterize the hydroclimate of a region. Quantification of these parameters in mountainous terrains is difficult because limited access often hampers the collection of representative ground data. To fulfill a need to characterize ecological zones in the Spring Mountains and Sheep Range of southern Nevada, spatially and temporally explicit estimates of these hydroclimatic parameters are determined from remote-sensing and model-based methodologies. Parameter-elevation Regressions on Independent Slopes Model (PRISM) precipitation estimates for this area ranges from about 100 millimeters (mm) in the low elevations of the study area (700 meters [m]) to more than 700 mm in the high elevations of the Spring Mountains (> 2,800 m). The PRISM model underestimates precipitation by 7–15 percent based on a comparison with four high‑elevation precipitation gages having more than 20 years of record. Precipitation at 3,000-m elevation is 50 percent greater in the Spring Mountains than in the Sheep Range. The lesser amount of precipitation in the Sheep Range is attributed to partial moisture depletion by the Spring Mountains of eastward-moving, cool-season (October–April) storms. Cool-season storms account for 66–76 percent of annual precipitation. Potential evapotranspiration estimates by the Basin Characterization Model range from about 700 mm in the high elevations of the Spring Mountains to 1,600 mm in the low elevations of the study area. The model realistically simulates lower potential evapotranspiration on northeast-to-northwest facing slopes compared to adjacent southeast-to-southwest facing slopes. Actual evapotranspiration, estimated using a Moderate Resolution Imaging Spectroradiometer based water-balance model, ranges from about 100 to 600 mm. The magnitude and spatial variation of simulated, actual evapotranspiration was validated by comparison to PRISM precipitation

  12. 9 CFR 91.8 - Sheep.

    Science.gov (United States)

    2010-01-01

    ...-positive animal or an exposed animal, as defined in 9 CFR parts 54 and 79, or if it has ever been in an infected flock, source flock, or trace flock, as defined in 9 CFR parts 54 and 79; or if it is the progeny... be identified by eartags or tattoos approved by the Administrator. 3 except that sheep for export...

  13. Breeding programmes for smallholder sheep farming systems: II. Optimization of cooperative village breeding schemes.

    Science.gov (United States)

    Gizaw, S; van Arendonk, J A M; Valle-Zárate, A; Haile, A; Rischkowsky, B; Dessie, T; Mwai, A O

    2014-10-01

    A simulation study was conducted to optimize a cooperative village-based sheep breeding scheme for Menz sheep of Ethiopia. Genetic gains and profits were estimated under nine levels of farmers' participation and three scenarios of controlled breeding achieved in the breeding programme, as well as under three cooperative flock sizes, ewe to ram mating ratios and durations of ram use for breeding. Under fully controlled breeding, that is, when there is no gene flow between participating (P) and non-participating (NP) flocks, profits ranged from Birr 36.9 at 90% of participation to Birr 21.3 at 10% of participation. However, genetic progress was not affected adversely. When there was gene flow from the NP to P flocks, profits declined from Birr 28.6 to Birr -3.7 as participation declined from 90 to 10%. Under the two-way gene flow model (i.e. when P and NP flocks are herded mixed in communal grazing areas), NP flocks benefited from the genetic gain achieved in the P flocks, but the benefits declined sharply when participation declined beyond 60%. Our results indicate that a cooperative breeding group can be established with as low as 600 breeding ewes mated at a ratio of 45 ewes to one ram, and the rams being used for breeding for a period of two years. This study showed that farmer cooperation is crucial to effect genetic improvement under smallholder low-input sheep farming systems.

  14. Assessment of the cervical range of motion over time, differences between results of the Flock of Birds and the EDI-320 : A comparison between an electromagnetic tracking system and an electronic inclinometer

    NARCIS (Netherlands)

    Assink, Nienke; Bergman, Gert J. D.; Knoester, Bianca; Winters, Jan C.; Dijkstra, Pieter U.

    2008-01-01

    The objective of this study was to analyse cervical range of motion, assessed over time by means of a digital inclinometer (EDI-320) and a three-dimensional electromagnetic tracking device (Flock of Birds). The maximum active cervical range of motion was assessed with two measurement devices in thre

  15. The oral secretion of infectious scrapie prions occurs in preclinical sheep with a range of PRNP genotypes.

    Science.gov (United States)

    Gough, Kevin C; Baker, Claire A; Rees, Helen C; Terry, Linda A; Spiropoulos, John; Thorne, Leigh; Maddison, Ben C

    2012-01-01

    Preclinical sheep with the highly scrapie-susceptible VRQ/VRQ PRNP genotype secrete prions from the oral cavity. In order to further understand the significance of orally available prions, buccal swabs were taken from sheep with a range of PRNP genotypes and analyzed by serial protein misfolding cyclic amplification (sPMCA). Prions were detected in buccal swabs from scrapie-exposed sheep of genotypes linked to high (VRQ/VRQ and ARQ/VRQ) and low (ARR/VRQ and AHQ/VRQ) lymphoreticular system involvement in scrapie pathogenesis. For both groups, the level of prion detection was significantly higher than that for scrapie-resistant ARR/ARR sheep which were kept in the same farm environment and acted as sentinel controls for prions derived from the environment which might contaminate the oral cavity. In addition, sheep with no exposure to the scrapie agent did not contain any measurable prions within the oral cavity. Furthermore, prions were detected in sheep over a wide age range representing various stages of preclinical disease. These data demonstrate that orally available scrapie prions may be a common feature in sheep incubating scrapie, regardless of the PRNP genotype and any associated high-level accumulation of PrP(Sc) within lymphoreticular tissues. PrP(Sc) was present in buccal swabs from a large proportion of sheep with PRNP genotypes associated with relatively low disease penetrance, indicating that subclinical scrapie infection is likely to be a common occurrence. The significance of positive sPMCA reactions was confirmed by the transmission of infectivity in buccal swab extracts to Tg338 mice, illustrating the likely importance of orally available prions in the horizontal transmission of scrapie.

  16. Comparative Susceptibility of Sheep of Different Origins, Breeds and PRNP Genotypes to Challenge with Bovine Spongiform Encephalopathy and Scrapie.

    Directory of Open Access Journals (Sweden)

    Fiona Houston

    Full Text Available Sheep are natural hosts of the prion disease, scrapie. They are also susceptible to experimental challenge with various scrapie strains and with bovine spongiform encephalopathy (BSE, which affects cattle and has been accidentally transmitted to a range of other species, including man. Incidence and incubation period of clinical disease in sheep following inoculation is controlled by the PRNP gene, which has different alleles defined on the basis of polymorphisms, particularly at codons 136, 154 and 171, although other codons are associated with survival time, and the exact responses of the sheep may be influenced by other breed-related differences. Here we report the results of a long term single study of experimental scrapie and BSE susceptibility of sheep of Cheviot, Poll Dorset and Suffolk breeds, originating from New Zealand and of a wide range of susceptible and resistant PRNP genotypes. Responses were compared with those of sheep from a closed Cheviot flock of UK origin (Roslin Cheviot flock. The unusually long observation period (6-8 years for most, but up to 12 years for others allows us to draw robust conclusions about rates of survival of animals previously regarded as resistant to infection, particularly PRNP heterozygotes, and is the most comprehensive such study reported to date. BSE inoculation by an intracerebral route produced disease in all genotype groups with differing incubation periods, although M112T and L141F polymorphisms seemed to give some protection. Scrapie isolate SSBP/1, which has the shortest incubation period in sheep with at least one VRQ PRNP allele, also produced disease following sub-cutaneous inoculation in ARQ/ARQ animals of New Zealand origin, but ARQ/ARQ sheep from the Roslin flock survived the challenge. Our results demonstrate that the links between PRNP genotype and clinical prion disease in sheep are much less secure than previously thought, and may break down when, for example, a different breed of

  17. Comparative Susceptibility of Sheep of Different Origins, Breeds and PRNP Genotypes to Challenge with Bovine Spongiform Encephalopathy and Scrapie.

    Science.gov (United States)

    Houston, Fiona; Goldmann, Wilfred; Foster, James; González, Lorenzo; Jeffrey, Martin; Hunter, Nora

    2015-01-01

    Sheep are natural hosts of the prion disease, scrapie. They are also susceptible to experimental challenge with various scrapie strains and with bovine spongiform encephalopathy (BSE), which affects cattle and has been accidentally transmitted to a range of other species, including man. Incidence and incubation period of clinical disease in sheep following inoculation is controlled by the PRNP gene, which has different alleles defined on the basis of polymorphisms, particularly at codons 136, 154 and 171, although other codons are associated with survival time, and the exact responses of the sheep may be influenced by other breed-related differences. Here we report the results of a long term single study of experimental scrapie and BSE susceptibility of sheep of Cheviot, Poll Dorset and Suffolk breeds, originating from New Zealand and of a wide range of susceptible and resistant PRNP genotypes. Responses were compared with those of sheep from a closed Cheviot flock of UK origin (Roslin Cheviot flock). The unusually long observation period (6-8 years for most, but up to 12 years for others) allows us to draw robust conclusions about rates of survival of animals previously regarded as resistant to infection, particularly PRNP heterozygotes, and is the most comprehensive such study reported to date. BSE inoculation by an intracerebral route produced disease in all genotype groups with differing incubation periods, although M112T and L141F polymorphisms seemed to give some protection. Scrapie isolate SSBP/1, which has the shortest incubation period in sheep with at least one VRQ PRNP allele, also produced disease following sub-cutaneous inoculation in ARQ/ARQ animals of New Zealand origin, but ARQ/ARQ sheep from the Roslin flock survived the challenge. Our results demonstrate that the links between PRNP genotype and clinical prion disease in sheep are much less secure than previously thought, and may break down when, for example, a different breed of sheep is moved

  18. Investigation of a Simple Model for Within-Flock Transmission of Scrapie.

    Science.gov (United States)

    Hagenaars, Thomas J; Windig, Jack J

    2015-01-01

    Genetic control programs for scrapie in sheep build on solid knowledge of how susceptibility to scrapie is modulated by the prion protein genotype at the level of an individual sheep. In order to satisfactorily analyze the effectivity of control programs at the population level, insight is needed at the flock level, i.e., how the grouping of sheep in flocks affects the population-level transmission risk. In particular, one would like to understand how this risk is affected by between-flock differences in genotype frequency distribution. A first step is to model the scrapie transmission risk within a flock as a function of the flock genotype profile. Here we do so by estimating parameters for a model of within-flock transmission using genotyping data on Dutch flocks affected by scrapie. We show that the data are consistent with a relatively simple transmission model assuming horizontal transmission and homogeneous mixing between animals. The model expresses the basic reproduction number for within-flock scrapie as a weighted average of genotype-specific susceptibilities, multiplied by a single overall transmission parameter. The value of the overall transmission parameter may vary between flocks to account for random between-flock variation in non-genetic determinants such as management practice. Here we provide an estimate of its mean value and variation for Dutch flocks.

  19. Sheep internal parasites on Rab and Pag

    Directory of Open Access Journals (Sweden)

    Relja Beck

    2010-01-01

    Full Text Available The purpose of our research was to determine which groups and species of internal parasites endanger the health of sheep on the islands of Rab and Pag. The research was carried out in 10 flocks on both islands taking the fresh dung out of 30% of the total number of sheep in each flock. It was ascertained that the gastrointestinal parasites and protozoa of Eimeria genus are present in most flocks on both islands. The presence of the fluke Dicrocoelium dendriticum was ascertained in considerably larger number of flocks on the island of Rab than on the island of Pag. On the other hand, the presence of parasites of Moniezia and Nematodirus genus was ascertained in larger number of flocks on the island of Pag. In two flocks on Rab parasites of Protostrongylus genus were ascertained while on the island of Pag they were not found in any flock.

  20. Sheep Feed and Scrapie, France

    Science.gov (United States)

    Philippe, Sandrine; Ducrot, Christian; Roy, Pascal; Remontet, Laurent; Jarrige, Nathalie

    2005-01-01

    Scrapie is a small ruminant, transmissible spongiform encephalopathy (TSE). Although in the past scrapie has not been considered a zoonosis, the emergence of bovine spongiform encephalopathy, transmissible to humans and experimentally to sheep, indicates that risk exists for small ruminant TSEs in humans. To identify the risk factors for introducing scrapie into sheep flocks, a case-control study was conducted in France from 1999 to 2000. Ninety-four case and 350 control flocks were matched by location and main breed. Three main hypotheses were tested: direct contact between flocks, indirect environmental contact, and foodborne risk. Statistical analysis was performed by using adjusted generalized linear models with the complementary log-log link function, considering flock size as an offset. A notable effect of using proprietary concentrates and milk replacers was observed. The risk was heterogeneous among feed factories. Contacts between flocks were not shown to be a risk factor. PMID:16102318

  1. Assessment of the cervical range of motion over time, differences between results of the Flock of Birds and the EDI-320: a comparison between an electromagnetic tracking system and an electronic inclinometer.

    Science.gov (United States)

    Assink, Nienke; Bergman, Gert J D; Knoester, Bianca; Winters, Jan C; Dijkstra, Pieter U

    2008-10-01

    The objective of this study was to analyse cervical range of motion, assessed over time by means of a digital inclinometer (EDI-320) and a three-dimensional electromagnetic tracking device (Flock of Birds). The maximum active cervical range of motion was assessed with two measurement devices in three sessions over time, with 6-week intervals. In total, 26 women and 24 men (mean age: 44.4, SD: 9.9) without known pathology of the cervical spine participated. Four movements were measured axial rotation with the cervical spine in a flexed and in an extended position, flexion-extension, and lateral bending. The results showed that the factor time was significant for rotation in extension and rotation in flexion. The factor device was significant for all movements measured, and the interaction term between time and device was significant for all movements except rotation in extension. The Flock of Birds measured significantly higher ranges of motion on all motions except for lateral bending. A substantial variation in cervical range of motion was observed over time (ranging from -5.6 to 8.1) as well as between devices (ranging from -13.1 to 29.9). Substantial and significant differences in cervical range of motion were found over time as well as differences between the Flock of Birds and the EDI-320.

  2. Sheep-associated malignant catarrhal fever in free-ranging moose (Alces alces) in Saskatchewan, Canada.

    Science.gov (United States)

    Neimanis, Aleksija S; Hill, Janet E; Jardine, Claire M; Bollinger, Trent K

    2009-01-01

    Malignant catarrhal fever (MCF) is a sporadic disease of artiodactyls caused by several viruses in the Gammaherpesvirinae. We report two cases of MCF in free-living moose (Alces alces) from Saskatchewan. One was a thin, dehydrated, adult male found recumbent in 2006. At necropsy, ulcers were found in the intestine, bladder, and corneas. Microscopically, there was lymphocytic vasculitis and perivasculitis in many organs with infrequent fibrinoid necrosis. Ovine herpes virus-2 (OHV-2) was identified by polymerase chain reaction. A segment of the herpesviral DNA polymerase gene was 99% identical to published OHV-2 sequences. During a retrospective search of earlier cases, a female moose with lymphoplasmacytic meningoencephalitis examined in 2003 was identified and OHV-2 was amplified from paraffin-embedded tissues from this animal. We believe this to be the first description of MCF in free-ranging moose in North America. Infection requires contact with infected sheep or goats, and MCF in moose may become more prevalent as moose distribution continues to expand into agricultural prairie.

  3. Flocking ferromagnetic colloids

    Science.gov (United States)

    Kaiser, Andreas; Snezhko, Alexey; Aranson, Igor S.

    2017-01-01

    Assemblages of microscopic colloidal particles exhibit fascinating collective motion when energized by electric or magnetic fields. The behaviors range from coherent vortical motion to phase separation and dynamic self-assembly. Although colloidal systems are relatively simple, understanding their collective response, especially under out-of-equilibrium conditions, remains elusive. We report on the emergence of flocking and global rotation in the system of rolling ferromagnetic microparticles energized by a vertical alternating magnetic field. By combing experiments and discrete particle simulations, we have identified primary physical mechanisms, leading to the emergence of large-scale collective motion: spontaneous symmetry breaking of the clockwise/counterclockwise particle rotation, collisional alignment of particle velocities, and random particle reorientations due to shape imperfections. We have also shown that hydrodynamic interactions between the particles do not have a qualitative effect on the collective dynamics. Our findings shed light on the onset of spatial and temporal coherence in a large class of active systems, both synthetic (colloids, swarms of robots, and biopolymers) and living (suspensions of bacteria, cell colonies, and bird flocks). PMID:28246633

  4. Turkey knockdown in successive flocks.

    Science.gov (United States)

    Evans, R D; Edson, R K; Watkins, K L; Robertson, J L; Meldrum, J B; Novilla, M N

    2000-01-01

    Turkey knockdown was diagnosed in three of five flocks of hen turkeys on a single farm within a 12-mo period. The age of birds in the flocks affected ranged from 6 wk 2 days to 7 wk 4 days. The attack rate ranged from 0.02% to 0.30% with a case fatality rate in affected birds ranging from 0 to 74%. The diagnosis was made on the basis of clinical signs and histopathologic lesions associated with knockdown. The feed in all flocks contained bacitracin methylene disalicylate and monensin (Coban). Affected birds were recumbent, demonstrated paresis, and were unable to vocalize. Postmortem examination revealed few significant lesions although pallor of the adductor muscles and petechiation in adductor and gastrocnemius muscles were noted. Birds that had been recumbent for extended periods were severely dehydrated. Consistent microscopic lesions included degeneration, necrosis, and regeneration of adductor, gastrocnemius, and abdominal muscles. No lesion in cardiac tissue was noted. Results of our investigation indicated that changes in water consumption, vitamin E status, and brooder to finisher movement correlated with the occurrence of knockdown. Turkey knockdown was defined in 1993 as any condition identified in a turkey flock that has affected the neuromuscular system to a degree that a turkey is unable to walk or stand. This definition was later modified to...neuromuscular or skeletal systems to a degree that a turkey is unable to walk or stand properly. Knockdown may be associated with numerous feed, management, or disease factors alone or in combination. Dosage of monensin, feed restriction/gorging, water restriction, heat stress, copper, mycotoxins, sodium chloride in feed, and sulfa drugs have all been suggested as contributing factors; however, laboratory studies to duplicate this have not been successful. This report presents observations from a single farm at which three of five hen flocks in a single year experienced knockdown. When a flock was reported as

  5. Asymmetric exchange in flocks

    CERN Document Server

    Dadhichi, Lokrshi Prawar; Maitra, Ananyo; Ramaswamy, Sriram

    2016-01-01

    As the constituents of a flock are polar, one expects a fore-aft asymmetry in their interactions. We show here that the resulting antisymmetric part of the "exchange coupling" between a bird and its neighbours, if large enough, destabilizes the flock through spontaneous turning of the birds. The same asymmetry also yields a natural mechanism for a difference between the speed of advection of information along the flock and the speed of the flock itself. We show that the absence of detailed balance, and not merely the breaking of Galilean invariance, is responsible for this difference. We delineate the conditions on parameters and wavenumber for the existence of the turning instability. Lastly we present an alternative perspective based on flow-alignment effects in an active liquid crystal with turning inertia in contact with a momentum sink.

  6. Association of Mycoplasma ovipneumoniae infection with population-limiting respiratory disease in free-ranging Rocky Mountain bighorn sheep (Ovis canadensis canadensis).

    Science.gov (United States)

    Besser, Thomas E; Cassirer, E Frances; Potter, Kathleen A; VanderSchalie, John; Fischer, Allison; Knowles, Donald P; Herndon, David R; Rurangirwa, Fred R; Weiser, Glen C; Srikumaran, Subramaniam

    2008-02-01

    Bronchopneumonia is a population-limiting disease in bighorn sheep in much of western North America. Previous investigators have isolated diverse bacteria from the lungs of affected sheep, but no single bacterial species is consistently present, even within single epizootics. We obtained high-quality diagnostic specimens from nine pneumonic bighorn sheep in three populations and analyzed the bacterial populations present in bronchoalveolar lavage specimens of seven by using a culture-independent method (16S rRNA gene amplification and clone library analyses). Mycoplasma ovipneumoniae was detected as a predominant member of the pneumonic lung flora in lambs with early lesions of bronchopneumonia. Specific PCR tests then revealed the consistent presence of M. ovipneumoniae in the lungs of pneumonic bighorn sheep in this study, and M. ovipneumoniae was isolated from lung specimens of five of the animals. Retrospective application of M. ovipneumoniae PCR to DNA extracted from archived formalin-fixed, paraffin-embedded lung tissues of historical adult bighorn sheep necropsy specimens supported the association of this agent with bronchopneumonia (16/34 pneumonic versus 0/17 nonpneumonic sheep were PCR positive [P M. ovipneumoniae antibody-positive animals and the occurrence of current or recent historical bronchopneumonia problems (seropositive animals detected in 9/9 versus 0/9 pneumonic and nonpneumonic populations, respectively [P M. ovipneumoniae is strongly associated with bronchopneumonia in free-ranging bighorn sheep and is a candidate primary etiologic agent for this disease.

  7. Association of Mycoplasma ovipneumoniae Infection with Population-Limiting Respiratory Disease in Free-Ranging Rocky Mountain Bighorn Sheep (Ovis canadensis canadensis)▿

    Science.gov (United States)

    Besser, Thomas E.; Cassirer, E. Frances; Potter, Kathleen A.; VanderSchalie, John; Fischer, Allison; Knowles, Donald P.; Herndon, David R.; Rurangirwa, Fred R.; Weiser, Glen C.; Srikumaran, Subramaniam

    2008-01-01

    Bronchopneumonia is a population-limiting disease in bighorn sheep in much of western North America. Previous investigators have isolated diverse bacteria from the lungs of affected sheep, but no single bacterial species is consistently present, even within single epizootics. We obtained high-quality diagnostic specimens from nine pneumonic bighorn sheep in three populations and analyzed the bacterial populations present in bronchoalveolar lavage specimens of seven by using a culture-independent method (16S rRNA gene amplification and clone library analyses). Mycoplasma ovipneumoniae was detected as a predominant member of the pneumonic lung flora in lambs with early lesions of bronchopneumonia. Specific PCR tests then revealed the consistent presence of M. ovipneumoniae in the lungs of pneumonic bighorn sheep in this study, and M. ovipneumoniae was isolated from lung specimens of five of the animals. Retrospective application of M. ovipneumoniae PCR to DNA extracted from archived formalin-fixed, paraffin-embedded lung tissues of historical adult bighorn sheep necropsy specimens supported the association of this agent with bronchopneumonia (16/34 pneumonic versus 0/17 nonpneumonic sheep were PCR positive [P M. ovipneumoniae antibody-positive animals and the occurrence of current or recent historical bronchopneumonia problems (seropositive animals detected in 9/9 versus 0/9 pneumonic and nonpneumonic populations, respectively [P M. ovipneumoniae is strongly associated with bronchopneumonia in free-ranging bighorn sheep and is a candidate primary etiologic agent for this disease. PMID:18057131

  8. Role of projection in the control of bird flocks.

    Science.gov (United States)

    Pearce, Daniel J G; Miller, Adam M; Rowlands, George; Turner, Matthew S

    2014-07-22

    Swarming is a conspicuous behavioral trait observed in bird flocks, fish shoals, insect swarms, and mammal herds. It is thought to improve collective awareness and offer protection from predators. Many current models involve the hypothesis that information coordinating motion is exchanged among neighbors. We argue that such local interactions alone are insufficient to explain the organization of large flocks of birds and that the mechanism for the exchange of long-range information necessary to control their density remains unknown. We show that large flocks self-organize to the maximum density at which a typical individual still can see out of the flock in many directions. Such flocks are marginally opaque--an external observer also still can see a substantial fraction of sky through the flock. Although this seems intuitive, we show it need not be the case; flocks might easily be highly diffuse or entirely opaque. The emergence of marginal opacity strongly constrains how individuals interact with one another within large swarms. It also provides a mechanism for global interactions: an individual can respond to the projection of the flock that it sees. This provides for faster information transfer and hence rapid flock dynamics, another advantage over local models. From a behavioral perspective, it optimizes the information available to each bird while maintaining the protection of a dense, coherent flock.

  9. Local equilibrium in bird flocks

    Science.gov (United States)

    Mora, Thierry; Walczak, Aleksandra M.; Del Castello, Lorenzo; Ginelli, Francesco; Melillo, Stefania; Parisi, Leonardo; Viale, Massimiliano; Cavagna, Andrea; Giardina, Irene

    2016-12-01

    The correlated motion of flocks is an example of global order emerging from local interactions. An essential difference with respect to analogous ferromagnetic systems is that flocks are active: animals move relative to each other, dynamically rearranging their interaction network. This non-equilibrium characteristic has been studied theoretically, but its impact on actual animal groups remains to be fully explored experimentally. Here, we introduce a novel dynamical inference technique, based on the principle of maximum entropy, which accommodates network rearrangements and overcomes the problem of slow experimental sampling rates. We use this method to infer the strength and range of alignment forces from data of starling flocks. We find that local bird alignment occurs on a much faster timescale than neighbour rearrangement. Accordingly, equilibrium inference, which assumes a fixed interaction network, gives results consistent with dynamical inference. We conclude that bird orientations are in a state of local quasi-equilibrium over the interaction length scale, providing firm ground for the applicability of statistical physics in certain active systems.

  10. Sheep-Associated Malignant Catarrhal Fever-Like Skin Disease in a Free-Ranging Bighorn Sheep ( Ovis canadensis ), Alberta, Canada.

    Science.gov (United States)

    Slater, Owen M; Peters-Kennedy, Jeanine; Lejeune, Manigandan; Gummer, David; Macbeth, Bryan; Warren, Amy; Joseph, Tomy; Li, Hong; Cunha, Cristina W; Duignan, Pádraig J

    2017-01-01

    Malignant catarrhal fever-like clinical disease was diagnosed in a free-ranging bighorn sheep ( Ovis canadensis ) from Alberta, Canada, in June 2015. Antemortem and gross pathology findings included muscle atrophy, marked weight loss, and bilaterally symmetric alopecia with hyperpigmentation and crusting over the face, medial surfaces of the pinnae, dorsal trunk, distal limbs, perineal area, and tail. Histologically, the skin lesions were characterized by granulomatous mural folliculitis with numerous multinucleated giant cells and fewer lymphocytes and eosinophils consistent with previous reports of chronic ovine herpesvirus-2 (OvHV-2) infection. Multiple skin samples were positive for OvHV-2 DNA on PCR, and on partial sequencing of the viral DNA, there was 94% homology with reference GenBank OvHV-2. Quantitative PCR confirmed an increased level of OvHV-2 DNA in the lesional skin tissues. Based on exclusion of other disease processes, gross and histological lesions, PCR, and viral DNA sequencing results, a diagnosis of OvHV-2-mediated malignant catarrhal fever-like dermatitis was made.

  11. Characterisation of terminal sire sheep farm systems, based on a range of environmental factors: a case study in the context of genotype by environment interactions using Charollais lambs.

    Science.gov (United States)

    McLaren, A; Lambe, N R; Morgan-Davies, C; Mrode, R; Brotherstone, S; Conington, J; Morgan-Davies, J; Bunger, L

    2014-06-01

    The objective of this study was to define different terminal sire flock environments, based on a range of environmental factors, and then investigate the presence of genotype by environment interactions (G×E) between the environments identified. Data from 79 different terminal sire flocks (40 Texel, 21 Charollais and 18 Suffolk), were analysed using principal coordinate and non-hierarchical cluster analyses, the results of which identified three distinct environmental cluster groups. The type of grazing, climatic conditions and the use of vitamins and mineral supplements were found to be the most important factors in the clustering of flocks. The presence of G×E was then investigated using data from the Charollais flocks only. Performance data were collected for 12 181 lambs, between 1990 and 2010, sired by 515 different sires. Fifty six of the sires had offspring in at least two of the three different cluster groups and pedigree information was available for a total of 161 431 animals. Traits studied were the 21-week old weight (21WT), ultrasound muscle depth (UMD) and log transformed backfat depth (LogUFD). Heritabilities estimated for each cluster, for each trait, ranged from 0.32 to 0.45. Genetic correlations estimated between Cluster 1 and Cluster 2 were all found to be significantly lower than unity, indicating the presence of G×E. They were 0.31 (±0.17), 0.68 (±0.14) and 0.18 (±0.21) for 21WT, UMD and LogUFD, respectively. Evidence of sires re-ranking across clusters was also observed. Providing a suitable strategy can be identified, there is potential for the optimisation of future breeding programmes, by taking into account the G×E observed. This would enable farmers to identify and select animals with an increased knowledge as to how they will perform in their specific farm environment thus reducing any unexpected differences in performance.

  12. A Case Report of Respiratory Mannheimiosis in Sheep and Goat ...

    African Journals Online (AJOL)

    In January 2007, an outbreak of acute respiratory disease in a flock of sheep and ... of the National Veterinary Research Institute, Vom, Nigeria, for investigation. ... In addition Bordetella parapertussis was isolated from the lung lesions of the ...

  13. Prevalence of anthelmintic resistance in gastrointestinal nematodes of sheep and goats in Norway.

    Science.gov (United States)

    Domke, Atle V Meling; Chartier, Christophe; Gjerde, Bjørn; Höglund, Johan; Leine, Nils; Vatn, Synnøve; Stuen, Snorre

    2012-07-01

    In the period of 2008–2009, the efficacies of the benzimidazole (BZ) albendazole and the macrocyclic lactone (ML) ivermectin against gastrointestinal nematodes (GIN) of small ruminants were evaluated by means of the fecal egg count reduction (FECR) test and by post-treatment identification of surviving third stage (L3) larvae after coproculture. Sheep (n=28) and goat (n=28) flocks from three areas of Norway were randomly selected to assess the prevalence of anthelmintic resistance (AR), whereas only lambs from non-randomly selected sheep flocks (n=32) with a farm management that could select for AR were investigated the second year. Only flocks with a mean excretion of nematode eggs per gram feces (EPG) ≥ 150 at time of treatment were included in the survey. In total, 48 (80%) and 13 (46.4%) of the selected sheep and goat flocks, respectively, fulfilled the inclusion criteria. The proportions of flocks classified as resistant (i.e., FECR nematode genera were Teladorsagia/Trichostrongylus in five flocks, Haemonchus in two flocks, and a mixture of these genera in the remaining two flocks. In the goat flocks, the pre-treatment infection levels of GIN were low compared to what was found in the sheep flocks. Still, in one flock, AR against BZ in Teladorsagia/Trichostrongylus was found. New strategies and recommendations to face the emerging AR situation in Rogaland County in order to limit the spread of resistant nematodes within and into other areas are urgently needed.

  14. Identification of lamb flocks susceptible and resistant against Brachiaria poisoning

    Directory of Open Access Journals (Sweden)

    Rayane C. Pupin

    2016-05-01

    Full Text Available Abstract: This study was designed to assess the influence of genetic resistance against brachiaria poisoning in sheep. Two groups of sheep, one identified as susceptible (formed by two ewes and one ram and the other as resistant against brachiaria poisoning (formed by three ewes and one ram were selected. Sheep considered susceptible were those that presented clinical signs of brachiaria poisoning at any time of their life; resistant sheep were those that even raised on Brachiaria spp. pastures, did not developed any sign of the poisoning during their life. The offspring of the two flocks (15 lambs from the sensitive flock and 9 lambs from the resistant flock were placed into brachiaria pasture (initially Brachiaria decumbens and B. brizantha,and only B. decumbens after weaning and followed up during two years (2013-2014. The determination of protodioscin levels in B. decumbens pasture was performed only in 2014 and revealed significant amounts of the toxic principle. Eleven lambs of the susceptible group were affected to some degree of brachiaria poisoning and six died; no lamb of the resistant group was affected. Clinical signs consisted of varying degrees of subcutaneous edema of the face and, erythema and loss of hair of the ears, crusts on the skin of ears, around the eyes and on planum nasale, scar deformation of the ears, and bilateral ocular discharge; affected lambs also sought for shadowy shelters and they were poor doers. Several sheep recovered from the condition and then relapsed. Necropsy findings in six lambs included pale mucous membranes, emaciation, dermatitis, scar deformation of the ears, large yellow livers with marked lobular pattern, and moderate infestation by Haemonchus contortus. Histologically the liver lesions were similar in all necropsied lambs but with varying degrees of severity; they were consistent with brachiaria poisoning and included architectural disruption of hepatocellular trabecula, clusters of foamy

  15. Detection of benzimidazole resistance in gastrointestinal nematodes of sheep and goats of sub-Himalyan region of northern India using different tests.

    Science.gov (United States)

    Rialch, Ajayta; Vatsya, Stuti; Kumar, Rajeev Ranjan

    2013-12-06

    The present investigation was planned with the objective of studying the status of benzimidazole (BZ) resistance in gastrointestinal nematodes (GIN) of sheep and goats of different agro-climatic zones of sub-Himalyan region of northern India using in vivo faecal egg count reduction test (FECRT) and in vitro tests namely egg hatch assay (EHA) and larval development assay (LDA). Out of fourteen flocks, FECRT detected resistance in eight flocks (two sheep flocks and six goat flocks) with FECR% ranging from 54.95 to 90.86. Pre treatment coproculture contained predominantly Haemonchus contortus, followed by Trichostrongylus spp., Oesophagostomum and Strongyloides, while post treatment coproculture results showed that only H. contortus survived fenbendazole (FBZ) (in FECRT) or thiabendazole (TBZ) (in LDA) treatment except in three flocks of Tarai region {one sheep flock (Us1), and two goat flocks (Ug1 and Ug5)} where BZ resistant Trichostrongylus were also detected. The GIN of those eight farms which were found resistant by FECRT were also detected resistant by EHA. Arithmetic mean and range of ED50 value of susceptible group was found to be 0.059 μg/ml and 0.037-0.096 μg/ml, respectively, and the same for the resistant group were found to be 0.119 μg/ml and 0.101-0.147 μg/ml, respectively. With LDA, the arithmetic mean and range of LC50 value of susceptible group was found 0.0030 μg/ml and 0.001-0.005 μg/ml, respectively, and those of resistant group was found 0.0105 μg/ml and 0.009-0.012 μg/ml, respectively. The values of Spearman rank correlation coefficient indicated that negative correlation was found between FECR% and ED50 and between FECR% and LC50 while positive correlation existed between ED50 and LC50 value and the p-values indicated that these correlations were statistically highly significant. In the present study, FECRT and EHA gave comparable results with regard to detection of BZ resistance in GIN in sheep and goats. Although with LDA, the

  16. Starling flock networks manage uncertainty in consensus at low cost.

    Directory of Open Access Journals (Sweden)

    George F Young

    Full Text Available Flocks of starlings exhibit a remarkable ability to maintain cohesion as a group in highly uncertain environments and with limited, noisy information. Recent work demonstrated that individual starlings within large flocks respond to a fixed number of nearest neighbors, but until now it was not understood why this number is seven. We analyze robustness to uncertainty of consensus in empirical data from multiple starling flocks and show that the flock interaction networks with six or seven neighbors optimize the trade-off between group cohesion and individual effort. We can distinguish these numbers of neighbors from fewer or greater numbers using our systems-theoretic approach to measuring robustness of interaction networks as a function of the network structure, i.e., who is sensing whom. The metric quantifies the disagreement within the network due to disturbances and noise during consensus behavior and can be evaluated over a parameterized family of hypothesized sensing strategies (here the parameter is number of neighbors. We use this approach to further show that for the range of flocks studied the optimal number of neighbors does not depend on the number of birds within a flock; rather, it depends on the shape, notably the thickness, of the flock. The results suggest that robustness to uncertainty may have been a factor in the evolution of flocking for starlings. More generally, our results elucidate the role of the interaction network on uncertainty management in collective behavior, and motivate the application of our approach to other biological networks.

  17. Scale-free correlations in starling flocks.

    Science.gov (United States)

    Cavagna, Andrea; Cimarelli, Alessio; Giardina, Irene; Parisi, Giorgio; Santagati, Raffaele; Stefanini, Fabio; Viale, Massimiliano

    2010-06-29

    From bird flocks to fish schools, animal groups often seem to react to environmental perturbations as if of one mind. Most studies in collective animal behavior have aimed to understand how a globally ordered state may emerge from simple behavioral rules. Less effort has been devoted to understanding the origin of collective response, namely the way the group as a whole reacts to its environment. Yet, in the presence of strong predatory pressure on the group, collective response may yield a significant adaptive advantage. Here we suggest that collective response in animal groups may be achieved through scale-free behavioral correlations. By reconstructing the 3D position and velocity of individual birds in large flocks of starlings, we measured to what extent the velocity fluctuations of different birds are correlated to each other. We found that the range of such spatial correlation does not have a constant value, but it scales with the linear size of the flock. This result indicates that behavioral correlations are scale free: The change in the behavioral state of one animal affects and is affected by that of all other animals in the group, no matter how large the group is. Scale-free correlations provide each animal with an effective perception range much larger than the direct interindividual interaction range, thus enhancing global response to perturbations. Our results suggest that flocks behave as critical systems, poised to respond maximally to environmental perturbations.

  18. A Study on Genes of Bayanbulak Sheep

    Directory of Open Access Journals (Sweden)

    Beiyao Zuo

    2013-01-01

    Full Text Available The average twin lambing rate of Bayanbulak sheep is 2% to 3%. However, a flock of sheep with a close genetic relationship and an average of 2 to 3 lambs per birth has been found recently. To determine the major genes controlling the prolificacy of the flock in the present study, the flock was designated A while 100 normal Bayanbulak sheep were randomly selected to comprise the control flock B. Ligase detection reaction method was applied to detect and analyze the 10 mutational loci of the 3 candidate prolificacy genes including bone morphogenetic protein type I receptors, bone morphogenetic protein 15, and growth differentiation factor 9. The 10 mutational loci are as follows: FecB locus of the BMPR-IB gene; FecXI, FecXB, FecXL, FecXH, FecXG, and FecXR of the BMP15 gene; and G1, G8, and FecTT of the GDF9 gene. Two mutations including BMPR-IB/FecB and GDF9/G1 were found in Bayanbulak sheep. Independence test results of the two flocks demonstrate that the FecB locus has a significant effect on the lambing number of Bayanbulak sheep. However, the mutation frequency of the G1 locus in GDF9 is very low. Independence test results demonstrate that the GDF9 locus does not have a significant impact on the lambing performance of Bayanbulak sheep. Among the 10 detected loci, BMPR-IB/FecB is the major gene that influences the high lambing rate of Bayanbulak sheep.

  19. The influence of livestock management on land use competition between domestic and wild ungulates: sheep and chamois Rupicapra pyrenaica parva Cabrera in the Cantabrian range

    Directory of Open Access Journals (Sweden)

    Rebollo, S.

    1993-12-01

    Full Text Available The spatial distribution and competition for the use of resources between sheep —transhumant merino— and chamois Rupicapra pyrenaica parva. Cabrera, 1910 has been analyzed during the summer grazing period in the Cantabrian range. The studied area, —a 750 ha. wide high pass— was divided into sectors depending on geophysical variables (substratum, aspect and elevation and vegetation types. Sheep land use was analyzed by direct observation of the flock and by means of enquiries to the shepherd. Chamois were studied before and during the time sheep were present in the pastureland, with the help of fixed itineraries that enabled us to visually cover the whole area. The assessment of land use was carried out by corrected frequency and preference index for each of the studied environmental variables. Sheep grazed in the whole area excepting for beech woods (Fagus sylvatica, rocky and steep zones and dense scrub patches.
    The location of the sheepfolds —shelters, enclosures and associated pastures— is a key factor in the management of the pastoral system. They are usually placed in a central position from where the flock make their every day course, normally directed to higher zones, in the studied area, chamois distribution is limited by the scarcity of zones over 1.800 m., and by the strong sheep grazing pressure at all elevations. Chamois leave the areas grazed by the sheep flock, creating an almost total segregation. They occupy steep rocky slopes and the beech woods edges close to them, both situated furthest away from the sheepfolds.

    [es] Durante el periodo estival de utilización de los pastos de puerto en la Cordillera Cantábrica, se analiza la distribución espacial de las ovejas —merinas trashumantes— y rebecos —Rupicapra pyrenaica parva. Cabrera 1910— y su posible competencia en el uso de los recursos. Como referencia se llevó a cabo una sectorización del territorio —750 ha.— seg

  20. Short communication: bulk tank total bacterial count in dairy sheep: factors of variation and relationship with somatic cell count.

    Science.gov (United States)

    Gonzalo, C; Carriedo, J A; Beneitez, E; Juárez, M T; De La Fuente, L F; San Primitivo, F

    2006-02-01

    A total of 9,353 records for bulk tank total bacterial count (TBC) were obtained over 1 yr from 315 dairy ewe flocks belonging to the Sheep Improvement Consortium (CPO) in Castilla-León (Spain). Analysis of variance showed significant effects of flock, breed, month within flock, dry therapy, milking type and installation, and logSCC on logTBC. Flock and month within flock were important variation factors as they accounted for 22.0 and 22.1% of the variance, respectively. Considerable repeatability values were obtained for both random factors. Hand milking and bucket-milking machines elicited highest logTBC (5.31), whereas parlor systems with looped milkline (5.01) elicited the lowest logTBC. The implementation of dry therapy practice (5.12) showed significantly lower logTBC than when not used (5.25). Variability in logTBC among breeds ranged from 5.24 (Awassi) to 5.07 (Churra). However, clinical outbreaks of contagious agalactia did not increase TBC significantly. A statistically significant relationship was found between logTBC and logSCC, the correlation coefficient between the variables being r = 0.23. Programs for improving milk hygiene should be implemented for both total bacterial count and somatic cell count variables at the same time.

  1. Epidemiology, sero-diagnosis and therapeutic studies on nematodes infection in balochi range-sheep at district quetta, balochistan, pakistan.

    Directory of Open Access Journals (Sweden)

    Abdul Razzaq

    2014-06-01

    Full Text Available Among the infectious organisms of parasitic origin, gastrointestinal nematodes are very important as they have been reported worldwide. The main aim of the present research study to highlight the annual epidemiological contributing factors associated with the prevalence of gastrointestinal nematodes and their control in sheep.A total 1200 faecal samples (100 per month were collected from farmers holding Balochi-sheep (either sexes, 1-5 years old during January-December 2012 and analyzed to determine the prevalence of nematodes based on microscopy and ELISA based diagnostic assay. Therapeutic efficacies of different synthetic and herbal medicines against these nematodes were assessed by field trials.Results showed that 23.92% Balochi-sheep were infected with nematodes. Five nematodes infections were recorded with highest prevalence of Haemonchus (7.75% followed by Nematodirus (7.58%, Strongyloides (4.42%, Trichostrongylus (2.33% and Trichuris (1.83%. The younger and older ewes (one and five years presented higher nematodes prevalence with peak during March/April and August/September. Haemonchus and Trichuris positive samples based on coprological examination were also showed 92-100% positive sensitivity for these nematodes by the ELISA. Sheep treated with Ivermectin showed higher reduction (97.76% in nematode egg counts followed by Atreefal deedan (96.42% and Oxfendazole (95.44%, respectively.The gastro-intestinal nematodes are prevalent in all age and either sex of Balochi-sheep with peak during summer. The ELISA based diagnosis is more accurte. The synthetic and herbal products are very effective against sheep nematodes.

  2. Coordinated Behaviour in Pigeon Flocks.

    Directory of Open Access Journals (Sweden)

    Makoto Yomosa

    Full Text Available We analysed pigeon flock flights using GPS trajectory data to reveal the most important kinematic aspects of flocking behaviour. We quantitatively investigated the internal motion of the flock based on pairwise statistics and found the following general relationships in all datasets: i the temporal order of decisions characterised by the delay between directional changes is strictly related to the spatial order characterised by the longitudinal relative position within the flock; ii during circling motion, pigeons use a mixture of two idealised and fundamentally different turning strategies, namely, parallel-path and equal-radius type turning. While pigeons tend to maintain their relative position within the flock on average, as in the parallel-path approximation, those who turn later also get behind as in the equal-radius case. Equal-radius type turning also tends to be expressed more during smaller radius turns.

  3. In vitro amplification of ovine prions from scrapie-infected sheep from Great Britain reveals distinct patterns of propagation

    Directory of Open Access Journals (Sweden)

    Thorne Leigh

    2012-11-01

    Full Text Available Abstract Background Protein misfolding cyclic amplification (PMCA is a method that facilitates the detection of prions from many sources of transmissible spongiform encephalopathy (TSE. Sheep scrapie represents a unique diversity of prion disease agents in a range of susceptible PRNP genotypes. In this study PMCA was assessed on a range of Great Britain (GB sheep scrapie isolates to determine the applicability to veterinary diagnosis of ovine TSE. Results PrPSc amplification by protein misfolding cyclic amplification (PMCA was assessed as a diagnostic tool for field cases of scrapie. The technique was initially applied to thirty-seven isolates of scrapie from diverse geographical locations around GB, and involved sheep of various breeds and PRNP genotypes. All samples were amplified in either VRQ and/or ARQ PrPC substrate. For PrPSc from sheep with at least one VRQ allele, all samples amplified efficiently in VRQ PrPC but only PrPSc from ARH/VRQ sheep amplified in both substrates. PrPSc from ARQ/ARQ sheep displayed two amplification patterns, one that amplified in both substrates and one that only amplified in ARQ PrPC. These amplification patterns were consistent for a further 14/15 flock/farm mates of these sheep. Furthermore experimental scrapie strains SSBP1, Dawson, CH1641 and MRI were analysed. SSBP1 and Dawson (from VRQ/VRQ sheep amplified in VRQ but not ARQ substrate. MRI scrapie (from ARQ/ARQ sheep nor CH1641 did not amplify in ARQ or VRQ substrate; these strains required an enhanced PMCA method incorporating polyadenylic acid (poly(A to achieve amplification. Conclusions PrPsc from 52 classical scrapie GB field isolates amplified in VRQ or ARQ or both substrates and supports the use of PMCA as a rapid assay for the detection of a wide range of ovine classical scrapie infections involving multiple PRNP genotypes and scrapie strains.

  4. Seroprevalence of ovine progressive pneumonia virus in sheep in the United States as assessed by analyses of voluntarily submitted samples.

    Science.gov (United States)

    Cutlip, R C; Lehmkuhl, H D; Sacks, J M; Weaver, A L

    1992-06-01

    Ovine progressive pneumonia (OPP) is a lentivirus-induced disease of sheep in the United States that is similar, if not identical, to maedi/visna in many other countries. Prevalence estimates of seropositivity to this virus in sheep in the United States have been confined to limited groups or flocks of sheep and have varied from 1 to 90%. In this study of detection of antibodies against OPP virus, we found a lower general prevalence of antibodies to OPP virus in sheep than was previously reported. Of 16,827 sheep from 29 states in the United States, 26% were seropositive and 48% of 164 flocks that were tested had 1 or more seropositive sheep. Seropositivity to OPP virus for sheep within special categories was determined, although nonrandom samples that were available may have biased the results. Within regions of the United States, prevalence was highest in the Rocky Mountain region at 49% and lowest in the northern Atlantic region at 9%. Seropositive sheep were not evenly distributed among flocks, but were clustered in a few flocks of sheep. A high number of flocks had no or few seropositive sheep. Prevalence increased with age from 4% at less than 1 year to a plateau of 34% at 4 years. Seropositivity was variable among breeds and was not associated with sex, wool class, or place of origin of ancestors.

  5. An ecologic study comparing distribution of Pasteurella trehalosi and Mannheimia haemolytica between Sierra Nevada bighorn sheep, White Mountain bighorn sheep, and domestic sheep.

    Science.gov (United States)

    Tomassini, Letizia; Gonzales, Ben; Weiser, Glen C; Sischo, William

    2009-10-01

    The prevalence and phenotypic variability of Pasteurella and Mannheimia isolates from Sierra Nevada bighorn sheep (Ovis canadensis sierrae), White Mountain bighorn sheep (Ovis canadensis nelsoni), and domestic sheep (Ovis aries) from California, USA, were compared. The White Mountain bighorn sheep population had a recent history of pneumonia-associated mortality, whereas the Sierra Nevada bighorn sheep population had no recent history of pneumonia-associated mortality. The domestic sheep flocks were pastured in areas geographically near both populations but were not known to have direct contact with either bighorn sheep population. Oropharyngeal swab samples were collected from healthy domestic and bighorn sheep and cultured to characterize bacterial species, hemolysis, biogroups, and biovariants. Pasteurella trehalosi and Mannheimia haemolytica were detected in all of the study populations, but the relative proportion of each bacterial species differed among sheep populations. Pasteurella trehalosi was more common than M. haemolytica in the bighorn sheep populations, whereas the opposite was true in domestic sheep. Mannheimia haemolytica was separated into 11 biogroups, and P. trehalosi was characterized into two biogroups. Biogroup distributions for M. haemolytica and P. trehalosi differed among the three populations; however, no difference was detected for the distribution of P. trehalosi biogroups between the Sierra Nevada bighorn sheep and domestic sheep. The prevalence odds ratios (pOR) for the distribution of M. haemolytica biogroups suggested little difference between White Mountain bighorn sheep and domestic sheep compared with Sierra Nevada bighorn sheep and domestic sheep, although these comparisons had relatively large confidence intervals for the point estimates. Hemolytic activity of the isolates was not different among the sheep populations for M. haemolytica but was different for P. trehalosi. No clear evidence of association was found in the

  6. Return of the Flock

    Directory of Open Access Journals (Sweden)

    David Middleton

    2005-01-01

    Full Text Available Across the blue horizon that divides Pale twilight skies from twilight-darkened earth A shepherd leads beneath a crescent moon His bending line of pliant moon-eyed sheep. The laggards and the leaders, nipped by dogs, Swirl from a formless mass of flesh and wool Toward faces separated yet the same, Soon lost to sun in starlight like the stars. The shepherd in procession grasps his staff, His right hand parting his cloak to show within His long blue shirt, a bishop’s under-robe, Literal symbols...

  7. A putative resistant DNA marker for wool yellowing susceptibility in sheep

    Directory of Open Access Journals (Sweden)

    Benavides M.V.

    2000-01-01

    Full Text Available An Australian Merino flock was screened for low (resistant and high (susceptible yellow predictive colour (YPC breeding values in order to compare extreme individuals using the differential display of mRNA technique. One differentially expressed cDNA band was visualised only in the resistant group. This band showed no identity with the DNA sequences of public databases; however, they showed short homologies with three database sequences related to transmembrane signalling functions. The use of these candidate genes as DNA markers needs to be confirmed against sheep with a wide range of susceptibility to wool yellowing to verify the results.

  8. Effective dimension in flocking mechanisms

    Science.gov (United States)

    Baglietto, Gabriel; Albano, Ezequiel V.

    2011-03-01

    Even in its minimal representation (Vicsek Model, VM [T. Vicsek, A. Czirok, E. Ben-Jacob, I. Cohen and O. Shochet. Phys. Rev. Lett. 75, 1226 (1995).]), the widespread phenomenon of flocking raises intriguing questions to the statistical physicists. While the VM is very close to the better understood XY Model because they share many symmetry properties, a major difference arises by the fact that the former can sustain long-range order in two dimensions, while the latter can not. Aiming to contribute to the understanding of this feature, by means of extensive numerical simulations of the VM, we study the network structure of clusters showing that they can also sustain purely orientational, mean-field-like, long-range order. We identify the reason of this capability with the key concept of "effective dimension." In fact, by analyzing the behavior of the average path length and the mean degree, we show that this dimension is very close to four, which coincides with the upper critical dimension of the XY Model, where orientational order is also of a mean-field nature. We expect that this methodology could be generalized to other types of dynamical systems.

  9. Prevalence and differentiation of diseases in Maryland backyard flocks.

    Science.gov (United States)

    Madsen, Jennifer M; Zimmermann, Nickolas G; Timmons, Jennifer; Tablante, Nathaniel L

    2013-09-01

    Several epidemiologic surveillance studies have implicated backyard flocks as a reservoir for poultry diseases; however, much debate still exists over the risk these small flocks pose. To evaluate this concern, the prevalence of Newcastle disease (ND), infectious laryngotracheitis (ILT), Mycoplasma gallisepticum (MG), and Salmonella was determined in 39 Maryland backyard flocks. Serum, tracheal, and cloacal swabs were randomly collected from 262 birds throughout nine counties in Maryland. Through PCR and ELISA analysis, disease prevalence and seroprevalence were determined in flocks, respectively, for the following: ND (0%, 23%); ILT (26%, 77%); MG (3%, 13%); and Salmonella (0%, not done). Vaccine status could not be accurately confirmed. Premise positives were further differentiated and identified by partial nucleotide sequencing. Screening of the 10 ILT premise positives showed that most were live attenuated vaccines: eight matched a tissue culture origin vaccine, one matched a chicken embryo origin (CEO) vaccine, and one was CEO related. The single MG-positive flock, also positive for the CEO-related sequence, was identified as the infectious S6 strain. The prevalence rates for these economically important poultry diseases ranged from none to relatively low, with the vast majority of sampled flocks presenting no clinical signs.

  10. Evaluation of Maryland backyard flocks and biosecurity practices.

    Science.gov (United States)

    Madsen, Jennifer M; Zimmermann, Nickolas G; Timmons, Jennifer; Tablante, Nathaniel L

    2013-06-01

    Domesticated poultry are susceptible to infectious and zoonotic diseases and can serve as a transmission source to other bird and human populations. In recent years, the number of noncommercial poultry has been on the rise in the United States. To evaluate potential risks of this growing population, a descriptive epidemiologic survey was conducted among Maryland backyard flocks. Owner and flock demographics were characterized as well as management practices such as husbandry, human-to-bird interaction, bird exposure risks, poultry health status, and biosecurity. Data from the 41 returned questionnaires indicated a median flock size of 38 birds (range, 3-901). Chickens accounted for 86.5% of the reported birds overall. Just over half of the owners (51.2%) kept chickens only, with the remaining backyard flocks consisting of chickens, other gallinaceous species, waterfowl, or a combination. Of flocks with multiple species, 70.0% of owners did not keep them separate. Almost two thirds of owners (61.0%) had kept poultry for backyard flocks. These results can be useful in developing educational extension and outreach programs as well as policies, in efforts to further mitigate the spread of diseases.

  11. Outdoor flocking of quadcopter drones with decentralized model predictive control.

    Science.gov (United States)

    Yuan, Quan; Zhan, Jingyuan; Li, Xiang

    2017-07-11

    In this paper, we present a multi-drone system featured with a decentralized model predictive control (DMPC) flocking algorithm. The drones gather localized information from neighbors and update their velocities using the DMPC flocking algorithm. In the multi-drone system, data packages are transmitted through XBee(®) wireless modules in broadcast mode, yielding such an anonymous and decentralized system where all the calculations and controls are completed on an onboard minicomputer of each drone. Each drone is a double-layered agent system with the coordination layer running multi-drone flocking algorithms and the flight control layer navigating the drone, and the final formation of the flock relies on both the communication range and the desired inter-drone distance. We give both numerical simulations and field tests with a flock of five drones, showing that the DMPC flocking algorithm performs well on the presented multi-drone system in both the convergence rate and the ability of tracking a desired path. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  12. RESISTÊNCIA ANTI-HELMÍNTICA EM REBANHOS OVINOS DA REGIÃO DA ASSOCIAÇÃO DOS MUNICÍPIOS DO ALTO IRANI (AMAI, OESTE DE SANTA CATARINA ANTHELMINTIC RESISTANCE ON SHEEP FLOCKS FROM ASSOCIATION OF THE MUNICIPALITIES OF THE ALTO IRANI REGION (AMAI, WEST OF SANTA CATARINA STATE, BRAZIL

    Directory of Open Access Journals (Sweden)

    Ingrid Kelly Zanchet

    2007-09-01

    Full Text Available

    Para conhecer a situação da resistência anti-hel-míntica em ovinos de propriedades localizadas nos mu-nicípios da Associação dos Municípios do Alto Irani (AMAI, oeste de Santa Catarina, Brasil, foram avalia-dos nove rebanhos pelo teste de redução da OPG (ovos por grama de fezes. Este teste consiste na comparação da média da OPG de um grupo de animais quatorze dias após o tratamento com a média de um grupo controle não-medicado. Consideraram-se efetivas as drogas capazes de reduzir a OPG em 95%. Os princípios ativos utilizados foram: levamisol (7,5 mg/kg, closantel (7,5 mg/Kg, al-bendazol (10 e 5 mg/Kg, ivermectin e moxidectin (0,2 mg/Kg. Detectou-se resistência dos nematódeos gastrin-testinais a todos os grupos anti-helmínticos testados, sen-do que 100% das propriedades apresentam resistência ao ivermectin; 66,7% ao moxidectin, 44,4% ao levamisol e 75% aos benzimidazóis. Para as lactonas macrocíclicas e benzimidazóis, tanto o gênero Haemonchus sp. quanto Trichostrongylus sp. apresentaram resistência. Para o le-vamisol, a resistência está restrita a Trichostrongylus sp. Também foi detectada a presença de uma população de Haemonchus sp. resistente ao closantel e uma de Nema-todirus sp. resistente ao albendazol. Estes dados mostram a urgência de difundir medidas de controle integrado de parasitoses, visando prolongar a vida  útil dos princípios ativos ainda disponíveis para uso.

    PALAVRAS-CHAVES: Ovinos, resistência anti-helmíntica, Santa Catarina.

    In order to know the situation of the anthelmintic resistance in sheep farms in the municipalities of Asso-ciation of the municipalities of the High Irani Region - AMAI, West of Santa Catarina State, Brazil, nine flocks were submitted to the faecal egg counts reduction test (FECRT. This test consists in comparing the mean FEC of a group of sheep, 14 days after treatment with the mean FEC of a non-treated control group. Only drugs that could

  13. Questioning the activity of active matter: the case of bird flocks

    Science.gov (United States)

    Mora, Thierry; Walczak, Aleksandra; Del Castello, Lorenzo; Ginelli, Francesco; Melillo, Stefania; Parisi, Leonardo; Viale, Massimiliano; Cavagna, Andrea; Giardina, Irene

    Animal flocking is a natural instance of active matter. What makes flocks active is the rearrangement of neighborhoods, which constantly remodels the network of interactions between individuals in the group, keeping the system out of equilibrium. Despite the predicted importance of this reshuffling, its true impact for natural flocks is not well understood. Here we analyse films of flocks of startlings with a novel statistical inference technique based on dynamical maximum entropy to measure the parameters of flock alignment - alignment strength, interaction range, and noise. We show that birds align their flight orientations must faster than they change neighbors. In the statistical mechanics sense, this means that flocks remain adiabatically in equilibrium, allowing for a rigorous analogy with equilibrium systems of interacting spins, and we show that an inference method based on equilibrium assumptions gives fully consistent results.

  14. Field trials with closantel and Haemonchus contortus in sheep in Papua New Guinea.

    Science.gov (United States)

    Owen, I L

    1988-09-01

    Sheep treated once with closantel at 7.5 or 15.0 mg/kg and grazing with untreated sheep remained free of Haemonchus contortus for at least 4 to 5 weeks and 6 to 7 weeks respectively after treatment. When the whole flock was treated with 15.0 mg/kg, H. contortus began to become re-established 7 to 8 weeks later. Maximum benefit of the residual anthelmintic effect of closantel against H.contortus was obtained only when all sheep in the flock were treated; it took 10 weeks longer for H.contortus to form 50% of larval cultures when the whole flock was treated than when only a part of the flock was treated.

  15. Natural and experimental infection of sheep with European bat lyssavirus type-1 of Danish bat origin

    DEFF Research Database (Denmark)

    Tjørnehøj, Kirsten; Fooks, A.R.; Agerholm, J.S.

    2006-01-01

    In 1998 and 2002, European bat lyssavirus type-1 (EBLV-1) was demonstrated in brain tissue of five Danish sheep suffering from micrological disorders. Four of the five sheep also had encephalic listeriosis. The animals originated from four flocks on pastures within a limited area of western Jutland...

  16. 9 CFR 79.2 - Identification of sheep and goats in interstate commerce.

    Science.gov (United States)

    2010-01-01

    ... official identification method or device approved by the Administrator. (3) The owner of the flock of... identification. Written requests for approval of sheep or goat identification devices and markings not listed in... devices and markings to the list of approved means of sheep and goat identification. ...

  17. Antibody prevalence of low-pathogenicity avian influenza and evaluation of management practices in Minnesota backyard poultry flocks.

    Science.gov (United States)

    Yendell, S J; Rubinoff, I; Lauer, D C; Bender, J B; Scheftel, J M

    2012-03-01

    Low-pathogenicity avian influenza (LPAI) viruses have caused illness in poultry and humans with poultry contact. To determine whether there is evidence of exposure to avian influenza viruses (AIV) among backyard poultry in Minnesota and their human caretakers, 150 flocks of backyard birds were sampled for antibodies to AIV from August 2007 through December 2008. One hundred flocks were tested through routine slaughter surveillance by the Minnesota Board of Animal Health and an additional 50 flocks were contacted and sampled by study investigators. Blood was collected from 10 to 13 birds from each flock and a survey of biosecurity and management practices was administered to the flock owner. Blood samples were tested by agar gel immunodiffusion (AGID) for influenza A antibodies. Tested flocks had a median flock size of 100 birds (range: 12-800 birds), and were most commonly owned for meat for personal use (81% of respondents), fun or hobby (58%) and eggs for personal use (56%). Although 7% of flock owners reported that their birds had shown respiratory signs in the previous 3 months, only 1 of 150 flocks tested positive for influenza by AGID. Antibodies to LPAI H6N1 were detected in the positive flock. The owner of the positive flock did not have antibodies to H6 or other common AIV. Based on the findings of this study, the risk of transmission of LPAI viruses from backyard poultry to owners in Minnesota appears to be low under current conditions and management practices.

  18. 9 CFR 147.21 - Flock sanitation.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Flock sanitation. 147.21 Section 147... LIVESTOCK IMPROVEMENT AUXILIARY PROVISIONS ON NATIONAL POULTRY IMPROVEMENT PLAN Sanitation Procedures § 147.21 Flock sanitation. To aid in the maintenance of healthy flocks, the following procedures should...

  19. Emerging cases of chlamydial abortion in sheep and goats in Croatia and Bosnia and Herzegovina.

    Science.gov (United States)

    Spičic, Silvio; Račić Ivana; Andrijanić, Milan; Duvnjak, Sanja; Zdelar-Tuk, Maja; Stepanić, Maja; Cvetnić, Zeljko

    2015-01-01

    In a recent lambing season (2012/2013), the seroprevalence of ovine chlamydiosis was monitored in small ruminant abortion cases in Croatia. Blood samples of 93 sheep and 69 goats were examined. In addition, 50 sheep and 61 goat samples were tested using molecular methods. Furthermore, 14 sheep blood samples, one goat blood sample and one sheep placenta sample from Bosnia and Herzegovina (BIH) were also tested as a part of inter-laboratory cooperation. Overall high seroprevalence was detected in sheep, 19.6% with the ELISA IDEXX kit and 20.5% with the ClVTEST kit. Seroprevalence in goats was 11.4%. In BIH, four sheep and one goat blood sample were seropositive for chlamydiosis. The disease causing agent, Chlamydia abortus (C. abortus) was confirmed using molecular methods in two sheep flocks in continental Croatia and in one sheep flock in BIH. In this study, C. abortus infection in sheep was identified for the first time in Croatia using species specific molecular methods. Ovine chlamydiosis is present in national sheep and goat flocks in Croatia and BIH. Thus should be subject to ongoing controls in the case of abortion. A combination of serological and molecular methods should be used for optimal laboratory diagnostics of C. abortus.

  20. Within-Flock Mortality During the High-Pathogenicity Avian Influenza (H7N7) Epidemic in the Netherlands in 2003: Implications for an Early Detection System

    NARCIS (Netherlands)

    Elbers, A.R.W.; Holtslag, J.B.; Bouma, A.; Koch, G.

    2007-01-01

    Daily within-flock mortality data, from a few days before until a few days after onset of increased mortality, from H7N7-infected flocks were analyzed with nonlinear regression for layer (organic and free-range or caged), broiler, and turkey flocks. The following notification thresholds were recomme

  1. Ovine paratuberculosis: a seroprevalence study in dairy flocks reared in the marche region, Italy.

    Science.gov (United States)

    Anna Rita, Attili; Victor, Ngu Ngwa; Silvia, Preziuso; Luciana, Pacifici; Anastasia, Domesi; Vincenzo, Cuteri

    2011-01-01

    In order to fulfil the seroprevalence gap on Mycobacterium avium subsp. paratuberculosis infection in ovine dairy farms of Marche region (central Italy), a stratified study was carried out on 2086 adult female sheep randomly chosen from 38 herds selected in Ancona and Macerata provinces. 73.7% flocks resulted infected by a commercial ELISA test (Pourquier, France), with a mean seroprevalence of 6.29% of sampled sheep in both provinces. A higher number of MAP seropositive ewes was recorded in the large herds' consistence than in the small and medium herds' consistence (P = 0.0269), and a greater percentage of infected sheep was obtained among female at early/late than in peak lactation stage (P = 0.0237). MAP infection was confirmed in 12.6% of infected farms by faecal culture. The true sheep-level seroprevalence was 15.1% ± 7.3%.

  2. Real-time qPCR is a powerful assay to estimate the 171 R/Q alleles at the PrP locus directly in a flock's raw milk: a comparison with the targeted next-generation sequencing.

    Science.gov (United States)

    Feligini, Maria; Bongioni, Graziella; Brambati, Eva; Amadesi, Alessandra; Cambuli, Caterina; Panelli, Simona; Bonacina, Cesare; Galli, Andrea

    2014-10-01

    The hazard to human health represented by transmissible spongiform encephalopathies in sheep is one of the major reasons for implementing the genetic selection plan to break down prion diseases. The problem is particularly important because of the risk of disease transmission from ewe to lamb via milk or colostrum. In order to establish an active and convenient monitoring of the flocks already undergone genetic selection and thus, indirectly increase consumers' security, the challenge of the work was quantifying the classical scrapie risk in bulk milk. A new quantitative real-time PCR assay for the estimation of the 171 R and Q allelic frequencies in a DNA pool representative of all the lactating ewes present in a flock was optimized and validated "in field". The repeatability range was 3.69-5.27 for R and 4.20-5.75 for Q. The ruggedness of the allele frequencies resulted 4.26 for R and 4.77 for Q. Regarding the validation "in field", none of the considered sources of variability (flock, month, number of genotyped animals and somatic cell count) showed a significant effect on flock and milk at the linear model. The targeted next-generation sequencing was also tested to evaluate its applicability in this context. Results show that the real-time PCR assay could represent a valid tool for the determination of 171 R/Q allele frequencies in bulk milk. The implementation of a service for breeder self-control along the production chain would aim to increase the production of high-security dairy products, while monitoring over time of the effects of genetic selection in the flocks.

  3. Graphics Processing Unit Enhanced Parallel Document Flocking Clustering

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xiaohui [ORNL; Potok, Thomas E [ORNL; ST Charles, Jesse Lee [ORNL

    2010-01-01

    Analyzing and clustering documents is a complex problem. One explored method of solving this problem borrows from nature, imitating the flocking behavior of birds. One limitation of this method of document clustering is its complexity O(n2). As the number of documents grows, it becomes increasingly difficult to generate results in a reasonable amount of time. In the last few years, the graphics processing unit (GPU) has received attention for its ability to solve highly-parallel and semi-parallel problems much faster than the traditional sequential processor. In this paper, we have conducted research to exploit this archi- tecture and apply its strengths to the flocking based document clustering problem. Using the CUDA platform from NVIDIA, we developed a doc- ument flocking implementation to be run on the NVIDIA GEFORCE GPU. Performance gains ranged from thirty-six to nearly sixty times improvement of the GPU over the CPU implementation.

  4. The evaluation of exposure risks for natural transmission of scrapie within an infected flock

    Directory of Open Access Journals (Sweden)

    Davis Andrew

    2009-10-01

    Full Text Available Abstract Background Although the epidemiology of scrapie has been broadly understood for many years, attempts to introduce voluntary or compulsory controls to eradicate the disease have frequently failed. Lack of precision in defining the risk factors on farm has been one of the challenges to designing control strategies. This study attempted to define which parts of the annual flock management cycle represented the greatest risk of infection to naive lambs exposed to the farm environment at different times. Results In VRQ/VRQ lambs exposed to infected sheep at pasture or during lambing, and exposed to the buildings in which lambing took place, the attack rate was high and survival times were short. Where exposure was to pasture alone the number of sheep affected in each experimental group was reduced, and survival times were longer and related to length of exposure. Conclusion At the flock level, eradication and control strategies for scrapie must take into account the need to decontaminate buildings used for lambing, and to reduce (or prevent the exposure of lambs to infected sheep, especially in the later stages of incubation, and at lambing. The potential for environmental contamination from pasture should also be considered. Genotype selection may still prove to be the only viable tool to prevent infection from contaminated pasture, reduce environmental contamination and limit direct transmission from sheep to sheep.

  5. Seroprevalence of Louping Ill virus (LIV antibodies in sheep submitted for post mortem examination in the North West of Ireland in 2011

    Directory of Open Access Journals (Sweden)

    Barrett Damien

    2012-12-01

    Full Text Available Abstract Blood samples were collected opportunistically at routine post mortem examination from 199 sheep which came from 152 flocks. The location of each submitting flock was mapped. Sera were tested using a goose blood haemagglutination inhibition assay for louping ill virus. There was an animal level prevalence of 8.5%, and a flock level prevalence of 9.8%. The greatest proportion of seropositive animals was identified among the animals older than 24 months of age. The elevation of the land associated with positive flocks was greater than that of negative flocks. Lesions of non-suppurative meningoencephalitis were observed in three of the 199 animals.

  6. Seroprevalence of Louping Ill virus (LIV) antibodies in sheep submitted for post mortem examination in the North West of Ireland in 2011.

    Science.gov (United States)

    Barrett, Damien; Collins, Daniel M; McGrath, Guy; O Muireagain, Colm

    2012-12-11

    Blood samples were collected opportunistically at routine post mortem examination from 199 sheep which came from 152 flocks. The location of each submitting flock was mapped. Sera were tested using a goose blood haemagglutination inhibition assay for louping ill virus. There was an animal level prevalence of 8.5%, and a flock level prevalence of 9.8%. The greatest proportion of seropositive animals was identified among the animals older than 24 months of age. The elevation of the land associated with positive flocks was greater than that of negative flocks. Lesions of non-suppurative meningoencephalitis were observed in three of the 199 animals.

  7. Pigmented spots in the wool-bearing skin on white merino sheep induced by ultraviolet light.

    Science.gov (United States)

    Forrest, J W; Fleet, M R

    1986-01-01

    Black-grey pigmented skin spots, some of which contained pigmented wool fibres, were observed in a flock of 8.5-year-old white Merino ewes. The spots were concentrated along the backline and increased in number following shearing, suggesting exposure to sunlight to be of importance in the development of these non-congenital pigmented skin spots in genetically white Merino sheep. To test the effect of ultraviolet light, white Merino sheep, ranging in age from 3 to 8 years, had a closely clipped midside area of wool-bearing skin irradiated on each of 28 consecutive days. Pigmented skin spots developed in 6 of the 16 white Merino sheep irradiated. Spots first appeared after 10 days of irradiation, the number subsequently increasing with time, and two skin spots were found to contain sparse numbers of black-grey pigmented wool fibres. Histological examination showed both the naturally occurring and irradiation-induced pigmented skin spots resulted from an increase in both number and activity of melanocytes localized along the epidermal-dermal border of the epidermis. With time, the melanocytes were observed to have entered, to varying depths, the outer-root sheath of follicles still producing white wool fibres. These ultraviolet-light-induced changes to epidermal melanocytes in white Merino sheep presumably occur due to alterations within the local tissue environment in which the melanocytes lie.

  8. Incidence of Peste des petits ruminants in nomadic sheep and goat of Jammu region

    Directory of Open Access Journals (Sweden)

    Sumit Mahajan

    Full Text Available Aim: The present study was planned with an aim to access the incidence of Peste des petits ruminants (PPR in nomadic sheep and goat of Jammu region of Jammu and Kashmir (J&K state of India. Materials and Methods:A total of 34 nasal swabs (13 sheep and 21 goats samples of 13 flocks suspected for PPR infection were screened for presence of PPR virus antigen by PPR sandwich-ELISA kit. Results: The overall incidence of PPR by sandwich ELISA was observed to be 55.55%, with higher incidence in goats (66.66% than in sheep (35.71%. Location wise incidence of PPR ranged between 33.33-100%. The overall age wise incidence of PPR was highest in young animals of 0-6 months (83.33%, followed by 6-12 months (66.66% and lowest in adults of >12 months (31.35 %. Whereas month wise incidence of PPR was highest in the month of February. Conclusion: In nut shell it can be concluded that PPR is fairly prevalent in nomadic sheep and goats of Jammu region of J&K state with the evidences of natural transmission of PPR. [Vet World 2013; 6(7.000: 384-387

  9. Rituals Cows or just another flock of Sheep?

    DEFF Research Database (Denmark)

    Bangsgaard, Pernille

    This dissertation examines the practises of faunal deposits at Pangrave and C-Group cemeteries. The faunal culture of the Middle Nubian Horizon has occasionally been mentioned in the literature and scholarly interest has included the topic of daily subsistence consumption as well as the symbolic ...

  10. Vancomycin-resistant enterococci (VRE) in broiler flocks 5 years after the avoparcin ban

    DEFF Research Database (Denmark)

    Heuer, Ole Eske; Pedersen, Karl; Andersen, J.S.

    2002-01-01

    The glycopeptide growth promoter avoparcin was banned from animal production in Denmark in 1995. In this study, we investigated the occurrence of vancomycin-resistant enterococci (VRE) in broiler flocks in the absence of the selective pressure exerted by the use of avoparcin. One hundred sixty......-two broiler flocks from rearing systems with different histories of avoparcin exposure were investigated for the presence of VRE. Using a direct selective plating procedure, VRE were isolated from 104 of 140 (74.3%) broiler flocks reared in broiler houses previously exposed to avoparcin on conventional...... and extensive indoor broiler farms. In contrast, only 2 of 22 (9.1%) organic broiler flocks reared on free-range farms with no history of previous exposure to avoparcin were VRE-positive. Furthermore, the occurrence of VRE over time in flocks reared in broiler houses previously exposed to avoparcin...

  11. Foot rot and other foot diseases of goat and sheep in the semiarid region of northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Gildeni M.N Aguiar

    2011-10-01

    Full Text Available This paper reports the occurrence and epidemiology of outbreaks of foot rot and other foot diseases in goats and sheep in the semiarid region of Paraíba, northeastern Brazil. Four farms were inspected for the presence of foot lesion in sheep and goats and for environmental conditions, general hygiene, pastures, and disease control measures. The prevalence of foot lesions was 19.41% (170/876 in sheep and 17.99% (52/289 in goats, ranging between 5.77% and 33.85% in different farms. Foot rot was the most common disease, affecting 12.1% of the animals examined (141/1165, but with significantly higher (p<0.05 prevalence in sheep (13.69% than in goats (7.27%. The frequency of malignant foot rot was also significantly lower (p<0.05 in goats (9.53% than in the sheep (40.83%. On one farm, Dorper sheep showed significantly higher (p<0.05 prevalence of foot rot (17.5% than Santa Inês sheep (6.79%, and the number of digits affected was also higher in the former. Dichelobacter nodosus and Fusobacterium necrophorum were isolated from cases of foot rot. White line disease was found in 3.95% of the animals, sole ulcers in 1.29%, foot abscess in 1.03% and hoof overgrowth in 0.5%. The high rainfall at the time of occurrence, grazing in wetlands, clay soils with poor drainage, presence of numerous stony grounds, closure of the flocks in pens at night, and introduction of affected animals were considered predisposing factors for the occurrence of foot diseases.

  12. An economic evaluation of preclinical testing strategies compared to the compulsory scrapie flock scheme in the control of classical scrapie.

    Science.gov (United States)

    Boden, Lisa; Handel, Ian; Hawkins, Neil; Houston, Fiona; Fryer, Helen; Kao, Rowland

    2012-01-01

    Cost-benefit is rarely combined with nonlinear dynamic models when evaluating control options for infectious diseases. The current strategy for scrapie in Great Britain requires that all genetically susceptible livestock in affected flocks be culled (Compulsory Scrapie Flock Scheme or CSFS). However, this results in the removal of many healthy sheep, and a recently developed pre-clinical test for scrapie now offers a strategy based on disease detection. We explore the flock level cost-effectiveness of scrapie control using a deterministic transmission model and industry estimates of costs associated with genotype testing, pre-clinical tests and the value of a sheep culled. Benefit was measured in terms of the reduction in the number of infected sheep sold on, compared to a baseline strategy of doing nothing, using Incremental Cost Effectiveness analysis to compare across strategies. As market data was not available for pre-clinical testing, a threshold analysis was used to set a unit-cost giving equal costs for CSFS and multiple pre-clinical testing (MT, one test each year for three consecutive years). Assuming a 40% within-flock proportion of susceptible genotypes and a test sensitivity of 90%, a single test (ST) was cheaper but less effective than either the CSFS or MT strategies (30 infected-sales-averted over the lifetime of the average epidemic). The MT strategy was slightly less effective than the CSFS and would be a dominated strategy unless preclinical testing was cheaper than the threshold price of £6.28, but may be appropriate for flocks with particularly valuable livestock. Though the ST is not currently recommended, the proportion of susceptible genotypes in the national flock is likely to continue to decrease; this may eventually make it a cost-effective alternative to the MT or CSFS.

  13. An economic evaluation of preclinical testing strategies compared to the compulsory scrapie flock scheme in the control of classical scrapie.

    Directory of Open Access Journals (Sweden)

    Lisa Boden

    Full Text Available Cost-benefit is rarely combined with nonlinear dynamic models when evaluating control options for infectious diseases. The current strategy for scrapie in Great Britain requires that all genetically susceptible livestock in affected flocks be culled (Compulsory Scrapie Flock Scheme or CSFS. However, this results in the removal of many healthy sheep, and a recently developed pre-clinical test for scrapie now offers a strategy based on disease detection. We explore the flock level cost-effectiveness of scrapie control using a deterministic transmission model and industry estimates of costs associated with genotype testing, pre-clinical tests and the value of a sheep culled. Benefit was measured in terms of the reduction in the number of infected sheep sold on, compared to a baseline strategy of doing nothing, using Incremental Cost Effectiveness analysis to compare across strategies. As market data was not available for pre-clinical testing, a threshold analysis was used to set a unit-cost giving equal costs for CSFS and multiple pre-clinical testing (MT, one test each year for three consecutive years. Assuming a 40% within-flock proportion of susceptible genotypes and a test sensitivity of 90%, a single test (ST was cheaper but less effective than either the CSFS or MT strategies (30 infected-sales-averted over the lifetime of the average epidemic. The MT strategy was slightly less effective than the CSFS and would be a dominated strategy unless preclinical testing was cheaper than the threshold price of £6.28, but may be appropriate for flocks with particularly valuable livestock. Though the ST is not currently recommended, the proportion of susceptible genotypes in the national flock is likely to continue to decrease; this may eventually make it a cost-effective alternative to the MT or CSFS.

  14. Pestivirus infection in sheep and goats in West Austria.

    Science.gov (United States)

    Krametter-Froetscher, R; Duenser, M; Preyler, B; Theiner, A; Benetka, V; Moestl, K; Baumgartner, W

    2010-12-01

    Blood samples from 3112 sheep (185 flocks) and 1196 goats (163 flocks) from the Western region of Austria were tested for pestivirus-specific RNA. In this area, communal Alpine pasturing of sheep, cattle and goats is an important part of farming. The prevalence of sheep persistently-infected (PI) with pestivirus was 0.32% (10 animals) and the PI animals originated from five flocks (2.7% of those investigated). In goats, only one PI animal (0.08%) was detected. Sequence analysis of the 5'-end untranslated region (UTR) revealed that the strains of Border disease virus (BDV) detected were closely related to genotype 3 but the PI animals did not show any clinical signs of Border disease. The goat was PI with bovine viral diarrhoea virus-1 (BVDV-1). On one farm a high abortion rate among sheep had been observed 1year before the study was carried out but the other farms did not show any evidence of reproductive failures. Pestiviruses are endemic in small ruminants in some Alpine regions of Austria and PI healthy animals as described here have a key epidemiological role. A successful BVDV eradication programme in Austria will create highly pestivirus-susceptible cattle populations. Sheep and goats present a high risk for the reintroduction of pestiviruses to cattle herds because they are less likely to be considered to be PI. The results underline the need for the immediate consideration of small ruminants in eradication programmes.

  15. Epidemiologic characterization of Colorado backyard bird flocks.

    Science.gov (United States)

    Smith, Emily I; Reif, John S; Hill, Ashley E; Slota, Katharine E; Miller, Ryan S; Bjork, Kathe E; Pabilonia, Kristy L

    2012-06-01

    Backyard gallinaceous bird flocks may play an important role in the spread of infectious diseases within poultry populations as well as the transmission of zoonotic diseases to humans. An epidemiologic characterization was conducted of Colorado backyard flocks to gather information on general flock characteristics, human movement of birds, human-bird interaction, biosecurity practices, and flock health. Our results suggest that backyard poultry flocks in Colorado are small-sized flocks (68.6% of flocks had backyard flock environment may promote bird-to-bird transmission as well as bird-to-human transmission of infectious disease. Birds are primarily housed with free access to the outside (96.85%), and many are moved from the home premises (46.06% within 1 yr). Human contact with backyard flocks is high, biosecurity practices are minimal, and bird health is negatively impacted by increased movement events. Increased knowledge of backyard bird characteristics and associated management practices can provide guidelines for the development of measures to decrease disease transmission between bird populations, decrease disease transmission from birds to humans, and increase the overall health of backyard birds.

  16. Design of Connectivity Preserving Flocking Using Control Lyapunov Function

    Directory of Open Access Journals (Sweden)

    Bayu Erfianto

    2016-01-01

    Full Text Available This paper investigates cooperative flocking control design with connectivity preserving mechanism. During flocking, interagent distance is measured to determine communication topology of the flocks. Then, cooperative flocking motion is built based on cooperative artificial potential field with connectivity preserving mechanism to achieve the common flocking objective. The flocking control input is then obtained by deriving cooperative artificial potential field using control Lyapunov function. As a result, we prove that our flocking protocol establishes group stabilization and the communication topology of multiagent flocking is always connected.

  17. Maintenance of a captive flock of house finches free of infection by Mycoplasma gallisepticum.

    Science.gov (United States)

    Nolan, P M; Duckworth, R A; Hill, G E; Roberts, S R

    2000-01-01

    Since the beginning of an epidemic of conjunctivitis in wild house finches caused by Mycoplasma gallisepticum (MG), all captive colonies established by capturing free-ranging house finches from the eastern population have also either been infected at the time of capture or developed infection shortly after capture. In an attempt to avoid this infection in captive flocks being maintained for studies of the finches' behavior and ecology, we compared two different flock management strategies and were able to prevent the development of mycoplasmal conjunctivitis with one of the strategies. Single-sex flocks were built by introducing only seronegative wild-caught birds showing no clinical signs of conjunctivitis and covering their outdoor flight cages with netting to prevent interaction with other wild birds although only the female flocks were initially treated with a 6-wk course of tylosin tartrate (0.3 mg/ml). The female flocks never developed conjunctivitis although the disease did develop in the male flocks. Furthermore, serologic assessments of the healthy flock by serum plate agglutination assays for MG indicated that the females remained free of MG infection in the final 7 wk of the study, during which they were unmedicated. We conclude that any low-level MG infection not diagnosed by the initial test for seroconversion was cleared by the prolonged drug treatment.

  18. Investigations concerning the prevalence of Coxiella burnetii and Chlamydia abortus in sheep in correlation with management systems and abortion rate in Lower Saxony in 2004.

    Science.gov (United States)

    Runge, Martin; Binder, Alfred; Schotte, Ulrich; Ganter, Martin

    2012-01-01

    The intracellular bacteria Coxiella (C) burnetii and Chlamydia (Chl) abortus induce abortion in sheep and also affect humans. While Chl. abortus only infrequently infects humans, C burnetii is the aetiological agent of numerous Q fever outbreaks during the last decades. There is only limited knowledge about the prevalence of both pathogens in sheep, although sheep are involved in almost all Q fever outbreaks in Germany. The aim of our study was to investigate the prevalence of both pathogens in flocks located in Lower Saxony, Germany, in correlation to the management form and abortion rate. Serum samples of 1714 sheep from 95 flocks located in Lower Saxony were investigated by ELISA. 2.7% of these samples were positive, 1.3% showed inconclusive results in the C. burnetii-ELISA. Elevated intra-flock seroprevalences were only detected in three migrating flocks. Chlamydia-specific antibodies could be detected in 15.1% serum samples of mainly shepherded and migrating flocks. In one of these flocks with a high intra-flock seroprevalence for C burnetii (27%) and Chlamydia (44.9%), C burnetii was detected in 21.6% of the placenta samples of normal births and in 12.5% of the colostrum samples by PCR. Aborted fetuses and the corresponding placentas were negative in C burnetii-PCR, but in most of them and also in many other placenta samples Chl. abortus could be detected by PCR and DNA microarray. This survey shows a low overall prevalence of C. burnetii in sheep in Lower Saxony in the year 2004. However, three migrating flocks with a high intra-flock prevalence are localized in the southern parts of Lower Saxony. Spreading of C burnetii could occur, because of the large radius of grazing of all three flocks.

  19. Epidemiological implications of the susceptibility to BSE of putatively resistant sheep.

    Science.gov (United States)

    Kao, R R; Houston, F; Baylis, M; Chihota, C M; Goldmann, W; Gravenor, M B; Hunter, N; McLean, A R

    2003-12-01

    The experimental infection of sheep with bovine spongiform encephalopathy (BSE) by the oral route and the likelihood that sheep were fed BSE-infected meat and bone meal has led to extensive speculation as to whether or not sheep are naturally infected with BSE. In response, the UK government has initiated the National Scrapie Plan (NSP), an ambitious pound 120 million per year project to create a BSE- and scrapie-resistant national sheep flock, by selectively breeding for a genotype of sheep believed to be resistant to both diseases. This genotype has recently been shown to be susceptible to BSE by intracerebral (i.c.) inoculation. Should these sheep be sufficiently susceptible to BSE via natural transmission, the NSP might fail. Here we estimate the susceptibility of this genotype to horizontal (sheep-to-sheep) transmission of BSE by comparison with more extensive oral and i.c. exposure data for other sheep genotypes. We show that a previous estimate of the risk of BSE transmission to sheep via the feedborne route remains robust. However, using a mathematical model for the within-flock transmission of BSE, we show that, while the best estimate indicates that the NSP should be successful, current data cannot exclude the failure of the NSP.

  20. Production and economic characteristics of sheep production on the island of Pag

    Directory of Open Access Journals (Sweden)

    Marina Krvavica

    2012-03-01

    Full Text Available The aim of the research was to learn from a survey about the production and economic characteristics of sheep production as well as economic position and developmental orientation of sheep breeders on the island of Pag. Data on production and economic characteristics of sheep production on the island of Pag were collected from a survey and processed through relevant descriptive statistics methods. The respondents have on average 47 breeding sheep, 2 rams and 9 sheep intended for flock renewal rate (not older than one year; which means an average flock has 58 sheep. The average total income from sheep production in 2009 was 72,460.10 HRK. The average total production costs in 2009 were 13,260.10 HRK, including the costs of fodder and veterinary services. All farms achieved positive financial results of 59,199.90 HRK in average. As many as three quarters of respondents indicated profitability of sheep production as the main motivation to engage in sheep production; very few indicated that heritage and inability to do other jobs were the main motivation. Important limiting factors for future development of sheep breeding on the island of Pag in most farms are lack of potential heirs and high average age of farm holders. Regarding the effects of joining the European Union, half the breeders intend to improve their production and harmonise it with the EU requirements and standards; one quarter of them intend to keep the existing production capacity; and another quarter intend to quit with production.

  1. Cluster randomised trial of the impact of biosecurity measures on poultry health in backyard flocks.

    Science.gov (United States)

    Conan, Anne; Goutard, Flavie Luce; Holl, Davun; Ra, Sok; Ponsich, Aurélia; Tarantola, Arnaud; Sorn, San; Vong, Sirenda

    2013-12-01

    In Cambodia, most poultry are raised in backyard flocks with a low level of biosecurity, which increases the risk of spread of infectious diseases. The aim of this study was to evaluate the effectiveness of a practical biosecurity intervention based on affordable basic measures. A cluster randomised trial was conducted in 18 villages in Cambodia from November 2009 to February 2011. Generalised estimating equations were used to test the association between the intervention and mortality rates in flocks of chickens and ducks. Mortality rates in chicken flocks in intervention villages (mean 6.3%, range 3.5-13.8%, per month) were significantly higher than in control villages (mean 4.5%, range 2.0-9.7%, per month; Pbiosecurity intervention implemented in this study was not associated with improvements in poultry mortality rates. These findings suggest that basic biosecurity measures may not suffice to limit the spread of infectious diseases in backyard poultry flocks in Cambodia.

  2. Milk yield and quality of Cres sheep and their crosses with Awassi and East Friesian sheep

    Directory of Open Access Journals (Sweden)

    Boro Mioč

    2009-09-01

    Full Text Available The objective of this study was to establish the impact of crossing the indigenous Cres sheep with Awassi and, respectively, Awassi and East Friesian sheep on the milk yield and quality. For this purpose, through regular monthly milk yield recordings a total of 824individual milk samples from 139 sheep in the second lactation of the same flock were collected, of which: 46 purebred Cres sheep, CS; 33 crosses with 50 % Cres sheep and 50 % Awassi, CA; 60 crosses with 50 % Cres sheep, 25 % Awassi and 25 % East Friesian, CAEF. The obtained results show a significant (P<0.05; P<0.01 impact of the genotype and the lactation stage on the yield and chemical composition of milk, and the somatic cell count. The most milk was yielded by CAEF crosses (690 mL/ewe/day, i.e., 133.8 L per lactation and the least by CS (340 mL/ewe/day, i.e., 58.48 L per lactation. The content of total solids, fat and protein increased as lactation advanced, whereas the trend of the lactose content was opposite. The highest content of total solids, fat and protein were established in the milk of the indigenous Cres sheep. A positive correlation was established between the amount of yielded milk and the somatic cell count, whereas a negative correlation was established between the amount of milk and the content of solids, fat and proteins.

  3. Estimation of the sensitivity of various environmental sampling methods for detection of Salmonella in duck flocks.

    Science.gov (United States)

    Arnold, Mark E; Mueller-Doblies, Doris; Gosling, Rebecca J; Martelli, Francesca; Davies, Robert H

    2015-01-01

    Reports of Salmonella in ducks in the UK currently rely upon voluntary submissions from the industry, and as there is no harmonized statutory monitoring and control programme, it is difficult to compare data from different years in order to evaluate any trends in Salmonella prevalence in relation to sampling methodology. Therefore, the aim of this project was to assess the sensitivity of a selection of environmental sampling methods, including the sampling of faeces, dust and water troughs or bowls for the detection of Salmonella in duck flocks, and a range of sampling methods were applied to 67 duck flocks. Bayesian methods in the absence of a gold standard were used to provide estimates of the sensitivity of each of the sampling methods relative to the within-flock prevalence. There was a large influence of the within-flock prevalence on the sensitivity of all sample types, with sensitivity reducing as the within-flock prevalence reduced. Boot swabs (individual and pool of four), swabs of faecally contaminated areas and whole house hand-held fabric swabs showed the overall highest sensitivity for low-prevalence flocks and are recommended for use to detect Salmonella in duck flocks. The sample type with the highest proportion positive was a pool of four hair nets used as boot swabs, but this was not the most sensitive sample for low-prevalence flocks. All the environmental sampling types (faeces swabs, litter pinches, drag swabs, water trough samples and dust) had higher sensitivity than individual faeces sampling. None of the methods consistently identified all the positive flocks, and at least 10 samples would be required for even the most sensitive method (pool of four boot swabs) to detect a 5% prevalence. The sampling of dust had a low sensitivity and is not recommended for ducks.

  4. Assessment of Poisson, probit and linear models for genetic analysis of presence and number of black spots in Corriedale sheep.

    Science.gov (United States)

    Peñagaricano, F; Urioste, J I; Naya, H; de los Campos, G; Gianola, D

    2011-04-01

    Black skin spots are associated with pigmented fibres in wool, an important quality fault. Our objective was to assess alternative models for genetic analysis of presence (BINBS) and number (NUMBS) of black spots in Corriedale sheep. During 2002-08, 5624 records from 2839 animals in two flocks, aged 1 through 6 years, were taken at shearing. Four models were considered: linear and probit for BINBS and linear and Poisson for NUMBS. All models included flock-year and age as fixed effects and animal and permanent environmental as random effects. Models were fitted to the whole data set and were also compared based on their predictive ability in cross-validation. Estimates of heritability ranged from 0.154 to 0.230 for BINBS and 0.269 to 0.474 for NUMBS. For BINBS, the probit model fitted slightly better to the data than the linear model. Predictions of random effects from these models were highly correlated, and both models exhibited similar predictive ability. For NUMBS, the Poisson model, with a residual term to account for overdispersion, performed better than the linear model in goodness of fit and predictive ability. Predictions of random effects from the Poisson model were more strongly correlated with those from BINBS models than those from the linear model. Overall, the use of probit or linear models for BINBS and of a Poisson model with a residual for NUMBS seems a reasonable choice for genetic selection purposes in Corriedale sheep.

  5. Evidence in sheep for pre-natal transmission of scrapie to lambs from infected mothers.

    Science.gov (United States)

    Foster, James D; Goldmann, Wilfred; Hunter, Nora

    2013-01-01

    Natural scrapie transmission from infected ewes to their lambs is thought to occur by the oral route around the time of birth. However the hypothesis that scrapie transmission can also occur before birth (in utero) is not currently favoured by most researchers. As scrapie is an opportunistic infection with multiple infection routes likely to be functional in sheep, definitive evidence for or against transmission from ewe to her developing fetus has been difficult to achieve. In addition the very early literature on maternal transmission of scrapie in sheep was compromised by lack of knowledge of the role of the PRNP (prion protein) gene in control of susceptibility to scrapie. In this study we experimentally infected pregnant ewes of known PRNP genotype with a distinctive scrapie strain (SSBP/1) and looked for evidence of transmission of SSBP/1 to the offspring. The sheep were from the NPU Cheviot flock, which has endemic natural scrapie from which SSBP/1 can be differentiated on the basis of histology, genetics of disease incidence and strain typing bioassay in mice. We used embryo transfer techniques to allow sheep fetuses of scrapie-susceptible PRNP genotypes to develop in a range of scrapie-resistant and susceptible recipient mothers and challenged the recipients with SSBP/1. Scrapie clinical disease, caused by both natural scrapie and SSBP/1, occurred in the progeny but evidence (including mouse strain typing) of SSBP/1 infection was found only in lambs born to fully susceptible recipient mothers. Progeny were not protected from transmission of natural scrapie or SSBP/1 by washing of embryos to International Embryo Transfer Society standards or by caesarean derivation and complete separation from their birth mothers. Our results strongly suggest that pre-natal (in utero) transmission of scrapie may have occurred in these sheep.

  6. Evaluation of effects of sciatic and femoral nerve blocks in sheep undergoing stifle surgery.

    Science.gov (United States)

    Wagner, Ann E; Mama, Khursheed R; Ruehlman, Dana L; Pelkey, Sheila; Turner, A Simon

    2011-04-01

    The authors evaluated the effects of locally anesthetizing the sciatic and femoral nerves in sheep undergoing stifle (femorotibial) surgery (16 sheep received nerve blocks; 16 sheep underwent a nerve localization procedure but received no nerve blocks). Heart rate, mean arterial blood pressure and end-tidal isoflurane were recorded every 5 min while sheep were anesthetized. At some of the observed time points, the mean heart rate in the sheep that had received no nerve blocks was significantly higher than in the sheep that had received the nerve blocks. Postoperatively, each sheep was assigned scores for comfort and attitude, movement, flock behavior, feeding behavior and appetite and respiratory rate (based on predefined descriptions). Though the authors found no undesirable effects of this local anesthesia, beneficial effects of the nerve blocks were minimal or not readily apparent under the conditions of this study.

  7. Optic neuropathy in sheep associated with overdosage of closantel.

    Science.gov (United States)

    Borges, A S; Mendes, L C; de Andrade, A L; Machado, G F; Peiro, J R

    1999-12-01

    This report describes clinical and pathological findings in 2 flocks in Brazil where blindness and deaths in sheep occurred after closantel overdosage. Depression, weakness, and blindness affected 37 animals and 17 died in 2 flocks of 190 animals. Two animals submitted for ophthalmic examination showed no inflammation in the anterior segment of both eyes; posterior segment evaluation by indirect ophthalmoscopy suggested retinal degeneration. One postmortem evaluation local spongy vacuolization was in several regions of the brain and the optical nerves had severe axonal degeneration.

  8. Fatal pneumonia following inoculation of healthy bighorn sheep with Pasteurella haemolytica from healthy domestic sheep.

    Science.gov (United States)

    Foreyt, W J; Snipes, K P; Kasten, R W

    1994-04-01

    In a series of three experiments, isolates of Pasteurella haemolytica biotype A, serotype 2, ribotype reference WSU-1, from healthy domestic sheep, were inoculated intratracheally into eight bighorn sheep (Ovis canadensis canadensis) and seven domestic sheep with doses of bacteria ranging from 5.3 x 10(8) to 8.6 x 10(11) colony forming units. Seven of eight inoculated bighorn sheep died from acute pneumonia within 48 hr of inoculation, whereas all seven domestic sheep inoculated with comparable or greater doses of bacteria remained healthy. One contact control bighorn sheep also died 6 days after its penmates received P. haemolytica. Three other noncontact control bighorn sheep remained healthy during the experiments. Pasteurella haemolytica biotype A, serotype 2, ribotype reference WSU-1 in the inocula was recovered from one or more tissues from all bighorns that died; whereas, it was not detected in any bighorn sheep before inoculation. Three different ribotypes of P. haemolytica A2 were recovered from bighorn sheep; however, only the ribotype reference WSU-1 in the domestic sheep-origin inoculum was recovered from all dead bighorn sheep, and was not recovered from bighorn sheep that survived the experiments. Thus, a relatively nonpathogenic and common isolate of P. haemolytica from healthy domestic sheep was lethal in bighorn sheep under experimental conditions.

  9. Paratuberculosis in sheep and goats.

    Science.gov (United States)

    Windsor, P A

    2015-12-14

    Paratuberculosis is a chronic insidious, often serious, disease of the global small ruminant industries, mainly causing losses from mortalities and reduced productivity on-farm, interference in trading and, in Australia, profound socio-economic impacts that have periodically compromised harmony of rural communities. The pathogenesis, diagnosis, impacts and disease management options for ovine and caprine paratuberculosis are reviewed, comparing current controls in the extensive management system for sheep in wool flocks in Australia with the semi-intensive system of dairy flocks/herds in Greece. Improved understanding of the immune and cellular profiles of sheep with varying paratuberculosis outcomes and the recognition of the need for prolonged vaccination and biosecurity is considered of relevance to future control strategies. Paratuberculosis in goats is also of global distribution although the prevalence, economic impact and strategic control options are less well recognized, possibly due to the relatively meagre resources available for goat industry research. Although there have been some recent advances, more work is required on developing control strategies for goats, particularly in dairy situations where there is an important need for validation of improved diagnostic assays and the recognition of the potential impacts for vaccination. For all species, a research priority remains the identification of tests that can detect latent and subclinical infections to enhance removal of future sources of infectious material from flocks/herds and the food chain, plus predict the likely outcomes of animals exposed to the organism at an early age. Improving national paratuberculosis control programs should also be a priority to manage disease risk from trade. The importance of strong leadership and communication, building trust within rural communities confused by the difficulties in managing this insidious disease, reflects the importance of change management

  10. Chronic fetal and maternal instrumentation in pregnant sheep: effect on gestation length and birthweight.

    Science.gov (United States)

    Bessette, Natalee W; Rurak, Dan W

    2010-01-01

    The objective was to compare gestation length in chronically instrumented (laboratory) pregnant sheep (n = 131) and in the breeding flock (n = 476) that provided the experimental sheep. In the breeding flock, gestation length was normally distributed and varied between 141 and 151 days (mean = 147 +/- 0.1 days). In the laboratory sheep, gestation length varied between 128 and 151 days (mean = 142 +/- 1 day), and was bimodal, with 35.9% delivering preterm (gestation length. The median values for the surgical (15 v. 12), overall complication (6 v. 2), maternal complication (2 v. 0) and fetal complication (2 v. 2) components were significantly greater in the preterm compared with the term groups. There was no relationship between fetal number and gestation length in either group. It is concluded that in chronic pregnant sheep preparations, there is a significant incidence of preterm birth and that this is associated with the severity of the surgical intervention and with several maternal and fetal complications.

  11. [An evaluation of the biological action of increased doses of EMI in the UV range on the functional state and productivity of sheep].

    Science.gov (United States)

    Ivanov, V L; Ipatova, A G; Zeĭnalov, A A; Kozlov, V A; Sarukhanov, V Ia

    2000-01-01

    The effect of increased UV-radiation doses modeling 25 and 50% of ozone layer depletion on sheep's organisms was studied in the field experiment. The character of changes in animal organisms was found to depend on irradiation doses, sensitivity of individual system of living organism to electromagnetic radiation and physiological peculiarities of protection.

  12. Flocking-based Document Clustering on the Graphics Processing Unit

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xiaohui [ORNL; Potok, Thomas E [ORNL; Patton, Robert M [ORNL; ST Charles, Jesse Lee [ORNL

    2008-01-01

    Abstract?Analyzing and grouping documents by content is a complex problem. One explored method of solving this problem borrows from nature, imitating the flocking behavior of birds. Each bird represents a single document and flies toward other documents that are similar to it. One limitation of this method of document clustering is its complexity O(n2). As the number of documents grows, it becomes increasingly difficult to receive results in a reasonable amount of time. However, flocking behavior, along with most naturally inspired algorithms such as ant colony optimization and particle swarm optimization, are highly parallel and have found increased performance on expensive cluster computers. In the last few years, the graphics processing unit (GPU) has received attention for its ability to solve highly-parallel and semi-parallel problems much faster than the traditional sequential processor. Some applications see a huge increase in performance on this new platform. The cost of these high-performance devices is also marginal when compared with the price of cluster machines. In this paper, we have conducted research to exploit this architecture and apply its strengths to the document flocking problem. Our results highlight the potential benefit the GPU brings to all naturally inspired algorithms. Using the CUDA platform from NIVIDA? we developed a document flocking implementation to be run on the NIVIDA?GEFORCE 8800. Additionally, we developed a similar but sequential implementation of the same algorithm to be run on a desktop CPU. We tested the performance of each on groups of news articles ranging in size from 200 to 3000 documents. The results of these tests were very significant. Performance gains ranged from three to nearly five times improvement of the GPU over the CPU implementation. This dramatic improvement in runtime makes the GPU a potentially revolutionary platform for document clustering algorithms.

  13. Occurrence of haemolytic Mannheimia spp. in apparently healthy sheep in Norway

    Directory of Open Access Journals (Sweden)

    Poulsen Louise L

    2006-10-01

    Full Text Available Abstract Background The occurrence of Mannheimia species in healthy sheep has only been investigated to a very limited extend since the genus and its five named species were established. The aim of the present study was to evaluate the occurrence of haemolytic Mannheimia species in apparently healthy sheep originating from four sheep flocks in South-Western Norway. Methods Typical β-haemolytic Pasteurellaceae were isolated from nasal swabs and subsequently subjected to bacteriological examination. A total of 57 Mannheimia isolates were obtained in pure culture. All isolates were genotyped by amplified fragment length polymorphisms (AFLP analysis and compared to six reference strains. The 16S rRNA gene sequences of two isolates were also determined. Results β-haemolytic Mannheimia species were isolated from 24% to 64% of the sheep in the four flocks. A total of 26 haemolytic M. ruminalis-like strains were isolated among which, a considerable genetic diversity was found. Eighteen M. glucosida isolates were obtained from three flocks, whereas M. haemolytica was only isolated from two flocks, 16 of them being from only one of the flocks. Conclusion We demonstrate that a relatively high number of apparently healthy sheep in Norway seem to carry the potentially pathogenic M. haemolytica and M. glucosida in the upper respiratory tract. An unexpectedly high number of haemolytic M. ruminalis-like organisms were also obtained in all four flocks. The usually non-haemolytic M. ruminalis are typically isolated from healthy ruminants. The significance of β-haemolytic M. ruminalis-like organisms is unknown and should be investigated in a future study.

  14. Bipartite flocking for multi-agent systems

    Science.gov (United States)

    Fan, Ming-Can; Zhang, Hai-Tao; Wang, Miaomiao

    2014-09-01

    This paper addresses the bipartite flock control problem where a multi-agent system splits into two clusters upon internal or external excitations. Using structurally balanced signed graph theory, LaSalle's invariance principle and Barbalat's Lemma, we prove that the proposed algorithm guarantees a bipartite flocking behavior. In each of the two disjoint clusters, all individuals move with the same direction. Meanwhile, every pair of agents in different clusters moves with opposite directions. Moreover, all agents in the two separated clusters approach a common velocity magnitude, and collision avoidance among all agents is ensured as well. Finally, the proposed bipartite flock control method is examined by numerical simulations. The bipartite flocking motion addressed by this paper has its references in both natural collective motions and human group behaviors such as predator-prey and panic escaping scenarios.

  15. Every flock generalised quadrangle has a hemisystem

    CERN Document Server

    Bamberg, John; Royle, Gordon

    2009-01-01

    We prove that every flock generalised quadrangle contains a hemisystem, and we provide a construction method which unifies our results with the examples of Cossidente and Penttila in the classical case.

  16. Detection of OvHV-2 from an outbreak of sheep associated malignant catarrhal fever from crossbred cattle of Southern India.

    Science.gov (United States)

    Vinod Kumar, N; Sreedevi, B; Karthik, A; Vijaya Lakshmi, S; Geetha Reddy, A; Sreenivasulu, D

    2014-12-01

    An outbreak of sheep associated malignant catarrhal fever in crossbred cattle in a village of Andhra Pradesh, southern India, affected thirteen adult cows and two calves from a population of forty animals. All the affected animals were died between December and January 2013-14. The clinical and gross postmortem findings were typical of MCF in Indian crossbred cattle. Migrating sheep flocks were suspected source of infection for the cattle. The diagnosis was confirmed by heminested PCR in all the affected cattle and the suspected sheep flock. The PCR provided evidence of ovine herpes virus type 2.

  17. Radiocaesium in grazing sheep. A statistical analysis of variability, survey methodology and long term behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Mehli, H.

    1996-05-01

    Since 1987 sheep grazing in the areas of Norway that received Chernobyl-fallout have been monitored before slaughter. These monitoring data formed the basis for development of a model describing the long term behaviour of radiocesium in unimproved pasture showing that in years with good mushroom abundance 70-80% of the radiocesium concentration in sheep is due to fungi consumption. A study of sampling strategy and variability of radiocesium concentration within flocks was also performed. 55 refs., 31 figs., 15 tabs.

  18. FOWL CHOLERA IN A BREEDER FLOCK

    Directory of Open Access Journals (Sweden)

    Z. Parveen, A. A. Nasir, K.Tasneem and A. Shah

    2003-12-01

    Full Text Available During January, 2003 Pasteurella multocida the causative agent of fowl cholera was isolated from a breeder flock in Lahore District. The age of the flock was 245 days. Increased mortality, swollen wattles and lameness were the clinical findings present in almost all the affected birds, while gross lesions were typical of fowl cholera. To prove the virulence of the organism, mice and six-week old cockerals were infected and P. multocida was reisolated.

  19. Detection of Chlamydophila abortus in Sheep (Ovis aries in Mexico

    Directory of Open Access Journals (Sweden)

    Juan M. Jiménez-Estrada

    2008-01-01

    Full Text Available Chlamydophila abortus is one of the pathogens which induce abortion in small ruminants; this pathogen has a tropism for ruminant placenta and causes the disease commonly referred to as Ovine Enzootic Abortion (OEA. In Europe are estimated economic losses of around 20 million pounds a year by OEA. In the American Continent the disease has been reported only in Canada, the United States, Colombia and Chile while in Mexico it is unknown whether OEA is common and it is causing abortions in flocks of sheep from “Estado de Mexico”. The objective of this study was investigating the prevalence of anti-Chlamydophila abortus IgG antibodies and detection of C. abortus DNA in sheep with clinical abort history by mean of ELISA assay (C. abortus ELISA, Institute Pourquier, Montpellier, France and molecular identification of the principal outer membrane protein (POMP 90-91B gene by PCR, respectively. A cross-sectional study was carried out to enroll and random sample of ewes from november 2003 until march 2005. A total of 349 sera and vaginal swabs samples were collected from 35 flocks of sheep from Xalatlaco. The results showed that the seropositive rate was 31.1% (14/45 for healthy and 21.3% (65/304 for sheep with history clinical of abort. In vaginal swabs, the PCR showed 0% (0/45 for healthy animals and 0.65% (2/304 for aborted sheep. Samples from the lungs and liver of the fetus of one of these animals were also positive for C. abortus. In conclusion, these results confirmed that infection with C. abortus is common and is affecting sheep flocks in the Mexican highlands. Therefore, is necessary that the authorities responsible for animal welfare in Mexico (SAGARPA to set up appropriate epidemiological surveillance and control programs to eradicate this disease.

  20. Typhlocolitis associated with spirochaetes in duck flocks.

    Science.gov (United States)

    Glávits, Róbert; Ivanics, Eva; Thuma, Akos; Kaszanyitzky, Eva; Samu, Péterné; Ursu, Krisztina; Dencso, László; Dán, Adám

    2011-02-01

    The aetiology of increased mortality observed in two breeder duck flocks (Flock A consisting of 3500 laying ducks and Flock B comprising 4300 laying ducks) during the first egg-laying season was studied. In Flocks A and B, 773 ducks and 715 ducks (18.4% and 16.6%) died within a 24-week and a 20-week period, respectively. Death was preceded by clinical signs including movement difficulties, lack of appetite and depression lasting for 1 to 2 days. Diarrhoea was not observed. On gross pathological examination, the ducks were found to have haemorrhagic to fibrinonecrotic typhlocolitis, renal degeneration accompanied by fibrosis and mineralization, hepatic and splenic amyloidosis, and swelling of some of the metatarsal and phalangeal joints. Histopathological and immunohistochemical examination consistently demonstrated spirochaetes in the mucous membrane of the affected large intestine. On the basis of their cultural and biochemical properties and polymerase chain reaction sequencing analysis, four out of seven spirochaete strains isolated from the ducks (Flock A) by culture on special media under anaerobic conditions were identified as Brachyspira hyodysenteriae, and five out of eight strains (Flock B) were identified as Brachyspira pilosicoli. This is the first report on the isolation of B. hyodysenteriae and B. pilosicoli from laying ducks affected by fibrinonecrotic typhlocolitis.

  1. A serological survey of leptospirosis in sheep in Chile.

    Science.gov (United States)

    Zamora, J; Riedemann, S; Tadich, N

    1999-01-01

    In order to investigate exposure to Leptospira spp. in sheep in the Xth Region in the south of Chile, 629 ovine serum samples were collected from 11 convenience selected sheep farms, using within farm random sampling. The sera collected were examined for antibodies to the following serovars; icterohaemorrhagiae, autumnalis, hardjo, pomona, ballum, and canicola, using the Microscopic Agglutination Test. Ten out of eleven flocks had sheep which were seropositive for at least one Leptospira spp. Positive tests, the majority at low titres, were obtained from 36/629 (5.7%) of all the serum samples tested. The most frequently detected serovars were, in descending order: icterohaemorrhagiae, autumnalis and hardjo. The greatest proportion of positive samples came from sheep which were over 30 months old.

  2. Towards evenly distributed grazing patterns: including social context in sheep management strategies

    Directory of Open Access Journals (Sweden)

    Agustina di Virgilio

    2016-06-01

    Full Text Available Background. A large proportion of natural grasslands around the world is exposed to overgrazing resulting in land degradation and biodiversity loss. Although there is an increasing effort in the promotion of sustainable livestock management, rangeland degradation still occurs because animals’ foraging behaviour is highly selective at different spatial scales. The assessment of the ecological mechanisms modulating the spatial distribution of grazing and how to control it has critical implications for long term conservation of resources and the sustainability of livestock production. Considering the relevance of social interactions on animals’ space use patterns, our aim was to explore the potential effects of including animals’ social context into management strategies using domestic sheep grazing in rangelands as case study. Methods. We used GPS data from 19 Merino sheep (approximately 10% of the flock grazing on three different paddocks (with sizes from 80 to 1000 Ha during a year, to estimate resource selection functions of sheep grazing in flocks of different levels of heterogeneity. We assessed the effects of sheep class (i.e., ewes, wethers, and hoggets, age, body condition and time since release on habitat selection patterns. Results. We found that social rank was reflected on sheep habitat use, where dominant individuals (i.e., reproductive females used more intensively the most preferred areas and low-ranked (i.e., yearlings used less preferred areas. Our results showed that when sheep grazed on more heterogeneous flocks, grazing patterns were more evenly distributed at all the paddocks considered in this study. On the other hand, when high-ranked individuals were removed from the flock, low-ranked sheep shifted their selection patterns by increasing the use of the most preferred areas and strongly avoided to use less preferred sites (i.e., a highly selective grazing behaviour. Discussion. Although homogenization and segregation of

  3. Survey on coenurosis in sheep and goats in Egypt

    Directory of Open Access Journals (Sweden)

    Enas A. Desouky

    2011-09-01

    Full Text Available A total of 75 sheep and goats from apparently healthy and from clinically affected flocks were examined for Coenurus cerebralis cysts from different localities in Egypt. Of 25 animals examined from clinically diseased sheep and goats, 25 (100% revealed the presence of infestation with one to four coenuri in the brain. The sites of predilection were the left hemisphere (48%, followed by the right hemisphere (40% and the cerebellum (12%. There was no apparent effect of the age of sheep and goats on susceptibility to infestation with C. cerebralis. Another 50 animals from apparently healthy sheep and goat herds presented no C. cerebralis cysts. The cysts from infested sheep could infest newborn puppies experimentally, with a prepatent period of 60 days post infestation. A total of 15 immature worms that were recovered from one puppy did not reach patency until 105 days post infestation with C. cerebralis cyst scolices. Pathological changes in C. cerebralis-infested sheep brain revealed parasitic elements, demyelinated nerve tracts, hyperaemic blood vessels with round cell infiltration, encephalomalacia with round cell infiltration and palisading macrophages and giant cells, as well as focal replacement of the brain parenchyma with caseated and calcified materials. The morphological characteristics of both the larval stage from sheep and goats and adult worms of Taenia multiceps from experimentally infested dogs are described. The results conclude that C. cerebralis is one of the principal causes of nervous manifestations of coenurosis in clinically diseased sheep and goats in Egypt.

  4. A simple system for recording lamb mortality used to improve flock management.

    Science.gov (United States)

    Eales, F A; Small, J; Gilmour, J S; Armstrong, R H; Gittus, G D

    1986-03-01

    Many commercial sheep farmers do not record either the extent or the causes of their lamb losses but this information is essential if losses are to be reduced in the future. The major causes of death in newborn lambs are reviewed together with the common predisposing factors. The development and practical application of a simple system for recording lamb deaths is described. It is concluded that the application of this type of system, initiated, supervised and interpreted by the farmer's own veterinary surgeon, would indicate how to reduce the losses of lambs and would be a useful component of any flock health scheme.

  5. [Seroprevalence of antibodies to ruminant pestiviruses in sheep and goats in Tyrol (Austria)].

    Science.gov (United States)

    Schiefer, P; Krametter-Frötscher, R; Schleiner, A; Loitsch, A; Golja, F; Möstl, K; Baumgartner, W

    2006-02-01

    In this study 2058 blood samples from sheep of 150 flocks from the province of Tyrol were tested by ELISA and serum neutralisation tests for antibodies to ruminant pestiviruses. In the ELISA, positive results were obtained with 34.9% of individual sheep sera and in 89.3% of the sheep flocks. The prevalence in sheep and sheep flocks varied according to areas. Seroprevalence of pestiviruses was significantly (p < 0.05) higher in small ruminants pastured during summertime on the Alps. Comparative neutralisation studies were carried out on all positive blood samples with BVDV-1, BVDV-2 and BDV. 443 seropositive sheep samples exhibited clearly the highest titre against one of the pestivirus strains tested. 413 revealed the highest titres (2 or more fold) to BVDV-1, 6 to BVDV-2 and 24 to BDV. In some areas a very high rate of pestivirus seroprevalence could be found. This fact could be harmful to the BVDV-Elimination and Controlling Program in cattle in Austria.

  6. Tick population in goats and sheep in Šabac

    Directory of Open Access Journals (Sweden)

    Ivan Pavlović

    2016-03-01

    Full Text Available During our examination performed in the period from 2010 to 2012, we collected ticks from 52 flocks of sheep and 38 goat flocks. Ticks infestation occured in 15.97% (214/1340 of sheep and 16.93% (107/632 of goats. The result showed the presence of Ixodes ricinus, Rhipicephalus sanguineus, R. bursa, Dermacentor marginatus, D. pictus, Haemaphysalis punctata and Ha. inermis. Additional to determination of tick species during the research, the sex ratio and the monthly influence of microclimate conditions (temperature, relative humidity and precipitation quantity on the dynamics of populations of ticks were followed. Obtained results indicate the importance of the impact of climatic factors on the population dynamics of some species of ticks as well as the dynamics and abundance of different sexes within established species of ticks.

  7. [Abortion in sheep: epidemic Salmonella abortusovis outbreak 2005 in Switzerland].

    Science.gov (United States)

    von Tavel, L; Fivian, R; Kirchhofer, M; Boujon, P; Hirsbrunner, G

    2005-10-01

    In spring 2005, the outbreak of contagious abortion caused by Salmonella Abortusovis in 6 sheep flocks in Switzerland led to considerable economic losses. The Swiss small ruminant health service (BGK) evaluated this case. The aim was to identify the source of the epidemic in order to avoid further spread of infection and to evaluate the possibility of using vaccination. Moreover, a strategy for prevention of future outbreaks was developed. This article aims to increase disease awareness of food animal practitioners for Salmonella Abortusovis abortion in sheep.

  8. Association analysis of a CCR5 variant with ewe lifetime production in 3 breeds of sheep.

    Science.gov (United States)

    A deletion in the promoter region of CCR5 associates with a 50% reduction in proviral concentration (log10 env copies/microgram DNA) of ovine progressive pneumonia virus (OPPV) in blood. Nearly half of all flocks in the U.S. have at least one sheep infected with OPPV. Because OPP provirus concentr...

  9. Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission

    Directory of Open Access Journals (Sweden)

    Timm eKonold

    2015-09-01

    Full Text Available Classical scrapie is an environmentally transmissible prion disease of sheep and goats. Prions can persist and remain potentially infectious in the environment for many years and thus pose a risk of infecting animals after re-stocking. In vitro studies using serial Protein Misfolding Cyclic Amplification (sPMCA have suggested that objects on a scrapie-affected sheep farm could contribute to disease transmission. This in vivo study aimed to determine the role of field furniture (water troughs, feeding troughs, fencing and other objects that sheep may rub against used by a scrapie-infected sheep flock as a vector for disease transmission to scrapie-free lambs with the prion protein genotype VRQ/VRQ, which is associated with high susceptibility to classical scrapie. When the field furniture was placed in clean accommodation sheep became infected when exposed to either a water trough (four out of five or to objects used for rubbing (four out of seven. This field furniture had been used by the scrapie-infected flock eight weeks earlier and had previously been shown to harbor scrapie prions by sPMCA. Sheep also became infected (20 out of 23 through exposure to contaminated field furniture placed within pasture not used by scrapie-infected sheep for 40 months, even though swabs from this furniture tested negative by PMCA. This infection rate decreased (1 out of 12 on the same paddock after replacement with clean field furniture. Twelve grazing sheep exposed to field furniture not in contact with scrapie-infected sheep for 18 months remained scrapie-free.The findings of this study highlight the role of field furniture used by scrapie-infected sheep to act as a reservoir for disease re-introduction although infectivity declines considerably if the field furniture has not been in contact with scrapie-infected sheep for several months. PMCA may not be as sensitive as VRQ/VRQ sheep to test for environmental contamination.

  10. Ethno-Veterinary Drug Therapy for Ear Mange in Sheep

    Directory of Open Access Journals (Sweden)

    S.D.Hagawane

    2010-12-01

    Full Text Available Sheep from two flocks showed scab lesions around nostrils, eyes and on the face with facial alopecia and thickening of the skin. The case was confirmed as ear mite (Psorcopt ovis by microscopic examination of skin scrapings. Percent incidence in flock I and Flock II recorded was 12.5, 11.4 respectively. Affected sheep were divided into two groups each containing nine animals. Group I was treated with preparation containing 50ml Azadirachta indica oil, 50ml Pogamia pinnata oil, 25gm Camphor, 50gm Sulphur powder and 500ml coconut oil applied on an affected skin twice a day for 15 days and Group II treated with preparation having 50gm of Curcuma longa rhizome and 25gm of Azadirachta indica oil applied once a day for 15 days. The first preparation was found highly effective against ear mange in sheep. It was found to be very convenient for use in field conditions, did not cause any adverse reaction locally as well as systemically. [Vet. World 2010; 3(6.000: 295-296

  11. Farmers flock to coastal cities.

    Science.gov (United States)

    Zhou, M; Mulley, S

    1994-01-01

    China's rural-urban migration flows, particularly into Shanghai, Guangdong province, Beijing, and coastal areas, present challenges for urban development. The impact on rural and urban areas and suggestions for minimizing undesirable consequences were discussed. Professor Zhang Qingwu, deputy director of the Population Research Institute of Xiamen University in Fujian province, believes that the large migrating populations and those without residence cards pose problems for heavily populated cities: they strain resources (housing, water and electricity supplies, transportation, telecommunication, environmental hygiene, food supplies, and educational facilities). Crime increases. Municipal departments must increase their administrative load in service sectors. The general idea is that rural-to-urban migration reflects social progress and adds to a productive work force. Flexible policies are recommended. In Guangdong province, where migrants arrived from Sichuan and Hunan provinces, counties from the latter two provinces have established offices for supervising their former residents. Employment adjustment can be anticipated when the major flock of migrants arrive after the Lantern Festival. Professor Gui Shixun of the Population Research Institute of East China Normal University and advisor to the State Family Planning Commission recommends that development strategies incorporate planning for imbalances between local population and migrant urban workers. In some areas, women represent the bulk of migrants, while in other areas men do. Cultural development should be stressed, with investments also improved in telecommunications, traffic and transportation, education, and hygiene. Professor Jiang Zhixue recommends shifting from labor-intensive enterprises to technology-intensive enterprises and a better trained work force. Other schemes, such as the purchase by migrants of residence cards in Xiamen, would entitle migrants to the same rights and obligations as

  12. Nematódeos resistentes a anti-helmíntico em rebanhos de ovinos e caprinos do estado do Ceará, Brasil Nematodes resistant to anthelmintics in sheep and goat flock in the State of Ceará, Brazil

    Directory of Open Access Journals (Sweden)

    Ana Carolina Fonseca Lindoso Melo

    2003-04-01

    Full Text Available O controle do parasitismo por nematódeos gastrintestinais é feito basicamente com a utilização de anti-helmínticos. Falhas no controle são o primeiro sinal do aparecimento de resistência anti-helmíntica. A real situação da prevalência da resistência anti-helmíntica, em fazendas comerciais de criação de ovinos e caprinos no Brasil, é desconhecida. Esse experimento teve como objetivo, estimar a ocorrência de resistência ao oxfendazol, levamisol e ivermectina em propriedades comerciais de criação de ovinos e caprinos, na região do médio e baixo Jaguaribe, através do teste de redução na contagem de ovos nas fezes acompanhados de coproculturas. O trabalho foi realizado em 25 criações, sendo 16 de ovinos, 7 de caprinos e uma de ovinos e caprinos. Os dados obtidos foram analisados pelo programa estatístico RESO (1989. A prevalência de nematódeos resistentes ao oxfendazol, levamisol e ivermectina em ovinos foi de 88%, 41% e 59%, e em caprinos de 87,5%, 75% e 37,5%, respectivamente. Observou-se que o gênero Haemonchus foi o mais prevalente na população resistente a todos os anti-helmínticos, tanto em ovinos quanto em caprinos, seguido de Trichostrongylus e Oesophagostomum.The control of gastrointestinal nematodes parasitism is made basically with anthelmintics. Control failure is the first sign of anthelmintic resistance development. The actual situation of anthelmintic resistance prevalence in commercial farms of sheep and goats in Brazil is unknown. The aim of this work was to estimate the occurrence of oxfendazole, levamisole and ivermectin resistance in sheep and goats from medio and baixo Jaguaribe region by faecal egg count reduction followed by coprocultures. The work involved 25 farms (16 sheep farms, 7 goat farms and one of sheep and goats. Data were analysed by RESO (1989. The prevalence of resistant nematodes to oxfendazole, levamisole and ivermectin was respectively 88%, 41% and 59% in sheep and 87.5%, 75

  13. Problems and Solution Proposals Related to Sheep and Goat Husbandry in Kastamonu Province

    Directory of Open Access Journals (Sweden)

    Hacer Tüfekci

    2015-07-01

    Full Text Available This study was conducted by using a survey made at 80 enterprises from 63 villages with the aim of determining situations, problems and solution proposals related to the sheep and goat farms in Kastamonu province. The average age of the farmers was 49.3 years. The farmers were 8.75% of primary school graduates, 68.75% of secondary school and also 22.6% of illiterate. The enterprises have raised animals as 31.75% of state + own land and 68.75%’ of private + leased land. Also they are kept the rate of 70% Hair goat, 30% Angora goat and 55% Merino sheep, 42.5% Akkaraman sheep, and 16.25% Turkmen genotype, 7.5% Sakız sheep and 6.25% of Kıvırcık Sheep. The average flock sizes goat and sheep enterprises were 77.3 head goats and 71.7 heads sheep, respectively. Sixty percent of the breeder feed their animals on the pasture for 8-10 months and only 30% the breeders give supplementary feeding before and during mating period. The enterprises have 31.2% parturition chamber and 92.5% lamb growth areas. While all enterprises are routinely used to protective vaccines but only used disinfectant of 73.7% enterprises. The reason of sheep and goat breeders is majority contributions of income and habits. So, flock sizes are small (74.5 heads animal. In conclusion, young people by encouraging small animal farming in the province of Kastamonu, should be given to technical, economic support and educational seminars. In the future, as the sole source of income and a large flock size may lead to a development of sheep and goat breeding in Kastamonu province.

  14. Hierarchical group dynamics in pigeon flocks.

    Science.gov (United States)

    Nagy, Máté; Akos, Zsuzsa; Biro, Dora; Vicsek, Tamás

    2010-04-08

    Animals that travel together in groups display a variety of fascinating motion patterns thought to be the result of delicate local interactions among group members. Although the most informative way of investigating and interpreting collective movement phenomena would be afforded by the collection of high-resolution spatiotemporal data from moving individuals, such data are scarce and are virtually non-existent for long-distance group motion within a natural setting because of the associated technological difficulties. Here we present results of experiments in which track logs of homing pigeons flying in flocks of up to 10 individuals have been obtained by high-resolution lightweight GPS devices and analysed using a variety of correlation functions inspired by approaches common in statistical physics. We find a well-defined hierarchy among flock members from data concerning leading roles in pairwise interactions, defined on the basis of characteristic delay times between birds' directional choices. The average spatial position of a pigeon within the flock strongly correlates with its place in the hierarchy, and birds respond more quickly to conspecifics perceived primarily through the left eye-both results revealing differential roles for birds that assume different positions with respect to flock-mates. From an evolutionary perspective, our results suggest that hierarchical organization of group flight may be more efficient than an egalitarian one, at least for those flock sizes that permit regular pairwise interactions among group members, during which leader-follower relationships are consistently manifested.

  15. Induction of photosensitivity in sheep with Erodium moschatum (L. L'Hérit

    Directory of Open Access Journals (Sweden)

    J.C. Stroebel

    2002-07-01

    Full Text Available Erodium moschatum is an exotic weed in the southern and southwestern coastal areas of the Western Cape Province (WCP, South Africa. It has been suspected as the cause of photosensitivity in sheep. However, attempts to induce photosensitivity by dosing it to sheep have thus far been unsuccessful. During August 1999, 2 sheep suffering from severe photosensitivity were presented for clinical examination to the Western Cape Provincial Veterinary Laboratory (WCPVL. One sheep was sacrificed for autopsy. Except for skin lesions associated with photosensitivity, no icterus or other lesions were present. Histopathological examination of affected skin revealed epidermal necrosis while the liver had no microscopic lesions. It was therefore concluded that the sheep might have been suffering from primary photosensitivity. The farmfrom which the sheep came, situated in the Malmesbury district, WCP, was visited to determine the source of the photodynamic agent. The flock from which the sheep originated had been grazing in a camp where E. moschatum was growing abundantly and had been heavily grazed. Some remaining Erodium in the camp was collected, pulped and dosed over a period of 7 days to an adult sheep. Another sheep was dosed simultaneously with Erodium growing on the premises of the WCPVL. Both sheep developed mild photosensitivity, which was confirmed by histopathological examination of skin biopsies. It was concluded that E. moschatum can induce photosensitivity (probably the primary type in sheep if ingested in large quantities.

  16. A survey on anthelmintic resistance in nematode parasites of sheep in the Slovak Republic.

    Science.gov (United States)

    Cernanská, D; Várady, M; Corba, J

    2006-01-15

    The prevalence of anthelmintic resistance on 27 sheep farms in Slovakia was investigated in 2003 and 2004 using the faecal egg count reduction test (FECRT) according to the WAAVP guidelines. Resistance to albendazole was detected on one farm (3.7%) and suspected on two farms (7.4%) out of 27 sheep flocks. Resistance to ivermectin was tested on 26 farms. On six (23.1%) farms, results indicated the presence of ivermectin resistance. Resistance to ivermectin was suspected on eight farms (30.8%). However, it is also possible that generic ivermectin anthelmintics used in survey have a lower efficacy against sheep nematodes.

  17. Functional Diversification within a Predatory Species Flock

    Science.gov (United States)

    Burress, Edward D.; Duarte, Alejandro; Serra, Wilson S.; Loueiro, Marcelo; Gangloff, Michael M.; Siefferman, Lynn

    2013-01-01

    Ecological speciation is well-known from adaptive radiations in cichlid fishes inhabiting lentic ecosystems throughout the African rift valley and Central America. Here, we investigate the ecological and morphological diversification of a recently discovered lotic predatory Neotropical cichlid species flock in subtropical South America. We document morphological and functional diversification using geometric morphometrics, stable C and N isotopes, stomach contents and character evolution. This species flock displays species-specific diets and skull and pharyngeal jaw morphology. Moreover, this lineage appears to have independently evolved away from piscivory multiple times and derived forms are highly specialized morphologically and functionally relative to ancestral states. Ecological speciation played a fundamental role in this radiation and our data reveal novel conditions of ecological speciation including a species flock that evolved: 1) in a piscivorous lineage, 2) under lotic conditions and 3) with pronounced morphological novelties, including hypertrophied lips that appear to have evolved rapidly. PMID:24278349

  18. Flocking and rendezvous in distributed robotics

    CERN Document Server

    Francis, Bruce A

    2016-01-01

    This brief describes the coordinated control of groups of robots using only sensory input – and no direct external commands. Furthermore, each robot employs the same local strategy, i.e., there are no leaders, and the text also deals with decentralized control, allowing for cases in which no single robot can sense all the others. One can get intuition for the problem from the natural world, for example, flocking birds. How do they achieve and maintain their flying formation? Recognizing their importance as the most basic coordination tasks for mobile robot networks, the brief details flocking and rendezvous. They are shown to be physical illustrations of emergent behaviors with global consensus arising from local interactions. The authors extend the consideration of these fundamental ideas to describe their operation in flying robots and prompt readers to pursue further research in the field.  Flocking and Rendezvous in Distributed Robotics will provide graduate students a firm grounding in the subject, w...

  19. Topological Sound and Flocking on Curved Surfaces

    Directory of Open Access Journals (Sweden)

    Suraj Shankar

    2017-09-01

    Full Text Available Active systems on curved geometries are ubiquitous in the living world. In the presence of curvature, orientationally ordered polar flocks are forced to be inhomogeneous, often requiring the presence of topological defects even in the steady state because of the constraints imposed by the topology of the underlying surface. In the presence of spontaneous flow, the system additionally supports long-wavelength propagating sound modes that get gapped by the curvature of the underlying substrate. We analytically compute the steady-state profile of an active polar flock on a two-sphere and a catenoid, and show that curvature and active flow together result in symmetry-protected topological modes that get localized to special geodesics on the surface (the equator or the neck, respectively. These modes are the analogue of edge states in electronic quantum Hall systems and provide unidirectional channels for information transport in the flock, robust against disorder and backscattering.

  20. Dynamics of Sheep Production in Brazil

    Directory of Open Access Journals (Sweden)

    Samuel Rezende Paiva

    2013-07-01

    Full Text Available Sheep production is present on all continents and has been practiced in Brazil since the colonization. In this study, the multitemporal dynamics of sheep production in Brazil is examined using official government data (Brazilian Institute for Geography and Statistics-IBGE from 1976 to 2010. Maps of flock growth rates and growth acceleration maps by municipality were elaborated. The Southern states are seen to show a reduction in production mainly due to the wool crisis in the 1970s and 80s. The Northeast is seen to be important for meat production. More recently, centerwest and northern states have shown an increase in growth rates but this is still incipient. The maps of growth, acceleration and midpoint for sheep production showed a noticeable return to an increase in production in the South in recent years. The midpoint of production flow was in the northeast direction, which has stagnated. There was great dynamics in sheep production over the whole Brazilian territory, which affected supply chains due to the expansion of domestic and foreign markets. Areas with higher fluctuations in production are more vulnerable in terms of investment policies.

  1. Impulsive Flocking of Dynamical Multiagent Systems with External Disturbances

    Directory of Open Access Journals (Sweden)

    Fujun Han

    2017-01-01

    Full Text Available Flocking motion of multiagent systems is influenced by various external disturbances in complex environment. By applying disturbance observer, flocking of multiagent systems with exogenous disturbances is studied. Based on the robust features of impulsive control, a distributed impulsive control protocol is presented with disturbance observer, and flocking motion of multiagent systems is analyzed. Moreover, a sufficient condition is obtained to ensure the flocking motion of multiagent systems following a leader. Finally, simulation results show the validity of the theoretical conclusion.

  2. Intraepithelial and interstitial deposition of pathological prion protein in kidneys of scrapie-affected sheep.

    Directory of Open Access Journals (Sweden)

    Ciriaco Ligios

    Full Text Available Prions have been documented in extra-neuronal and extra-lymphatic tissues of humans and various ruminants affected by Transmissible Spongiform Encephalopathy (TSE. The presence of prion infectivity detected in cervid and ovine blood tempted us to reason that kidney, the organ filtrating blood derived proteins, may accumulate disease associated PrP(Sc. We collected and screened kidneys of experimentally, naturally scrapie-affected and control sheep for renal deposition of PrP(Sc from distinct, geographically separated flocks. By performing Western blot, PET blot analysis and immunohistochemistry we found intraepithelial (cortex, medulla and papilla and occasional interstitial (papilla deposition of PrP(Sc in kidneys of scrapie-affected sheep. Interestingly, glomerula lacked detectable signals indicative of PrP(Sc. PrP(Sc was also detected in kidneys of subclinical sheep, but to significantly lower degree. Depending on the stage of the disease the incidence of PrP(Sc in kidney varied from approximately 27% (subclinical to 73.6% (clinical in naturally scrapie-affected sheep. Kidneys from flocks without scrapie outbreak were devoid of PrP(Sc. Here we demonstrate unexpectedly frequent deposition of high levels of PrP(Sc in ovine kidneys of various flocks. Renal deposition of PrP(Sc is likely to be a pre-requisite enabling prionuria, a possible co-factor of horizontal prion-transmission in sheep.

  3. Genetic diversity of Gallibacterium anatis isolates from different chicken flocks

    DEFF Research Database (Denmark)

    Bojesen, A.M.; Torpdahl, Mia; Christensen, H.

    2003-01-01

    of chickens from an organic, egg-producing flock and a layer parent flock. A subset of strains was also characterized by pulsed-field gel electrophoresis and biotyping. The organic flock isolates were characterized by more than 94% genetic similarity, indicating that only a single clone was apparent...

  4. Some causes of the variable shape of flocks of birds.

    Directory of Open Access Journals (Sweden)

    Charlotte K Hemelrijk

    Full Text Available Flocks of birds are highly variable in shape in all contexts (while travelling, avoiding predation, wheeling above the roost. Particularly amazing in this respect are the aerial displays of huge flocks of starlings (Sturnus vulgaris above the sleeping site at dawn. The causes of this variability are hardly known, however. Here we hypothesise that variability of shape increases when there are larger local differences in movement behaviour in the flock. We investigate this hypothesis with the help of a model of the self-organisation of travelling groups, called StarDisplay, since such a model has also increased our understanding of what causes the oblong shape of schools of fish. The flocking patterns in the model prove to resemble those of real birds, in particular of starlings and rock doves. As to shape, we measure the relative proportions of the flock in several ways, which either depend on the direction of movement or do not. We confirm that flock shape is usually more variable when local differences in movement in the flock are larger. This happens when a flock size is larger, b interacting partners are fewer, c the flock turnings are stronger, and d individuals roll into the turn. In contrast to our expectations, when variability of speed in the flock is higher, flock shape and the positions of members in the flock are more static. We explain this and indicate the adaptive value of low variability of speed and spatial restriction of interaction and develop testable hypotheses.

  5. Assessment of transthoracic ultrasound diagnosis of ovine pulmonary adenocarcinoma in adult sheep.

    Science.gov (United States)

    Cousens, C; Scott, P R

    2015-10-10

    Ovine pulmonary adenocarcinoma (OPA), caused by Jaagsiekte sheep retrovirus (JSRV), is a disease of increasing concern in the sheep industry. There is no commercial antemortem test for OPA; therefore, an early evaluation phase study was undertaken to examine the accuracy of transthoracic ultrasound examination using a 5-6.5 MHz sector ultrasound machine widely available in veterinary practice in the UK to diagnose OPA. Restraint, preparation and examination time was restricted to five minutes per sheep to represent the cost limitations of commercial sheep farming. One hundred sheep were examined. All 41 cases identified with suspect OPA lesions during transthoracic ultrasound examination had the diagnosis confirmed at postmortem examination, while sheep without ultrasonographic changes characteristic of OPA had no gross lesions of OPA at postmortem examination. This demonstrates the specificity of transthoracic ultrasound for diagnosis of OPA. The authors propose that, in the absence of any other reliable preclinical diagnostic test, the use of transthoracic ultrasound examination should be considered for a second opinion on an initial diagnosis of OPA, for screening purchased adult flock replacements for OPA, or for screening sheep in a known OPA-affected flock. However, the authors emphasise that a negative scan cannot provide a guarantee that the animal is free of JSRV infection nor early OPA.

  6. How backyard poultry flocks influence the effort required to curtail avian influenza epidemics in commercial poultry flocks

    OpenAIRE

    2011-01-01

    This paper summarizes the evidence that the contribution of backyard poultry flocks to the on-going transmission dynamics of an avian influenza epidemic in commercial flocks is modest at best. Nevertheless, while disease control strategies need not involve the backyard flocks, an analysis of the contribution of each element of the next generation matrix to the basic reproduction number indicates that models which ignores the contribution of backyard flocks in estimating the effort required of...

  7. Small ruminant lentivirus-induced arthritis: clinicopathologic findings in sheep infected by a highly replicative SRLV B2 genotype.

    Science.gov (United States)

    Pérez, M; Biescas, E; Reina, R; Glaria, I; Marín, B; Marquina, A; Salazar, E; Álvarez, N; de Andrés, D; Fantova, E; Badiola, J J; Amorena, B; Luján, L

    2015-01-01

    We describe the clinicopathologic features of an arthritis outbreak in sheep induced by small ruminant lentivirus (SRLV), linked to the presence of a new SRLV isolate phylogenetically assigned to caprine arthritis encephalitis virus-like subgroup B2. Thirteen SRLV seropositive Rasa Aragonesa adult ewes were selected from 5 SRLV highly infected flocks (mean seroprevalence, 90.7%) for presenting uni- or bilateral chronic arthritis in the carpal joint. A complete study was performed, including symptomatology, histopathology, immunocytochemistry, immunohistochemistry, in situ hybridization, and microbiology. The carpus was the joint almost exclusively affected, with 10 sheep (76%) showing a moderate increase in carpal joint size (diameter range, 18-20 cm; normal range, 15-16 cm) without signs of locomotion problems and with 3 ewes (23%) showing severe inflammation with marked increase in diameter (21-24 cm), pain at palpation, and abnormal standing position. Grossly, chronic proliferative arthritis was observed in affected joints characterized by an increased thickness of the synovial capsule and synovial membrane proliferation. Microscopically, synovial membrane inflammation and proliferation and hyperplasia of synoviocytes were observed. More positive cases of SLRV infection were detected by immunocytochemistry of articular fluid than of bronchoalveolar lavage fluid. Immunohistochemistry and in situ hybridization also detected positive cells in the subsynovial connective tissue, lung, mediastinal lymph node, mammary gland, and mammary lymph node. All animals were negative for the presence of Mycoplasma or other bacteria in the articular space. The present outbreak likely represents an adaptation of a caprine virus to sheep. Our results underline the importance of the arthritis induced by SRLV in sheep, a clinical form that might be underestimated.

  8. How backyard poultry flocks influence the effort required to curtail avian influenza epidemics in commercial poultry flocks.

    Science.gov (United States)

    Smith, G; Dunipace, S

    2011-06-01

    This paper summarizes the evidence that the contribution of backyard poultry flocks to the on-going transmission dynamics of an avian influenza epidemic in commercial flocks is modest at best. Nevertheless, while disease control strategies need not involve the backyard flocks, an analysis of the contribution of each element of the next generation matrix to the basic reproduction number indicates that models which ignores the contribution of backyard flocks in estimating the effort required of strategies focused one host type (e.g. commercial flocks only) necessarily underestimate the level of effort to an extent that may matter to policy makers.

  9. Prevalence, distribution, and risk factor for sheep pox and goat pox (SPGP) in Algeria.

    Science.gov (United States)

    Kardjadj, Moustafa

    2017-03-01

    A cross-sectional study using a tested questionnaire was carried out across Algeria between January and June 2014. Our investigation demonstrated that of the 150 flocks visited, 21 were positive for sheep pox and goat pox (SPGP) with an overall flock prevalence of 14% (95% CI 11.08-16.92%) suggesting that SPGP is endemic in Algeria. Our results showed also that the disease appears only in sheep and no case affecting goats has been reported. For the risk factor analysis, univariate analysis of variables followed by a multiple logistic regression identified steppe region (OR = 1.81, 95% CI 0.87-2.57; P = 0.037), large flocks (OR = 2. 19, 95% CI 1.02-3.36; P = 0.027), and transhumance (OR = 3.98, 95% CI 2.59-5.34; P = 0.021) as risk factors in the spread of the disease. Furthermore, our study revealed that the use of vaccination as preventive measures in the selected flocks decreased the odds for SPGP positivity by 5.78 (95% CI 2.22-9.34; P < 0.001) times compared to non vaccinated flocks. In conclusion, our findings documented an evidence of a widespread distribution and endemic establishment of the SPGP in Algerian sheep population despite the annual vaccination program. Consequently, the vaccination must cover all the Algerian sheep population to improve animal welfare and reduce economic losses associated with outbreak episodes.

  10. Utilization of year round data in the estimation of genetic parameters for internal parasite resistance traits in Dorper sheep

    Science.gov (United States)

    The objective of this study was to evaluate the effect on the estimates of heritability and permanent environmental effects as a proportion of phenotypic variance when year round records are used. Records from 1,008 Dorper sheep in a private South African flock comprised 17,711 FAMACHA scores, 3,758...

  11. Diffusion and topological neighbours in flocks of starlings: relating a model to empirical data.

    Science.gov (United States)

    Hemelrijk, Charlotte K; Hildenbrandt, Hanno

    2015-01-01

    Moving in a group while avoiding collisions with group members causes internal dynamics in the group. Although these dynamics have recently been measured quantitatively in starling flocks (Sturnus vulgaris), it is unknown what causes them. Computational models have shown that collective motion in groups is likely due to attraction, avoidance and, possibly, alignment among group members. Empirical studies show that starlings adjust their movement to a fixed number of closest neighbours or topological range, namely 6 or 7 and assume that each of the three activities is done with the same number of neighbours (topological range). Here, we start from the hypothesis that escape behavior is more effective at preventing collisions in a flock when avoiding the single closest neighbor than compromising by avoiding 6 or 7 of them. For alignment and attraction, we keep to the empirical topological range. We investigate how avoiding one or several neighbours affects the internal dynamics of flocks of starlings in our computational model StarDisplay. By comparing to empirical data, we confirm that internal dynamics resemble empirical data more closely if flock members avoid merely their single, closest neighbor. Our model shows that considering a different number of interaction partners per activity represents a useful perspective and that changing a single parameter, namely the number of interaction partners that are avoided, has several effects through selforganisation.

  12. Temporal and contextual consistency of leadership in homing pigeon flocks.

    Directory of Open Access Journals (Sweden)

    Carlos D Santos

    Full Text Available Organized flight of homing pigeons (Columba livia was previously shown to rely on simple leadership rules between flock mates, yet the stability of this social structuring over time and across different contexts remains unclear. We quantified the repeatability of leadership-based flock structures within a flight and across multiple flights conducted with the same animals. We compared two contexts of flock composition: flocks of birds of the same age and flight experience; and, flocks of birds of different ages and flight experience. All flocks displayed consistent leadership-based structures over time, showing that individuals have stable roles in the navigational decisions of the flock. However, flocks of balanced age and flight experience exhibited reduced leadership stability, indicating that these factors promote flock structuring. Our study empirically demonstrates that leadership and followership are consistent behaviours in homing pigeon flocks, but such consistency is affected by the heterogeneity of individual flight experiences and/or age. Similar evidence from other species suggests leadership as an important mechanism for coordinated motion in small groups of animals with strong social bonds.

  13. A Flocking Based algorithm for Document Clustering Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xiaohui [ORNL; Gao, Jinzhu [ORNL; Potok, Thomas E [ORNL

    2006-01-01

    Social animals or insects in nature often exhibit a form of emergent collective behavior known as flocking. In this paper, we present a novel Flocking based approach for document clustering analysis. Our Flocking clustering algorithm uses stochastic and heuristic principles discovered from observing bird flocks or fish schools. Unlike other partition clustering algorithm such as K-means, the Flocking based algorithm does not require initial partitional seeds. The algorithm generates a clustering of a given set of data through the embedding of the high-dimensional data items on a two-dimensional grid for easy clustering result retrieval and visualization. Inspired by the self-organized behavior of bird flocks, we represent each document object with a flock boid. The simple local rules followed by each flock boid result in the entire document flock generating complex global behaviors, which eventually result in a clustering of the documents. We evaluate the efficiency of our algorithm with both a synthetic dataset and a real document collection that includes 100 news articles collected from the Internet. Our results show that the Flocking clustering algorithm achieves better performance compared to the K- means and the Ant clustering algorithm for real document clustering.

  14. Hierarchical group dynamics in pigeon flocks

    CERN Document Server

    Nagy, Mate; Biro, Dora; Vicsek, Tamas; 10.1038/nature08891

    2010-01-01

    Animals that travel together in groups display a variety of fascinating motion patterns thought to be the result of delicate local interactions among group members. Although the most informative way of investigating and interpreting collective movement phenomena would be afforded by the collection of high-resolution spatiotemporal data from moving individuals, such data are scarce and are virtually non-existent for long-distance group motion within a natural setting because of the associated technological difficulties. Here we present results of experiments in which track logs of homing pigeons flying in flocks of up to 10 individuals have been obtained by high-resolution lightweight GPS devices and analyzed using a variety of correlation functions inspired by approaches common in statistical physics. We find a well-defined hierarchy among flock members from data concerning leading roles in pairwise interactions, defined on the basis of characteristic delay times between birds' directional choices. The averag...

  15. Misinformed leaders lose influence over pigeon flocks.

    Science.gov (United States)

    Watts, Isobel; Nagy, Máté; Burt de Perera, Theresa; Biro, Dora

    2016-09-01

    In animal groups where certain individuals have disproportionate influence over collective decisions, the whole group's performance may suffer if these individuals possess inaccurate information. Whether in such situations leaders can be replaced in their roles by better-informed group mates represents an important question in understanding the adaptive consequences of collective decision-making. Here, we use a clock-shifting procedure to predictably manipulate the directional error in navigational information possessed by established leaders within hierarchically structured flocks of homing pigeons (Columba livia). We demonstrate that in the majority of cases when leaders hold inaccurate information they lose their influence over the flock. In these cases, inaccurate information is filtered out through the rearrangement of hierarchical positions, preventing errors by former leaders from propagating down the hierarchy. Our study demonstrates that flexible decision-making structures can be valuable in situations where 'bad' information is introduced by otherwise influential individuals.

  16. Anthelmintic resistance in Northern Ireland (III): uptake of 'SCOPS' (Sustainable Control of Parasites in Sheep) recommendations by sheep farmers.

    Science.gov (United States)

    McMahon, C; McCoy, M; Ellison, S E; Barley, J P; Edgar, H W J; Hanna, R E B; Malone, F E; Brennan, G P; Fairweather, I

    2013-03-31

    Reports of anthelmintic resistance to multiple drugs in individual parasite species, and in multiple parasite species across virtually all livestock hosts, are increasingly common. A working group of UK researchers and practitioners devised a set of guidelines in 2003 (Sustainable Control of Parasites in Sheep, 'SCOPS') aimed at maintaining anthelmintic efficacy on farms. Over the years that followed, these guidelines were promoted through meetings, promotional literature and the agricultural press. Results from questionnaires conducted in Northern Ireland (NI) in 2005 (covering 1999-2004) and 2011 (covering 2008-2011) have provided an opportunity to examine the extent to which these campaigns have influenced parasite control on sheep farms. The percentage of flocks at risk of under-dosing through inaccurate weight estimation in NI has increased by 15.9% since 2005. The number of flocks at risk of under-dosing through non-calibrated equipment has increased by 14.3% since 2005. The size of the in refugia population may have potentially doubled, as indicated by an increased compliance with the recommendation (wherever possible) to leave a portion of the flock untreated. However, whether this is indeed the case cannot be explicitly determined without a measure of the impact of various factors, including host immunity, environment/climate, previous anthelmintic treatment and the species of parasite present. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Individual Ranging Behaviour Patterns in Commercial Free-Range Layers as Observed through RFID Tracking

    Science.gov (United States)

    Larsen, Hannah; Cronin, Greg M.; Gebhardt-Henrich, Sabine G.; Smith, Carolynn L.; Hemsworth, Paul H.; Rault, Jean-Loup

    2017-01-01

    Simple Summary Understanding of how free-range laying hens on commercial farms utilize the outdoor space provided is limited. In order to optimise use of the range, it is important to understand whether hens vary in their ranging behaviour, both between and within individual hens. In our study, we used individual tracking technology to assess how hens in two commercial free-range flocks used the range and whether they varied in their use of the range. We assessed use of three areas at increasing distance from the shed; the veranda [0–2.4 m], close range [2.4–11.4 m], and far range [>11.4 m]. Most hens accessed the range every day (68.6% in Flock A, and 82.2% in Flock B), and most hens that ranged accessed all three areas (73.7% in Flock A, and 84.5% in Flock B). Hens spent half of their time outside in the veranda adjacent to the shed. We found that some hens within the flocks would range consistently (similar duration and frequency) daily, whereas others would range inconsistently. Hens that were more consistent in their ranging behaviour spent more time on the range overall than those that were inconsistent. These different patterns of range use should be taken into account to assess the implications of ranging for laying hens. Abstract In this exploratory study, we tracked free-range laying hens on two commercial flocks with Radio Frequency Identification (RFID) technology with the aim to examine individual hen variation in range use. Three distinct outdoor zones were identified at increasing distances from the shed; the veranda [0–2.4 m], close range [2.4–11.4 m], and far range [>11.4 m]. Hens’ movements between these areas were tracked using radio frequency identification technology. Most of the hens in both flocks (68.6% in Flock A, and 82.2% in Flock B) accessed the range every day during the study. Of the hens that accessed the range, most hens accessed all three zones (73.7% in Flock A, and 84.5% in Flock B). Hens spent half of their time

  18. A Monocular Vision Based Approach to Flocking

    Science.gov (United States)

    2006-03-01

    The bird represented with the green triangle desires to move away from its neighbors to avoid overcrowding . The bird reacts the most strongly to the... brightness gradients [35], neural networks [18, 19], and other vision-based methods [6, 26, 33]. For the purposes of this thesis effort, it is assumed that...Once started, however, maneuver waves spread through the flock at a mean speed of less than 15 milliseconds [43]. 2.5.3 Too Perfect. In nature, a bird

  19. Flocking in Distributed Control and Optimization

    Science.gov (United States)

    2015-06-01

    IEEE Transactions on Automatic Control . In this paper, In this paper we develop a mathematical model for analyzing the benefits...Z. Lin “Noise Reduction by Swarming in Social Foraging” under review at IEEE Transactions on Automatic Control . 10. P. Shi and A. Garcia “Flocking...P. Shi, A. Garcia and Z. Lin ``Noise Reduction by Swarming in Social Foraging" under review at IEEE Transactions on Automatic Control . 10. P.

  20. Factors of welfare reduction in dairy sheep and goats

    Directory of Open Access Journals (Sweden)

    Antonio Pazzona

    2010-01-01

    Full Text Available Scientific research on factors causing the reduction of well-being in sheep and goats is rather recent, as are studies of strategies to minimize the adverse effects of environmental challenges and improper management practices on flock welfare. Sheep and goats, considered very rustic animals, are reared prevalently under extensive production systems and are widespread mainly in marginal areas. For these reasons, only few studies on the welfare of these species have been carried out in the past. More recently, the scenario has changed, due to a gradual diffusion of intensive and semi-intensive production systems, especially in dairy sheep and goat breeds, to the growing concern of consumers about the life conditions of farmed animals, and to the issuing of a number of rules and laws on the safety of animal products and well-being of farmed livestock. As a consequence, several research groups have turned their attention to the welfare of sheep and goats. Nevertheless, information on this topic is still scarce. This paper reviews major critical points regarding the endangerment of welfare in farmed sheep and goats. Climatic extremes and seasonal fluctuations in herbage amount and quality are discussed as important causes of the reduction of well-being in extensive production systems, which can impair production efficiency of grazing animals and dramatically affect the welfare and health status of sheep and goats. Space allowance and structures of sheep and goat houses are described as the main potential sources of discomfort for housed flocks, together with inadequate control of micro-environment, and inappropriate milking procedures and human-animal interactions. Recent studies on the impact of high ambient temperature, different ventilation regimes, high stocking densities, reduced airspace and poor litter management on behaviour, immune and endocrine response, and on performance of sheep and goats are discussed. The effects of inadequate milking

  1. Survey on coenurosis in sheep and goats in Egypt.

    Science.gov (United States)

    Desouky, Enas A; Badawy, Ahmed I; Refaat, Refaat A

    2011-01-01

    A total of 75 sheep and goats from apparently healthy and from clinically affected flocks were examined for Coenurus cerebralis cysts from different localities in Egypt. Of 25 animals examined from clinically diseased sheep and goats, 25 (100%) revealed the presence of infestation with one to four coenuri in the brain. The sites of predilection were the left hemisphere (48%), followed by the right hemisphere (40%) and the cerebellum (12%). There was no apparent effect of the age of sheep and goats on susceptibility to infestation with C. cerebralis. Another 50 animals from apparently healthy sheep and goat herds presented no C. cerebralis cysts. The cysts from infested sheep could infest newborn puppies experimentally, with a prepatent period of 60 days post infestation. A total of 15 immature worms that were recovered from one puppy did not reach patency until 105 days post infestation with C. cerebralis cyst scolices. Pathological changes in C. cerebralis-infested sheep brain revealed parasitic elements, demyelinated nerve tracts, hyperaemic blood vessels with round cell infiltration, encephalomalacia with round cell infiltration and palisading macrophages and giant cells, as well as focal replacement of the brain parenchyma with caseated and calcified materials. The morphological characteristics of both the larval stage from sheep and goats and adult worms of Taenia multiceps from experimentally infested dogs are described. The results conclude that C. cerebralis is one of the principal causes of nervous manifestations of coenurosis in clinically diseased sheep and goats in Egypt.

  2. Nylon flocked swab severely reduces Hexagon Obti sensibility.

    Science.gov (United States)

    Frippiat, Christophe; De Roy, Gilbert; Fontaine, Louis-Marie; Dognaux, Sophie; Noel, Fabrice; Heudt, Laeticia; Lepot, Laurent

    2015-02-01

    Hexagon Obti immunological blood test and flocked swab are widely used in forensic laboratories. Nevertheless, up to now, no compatibility tests have been published between sampling with the ethylene oxide treated flocked swab and the Hexagon Obti blood detection strip. In this study, we investigated this compatibility. Our work shows that sampling with ethylene oxide treated flocked swab reduces by a factor of at least 100 the detection threshold of blood using the Hexagon Obti immunological test.

  3. Some Causes of the Variable Shape of Flocks of Birds

    OpenAIRE

    Hemelrijk, Charlotte K.; Hanno Hildenbrandt

    2011-01-01

    Flocks of birds are highly variable in shape in all contexts (while travelling, avoiding predation, wheeling above the roost). Particularly amazing in this respect are the aerial displays of huge flocks of starlings (Sturnus vulgaris) above the sleeping site at dawn. The causes of this variability are hardly known, however. Here we hypothesise that variability of shape increases when there are larger local differences in movement behaviour in the flock. We investigate this hypothesis with the...

  4. Invited review: Current state of genetic improvement in dairy sheep.

    Science.gov (United States)

    Carta, A; Casu, Sara; Salaris, S

    2009-12-01

    Dairy sheep have been farmed traditionally in the Mediterranean basin in southern Europe, central Europe, eastern Europe, and in Near East countries. Currently, dairy sheep farming systems vary from extensive to intensive according to the economic relevance of the production chain and the specific environment and breed. Modern breeding programs were conceived in the 1960s. The most efficient selection scheme for local dairy sheep breeds is based on pyramidal management of the population with the breeders of nucleus flocks at the top, where pedigree and official milk recording, artificial insemination, controlled natural mating, and breeding value estimation are carried out to generate genetic progress. The genetic progress is then transferred to the commercial flocks through artificial insemination or natural-mating rams. Increasing milk yield is still the most profitable breeding objective for several breeds. Almost all milk is used for cheese production and, consequently, milk content traits are very important. Moreover, other traits are gaining interest for selection: machine milking ability and udder morphology, resistance to diseases (mastitis, internal parasites, scrapie), and traits related to the nutritional value of milk (fatty acid composition). Current breeding programs based on the traditional quantitative approach have achieved appreciable genetic gains for milk yield. In many cases, further selection goals such as milk composition, udder morphology, somatic cell count, and scrapie resistance have been implemented. However, the possibility of including other traits of selective interest is limited by high recording costs. Also, the organizational effort needed to apply the traditional quantitative approach limits the diffusion of current selection programs outside the European Mediterranean area. In this context, the application of selection schemes assisted by molecular information, to improve either traditional dairy traits or traits costly to record

  5. Self-Organized Fission Control for Flocking System

    Directory of Open Access Journals (Sweden)

    Mingyong Liu

    2015-01-01

    Full Text Available This paper studies the self-organized fission control problem for flocking system. Motivated by the fission behavior of biological flocks, information coupling degree (ICD is firstly designed to represent the interaction intensity between individuals. Then, from the information transfer perspective, a “maximum-ICD” based pairwise interaction rule is proposed to realize the directional information propagation within the flock. Together with the “separation/alignment/cohesion” rules, a self-organized fission control algorithm is established that achieves the spontaneous splitting of flocking system under conflict external stimuli. Finally, numerical simulations are provided to demonstrate the effectiveness of the proposed algorithm.

  6. Research on an Infectious Disease Transmission by Flocking Birds

    Directory of Open Access Journals (Sweden)

    Mingsheng Tang

    2013-01-01

    Full Text Available The swarm intelligence is becoming a hot topic. The flocking of birds is a natural phenomenon, which is formed and organized without central or external controls for some benefits (e.g., reduction of energy consummation. However, the flocking also has some negative effects on the human, as the infectious disease H7N9 will easily be transmited from the denser flocking birds to the human. Zombie-city model has been proposed to help analyzing and modeling the flocking birds and the artificial society. This paper focuses on the H7N9 virus transmission in the flocking birds and from the flocking birds to the human. And some interesting results have been shown: (1 only some simple rules could result in an emergence such as the flocking; (2 the minimum distance between birds could affect H7N9 virus transmission in the flocking birds and even affect the virus transmissions from the flocking birds to the human.

  7. AN OUTBREAK OF PESTE DES PETITS RUMINANTS (PPR IN A GOAT FLOCK IN OKARA, PAKISTAN

    Directory of Open Access Journals (Sweden)

    K. Ahmad, S. M. Jamal, Q. Ali and M. Hussain

    2005-07-01

    Full Text Available An outbreak of Peste des Petits Ruminants (PPR was investigated in a goat flock maintained at the Livestock Production and Research Institute (LPRI, Bahadurnagar, Okara, Pakistan. Clinical signs and postmortem findings led to the suspicion of outbreak of PPR. Thirty-five serum samples from affected, recovered and apparently normal animals were tested for the presence of PPR antibodies by competitive ELISA. There was no history of PPR vaccination, however, serum samples from all the recovered and apparently healthy goats were found positive for PPR antibodies. Thirteen of 15 affected goats also had anti-PPR antibodies. However, no PPR antibodies were detected in apparently healthy sheep (n=2 reared in the vicinity of the affected goat herd.

  8. Epidemiological, clinical and diagnostic aspects of sheep conidiobolomycosis in Brazil

    Directory of Open Access Journals (Sweden)

    Carla Weiblen

    2016-05-01

    Full Text Available ABSTRACT: Conidiobolomycosis is an emerging disease caused by fungi of the cosmopolitan genus Conidiobolus . Particular strains of Conidiobolus coronatus, Conidiobolus incongruus and Conidiobolus lamprauges , mainly from tropical or sub-tropical origin, cause the mycosis in humans and animals, domestic or wild. Lesions are usually granulomatous and necrotic in character, presenting two clinical forms: rhinofacial and nasopharyngeal. This review includes the main features of the disease in sheep, with an emphasis on the epidemiology, clinical aspects, and diagnosis of infections caused by Conidiobolus spp. in Brazil. In this country, the disease is endemic in the Northeast and Midwest, affecting predominantly woolless sheep breeds and occasioning death in the majority of the studied cases. The species responsible for infections of sheep are C. coronatus and C. lamprauges and the predominant clinical presentation is nasopharyngeal. These fungal infections are very important, since they compromise the health status of the sheep flock and cause serious economic losses to the sheep industry. Thus, research is needed to investigate faster tools for diagnosis and effective methods for the control and treatment of conidiobolomycosis.

  9. Prevalence and antimicrobial susceptibility of thermophilic Campylobacter in organic and conventional broiler flocks

    DEFF Research Database (Denmark)

    Heuer, Ole Eske; Pedersen, Karl; Andersen, J.S.;

    2001-01-01

    Aims: To determine the flock prevalence and to estimate the within flock prevalence of Campylobacter in broiler flocks from different rearing systems, and to determine the antimicrobial susceptibility of Campylobacter isolates to selected antimicrobial substances. Methods and Results: One hundred...

  10. Complex network structure of flocks in the Vicsek Model with Vectorial Noise

    Science.gov (United States)

    Baglietto, Gabriel; Albano, Ezequiel V.; Candia, Julián

    2014-09-01

    In the Vicsek Model (VM), self-driven individuals try to adopt the direction of movement of their neighbors under the influence of noise, thus leading to a noise-driven order-disorder phase transition. By implementing the so-called Vectorial Noise (VN) variant of the VM (i.e. the VM-VN model), this phase transition has been shown to be discontinuous (first-order). In this paper, we perform an extensive complex network study of VM-VN flocks and show that their topology can be described as highly clustered, assortative, and nonhierarchical. We also study the behavior of the VM-VN model in the case of "frozen flocks" in which, after the flocks are formed using the full dynamics, particle displacements are suppressed (i.e. only rotations are allowed). Under this kind of restricted dynamics, we show that VM-VN flocks are unable to support the ordered phase. Therefore, we conclude that the particle displacements at every time-step in the VM-VN dynamics are a key element needed to sustain long-range ordering throughout.

  11. Epidemiological characteristics and clinicopathological features of bluetongue in sheep and cattle, during the 2014 BTV serotype 4 incursion in Greece.

    Science.gov (United States)

    Katsoulos, Panagiotis-Dimitrios; Giadinis, Nektarios D; Chaintoutis, Serafeim C; Dovas, Chrysostomos I; Kiossis, Evangelos; Tsousis, Georgios; Psychas, Vassilios; Vlemmas, Ioannis; Papadopoulos, Theologos; Papadopoulos, Orestis; Zientara, Stéphan; Karatzias, Harilaos; Boscos, Constantinos

    2016-03-01

    During 2014, an outbreak of Bluetongue virus (BTV) infections attributed to serotype 4 occurred in Greece and spread to south-eastern Europe. In the present article, the clinical and epidemiological data of 15 sheep flocks and 5 dairy cattle herds affected in Greece are described. In sheep, the most frequent clinical signs observed were fever, hyporexia, and edema of the face. A number of clinically affected sheep had chronic laminitis resulting in chronic lameness. Confirmation of suspect clinical cases was performed using BTV-specific real-time RT-PCR, and serotype 4-specific RT-PCR. The average morbidity of bluetongue in the sheep flocks was estimated to be 15.3 % (95 % C.I. 6.8-23.8 %) and the average mortality and case fatality were 4.5 % (95 % C.I. 1.5-7.6 %) and 32.0 % (95 % C.I. 18.1-42.9 %), respectively. The BTV seroprevalence and the ratio of clinical manifestations-to-infections determined in seven of these flocks, were on average 36.5 % (95 % C.I. 15.7-57.3 %) and 24.6 % (95 % C.I. 12.8-36.3 %). BTV ratio of clinical manifestations-to-infections was higher in the imported western European sheep breeds examined compared to the local ones. In dairy cattle, the average herd prevalence of viremia was 48.8 % (95 % C.I. 15.3-82.4 %) and none had signs associated with bluetongue. The results of this study indicate that the 2014 Greek BTV-4 has significant impact on the health status and the viability of sheep in affected flocks but does not cause clinical signs in cattle, despite the high prevalence of viremia.

  12. Development and field application of a new combined vaccine against Peste des Petits Ruminants and Sheep Pox

    Directory of Open Access Journals (Sweden)

    F. Fakri

    2015-01-01

    Full Text Available A combined vaccine against Peste des Petits Ruminants (PPR and Sheep/Goat Pox (SGP was developed and applied in the field, using a new association of vaccine strains: PPR Nigeria 75 strain with a titre of 104.1 TCID50 and Sheep Pox Romania strain with a titre of 104.0 TCID50. Safety and efficacy were evaluated on goats and sheep in comparison with monovalent PPR and SGP vaccines. Goats were challenged by PPR virulent strain and sheep by SP virulent strain. The result shows that the combined PPR/SGP vaccine confers a good protection against both PPR and SGP infection with no significant difference with monovalent vaccines. The combined vaccine was used in the field on sheep flocks and good sero-conversion was detected for both diseases as soon as 14 days post vaccination.

  13. Sheep lymph-nodes as a biological indicator of environmental exposure to fluoro-edenite.

    Science.gov (United States)

    Ledda, Caterina; Loreto, Carla; Pomara, Cristoforo; Rapisarda, Giuseppe; Fiore, Maria; Ferrante, Margherita; Bracci, Massimo; Santarelli, Lory; Fenga, Concettina; Rapisarda, Venerando

    2016-05-01

    A significantly increased incidence of pleural mesothelioma in Biancavilla (Sicily, Italy) has been attributed to exposure to fluoro-edenite (FE), a fibrous amphibole extracted from a local stone quarry. The lymph-nodes draining the pulmonary lobes of sheep grazing around the town were examined, to gain insights into fibre diffusion. The pasture areas of six sheep flocks lying about 3km from Biancavilla were located using the global positioning system. The cranial tracheobronchial and one middle mediastinal lymph-node as well as four lung tissue samples were collected from 10 animals from each flock and from 10 control sheep for light and scanning electron microscopy (SEM) examination. The lymph-nodes from exposed sheep were enlarged and exhibited signs of anthracosis. Histologically, especially at the paracortical level, they showed lymph-follicle hyperplasia with large reactive cores and several macrophages (coniophages) containing grey-brownish particulate interspersed with elements with a fibril structure, forming aggregates of varying dimensions (coniophage nodules). Similar findings were detected in some peribronchiolar areas of the lung parenchyma. SEM examination showed that FE fibres measured 8-41µm in length and 0.4-1.39µm in diameter in both lymph-nodes and lung tissue. Monitoring of FE fibres in sheep lymph-nodes using appropriate techniques can help set up environmental pollution surveillance.

  14. Molecular characterization and phylogenetic analysis of small ruminant lentiviruses isolated from Canadian sheep and goats

    Directory of Open Access Journals (Sweden)

    Bertoni Giuseppe

    2011-06-01

    Full Text Available Abstract Background Small Ruminant Lentiviruses (SRLV are widespread in Canadian sheep and goats and represent an important health issue in these animals. There is however no data about the genetic diversity of Caprine Arthritis Encephalitis Virus (CAEV or Maedi Visna Virus (MVV in this country. Findings We performed a molecular and phylogenetic analysis of sheep and goat lentiviruses from a small geographic area in Canada using long sequences from the gag region of 30 infected sheep and 36 infected goats originating from 14 different flocks. Pairwise DNA distance and phylogenetic analyses revealed that all SRLV sequences obtained from sheep clustered tightly with prototypical Maedi visna sequences from America. Similarly, all SRLV strains obtained from goats clustered tightly with prototypical US CAEV-Cork strain. Conclusions The data reported in this study suggests that Canadian and US SRLV strains share common origins. In addition, the molecular data failed to bring to light any evidence of past cross species transmission between sheep and goats, which is consistent with the type of farming practiced in this part of the country where single species flocks predominate and where opportunities of cross species transmissions are proportionately low.

  15. Seroprevalence and risk factors associated with within-flock transmission of Leptospira interrogans in transhumant farming systems in Mexico.

    Science.gov (United States)

    Arteaga-Troncoso, G; Jiménez-Estrada, J M; Montes De Oca-Jimenez, R; López-Hurtado, M; Luna-Alvarez, M; Hernandez-Andrade, L; Moreno-Alfaro, A; Galan-Herrera, J F; Guerra-Infante, F M

    2015-10-01

    A number of recent reports emphasize the risk of zoonotic diseases and the high degree of prevalence of asymptomatic animals infected with Leptospira interrogans. This report sought to assess the prevalence of antibodies to certain serovars of L. interrogans, and to describe the association between seropositivity and risk factors associated with within-flock transmission in a mountainous region of Mexico. Overall seroprevalence to L. interrogans was 54·5% (95% confidence interval 48·3-60·7); the most frequent serovar was Icterohaemorrhagiae. The accumulation of placentas and fetuses at a site close to lambing paddocks can play a significant role as a risk factor for within-flock transmission of L. interrogans in transhumant farming systems in the municipality of Xalatlaco. The high prevalence of L. interrogans antibodies supports the hypothesis that natural foci of this zoonosis are present in sheep flocks in this area. These findings emphasize the need for planning and implementation of control programmes for ovine leptospirosis in Mexico and elsewhere.

  16. Efficiency of selection for body weight in a cooperative village breeding program of Menz sheep under smallholder farming system.

    Science.gov (United States)

    Gizaw, S; Getachew, T; Goshme, S; Valle-Zárate, A; van Arendonk, J A M; Kemp, S; Mwai, A O; Dessie, T

    2014-08-01

    We evaluated the efficiency of selection for body weight in a cooperative village breeding program for Menz sheep of Ethiopia under smallholder farming system. The design of the program involved organizing villagers in a cooperative breeding group to implement selective breeding of their sheep. The program was jump-started through a one-time provision of elite rams from a central nucleus flock, but subsequent replacement rams were selected from within the village flocks. We also evaluated body weight trends in a village where cooperative breeding was not implemented and individual farmers managed their flocks under traditional breeding practices. Under traditional breeding practices, genetic progress over 8 years either stagnated or declined in all the weights recorded. In the cooperative villages, selection differentials of 2.44 and 2.45 kg were achieved in 2010 and 2011 selection seasons, respectively. Birth weight, 3-month weight and 6-month weight increased, respectively, by 0.49, 2.29 and 2.46 kg in the third-generation lambs over the base generation. Improved rams supplied from the central nucleus flock gave an initial genetic lift of 14.4% in the 6-month weight. This was higher than the gain achieved from selection in the village flocks, which was 5.2%. Our results showed that village-based genetic improvement in body weights under smallholder conditions could be feasible if appropriate designs are adopted and that commencing with elite central nucleus rams help jump-start village-based programs.

  17. Stability of model flocks in a vortical flow

    Science.gov (United States)

    Baggaley, A. W.

    2016-06-01

    We investigate the stability of self-propelled particle flocks in the Taylor-Green vortex, a steady vortical flow. We consider a model in which particles align themselves to a combination of the orientation and the acceleration of particles within a critical radius. We identify two distinct regimes: If alignment with orientation is dominant, the particles tend to be expelled from regions of high vorticity. In contrast, if anticipation is dominant, the particles accumulate in areas of large vorticity. In both regimes, the relative order of the flock is reduced. However, we show that there can be a critical balance of the two effects that stabilizes the flock in the presence of external fluid forcing. This strategy could provide a mechanism for animal flocks to remain globally ordered in the presence of fluid forcing, and it may also have applications in the design of flocking autonomous drones and artificial microswimmers.

  18. A retrospective study on salmonella infection in Danish broiler flocks

    DEFF Research Database (Denmark)

    Angen, Øystein; Skov, M. N.; Chriél, Mariann

    1996-01-01

    -year period from 1992 to 1993 in Denmark. The AM database contains information collected by the ante-mortem veterinarians, from the slaughterhouses, and from the salmonella examinations carried out at the National Veterinary Laboratory. The epidemiological unit was the individual broiler flock....... The salmonella status of the flock was determined by examining the caecal tonsils from 16 3-week-old chickens from each flock. This procedure would detect a salmonella-infected flock, with a probability above 95%, if the prevalence is above 20%. Furthermore, the structure and quality of the collected data have...... been evaluated. Fourteen variables were selected for analysis by multivariable logistic regression. An increased risk of salmonella infection in the broiler Becks was associated with the biggest hatcheries and feedmill, with an increasing number of houses on the farm, if the preceding flock...

  19. Naturally resident and exogenously applied T4-like and T5-like bacteriophages can reduce Escherichia coli O157:H7 levels in sheep guts

    Science.gov (United States)

    In preparing sheep for an in vivo Escherichia coli O157:H7 eradication trial, we found that 20/39 members of a single flock were naturally colonized by O157:H7-infecting phages. Characterization showed these were all one phage type (subsequently named CEV2) infecting 15/16 O157:H7, 7/72 ECOR, and c...

  20. Development and validation of real-time PCR methods for diagnosis of Teladorsagia circumcincta and Haemonchus contortus in sheep.

    Science.gov (United States)

    Learmount, Jane; Conyers, Chris; Hird, Hez; Morgan, Colin; Craig, Barbara H; von Samson-Himmelstjerna, Georg; Taylor, Mike

    2009-12-23

    Parasitic gastroenteritis, a disease caused by parasitic nematodes, is of major concern to the sheep industry and threatens sustainability. Traditional methods for diagnosis of the type and level of infection in a sheep flock require laborious laboratory extraction, culture and microscopic examination of eggs or larvae from faecal samples. Advances in molecular technology offer the potential for more efficient and reliable methods. This study aimed to develop and test a real-time PCR method for routine diagnosis of infection by Teladorsagia circumcincta and Haemonchus contortus in sheep. Primer/probe sets were designed around the ribosomal internal transcribed spacer 2 (ITS2) region as sequence data was available from other studies and so tests used published primer/probe sets, as well as those designed at the Food and Environment Research Agency (Fera). Different primer/probe combinations were tested for specificity against DNA extracted from T. circumcincta larvae or H. contortus DNA. All sets were tested for cross reactivity against four other closely related species, using real-time PCR technology. Reactions were optimised with the best primer/probe combination for each species and then tested for sensitivity against samples containing different T. circumcincta or H. contortus DNA concentrations. Faecal samples were collected from sheep infected with T. circumcincta or H. contortus alone and the eggs harvested, counted and DNA extracted. Serial dilutions were prepared to give a range of concentrations between approximately 3000 and 50 eggs per sample and real-time PCR reactions were carried out for each and mean cycle time (Ct) values were calculated. These Ct values were plotted against the sample egg concentration to produce a standard curve. Regression analysis was carried out using the generated data. Eggs were then harvested from faecal samples collected in the field from sheep carrying natural mixed infections, DNA extracted and Ct values recorded as

  1. Technological level and epidemiological aspects of sheep husbandry in Minas Gerais, southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Aurora M.G. Gouveia

    2014-09-01

    Full Text Available Epidemiological and health aspects of sheep husbandry were assessed on 213 sheep flocks in 142 municipalities from the state of Minas Gerais, southeastern Brazil. An updated questionnaire was filled out for each flock, requesting data on the farm, the flock and the farmer by the veterinarians of the State Government Agency for Animal Health (Instituto Mineiro de Agropecuária. Thirteen important variables were selected and scored to determine the technological level of the 117 farms; 0.9% of them was classified as high technological level, 45.3% as medium technological level and 53.0% as low technological level. Lamb production was the main objective of the farms and the main features were low-frequencies of individual identification of animals (16.9%, technical assistance (31.9%, use of quarantine for newly acquired animals (0.9% the separation of animals by age group (3.7% and requeste the sanitary certificate at purchasing of animals (11.7%. The main health problems reported were abortion (23.9%, keratoconjunctivitis (17.9%, contagious ecthyma (13.6%, pneumonia (10.3%, diarrhea (9.3% and caseous lymphadenitis (6.1%. Information of the epidemiological situation and the mainly health measures used in the sheep farms are important to improve the productivity and quality of the lamb.

  2. Fasciola hepatica: a comparative survey of adult fluke resistance to triclabendazole, nitroxynil and closantel on selected upland and lowland sheep farms in Northern Ireland using faecal egg counting, coproantigen ELISA testing and fluke histology.

    Science.gov (United States)

    Hanna, R E B; McMahon, C; Ellison, S; Edgar, H W; Kajugu, P-E; Gordon, A; Irwin, D; Barley, J P; Malone, F E; Brennan, G P; Fairweather, I

    2015-01-15

    In order to investigate the incidence and distribution of adult fluke resistance to the fasciolicide tricalbendazole (TCBZ) amongst populations of Fasciola hepatica in sheep flocks in Northern Ireland (NI), individual rectal faeces samples were collected from 3 groups of 20 sheep, before (pre-dose), and 21 days after (post-dose) treatment of the animals with TCBZ, nitroxynil or closantel, on each of 13 well-managed sheep farms distributed across the province. The efficacy of each flukicide was determined for each farm, using faecal egg count reduction (FECRT) and F. hepatica coproantigen ELISA testing. In certain flocks, 2 sheep with high pre-dose faecal egg counts (FEC) were killed 3 days and 21 days respectively after TCBZ treatment, and the histology of the fluke reproductive organs was compared with that of flukes from untreated sheep, and from sheep treated with nitroxynil or closantel 2 days prior to death, using haematoxylin and eosin (H&E) staining and an in situ hybridisation method (TdT-mediated dUDP nick end labelling [TUNEL]) to demonstrate apoptosis. Results from FECRT revealed that in all flocks with a high fluke burden, TCBZ was ineffective in treating chronic fasciolosis, and this finding was generally supported by the results of the coproantigen reduction test (CRT). The histology of reproductive organs of flukes from TCBZ-treated sheep in these flocks was normal, when compared with untreated flukes, and this, together with the FECRT and CRT findings, indicated a likely diagnosis of TCBZ resistance in all the flocks with a high fluke burden. In contrast, nitroxynil and closantel were found to be fully effective against TCBZ-resistant flukes in each of the flocks bearing a high chronic fluke burden. All of the flocks with a high fluke burden and TCBZ resistance were managed on lowland in the South and East of NI. Upland flocks, in the North and West, had low fluke burdens, or were clear of infection; and FECs were too low to allow valid resistance

  3. Individual Ranging Behaviour Patterns in Commercial Free-Range Layers as Observed through RFID Tracking.

    Science.gov (United States)

    Larsen, Hannah; Cronin, Greg M; Gebhardt-Henrich, Sabine G; Smith, Carolynn L; Hemsworth, Paul H; Rault, Jean-Loup

    2017-03-09

    In this exploratory study, we tracked free-range laying hens on two commercial flocks with Radio Frequency Identification (RFID) technology with the aim to examine individual hen variation in range use. Three distinct outdoor zones were identified at increasing distances from the shed; the veranda [0-2.4 m], close range [2.4-11.4 m], and far range [>11.4 m]. Hens' movements between these areas were tracked using radio frequency identification technology. Most of the hens in both flocks (68.6% in Flock A, and 82.2% in Flock B) accessed the range every day during the study. Of the hens that accessed the range, most hens accessed all three zones (73.7% in Flock A, and 84.5% in Flock B). Hens spent half of their time outdoors in the veranda area. Within-individual consistency of range use (daily duration and frequency) varied considerably, and hens which were more consistent in their daily range use spent more time on the range overall (p < 0.001). Understanding variation within and between individuals in ranging behaviour may help elucidate the implications of ranging for laying hens.

  4. Prevalence of antibodies to Brucella spp. and individual risk factors of infection in traditional cattle, goats and sheep reared in livestock-wildlife interface areas of Zambia.

    Science.gov (United States)

    Muma, J B; Samui, K L; Siamudaala, V M; Oloya, J; Matop, G; Omer, M K; Munyeme, M; Mubita, C; Skjerve, E

    2006-04-01

    A cross-sectional study was performed in the livestock-wildlife interface areas of Lochinvar and Blue Lagoon National Parks and the non-interface area of Kazungula to determine the prevalence of antibodies to Brucella spp. in domestic ruminants and identify individual animal risk factors of infection. A total of 1245 cattle from 124 herds and 280 goats and sheep from 29 flocks were tested sequentially for Brucella antibodies using the Rose Bengal test (RBT) and competitive ELISA. In cattle, individual seroprevalence ranged from 14.1% to 28.1%, while herd sero-prevalence ranged from 46.2% to 74.0% in the three study areas. No goat or sheep tested positive for Brucella antibodies. Three types of cattle grazing strategies were encountered: locally grazed herds (LGH), transhumantly grazed herds (TGH) and river flood plain grazed herds (FGH). Brucella seroprevalence was seen to vary according to area and grazing strategy: Lochinvar and transhumant grazed herds recorded the highest figures, respectively. Age, sex and history of abortion were found to have independent effects on individual seroprevalence. This study establishes that brucellosis is endemic in domestic animals in the livestock-wildlife interface areas of Blue Lagoon and Lochinvar national parks and the disease is also present in Kazungula. We observed that type of grazing strategy had significant impact on cattle Brucella seroprevalence and that transhumant herds were at high risk of being infected.

  5. Effectiveness of a commercial leptospiral vaccine on urinary shedding in naturally exposed sheep in New Zealand.

    Science.gov (United States)

    Vallée, Emilie; Ridler, Anne L; Heuer, Cord; Collins-Emerson, Julie M; Benschop, Jackie; Wilson, Peter R

    2017-03-01

    L. borgpetersenii serovar Hardjo and L. interrogans serovar Pomona are endemic in New Zealand sheep. An effective vaccine and vaccination strategy would protect both humans and livestock. Four to 12 lambs were selected from each of eight farms (total=84, vaccinated group), while four to 16 lambs (total=98) served as unvaccinated controls. A commercial Hardjo/Pomona vaccine was given at 1-6 weeks of age, 5-11 weeks later and 33-67 weeks later on seven farms and at 18 weeks of age and 5 weeks later on the eighth farm. Vaccinates and controls were grazed together. Blood was regularly collected from the control group to assess flock exposure. Urine was collected from both groups 26-82 weeks after the second vaccination and tested by quantitative PCR. Seroprevalence in controls at the time of urine sampling ranged from 2.7 to 98.2% for Hardjo and from 0 to 54.1% for Pomona with seroconversion occurring 13 to 67 weeks after the second vaccination in all but one farm where exposure had happened by the time of vaccination. The shedding prevalence adjusted for clustering in farms was 45.1% [95% CI 17.6-72.7] (for an observed number of 50/98) in the control animals and 1.8% [95% CI 0.0-10.1] (for an observed number of 5/84) in the vaccinated animals. The vaccine was 100% effective on five farms where animals were vaccinated before 12 weeks of age and before natural exposure occurred, but the effectiveness was 80% [0-97] on one farm where the lambs were exposed before vaccination and 65% [9-87] to 80% [0-97] on one farm where the animals were fully vaccinated by 24 weeks of age. The overall vaccine effectiveness was 86.3% [63.6-94.8%] despite maternal antibodies in some flocks at first vaccination. Vaccination timing seemed to be crucial in achieving optimum reduction in shedding in urine in vaccinated sheep. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Prevalence of Campylobacter jejuni in poultry breeder flocks

    Directory of Open Access Journals (Sweden)

    Ludovico Dipineto

    2010-01-01

    Full Text Available The aim of this work is to present the preliminary results of a study about the prevalence of Campylobacter jejuni in poultry breeder flocks. It was examined three different breeder flocks of Bojano in Molise region. A total of 360 cloacal swabs and 80 enviromental swabs was collected. Of the 3 flocks studied, 6.9% tested were positive for Campylobacter spp. The most-prevalent isolated species is C. jejuni (8.2%. Only 3 of the 360 cloacal swabs samples examined were associated with C. coli. The environmental swabs resulted negative. This results confirms again that poultry is a reservoir of this germ.

  7. Antimicrobial resistance in enterococci isolated from Turkey flocks fed virginiamycin.

    Science.gov (United States)

    Welton, L A; Thal, L A; Perri, M B; Donabedian, S; McMahon, J; Chow, J W; Zervos, M J

    1998-03-01

    From 125 separate cloacal cultures from three turkey flocks fed virginiamycin, 104 Enterococcus faecium and 186 Enterococcus faecalis isolates were obtained. As the turkeys aged, there was a higher percentage of quinupristin-dalfopristin-resistant E. faecium isolates, with isolates from the oldest flock being 100% resistant. There were no vancomycin-resistant enterococci. Results of pulsed-field gel electrophoresis (PFGE) indicated there were 11 PFGE types of E. faecalis and 7 PFGE types of E. faecium that were in more than one group of flock cultures.

  8. Zoonoses, public health, and the backyard poultry flock.

    Science.gov (United States)

    Grunkemeyer, Vanessa L

    2011-09-01

    Raising a small flock of poultry for eggs, meat, and possibly companionship is becoming an increasingly popular hobby in the United States. Domestic chickens (Gallus gallus, forma domestica), turkeys (Meleagris gallopavo, forma domestica), and members of the family Anatidae including ducks, geese, and swans are commonly kept in these privately owned backyard flocks. Multiple bacterial, viral, fungal, and parasitic diseases which affect poultry are known zoonotic pathogens. This article reviews these zoonoses and gives recommendations for flock biosecurity, as well as for prevention of infection in both birds and humans. Diseases associated with other gallinaceous birds are only selectively discussed.

  9. Cucker-Smale Flocking with Bounded Cohesive and Repulsive Forces

    Directory of Open Access Journals (Sweden)

    Qiang Song

    2013-01-01

    Full Text Available This paper proposes two Cucker-Smale-type flocking models by introducing both cohesive and repulsive forces to second-order multiagent systems. Under some mild conditions on the initial state of the flocking system, it is shown that the velocity consensus of the agents can be reached independent of the parameter which describes the decay of communication rates. In particular, the collision between any two agents can always be avoided by designing an appropriate bounded repulsive function based on the initial energy of the flock. Numerical examples are given to demonstrate the effectiveness of the theoretical analysis.

  10. Leptospirosis in sheep and goats under tropical conditions.

    Science.gov (United States)

    Martins, Gabriel; Lilenbaum, Walter

    2014-01-01

    Inadequate management practices and poor reproductive performance have been reported as fundamental factors on reducing the levels of productivity in livestock. Different pathogens have been reported in small ruminants' herds/flocks with reproductive failures. The aim of the present study was to review aspects of leptospirosis in small ruminants, mainly its impact on reproduction and consequently on productivity of the herds/flocks under tropical conditions. Leptospiral infection in goats and sheep is common in several countries, and those species can also act as carriers of leptospires. Severe disease is often associated to young animals and is frequently associated to incidental serovars. In contrast, subclinical infection is mainly characterized by reproductive problems, such as infertility, abortion, occurrence of stillbirths, and weak lambs/goat kids. Moreover, laboratorial tests are essential to achieve an accurate diagnosis of the infection. Microscopic agglutination test is the most common indirect test of leptospirosis, being used worldwide. In small ruminants, PCR consists on a recommendable method for diagnosing animals that carry leptospires. Control of leptospirosis in small ruminants involves measures such as the identification and treatment of the carriers and other sources of infection, quarantine in acquired animals, and systematic immunization with commercial vaccines containing the circulating serovars in the herd/flock. Productivity of small ruminant breeding can dramatically increase with adequate sanitary conditions and control of leptospirosis. Immunization of all the animals combined to the treatment of carriers may successfully control the infection and importantly reduce the economic reproductive hazards that are observed under tropical conditions.

  11. Investigation of prolific sheep from UK and Ireland for evidence on origin of the mutations in BMP15 (FecX(G), FecX(B)) and GDF9 (FecG(H)) in Belclare and Cambridge sheep.

    Science.gov (United States)

    Mullen, Michael P; Hanrahan, James P; Howard, Dawn J; Powell, Richard

    2013-01-01

    This paper concerns the likely origin of three mutations with large effects on ovulation rate identified in the Belclare and Cambridge sheep breeds; two in the BMP15 gene (FecX(G) and FecX(B)) and the third (FecG(H)) in GDF9. All three mutations segregate in Belclare sheep while one, FecX(B), has not been found in the Cambridge. Both Belclare and Cambridge breeds are relatively recently developed composites that have common ancestry through the use of genetic material from the Finnish Landrace and Lleyn breeds. The development of both composites also involved major contributions from exceptionally prolific ewes screened from flocks in Ireland (Belclare) and Britain (Cambridge) during the 1960s. The objective of the current study was to establish the likely origin of the mutations (FecX(G), FecX(B) and FecG(H)) through analysis of DNA from Finnish Landrace and Lleyn sheep, and Galway and Texel breeds which contributed to the development of the Belclare breed. Ewes with exceptionally high prolificacy (hyper-prolific ewes) in current flocks on Irish farms were identified to simulate the screening of ewes from Irish flocks in the 1960s. DNA was obtained from: prolific ewes in extant flocks of Lleyn sheep (n = 44) on the Lleyn peninsula in Wales; hyper-prolific ewes (n = 41); prolific Galway (n = 41) ewes; Finnish Landrace (n = 124) and Texel (n = 19) ewes. The FecX(G) mutation was identified in Lleyn but not in Finnish Landrace, Galway or Texel sheep; FecX(B) was only found among the hyper-prolific ewes. The FecG(H) mutation was identified in the sample of Lleyn sheep. It was concluded from these findings that the Lleyn breed was the most likely source of the FecX(G) and FecG(H) mutations in Belclare and Cambridge sheep and that the FecX(B) mutation came from the High Fertility line that was developed using prolific ewes selected from commercial flocks in Ireland in the 1960's and subsequently used in the genesis of the Belclare.

  12. Inhibitory effect of selenium supplementation on the reproductive performance in synchronized Merino sheep at range conditions in a selenium-deficient area.

    Science.gov (United States)

    Sánchez, J; Jiménez, A; Regodón, S; Andrés, S

    2008-06-01

    The effect of selenium (Se) supplementation on the reproductive performance of Merino ewes mated out of the normal breeding season was studied in a 2 (no Se supplementation vs Se supplementation) x 2 (ewes mated at natural oestrus vs synchronized oestrus) factorial design with 50 ewes per treatment combination. Synchronization of oestrus was achieved by intravaginal insertion of 40 mg cronolone sponges for 14 days and administration of 440 IU PMSG at sponge withdrawal. Se supplementation was by the addition to the concentrate with 0.5 mg/kg of Se in the form of selenomethionin, for the 3 months prior to the mating and during gestation. Ewes were kept under range conditions in south-west Spain, and exposed to Merino rams at a female: male ratio of 4 : 1 from 2 days following sponge withdrawal, or the equivalent time, for 21 days. Se supplementation alone did not improve significantly ewe fertility or lamb birth weight, but there was a positive effect of synchronizing ewes mated out of the breeding season as more of these ewes lambed and produced more lambs than those not synchronized. However, a strong interaction was found between synchronization and Se supplementation, causing a deleterious effect on the reproductive performance of ewes. This negative effect, presumably related to high embrionary mortality caused by Se toxicity, should be taken into account for oestrus synchronizing in Se-deficient areas. The supplementation with Se, for the prevention of nutritional myodystrophy degeneration in lambs, should be conducted in a fashion which does not generate high levels of Se in the ewes around the mating period.

  13. Interobserver reliability of neck-mobility measurement by means of the flock-of-birds electromagnetic tracking system

    NARCIS (Netherlands)

    Assink, N; Bergman, GJD; Knoester, B; Winters, JC; Dijkstra, PU; Postema, K

    2005-01-01

    Objective: To establish the interobserver reliability for measuring neck mobility in human subjects by means of an electromagnetic tracking device, the Flock-of-Birds system. Methods: Two observers independently and in random order assessed the cervical range-of-motion in 30 subjects with a dysfunct

  14. Breeding objectives for Targhee sheep.

    Science.gov (United States)

    Borg, R C; Notter, D R; Kuehn, L A; Kott, R W

    2007-11-01

    Breeding objectives were developed for Targhee sheep under rangeland production conditions. Traits considered were those for which EPD were available from the US National Sheep Improvement Program and included direct and maternal effects on 120-d weaning weight (WW and MM, respectively); yearling weight (YW); yearling fleece weight, fiber diameter, and staple length; and percent lamb crop (PLC), measured as the number of lambs born per 100 ewes lambing. A bioeconomic model was used to predict the effects of a change of 1 additive SD in EPD for each trait, holding all other traits constant at their mean, on animal performance, feed requirements, feed costs, and economic returns. Resulting economic weightings were then used to derive selection indexes. Indexes were derived separately for 3 prolificacy levels (1.41, 1.55, and 1.70 lambs/ewe lambing), 2 triplet survival levels (50 and 67%), 2 lamb pricing policies (with or without discounting of prices for heavy feeder lambs), and 3 forage cost scenarios (renting pasture, purchasing hay, or reducing flock size to accommodate increased nutrient requirements for production). Increasing PLC generally had the largest impact on profitability, although an increase in WW was equally important, with low feed costs and no discounting of prices for heavy feeder lambs. Increases in PLC were recommended at all 3 prolificacy levels, but with low triplet survival the value of increasing PLC eventually declined as the mean litter size increased to approximately 2.15 lambs/ewe lambing and above. Increasing YW (independent of WW) increased ewe maintenance costs and reduced profitability. Predicted changes in breeding values for WW and YW under index selection varied with lamb pricing policy and feed costs. With low feed costs or no discounts for heavy lambs, YW increased at a modest rate in association with increasing WW, but with high feed costs or discounting of heavy lambs, genetic trends in WW were reduced by approximately 50% to

  15. An epizootic of Mycoplasma ovipneumoniae infection in captive Dall's sheep (Ovis dalli dalli).

    Science.gov (United States)

    Black, S R; Barker, I K; Mehren, K G; Crawshaw, G J; Rosendal, S; Ruhnke, L; Thorsen, J; Carman, P S

    1988-10-01

    In late spring of 1986, 10 of 23 Dall's sheep (Ovis dalli dalli) at the Metropolitan Toronto Zoo were moved to a new exhibit, where all developed severe respiratory signs refractory to anthelmintic and antibiotic therapy. In July, two animals died with chronic active bronch-pneumonia, and a third was euthanized because of pneumonia several months later. Bacteria were not isolated from the lungs of the first, steptococci and Pasteurella hemolytica were isolated from the other two, respectively; Mycoplasma ovipneumoniae was isolated from both. Pulmonary lesions in all three sheep were consistent with Mycoplasma sp. infection. Nasal swabs of the remaining animals yielded no consistent bacterial isolates; however, four of eight sheep were positive for M. ovipneumoniae. Viral cultures yielded an as yet unidentified herpesvirus. Sheep in the original and new herds had no serologic titers to parainfluenza-3, equine viral rhinopneumonitis, or infectious bovine rhinotracheitis, and had variable titers against bovine respiratory syncytial virus. No titers against M. ovipneumoniae were present in 13 sheep still in the original exhibit, but titers varied from 1:32 to 1:256 in eight pneumonic sheep. Sera taken from three sheep before or early in the outbreak were all negative for antibody to M. ovipneumoniae. Two of the affected Dall's sheep had been in contact with domestic sheep in the winter of 1985-1986, and M. ovipneumoniae was subsequently cultured from the domestic flock. Exposure to a new pathogen, and environmental and social stress in a new exhibit may have resulted in this severe disease in Dall's sheep.

  16. 9 CFR 93.435 - Sheep and goats.

    Science.gov (United States)

    2010-01-01

    ... must be placed in a flock or herd in the United States that participates in the Voluntary Scrapie Flock... compliance with all requirements of the Voluntary Scrapie Flock Certification Program until the flock or herd... Voluntary Scrapie Flock Certification Program identification number of the receiving flock or herd as...

  17. Epidemiological studies of clinical and subclinical ovine mastitis in Awassi sheep in northern Jordan.

    Science.gov (United States)

    Lafi, S Q; al-Majali, A M; Rousan, M D; Alawneh, J M

    1998-01-01

    Forty-six Awassi sheep flocks selected by stratified random sampling were subjected to a cross-sectional study to determine the prevalence of intramammary infections, to assess the influence of flock size and parity on the prevalence of somatic cell count (SCC) and to identify major udder pathogens. Of the 3472 udder halves examined, 29.8% had over 10(6) SCC/ml and 0.03% had dry teats due to chronic mastitis. Flocks with 30-49 milking ewes (small flock size) were much younger (P or = 100 ewes (large). Pairwise analysis of the InSCC of both halves of the udders revealed significant mean differences for small and large flock size (P < 0.05), and for medium and large flock size (P < 0.001). Mean InSCC was lower (P < 0.05) in samples obtained from the left half compared with samples of the right half of the udder. Multiparous ewes had higher (P < 0.001) mean InSCC than primiparous ewes. Also, ewes with twin lambs had higher (P < 0.001) mean InSCC in the right half of the udder compared with single-lamb ewes. Samples collected in January (winter) had lower (P < 0.05) mean InSCC compared with samples collected in June. The most common organisms isolated from subclinical mastitis cases were coagulase-negative Staphylococci (17.8%), E. coli (13.6%), Streptococcus agalactiae (6.8%) and Staphylococcus aureus (6.8%). Of the 46 flocks, 20 were monitored monthly for 9 consecutive months to determine the incidence of clinical mastitis diagnosed by shepherds or/and sheep farmers with major pathogens. The incidence of clinical mastitis (expressed as the number of clinical cases per 100 ewe-months) were 2.1 +/- 1.9 (SD), 1.9 +/- 1.1, and 1.2 +/- 2.1 for small, medium and large flocks size strata, respectively. The overall population estimate was 1.7 +/- 0.02 cases per 100 ewe-months. The most-common clinical isolates were S. aureus (22% of all clinical isolates) and E. coli (14.2%).

  18. Identification of Leptospira spp. carriers among seroreactive goats and sheep by polymerase chain reaction.

    Science.gov (United States)

    Lilenbaum, W; Varges, R; Ristow, P; Cortez, A; Souza, S O; Richtzenhain, L J; Vasconcellos, S A

    2009-08-01

    Few studies were conducted on the diagnosis and control of small ruminants' leptospirosis. Thirteen goat herds and seven sheep flocks located in the state of Rio de Janeiro, Brazil, were screened for leptospirosis. From the three herds and three flocks with greatest seroreactivity by MAT (Microscopic Agglutination Test), 19 and 40 seropositive goats and sheep, respectively, were selected, and urine samples were collected for bacteriology and PCR. For both species of animals, the most prevalent reactions were due to serogroups Sejroe and Shermani. Although leptospires were observed by darkfield microscopy in eight samples, pure isolates were obtained by bacteriological culture from only two samples. However, twelve urine samples (six goats and six sheep) were positive by PCR. Based on these findings, we consider that the combined use of MAT as a screening test followed by urine PCR for the direct detection of Leptospira spp. DNA was adequate for the identification of carrier animals among goats and sheep. These are valuable tools for the control of leptospirosis in small ruminants.

  19. Complex Network Structure of Flocks in the Standard Vicsek Model

    Science.gov (United States)

    Baglietto, Gabriel; Albano, Ezequiel V.; Candia, Julián

    2013-10-01

    In flocking models, the collective motion of self-driven individuals leads to the formation of complex spatiotemporal patterns. The Standard Vicsek Model (SVM) considers individuals that tend to adopt the direction of movement of their neighbors under the influence of noise. By performing an extensive complex network characterization of the structure of SVM flocks, we show that flocks are highly clustered, assortative, and non-hierarchical networks with short-tailed degree distributions. Moreover, we also find that the SVM dynamics leads to the formation of complex structures with an effective dimension higher than that of the space where the actual displacements take place. Furthermore, we show that these structures are capable of sustaining mean-field-like orientationally ordered states when the displacements are suppressed, thus suggesting a linkage between the onset of order and the enhanced dimensionality of SVM flocks.

  20. Flocking shape analysis of multi-agent systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this paper,we consider the shape control in flocking behavior of a multi-agent system with a virtual leader.Besides the traditional flocking control terms,which include a gradient-based term,a velocity consensus term and a navigational feed-back in general,a new piecewise smooth neighbor-based local controller is added to regulate the configuration to the desired flocking shape.All agent velocities approach the desired velocity asymptotically,while collisions among agents can be avoided.Furthermore,based on the proved stability,we obtain three kinds of flocking shapes,such as those in a single line,vee shape or corner shape.Some numerical simulation results are provided to demonstrate theoretical issues.

  1. Flocking in the depths of strategic iterated reasoning

    CERN Document Server

    Frey, Seth

    2015-01-01

    Must it be the case that increasingly deep levels of strategic iterated reasoning by humans give increasingly close approximations of normative economic rationality? And if not, what might they do instead? We argue that human higher-level reasoning processes may support non-equilibrium, non-convergent "flocking" behavior. Flocking in the physical world is the sustained convergence of both the positions and velocities of the members of a group. We make the metaphor to flocking in our experiments by introducing decision environments in which participants' choices and reasoning processes function as their positions and velocities, respectively. With this definition, we demonstrate flocking in multiple group experiments over three unrelated economic games. The first game is the classic Beauty Pageant, the second is called the Mod Game, and we introduce the Runway Game. Though they three bear no formal resemblance to each other, subjects play them the same: as eliciting iterated reasoning in a way that causes indi...

  2. A report on the Agassiz flock of Canada geese

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the history of Canada goose production by the Agassiz National Wildlife Refuge (NWR) flock from 1955 to 1964. Attached is a nesting structure...

  3. Clusterflock: a flocking algorithm for isolating congruent phylogenomic datasets

    National Research Council Canada - National Science Library

    Apurva Narechania; Richard Baker; Rob DeSallerun Mathema; Sergios-Orestis Kolokotronisrry Kreiswirth; Paul J Planet

    2016-01-01

      Background Collective animal behavior, such as the flocking of birds or the shoaling of fish, has inspired a class of algorithms designed to optimize distance-based clusters in various applications...

  4. AD HOC TEAMWORK BEHAVIORS FOR INFLUENCING A FLOCK

    Directory of Open Access Journals (Sweden)

    Katie Genter

    2016-02-01

    Full Text Available Ad hoc teamwork refers to the challenge of designing agents that can influence the behavior of a team, without prior coordination with its teammates. This paper considers influencing a flock of simple robotic agents to adopt a desired behavior within the context of ad hoc teamwork. Specifically, we examine how the ad hoc agents should behave in order to orient a flock towards a target heading as quickly as possible when given knowledge of, but no direct control over, the behavior of the flock. We introduce three algorithms which the ad hoc agents can use to influence the flock, and we examine the relative importance of coordinating the ad hoc agents versus planning farther ahead when given fixed computational resources. We present detailed experimental results for each of these algorithms, concluding that in this setting, inter-agent coordination and deeper lookahead planning are no more beneficial than short-term lookahead planning.

  5. Antimicrobial resistance in Campylobacter spp isolated from broiler flocks

    OpenAIRE

    Kuana, Suzete Lora; SANTOS Luciana Ruschel dos; RODRIGUES, Laura Beatriz; Anderlise BORSOI; Moraes, Hamilton Luis do Souza; Salle, Carlos Tadeu Pippi; Nascimento, Vladimir Pinheiro do

    2008-01-01

    The aim of this study was to assess the antimicrobial susceptibility of 62 Campylobacter spp. strains obtained from broiler flocks using the agar diffusion method. The Campylobacter spp strains were isolated from 22 flocks aged between 3 and 5 weeks of life, isolated from cloacae swabs, stools and cecal droppings in the farm and from the carcass rinsing in the slaughterhouse. Campylobacter spp strains were tested on Mueller-Hilton (MH) agar (27 samples) and MH plus TTC agar (35 samples). The ...

  6. Emerging parasitic diseases of sheep.

    Science.gov (United States)

    Taylor, M A

    2012-09-30

    There have been changes in the emergence and inability to control of a number of sheep parasitic infections over the last decade. This review focuses on the more globally important sheep parasites, whose reported changes in epidemiology, occurrence or failure to control are becoming increasingly evident. One of the main perceived driving forces is climate change, which can have profound effects on parasite epidemiology, especially for those parasitic diseases where weather has a direct effect on the development of free-living stages. The emergence of anthelmintic-resistant strains of parasitic nematodes and the increasing reliance placed on anthelmintics for their control, can exert profound changes on the epidemiology of those nematodes causing parasitic gastroenteritis. As a consequence, the effectiveness of existing control strategies presents a major threat to sheep production in many areas around the world. The incidence of the liver fluke, Fasciola hepatica, is inextricably linked to high rainfall and is particularly prevalent in high rainfall years. Over the last few decades, there have also been increasing reports of other fluke associated diseases, such as dicroceliosis and paramphistomosis, in a number of western European countries, possibly introduced through animal movements, and able to establish with changing climates. External parasite infections, such as myiasis, can cause significant economic loss and presents as a major welfare problem. The range of elevated temperatures predicted by current climate change scenarios, result in an elongated blowfly season with earlier spring emergence and a higher cumulative incidence of fly strike. Additionally, legislative decisions leading to enforced changes in pesticide usage and choices have resulted in increased reports and spread of ectoparasitic infections, particularly mite, lice and tick infestations in sheep. Factors, such as dip disposal and associated environmental concerns, and, perhaps more

  7. Emergence of Anisotropy in Flock Simulations and Its Computational Analysis

    Science.gov (United States)

    Makiguchi, Motohiro; Inoue, Jun-Ichi

    2010-03-01

    In real flocks, it was revealed that the angular density of nearest neighbors shows a strong anisotropic structure of individuals by very recent extensive field studies [Ballerini et al, Proceedings of the National Academy of Sciences USA 105, pp. 1232-1237 (2008)]. In this paper, we show that this structure of anisotropy also emerges in an artificial flock simulation, namely, Boid simulation by Reynolds [C.W. Reynolds, Flocks, Herds, and Schools: A Distributed Behavioral Model, Computer Graphics, 21, pp. 25-34 (1987)]. To quantify the anisotropy, we evaluate a useful statistics, that is to say, the so-called γ-value which is defined as an inner product between the vector in the direction of the lowest angular density of flocks and the vector in the direction of the flock is moving. Our results concerning the emergence of the anisotropy through the γ-value might enable us to judge whether an optimal flock simulation seems to be realistic or not.

  8. Switching hierarchical leadership mechanism in homing flight of pigeon flocks

    Science.gov (United States)

    Chen, Duxin; Vicsek, Tamás; Liu, Xiaolu; Zhou, Tao; Zhang, Hai-Tao

    2016-06-01

    To explore the fascinating inter-individual interaction mechanism governing the abundant biological grouping behaviors, more and more efforts have been devoted to collective motion investigation in recent years. Therein, bird flocking is one of the most intensively studied behaviors. A previous study (Nagy M. et al., Nature, 464 (2010) 890.) claims the existence of a well-defined hierarchical structure in pigeon flocks, which implies that a multi-layer leadership network leads to the occurrence of highly coordinated pigeon flock movements. However, in this study, by using high-resolution GPS data of homing flight of pigeon flocks, we reveal an explicit switching hierarchical mechanism underlying the group motions of pigeons. That is, a pigeon flock has a long-term leader for smooth moving trajectories, whereas the leading tenure passes to a temporary one upon sudden turns or zigzags. Therefore, the present observation helps explore more deeply into the principle of a huge volume of bird flocking dynamics. Meanwhile, from the engineering point of view, it may shed some light onto industrial multi-robot coordination and unmanned air vehicle formation control.

  9. Prevalence of three liver parasites in sheep and goats in Al-Madinah Al-Munawwarah, Saudi Arabia Kingdom.

    Science.gov (United States)

    Soliman, Mohammad I; Taha, Hoda A

    2012-08-01

    The epidemiological status of cysticercosis, hydatidosis and dicrocoelosis in sheep and the production practices of sheep farmers that increase the risk of exposure of sheep to their infectious agents were studied in Al-Madinah, during 2011-2012. A total of 450 sheep and 1650 goats were inspected randomly at an abattoir survey and the prevalence of hydatidosis, cysticercosis and dicrocoelosis was recorded as 0.4%, 13.3% & 0.6% in sheep and 0.16%, 1.8% & 0.0% in goats respectively. The prevalence of cysticercosis increased dramatically in days of wedding parties to more than 75% because a large number of sheep was brought from one grazing endemic farm. The improper disposal of dead animals, the access of farm dogs to offal of slaughtered sheep, the farmers carelessness to treat their dogs with anthelmintic, and the grazing of flocks in fields where stray dogs have free access; increased the sheep and goats risk of exposure to hydatidosis and cysticercosis.

  10. Rapeseed and sunflower oilcake as supplements for dairy sheep: animal performance and milk fatty acid concentrations.

    Science.gov (United States)

    Amores, Gustavo; Virto, Mailo; Nájera, Ana Isabel; Mandaluniz, Nerea; Arranz, Josune; Bustamante, María Angeles; Valdivielso, Izaskun; Ruiz de Gordoa, Juan Carlos; García-Rodríguez, Aser; Barron, Luis J R; de Renobales, Mertxe

    2014-11-01

    The influence of different amounts of oilseed cake (rapeseed and sunflower) on animal production parameters and fatty acid (FA) concentrations of the milk was studied in a Latxa dairy sheep experimental flock, both in winter (50% oilcakes; indoor feeding) and in spring (30% oilcakes; part-time grazing). The two different levels of the oilcakes tested did not affect animal production parameters or milk yield. Milk fat content and the fat/protein ratio decreased significantly with 30 and 50% sunflower cake. Yet, fat/protein ratio values were within the range for cheesemaking. Both levels of either type of oilcake tested significantly increased the concentrations of nutritionally interesting FA (CLA isomer C18:2cis-9, trans-11, vaccenic, oleic, and total unsaturated FA), while simultaneously decreasing the concentration of atherogenic FA. The atherogenicity indexes of milks from ewes fed 50 or 30% of either oilcake were significantly lower than those of their corresponding control. The use of cakes in winter increased the concentration of nutritionally interesting FA to the values obtained with part-time grazing.

  11. EFFECT OF INBREEDING ON PRE-WEANING GROWTH TRAITS IN THALLI SHEEP

    Directory of Open Access Journals (Sweden)

    A. HUSSAIN, P. AKHTAR, S. ALI, M. YOUNAS1 AND M. SHAFIQ2

    2006-07-01

    Full Text Available Pedigree records of 17250 Thalli sheep with 17030 lambings maintained at the Livestock Experiment Station, Rakh Ghulaman, Distt. Bhakkar, Pakistan during the period from 1975 to 2004 were utilized in the present study. Average values for birth weight, weights at 60 and 90 days of age, weaning weight and pre-weaning average daily gain were 4.11 ± 0.82, 11.58 ± 3.57, 14.92 ± 4.56, 18.95 ± 4.56 and 0.12 ± 0.04 kg, respectively. Coefficients of inbreeding ranged from 10.15 to 37.50 percent for 295 animals, being 1.70 percent of the flock. Inbreeding significantly (P<0.01 affected birth and 60 days weight. Birth weight and 60 days weight decreased by 0.051 and 0.048 kg for each 1 percent increase in the level of inbreeding. However, inbreeding had non significant effect on weight at 90 days of age, weaning weight and pre-weaning average daily gain. The regression values for these traits were 0.010, 0.083 and 0.105, respectively. It was concluded that inbreeding showed deleterious effects only in early stages of life but as the lambs grew older the effect of inbreeding on pre-weaning traits diminished.

  12. An immunohistochemical study of the distribution of border disease virus in persistently infected sheep.

    Science.gov (United States)

    Waldvogel, A S; Ehrensperger, F; Straub, O C; Pospischil, A

    1995-08-01

    Three seronegative sheep persistently infected with Border disease virus and six seropositive, non-viraemic sheep were examined for the cellular distribution of the agent. These animals originated from a closed flock which had been kept in an isolation facility for 5 years. They were killed and immediately necropsied. There were no gross abnormalities other than reduced body weight of the persistently infected sheep. Two samples of each major organ were collected. The first sample was fixed by immersion in formalin and processed for histological examination, which showed no lesions unequivocally attributable to the viral infection. The second sample was snap-frozen for immunohistochemical examination. This revealed viral antigen in all organs of the persistently infected, but in none of the seropositive animals. The infected cells included smooth muscle cells of hollow organs and blood vessels, epithelial cells of the alimentary tract and urogenital organs, lymphocytes in lymphoid organs, endocrine cells, neurons and glial cell.

  13. Ranging Behaviour of Commercial Free-Range Broiler Chickens 2: Individual Variation

    Science.gov (United States)

    Groves, Peter J.; Rault, Jean-Loup

    2017-01-01

    Simple Summary Although the consumption of free-range chicken meat has increased, little is known about the ranging behaviour of meat chickens on commercial farms. Studies suggest range use is low and not all chickens access the range when given the opportunity. Whether ranging behaviour differs between individuals within a flock remains largely unknown and may have consequences for animal welfare and management. We monitored individual chicken ranging behaviour from four mixed sex flocks on a commercial farm across two seasons. Not all chickens accessed the range. We identified groups of chickens that differed in ranging behaviour (classified by frequency of range visits): chickens that accessed the range only once, low frequency ranging chickens and high frequency ranging chickens, the latter accounting for one-third to one half of all range visits. Sex was not predictive of whether a chicken would access the range or the number of range visits, but males spent more time on the range in winter. We found evidence that free-range chicken ranging varies between individuals within the same flock on a commercial farm. Whether such variation in ranging behaviour relates to variation in chicken welfare remains to be investigated. Abstract Little is known about broiler chicken ranging behaviour. Previous studies have monitored ranging behaviour at flock level but whether individual ranging behaviour varies within a flock is unknown. Using Radio Frequency Identification technology, we tracked 1200 individual ROSS 308 broiler chickens across four mixed sex flocks in two seasons on one commercial farm. Ranging behaviour was tracked from first day of range access (21 days of age) until 35 days of age in winter flocks and 44 days of age in summer flocks. We identified groups of chickens that differed in frequency of range visits: chickens that never accessed the range (13 to 67% of tagged chickens), low ranging chickens (15 to 44% of tagged chickens) that accounted for <15

  14. Recent studies on Dictyocaulus filaria and other lungworms of sheep and goats in India

    Energy Technology Data Exchange (ETDEWEB)

    Dhar, D.N. (Indian Veterinary Research Inst., Srinagar. Regional Centre)

    1982-03-01

    Additional areas of the country were surveyed for lungworm infections in sheep and goats. More sheep than goats and more sheep of the private breeders in comparison to Government flocks were found infected. Infection with Dictyocaulus filaria and un-identified species of Varestrongylus and Protostrongylus were reported from sheep and goats and Muellerius spp, only from sheep. About 0.36 million lambs have been successfully immunized against D. filaria in the endemic areas with the radiation-attenuated vaccine produced at the Srinagar laboratory. It has been shown that lambs infected with D. filaria at the time of vaccination develop a poor protection following vaccination in comparison to lambs free from the infection. This has posed a problem in the field of stimulating a satisfactory protection in lambs found infected with D. filaria at the time of vaccination. In consequence, very young lambs, aged 6-10 week have been effectively protected against D. filaria by vaccination under field conditions. Goats are more succeptible hosts to D. filaria than sheep. Laboratory studies have shown that young kids, like lambs, can be effectively immunized against D. filaria by double vaccination with 50 Krad gamma irradiated larvae.

  15. Acute and chronic disease associated with naturally occurring T-2 mycotoxicosis in sheep.

    Science.gov (United States)

    Ferreras, M C; Benavides, J; García-Pariente, C; Delgado, L; Fuertes, M; Muñoz, M; García-Marín, J F; Pérez, V

    2013-02-01

    A flock of approximately 1,000 sheep were exposed intermittently to food contaminated with T-2 toxin (T-2), a potent type-A trichothecene mycotoxin produced primarily by Fusarium sporotrichioides and Fusarium poae. In the acute stage of the intoxication, affected sheep developed anorexia, decreased water consumption, ruminal atony, soft faeces and apathy. One hundred and ninety of the exposed sheep died. The main gross lesions observed in animals dying during the acute disease were rumenitis and ulcerative abomasitis, depletion of lymphocytes in lymphoid organs, necrosis of the exocrine pancreas, myocarditis and intense oedema of the skin and brain. Sheep developing the chronic stage of disease showed weight loss and reproductive inefficiency and the main pathological features observed in animals dying during this stage were gastrointestinal inflammation, myocardial fibrosis and necrotic and suppurative lesions in the oral cavity. Opportunistic infections (e.g. mycotic mastitis or parasitic pneumonia) were also identified in these animals. Increased serum concentrations of lactate dehydrogenase and creatine kinase were observed, most likely related to heart lesions. T-2 toxins were detected in all samples of the diet of these animals that were analyzed. The changes in the sheep reported here are similar to those described previously in experimental studies. Lesions observed in the present animals suggest an additional cardiotoxic effect of T-2 in sheep. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Air samplings in a Campylobacter jejuni positive laying hen flock.

    Science.gov (United States)

    Ahmed, Marwa Fawzy El Metwaly; Schulz, Jochen; Hartung, Joerg

    2013-01-01

    The air in laying hen houses contains high concentrations of airborne bacteria. The numbers of these bacteria can be influenced by the efficiency of the chosen sampling method. In the presented study, AGI-30 Impingers and the Coriolis(®)µ air Sampler were compared in terms of their efficiency in sampling aerobic mesophilic bacteria in a laying hen house. Measurements were conducted in a laying hen flock with high prevalences of C. jejuni in order to investigate if culturable cells of this organism can also be detected by the applied methods. Airborne dust was also analyzed for the presence of C. jejuni specific DNA to assess the possible occurrence of non-culturable C. jejuni in the hen house air. The numbers of mesophilic airborne bacteria ranged from 8 × 10(4) - 2 × 10(6) CFU/m(-3) when sampled using AGI-30 Impingers, and from 2 × 10(5) - 4 × 10(6) CFU/m -3 when sampled using a Coriolis(®)µ air Sampler. The concentrations detected simultaneously by both devices correlated well (rPearson = 0.755), but the Coriolis(®)µ air Sampler showed a significantly higher sampling efficiency (phen house air, and in future it should be verified whether sampling stress of the air sampling methods could induce the non-culturable state.

  17. Factors affecting on longevity in Northern Khorasan Kordish sheep

    Directory of Open Access Journals (Sweden)

    razieh saghi

    2016-04-01

    Full Text Available Introduction The longevity is normally defined as the length of its productive life in the flock, which is the amount of time an animal spends producing (1. Longevity reflects the ability of ewe to avoid being culled for low production, low fertility, illness and influences the number and cost of replacements required to maintain the flock size. The benefit of increasing longevity are increased average age of the flock, having more ewes available for sale at the end of their four parity, having more ewe lambs to sell, and higher productivity from a slightly older flock age profile (2. Sheep population of Khorasan province (10. In sheep production, longevity has an important influence on the economic returns. Reliable estimates of non genetic effects of longevity are needed to aid establishing an efficient strategy for improving ewe productivity. Thus, the objective of this study was the factors affecting on longevity in Northern Khorasan Kordish sheep. We want to determine effect of environmental and non-genetic factors on longevity. Material and Methods In order to investigate on factors affecting longevity trait in Northen Khorasan Kordish sheep, records of 7469 sheep (187 sire and 2258 dam between 1990 to 2012 that were collected by breeding station of Hossein Abad in Shirvan (This city is located in the north of Mashhad were used. Flock has been kept under village system. Breeding ewes were identified in the data set as those that lambed at 2 year of age and culled at 6 to 7 year of age duo to oldness. Ram kept until a male offspring was available for replacement. In this study longevity was defined as the age of a ewe (in day when it leaves the flock. Ewes were generally removed from the flock due to poor production, low fertility, death and illness. Ewes were identified as being removed from the flock if a lambing record was present at n year of age but not at n+1 years of age. All females were culled before reaching 7 years of age

  18. Interannual and geographical reproducibility of the nutritional quality of milk fat from commercial grazing flocks.

    Science.gov (United States)

    Virto, Mailo; Bustamante, Marian; Ruiz de Gordoa, Juan Carlos; Amores, Gustavo; Fernández-Caballero, Paula N; Mandaluniz, Nerea; Arranz, Josune; Nájera, Ana I; Albisu, Marta; Pérez-Elortondo, Francisco J; Barron, Luis J R; de Renobales, Mertxe

    2012-11-01

    The objective of the present work was to study the differences in the fatty acid (FA) composition of raw sheep milk fat under commercial milk production conditions throughout lactation, in two consecutive years. Particular attention was placed on the C18:2cis-9,trans-11 isomer, C18:1trans-11 acid, and unsaturated FA as the feeding regimen of 10 commercial flocks of latxa dairy sheep changed from indoor feeding to part-time grazing conditions (from early spring) as traditionally practiced in the Basque Country (Northern Spain). Farms located at an altitude of between 600 and 700 m, in two different geographical areas with different rainfall were selected. Milk samples were collected monthly from late January (indoor feeding) until mid-, or end of, June (outdoor feeding), during two consecutive years. In spite of some interannual variability (most likely due to large differences in rainfall), the evolution of individual FA throughout lactation was comparable between years, indicating that it was reproducible under commercial milk production conditions. The average concentrations of C18:2cis-9,trans-11 isomer and C18:1trans-11 acid in milk from the commercial flocks increased about 200% during the transition period (end of March or early April until May), from indoor feeding (late January or early February until the end of March) to the outdoor period (early May to mid-June), remaining constant during the outdoor period (27·53 ± 9·32 μmol/g fat and 71·58 ± 20·53 μmol/g fat, respectively). Non-atherogenic FA comprised approximately 50% of all saturated FA at any time during lactation, whereas the milk atherogenicity index decreased significantly during the outdoor period. The Trolox-equivalent antioxidant capacity of the water-soluble milk fraction did not appear to be influenced by feeding management. The FA composition of cheeses made during the second year with milk from the indoor or outdoor periods reflected those of the corresponding milks. A

  19. Lipid profiles in brains from sheep with natural scrapie.

    Science.gov (United States)

    Rosa, Antonella; Scano, Paola; Incani, Alessandra; Pilla, Federica; Maestrale, Caterina; Manca, Matteo; Ligios, Ciriaco; Pani, Alessandra

    2013-01-01

    Prion diseases are fatal neurodegenerative disorders affecting many mammals, ovine scrapie being the archetypal prion disease. Several independent studies in murine and cell-based models of scrapie have highlighted the presence of a link between prion generation and lipid alterations; yet, no data on natural disease are available. In this study we investigated levels of total lipids and cholesterol as well as profiles of fatty acids in brain homogenates from symptomatic and asymptomatic scrapie-infected sheep vs. healthy sheep, all belonging to the same flock. Lipid extracts were analyzed by means of gas chromatography and high performance liquid chromatography. Data of fatty acids were submitted to multivariate statistical analysis to give a picture of the brain lipid profiles of sheep. Interestingly, results revealed abnormalities in the brain fatty acid unsaturation of infected/symptomatic animals. Significant reduction of monoene 18:1 n-9 was detected in brain lipids from infected/symptomatic sheep, as compared to healthy and infected/asymptomatic animals, and this alteration occurred in combination with a significant increase in 18:0 level. The unsupervised Principal Component Analysis showed that infected/symptomatic and healthy sheep samples lie in two different regions of the plot, infected/asymptomatic lie mostly next to healthy. The increase of cerebral saturated fatty acids provides a rough indication of presumed alterations in lipid raft domains of nervous cells during scrapie, suggesting that they may exist in a notable viscous liquid-ordered state. Such physicochemical alteration would have a profound impact on the raft thermodynamic properties, its spatial organization, and signal transduction, all potentially relevant for prion generation.

  20. Effect of management practices on screw-worm among sheep in São Paulo State, Brazil.

    Science.gov (United States)

    Madeira, N G; Amarante, A F; Padovani, C R

    1998-06-01

    The screw-worm Cochliomyia hominivorax (Coquerel), whose larvae develop in wild and domestic animals as well as in man, is one of the major causes of myiasis in Brazil. Sheep raising is expanding in the state of São Paulo, where information about the infestation of screw-worm is necessary for appropriate control measures. The present data were obtained from questionnaires sent to all sheep breeders belonging to Associacão Paulista de Criadores de Ovinos--ASPACO (São Paulo State Association of Sheep Breeders). Response reliability was tested by random visits paid to 10.6% of the respondents. The results show that screw-worm is the most frequent ectoparasite in the flocks and is responsible for the greatest economic losses. Its occurrence is strongly associated with flock size, reaching 100% in flocks consisting of more than 500 animals. Infestation is higher in spring and summer and lowest in the fall. The number of cases increases in the presence of some management practices such as tail amputation. Furthermore, several other associations between the indicators surveyed were also found to be significant. The data obtained will permit the elaboration of strategies for the control of this parasitosis.

  1. Dairy Sheep Nutrition

    OpenAIRE

    Rosanna Scipioni

    2010-01-01

    This book, edited by the colleague Giuseppe Pulina, is the result of the project "Further development of a diet formulation model for sheep and goat", supported by the Ministry of Agricultural and Forestry Policies, in Italy.

  2. Cyclic and Coherent States in Flocks with Topological Distance

    CERN Document Server

    Bhattacherjee, Biplab; Manna, S S

    2014-01-01

    A simple model of the two dimensional collective motion of a group of mobile agents have been studied. Like birds, these agents travel in open free space where each of them interacts with the first $n$ neighbors determined by the topological distance with a free boundary condition. Using the same prescription for interactions used in the Vicsek model with scalar noise it has been observed that the flock, in absence of the noise, arrives at a number of interesting stationary states. In the `single sink state' the entire flock maintains perfect cohesion and coherence. In the `cyclic state' every agent executes a uniform circular motion, and the entire flock executes a pulsating dynamics i.e., expands and contracts periodically between a minimum and a maximum size of the flock. When refreshing rate of the interaction zone is the fastest, the entire flock gets fragmented into smaller clusters of different sizes. On introduction of scalar noise a crossover is observed when the agents cross over from a ballistic mo...

  3. Minimum Effective Dose of Cattle and Sheep BSE for Oral Sheep Infection.

    Directory of Open Access Journals (Sweden)

    Gillian McGovern

    Full Text Available The minimum dose required to cause infection of Romney and Suffolk sheep of the ARQ/ARQ or ARQ/ARR prion protein gene genotypes following oral inoculation with Romney or Suffolk a sheep Bovine spongiform encephalopathy (BSE-derived or cattle BSE-derived agent was investigated using doses ranging from 0.0005g to 5g. ARQ/ARQ sheep which were methionine (M / threonine (T heterozygous or T/T homozygous at codon 112 of the Prnp gene, dosed ARQ/ARR sheep and undosed controls did not show any evidence of infection. Within groups of susceptible sheep, the minimum effective oral dose of BSE was found to be 0.05g, with higher attack rates following inoculation with the 5g dose. Surprisingly, this study found no effect of dose on survival time suggesting a possible lack of homogeneity within the inoculum. All clinical BSE cases showed PrPd accumulation in brain; however, following cattle BSE inoculation, LRS involvement within Romney recipients was found to be significantly lower than within the Suffolk sheep inoculated group which is in agreement with previous reports.

  4. Optimization of artificial flockings by means of anisotropy measurements

    CERN Document Server

    Makiguchi, Motohiro

    2010-01-01

    An effective procedure to determine the optimal parameters appearing in artificial flockings is proposed in terms of optimization problems. We numerically examine genetic algorithms (GAs) to determine the optimal set of such parameters such as the weights for three essential interactions in BOIDS by Reynolds (1987) under `zero-collision' and `no-breaking-up' constraints. As a fitness function (the energy function) to be maximized by the GA, we choose the so-called the $\\textyen gamma$-value of anisotropy which can be observed empirically in typical flocks of starling. We confirm that the GA successfully finds the solution having a large $\\textyen gamma$-value leading-up to a strong anisotropy. The numerical experience shows that the procedure might enable us to make more realistic and efficient artificial flocking of starling even in our personal computers.

  5. Reliability evaluation of sampling plan fixed by Council Directive 91/68/EEC for the maintenance of officially brucellosis-free flock status.

    Science.gov (United States)

    De Massis, F; Petrini, A; Giovannini, A

    2005-08-01

    The European Union (EU) strategy with respect to sheep and goat brucellosis aims to eradicate the infection and achieve officially brucellosis-free (OBF) status in all EU holdings and territories. Council Directive 91/68/EEC of 28 January 1991 states that to maintain OBF status of ovine or caprine holdings located outside an OBF territory, only a representative number of animals need to be tested annually. However, depending on the number of animals in a holding, this testing method risks non-detection of the infection, thereby reducing the efficacy of the brucellosis control plan. The recommended sampling procedure has a low sensitivity for detecting infection in medium-sized flocks; furthermore, the risk of not detecting re-infection in OBF flocks, particularly in territories that have not yet gained OBF status, is also not acceptable. Moreover, in large-sized flocks, the Directive sampling procedure entails taking an excessive number of samples, which can be very expensive. The authors evaluated, by using statistical analyses and a simulation model based on field data, the possible consequences of the current EU strategy. It is suggested that the sampling criteria for the maintenance of OBF status in the EU should be modified and that a statistically based sampling method should be applied instead of the fixed percentage method that is currently in use.

  6. Prevalence and antimicrobial susceptibility of thermophilic Campylobacter in organic and conventional broiler flocks

    DEFF Research Database (Denmark)

    Heuer, Ole Eske; Pedersen, Karl; Andersen, J.S.

    2001-01-01

    Aims: To determine the flock prevalence and to estimate the within flock prevalence of Campylobacter in broiler flocks from different rearing systems, and to determine the antimicrobial susceptibility of Campylobacter isolates to selected antimicrobial substances. Methods and Results: One hundred...... and sixty broiler flocks originating from organic, conventional and extensive indoor production farms were investigated for the presence of Campylobacter at the time of slaughter. Campylobacter isolates from a subsample of positive flocks were subjected to susceptibility testing. Campylobacter spp. were...... isolated from 100% of organic broiler flocks, from 36.7% of conventional broiler flocks and from 49.2% of extensive indoor broiler flocks. Six of 62 Campylobacter isolates were resistant to one or more of the antimicrobials tested. Conclusions: These results indicate that the special characteristics...

  7. Occurrence of quinolone- and beta-lactam-resistant Escherichia coli in danish broiler flocks

    DEFF Research Database (Denmark)

    Bortolaia, Valeria; Guardabassi, Luca; Bisgaard, Magne

    ). In Denmark, antimicrobial resistance is annually monitored in both clinical and indicator E. coli isolated from poultry (DANMAP, 2006). However, very little is known on the prevalence of resistance at the flock level. The aim of this study was to determine the prevalence of flocks positive for E. coli...... resistant to quinolones or ß-lactams. Sock samples were collected from 10 broiler parent flocks and 10 broiler offspring flocks. Five pairs of socks were collected from each house. Samples were enriched in McConkey broth and streaked on McConkey agar added with nalidixic acid (32 µg/ml), ciprofloxacin (2 µg...... and nalidixic acid resistances were detected in all flocks. The numbers of E. coli resistant to these drugs were higher in plates from parent flocks than in those from offspring flocks. A broiler parent flock without any history of quinolone usage tested positive for ciprofloxacin-resistant E. coli, although...

  8. The ecological adaptability of cloned sheep to free-grazing in the Tengger Desert of Inner Mongolia, China

    Directory of Open Access Journals (Sweden)

    Xinxin LI,Huijuan WANG,Guanghua SU,Zhuying WEI,Chunling BAI,Wuni-MENGHE,Yanhui HOU,Changqing YU,Shorgan BOU,Guangpeng LI

    2014-09-01

    Full Text Available Since the birth of the first cloned sheep, somatic cell nuclear transfer technology has been successfully used to clone a variety of mammals. Cloned livestock have no apparent health risks, and the quality and safety of the cloned animal products are similar to non-cloned animals. The social behavior and environmental adaptability of postnatal cloned animals, especially when used for grassland farm production purposes, is unknown. In the present study, the cloned Dorper sheep equipped with GPS location devices were free-grazed in a harsh natural environment similar to conditions commonly experienced by Mongolian sheep. The main findings of this research were as follows. (1 Under free-grazing conditions, the cloned sheep showed excellent climatic and ecological adaptability. In extreme temperature conditions ranging from -30 to 40ºC, the cloned sheep maintained acceptable body condition and behaved as other sheep. (2 The cloned sheep quickly adapted from a herd feeding strategy to the harsh environment and quickly exhibited a grazing regimen as other free-grazing sheep. (3 The cloned sheep exhibited free-grazing patterns and social behavior as other sheep. (4 The cloned sheep in the harsh environment thrived and produced healthy lambs. Overall, the cloned Dorper sheep exhibited excellent ecological adaptation, which is an important consideration for breeding meat sheep by cloning. The Dorper sheep readily adapted to the free-grazing conditions on the Mongolian plateau grassland, which attests to their ability to withstand harsh environmental conditions.

  9. A genome scan for quantitative trait loci affecting resistance to Trichostrongylus colubriformis in sheep.

    Science.gov (United States)

    Beh, K J; Hulme, D J; Callaghan, M J; Leish, Z; Lenane, I; Windon, R G; Maddox, J F

    2002-04-01

    A genome linkage scan was carried out using a resource flock of 1029 sheep in six half-sib families. The families were offspring of sires derived by crossing divergent lines of sheep selected for response to challenge with the intestinal parasitic nematode Trichostrongylus colubriformis. All animals in the resource flock were phenotypically assessed for worm resistance soon after weaning using a vaccination/challenge regime. After correcting for fixed effects using a least squares linear model the faecal egg count data obtained following the first challenge and the faecal egg count data obtained after the second challenge were designated Trait 1 and Trait 2, respectively. A total of 472 lambs drawn from the phenotypic extremes of the Trait 2 faecal egg count distribution were genotyped with a panel of 133 microsatellite markers covering all 26 sheep autosomes. Detection of quantitative trait loci (QTL) for each of the faecal egg count traits was determined using interval analysis with the Animap program with recombination rates between markers derived from an existing marker map. No chromosomal regions attained genome-wide significance for QTL influencing either of the traits. However, one region attained chromosome-wide significance and five other regions attained point-wise significance for the presence of QTL affecting parasite resistance.

  10. The use of a Psoroptes ovis serodiagnostic test for the analysis of a natural outbreak of sheep scab

    Directory of Open Access Journals (Sweden)

    Burgess Stewart TG

    2012-01-01

    Full Text Available Abstract Background Sheep scab is a highly contagious disease of sheep caused by the ectoparasitic mite Psoroptes ovis. The disease is endemic in the UK and has significant economic impact through its effects on performance and welfare. Diagnosis of sheep scab is achieved through observation of clinical signs e.g. itching, pruritis and wool loss and ultimately through the detection of mites in skin scrapings. Early stages of infestation are often difficult to diagnose and sub-clinical animals can be a major factor in disease spread. The development of a diagnostic assay would enable farmers and veterinarians to detect disease at an early stage, reducing the risk of developing clinical disease and limiting spread. Methods Serum samples were obtained from an outbreak of sheep scab within an experimental flock (n = 480 (3 samples each from 160 sheep allowing the assessment, by ELISA of sheep scab specific antibody prior to infestation, mid-outbreak (combined with clinical assessment and post-treatment. Results Analysis of pre-infestation samples demonstrated low levels of potential false positives (3.8%. Of the 27 animals with clinical or behavioural signs of disease 25 tested positive at the mid-outbreak sampling period, however, the remaining 2 sheep tested positive at the subsequent sampling period. Clinical assessment revealed the absence of clinical or behavioural signs of disease in 132 sheep, whilst analysis of mid-outbreak samples showed that 105 of these clinically negative animals were serologically positive, representing potential sub-clinical infestations. Conclusions This study demonstrates that this ELISA test can effectively diagnose sheep scab in a natural outbreak of disease, and more importantly, highlights its ability to detect sub-clinically infested animals. This ELISA, employing a single recombinant antigen, represents a major step forward in the diagnosis of sheep scab and may prove to be critical in any future control

  11. A quantitative analysis of attitudes and behaviours concerning sustainable parasite control practices from Scottish sheep farmers.

    Science.gov (United States)

    Jack, Corin; Hotchkiss, Emily; Sargison, Neil D; Toma, Luiza; Milne, Catherine; Bartley, David J

    2017-04-01

    Nematode control in sheep, by strategic use of anthelmintics, is threatened by the emergence of roundworms populations that are resistant to one or more of the currently available drugs. In response to growing concerns of Anthelmintic Resistance (AR) development in UK sheep flocks, the Sustainable Control of Parasites in Sheep (SCOPS) initiative was set up in 2003 in order to promote practical guidelines for producers and advisors. To facilitate the uptake of 'best practice' approaches to nematode management, a comprehensive understanding of the various factors influencing sheep farmers' adoption of the SCOPS principles is required. A telephone survey of 400 Scottish sheep farmers was conducted to elicit attitudes regarding roundworm control, AR and 'best practice' recommendations. A quantitative statistical analysis approach using structural equation modelling was chosen to test the relationships between both observed and latent variables relating to general roundworm control beliefs. A model framework was developed to test the influence of socio-psychological factors on the uptake of sustainable (SCOPS) and known unsustainable (AR selective) roundworm control practices. The analysis identified eleven factors with significant influences on the adoption of SCOPS recommended practices and AR selective practices. Two models established a good fit with the observed data with each model explaining 54% and 47% of the variance in SCOPS and AR selective behaviours, respectively. The key influences toward the adoption of best practice parasite management, as well as demonstrating negative influences on employing AR selective practices were farmer's base line understanding about roundworm control and confirmation about lack of anthelmintic efficacy in a flock. The findings suggest that improving farmers' acceptance and uptake of diagnostic testing and improving underlying knowledge and awareness about nematode control may influence adoption of best practice behaviour

  12. 9 CFR 145.23 - Terminology and classification; flocks and products.

    Science.gov (United States)

    2010-01-01

    ... SERVICE, DEPARTMENT OF AGRICULTURE LIVESTOCK IMPROVEMENT NATIONAL POULTRY IMPROVEMENT PLAN FOR BREEDING POULTRY Special Provisions for Multiplier Egg-Type Chicken Breeding Flocks and Products § 145.23... breeding chickens through routine serological surveillance of each participating breeding flock. A flock...

  13. Effects of Dynamically Weighting Autonomous Rules in an Unmanned Aircraft System (UAS) Flocking Model

    Science.gov (United States)

    2014-09-18

    model is based around Ft Benning, GA using MATLAB ®, Simulink ®, and CMEX to simulate flock behavior in a dense urban environment. The flocks are...23 Point ISR Flock Applicability .................................................................................................... 25 MATLAB ...38 Figure 5. MATLAB ® Screenshot of States 1 through 3

  14. 9 CFR 145.63 - Terminology and classification; flocks and products.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Terminology and classification; flocks and products. 145.63 Section 145.63 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... Terminology and classification; flocks and products. Participating flocks, and the eggs and baby...

  15. Bovine spongiform encephalopathy in sheep?

    NARCIS (Netherlands)

    Schreuder, B.E.C.; Somerville, R.A.

    2003-01-01

    Bovine spongiform encephalopathy (BSE) in sheep has not been identified under natural conditions at the time of writing and remains a hypothetical issue. However, rumours about the possible finding of a BSE-like isolate in sheep have led to great unrest within the sheep industry, among the general p

  16. Salmonella Prevalence and Antimicrobial Susceptibility from the National Animal Health Monitoring System Sheep 2011 Study.

    Science.gov (United States)

    Dargatz, David A; Marshall, Katherine L; Fedorka-Cray, Paula J; Erdman, Matthew M; Kopral, Christine A

    2015-12-01

    Salmonella is a major cause of foodborne illness and can cause clinical disease in animals. Understanding the on-farm ecology of Salmonella will be helpful in decreasing the risk of foodborne transmission. An objective of this study was to determine the prevalence of Salmonella among fecal samples collected on sheep operations in the United States. Another objective was to compare the use of composite fecal samples with fecal samples collected from individual sheep as a tool for screening sheep flocks for Salmonella. Sheep fecal samples (individual and composite) were collected on operations in 22 states. Salmonella isolates were characterized with regard to species, serotype, and antimicrobial susceptibility profile. Most operations (72.1%) had at least one positive sample and overall 26.9% of samples were positive. The percentage of positive samples varied by animal age class. Composite and individual samples gave similar results. The majority of the isolates (94%) were Salmonella enterica subspecies diarizonae serotype 61:-:1,5,7. Nearly all of the isolates (91.2%) tested for antimicrobial susceptibility were susceptible to all antimicrobials in the panel. The findings suggest that salmonellae typically associated with foodborne disease transmission are infrequently found on sheep operations in the United States.

  17. Lack of efficacy of monepantel against Trichostrongylus colubriformis in sheep in Brazil.

    Science.gov (United States)

    Cintra, M C R; Teixeira, V N; Nascimento, L V; Sotomaior, C S

    2016-01-30

    Multiple drug resistance of nematodes against anthelmintics has become one of the most important economic problems in sheep production worldwide. The aim of this experiment was to evaluate the efficacy of monepantel (2.5mg/kg) against gastrointestinal nematodes in fecal egg count reduction test (FECRT) and controlled efficacy test (CT) in naturally infected sheep. We used 30 sheep for the FECRT and 20 sheep for the CT, equally divided into control and treated groups. In the FECRT, the reduction was 98%. Larval identification of pre-treatment coprocultures revealed 100% Haemonchus spp. for both control and treated groups. Post-treatment culture of treated sheep was 100% Oesophagostomum spp., but only few larvae were recovered. In the control group, they were 99% Haemonchus spp and 1% Oesophagostomum spp. larvae. Based on the FECRT, Haemonchus spp. was considered susceptible to monepantel. The efficacy of monepantel in the CT against Haemonchus contortus and Trichostrongylus axei was 100% and against Cooperia curticei was 99.7%. For Trichostrongylus colubriformis, the efficacy was -21.5%. In both treated and untreated animals, Oesophagostomum columbianum was recovered from the large intestines. Based on FECRT and CT and in accordance with WAAVP standards, monepantel was ineffective against T. colubriformis and O. columbianum, but effective against H. contortus, T. axei and C. curticei in the studied flock.

  18. Determination of the seroprevalence of Newcastle disease virus (avian paramyxovirus type 1 in Zambian backyard chicken flocks

    Directory of Open Access Journals (Sweden)

    Chimuka Musako

    2012-02-01

    Full Text Available A cross-sectional study was conducted in five provinces and 11 districts of Zambia to determine the seroprevalence of Newcastle disease in Zambian backyard chicken flocks. Of the chickens sampled, 73.9% tested positive for avian paramyxovirus type 1 antibodies by means of an enzyme-linked immunosorbent assay. Seroprevalence varied amongst the five provinces sampled, ranging from 82.6% in the Eastern Province to 48.3% in Luapula Province. Seroprevalence also varied amongst the 11 districts sampled, ranging from 91.3% in Monze district of Southern Province to 22.8% in Mufulira district of the Copperbelt province. Overall, the seroprevalence of Newcastle disease in Zambian backyard chicken flocks has increased since the previous study conducted in 1994.

  19. [Sheep wool granuloma].

    Science.gov (United States)

    Lambert, D; Terrussot, M C; Dalac, S; Boulitrop-Morvan, C

    1995-01-01

    We report the unusual case of cutaneous foreign body granulomas provoked by sheep wool. A 45-years old woman presented within one year two episodes of a papular eruption on her neck and limbs. She was working as a farmer's wife and each episode occurred after preparing the ewes for coupling. She had to keep a tight hold on the ewes while the farmer introduced warm and moist compresses in the genitals of the animals. Each diseased skin area was closely related to the tight contact with the sheep's wool and on histological slides each granuloma was centered by a tiny ply of wool. This foreign body reaction may be compared to the trichogranulomas of hairdressers. In sheep breeders this occupational practice is very usual and one may wonder why this type of reaction seems so rare.

  20. Impact of virus strain characteristics on early detection of highly pathogenic avian influenza infection in commercial table-egg layer flocks and implications for outbreak control.

    Science.gov (United States)

    Weaver, J Todd; Malladi, Sasidhar; Goldsmith, Timothy J; Hueston, Will; Hennessey, Morgan; Lee, Brendan; Voss, Shauna; Funk, Janel; Der, Christina; Bjork, Kathe E; Clouse, Timothy L; Halvorson, David A

    2012-12-01

    Early detection of highly pathogenic avian influenza (HPAI) infection in commercial poultry flocks is a critical component of outbreak control. Reducing the time to detect HPAI infection can reduce the risk of disease transmission to other flocks. The timeliness of different types of detection triggers could be dependent on clinical signs that are first observed in a flock, signs that might vary due to HPAI virus strain characteristics. We developed a stochastic disease transmission model to evaluate how transmission characteristics of various HPAI strains might effect the relative importance of increased mortality, drop in egg production, or daily real-time reverse transcriptase (RRT)-PCR testing, toward detecting HPAI infection in a commercial table-egg layer flock. On average, daily RRT-PCR testing resulted in the shortest time to detection (from 3.5 to 6.1 days) depending on the HPAI virus strain and was less variable over a range of transmission parameters compared with other triggers evaluated. Our results indicate that a trigger to detect a drop in egg production would be useful for HPAI virus strains with long infectious periods (6-8 days) and including an egg-drop detection trigger in emergency response plans would lead to earlier and consistent reporting in some cases. We discuss implications for outbreak control and risk of HPAI spread attributed to different HPAI strain characteristics where an increase in mortality or a drop in egg production or both would be among the first clinical signs observed in an infected flock.

  1. Quantifying Transmission of Campylobacter jejuni in Commercial Broiler Flocks

    NARCIS (Netherlands)

    Gerwe, van T.; Miflin, J.K.; Templeton, J.M.; Bouma, A.; Wagenaar, J.A.; Jacobs-Reitsma, W.F.; Stegeman, A.; Klinkenberg, D.

    2009-01-01

    Since meat from poultry colonized with Campylobacter spp. is a major cause of bacterial gastroenteritis, human exposure should be reduced by, among other things, prevention of colonization of broiler flocks. To obtain more insight into possible sources of introduction of Campylobacter into broiler f

  2. Two-level leader-follower organization in pigeon flocks

    Science.gov (United States)

    Chen, Zhiyong; Zhang, Hai-Tao; Chen, Xi; Chen, Duxin; Zhou, Tao

    2015-10-01

    The most attractive trait of collective animal behavior is the emergence of highly ordered structures (Cavagna A., Giardina I. and Ginelli F., Phys. Rev. Lett., 110 (2013) 168107). It has been conjectured that the interaction mechanism in pigeon flock dynamics follows a hierarchical leader-follower influential network (Nagy M., Ákos Z., Biro D. and Vicsek T., Nature, 464 (2010) 890). In this paper, a new observation is reported that shows that pigeon flocks actually adopt a much simpler two-level interactive network composed of one leader and some followers. By statistically analyzing the same experimental dataset, we show that for a certain period of time a sole leader determines the motion of the flock while the remaining birds are all followers directly copying the leader's direction with specific time delays. This simple two-level despotic organization is expected to save both motional energy and communication cost, while retaining agility and robustness of the whole group. From an evolutionary perspective, our results suggest that a two-level organization of group flight may be more efficient than a multilevel topology for small pigeon flocks.

  3. Speed Determines Leadership and Leadership Determines Learning during Pigeon Flocking.

    Science.gov (United States)

    Pettit, Benjamin; Ákos, Zsuzsa; Vicsek, Tamás; Biro, Dora

    2015-12-01

    A key question in collective behavior is how individual differences structure animal groups, affect the flow of information, and give some group members greater weight in decisions. Depending on what factors contribute to leadership, despotic decisions could either improve decision accuracy or interfere with swarm intelligence. The mechanisms behind leadership are therefore important for understanding its functional significance. In this study, we compared pigeons' relative influence over flock direction to their solo flight characteristics. A pigeon's degree of leadership was predicted by its ground speeds from earlier solo flights, but not by the straightness of its previous solo route. By testing the birds individually after a series of flock flights, we found that leaders had learned straighter homing routes than followers, as we would expect if followers attended less to the landscape and more to conspecifics. We repeated the experiment from three homing sites using multiple independent flocks and found individual consistency in leadership and speed. Our results suggest that the leadership hierarchies observed in previous studies could arise from differences in the birds' typical speeds. Rather than reflecting social preferences that optimize group decisions, leadership may be an inevitable consequence of heterogeneous flight characteristics within self-organized flocks. We also found that leaders learn faster and become better navigators, even if leadership is not initially due to navigational ability. The roles that individuals fall into during collective motion might therefore have far-reaching effects on how they learn about the environment and use social information.

  4. Three phenotypes of glucosephosphate isomerase in sheep: improved staining recipe.

    Science.gov (United States)

    Manwell, C; Baker, C M; Graydon, R J

    1985-01-01

    Contrary to results published recently, we observe three, rather than two, phenotypes for the enzyme glucosephosphate isomerase (EC 5.3.1.9) from sheep. The phenotypic electrophoretic patterns conform to the patterns observed for this dimeric enzyme in other species. Genotype frequencies in a flock of Southdowns do not deviate significantly from those predicted under the assumption of the Hardy-Weinberg equilibrium. A remarkable observation is that the electrophoretically distinct phenotypes of GPI are largely or entirely obliterated by the addition of 1-10 mmol/l MgCl2 to the electrophoretic buffers. Modification of the usual staining recipe for GPI result in greater resolution and shorter staining times.

  5. PrP(Sc) detection and infectivity in semen from scrapie-infected sheep.

    Science.gov (United States)

    Rubenstein, Richard; Bulgin, Marie S; Chang, Binggong; Sorensen-Melson, Sharon; Petersen, Robert B; LaFauci, Giuseppe

    2012-06-01

    A scrapie-positive ewe was found in a flock that had been scrapie-free for 13 years, but housed adjacent to scrapie-positive animals, separated by a wire fence. Live animal testing of the entire flock of 24 animals revealed seven more subclinical scrapie-positive ewes. We hypothesized that they may have contracted the disease from scrapie-positive rams used for breeding 4 months prior, possibly through the semen. The genotypes of the ewe flock were highly scrapie-susceptible and the rams were infected with the 'Caine' scrapie strain having a short incubation time of 4.3-14.6 months in sheep with 136/171 VQ/VQ and AQ/VQ genotypes. PrP(Sc) accumulates in a variety of tissues in addition to the central nervous system. Although transmission of prion diseases, or transmissible spongiform encephalopathies, has been achieved via peripheral organ or tissue homogenates as well as by blood transfusion, neither infectivity nor PrP(Sc) have been found in semen from scrapie-infected animals. Using serial protein misfolding cyclic amplification followed by a surround optical fibre immunoassay, we demonstrate that semen from rams infected with a short-incubation-time scrapie strain contains prion disease-associated-seeding activity that generated PrP(Sc) in sPMCA (serial protein misfolding cyclic amplification). Injection of the ovinized transgenic mouse line TgSShpPrP with semen from scrapie-infected sheep resulted in PrP(Sc)-seeding activity in clinical and, probably as a result of the low titre, non-clinical mouse brain. These results suggest that the transmissible agent, or at least the seeding activity, for sheep scrapie is present in semen. This may be a strain-specific phenomenon.

  6. A Labratory Survey on Drug Resistance in Gastrointestinal Nematodes of Sheep in Iran

    Directory of Open Access Journals (Sweden)

    A Gholamian

    2007-06-01

    Full Text Available Background: Broad spectrum anthelmintics had been used for about 50 years to control internal parasites of human and animals. Methods: In this survey, resistance in gastrointestinal nematode of sheep to levamisole and albendazole were investigated in 15 sheep flocks. On each flock, faecal samples were taken from 20 randomly selected sheep. Nematode eggs were separated from the samples and placed in microplate for 24 hours at 25 °C to hatch and then Nutritive media, Escherichia coli and different concentrations of levamisole or albendazole were added to first stage larvae and incubated at 25 °C for 6 more days. LD50 of these drugs in each flock were calculated according to precent of larval development parameter in different concentration of levamisole or albendazole (Hubert and Kerboeuf, 1992. Results: LD50 of levamisole were varied between 0.021 to 0.27 μg /ml and LD50 of albendazole between 0.021 to 0.13 μg/ml. In negative control samples with no anthelmintic average larval development was 65% and third stage larvae were mostly composed of Ostertagia (59%, Trichostrongylus (20% and Haemonchus (21% but in positive contol samples with the highest concentration of levamisole Ostertagia spp and Trichostrongylus spp and albendazole Ostertagia spp were detected. Conclusion: Therefore we can conclude that resistance have been developed in some isolates of Ostertagia spp and Trichostrongylus spp to levamisole and to in some isolates of Ostertagia spp to benzimidazoles that can be alarming for treatment of trichotrongylus in people.

  7. Epidemic pasteurellosis in a bighorn sheep population coinciding with the appearance of a domestic sheep.

    Science.gov (United States)

    George, Janet L; Martin, Daniel J; Lukacs, Paul M; Miller, Michael W

    2008-04-01

    A pneumonia epidemic reduced bighorn sheep (Ovis canadensis) survival and recruitment during 1997-2000 in a population comprised of three interconnected wintering herds (Kenosha Mountains, Sugarloaf Mountain, Twin Eagles) that inhabited the Kenosha and Tarryall Mountain ranges in central Colorado, USA. The onset of this epidemic coincided temporally and spatially with the appearance of a single domestic sheep (Ovis aires) on the Sugarloaf Mountain herd's winter range in December 1997. Although only bighorns in the Sugarloaf Mountain herd were affected in 1997-98, cases also occurred during 1998-99 in the other two wintering herds, likely after the epidemic spread via established seasonal movements of male bighorns. In all, we located 86 bighorn carcasses during 1997-2000. Three species of Pasteurella were isolated in various combinations from affected lung tissues from 20 bighorn carcasses where tissues were available and suitable for diagnostic evaluation; with one exception, beta-hemolytic mannheimia (Pasteurella) haemolytica (primarily reported as biogroup 1(G) or 1(alphaG)) was isolated from lung tissues of cases evaluated during winter 1997-98. The epidemic dramatically lowered adult bighorn monthly survival in all three herds; a model that included an acute epidemic effect, differing between sexes and with vaccination status, that diminished linearly over the next 12 mo best represented field data. In addition to the direct mortality associated with epidemics in these three herds, lamb recruitment in years following the pneumonia epidemic also was depressed as compared to years prior to the epidemic. Based on observations presented here, pasteurellosis epidemics in free-ranging bighorn sheep can arise through incursion of domestic sheep onto native ranges, and thus minimizing contact between domestic and bighorn sheep appears to be a logical principle for bighorn sheep conservation.

  8. Reduced lentivirus susceptibility in sheep with TMEM154 mutations.

    Science.gov (United States)

    Heaton, Michael P; Clawson, Michael L; Chitko-Mckown, Carol G; Leymaster, Kreg A; Smith, Timothy P L; Harhay, Gregory P; White, Stephen N; Herrmann-Hoesing, Lynn M; Mousel, Michelle R; Lewis, Gregory S; Kalbfleisch, Theodore S; Keen, James E; Laegreid, William W

    2012-01-01

    Visna/Maedi, or ovine progressive pneumonia (OPP) as it is known in the United States, is an incurable slow-acting disease of sheep caused by persistent lentivirus infection. This disease affects multiple tissues, including those of the respiratory and central nervous systems. Our aim was to identify ovine genetic risk factors for lentivirus infection. Sixty-nine matched pairs of infected cases and uninfected controls were identified among 736 naturally exposed sheep older than five years of age. These pairs were used in a genome-wide association study with 50,614 markers. A single SNP was identified in the ovine transmembrane protein (TMEM154) that exceeded genome-wide significance (unadjusted p-value 3×10(-9)). Sanger sequencing of the ovine TMEM154 coding region identified six missense and two frameshift deletion mutations in the predicted signal peptide and extracellular domain. Two TMEM154 haplotypes encoding glutamate (E) at position 35 were associated with infection while a third haplotype with lysine (K) at position 35 was not. Haplotypes encoding full-length E35 isoforms were analyzed together as genetic risk factors in a multi-breed, matched case-control design, with 61 pairs of 4-year-old ewes. The odds of infection for ewes with one copy of a full-length TMEM154 E35 allele were 28 times greater than the odds for those without (p-valuesheep from Nebraska, Idaho, and Iowa, the relative risk of infection was 2.85 times greater for sheep with a full-length TMEM154 E35 allele (p-valuesheep were homozygous for TMEM154 deletion mutations and remained uninfected despite a lifetime of significant exposure. Together, these findings indicate that TMEM154 may play a central role in ovine lentivirus infection and removing sheep with the most susceptible genotypes may help eradicate OPP and protect flocks from reinfection.

  9. PREVALENCE OF MASTITIS PATHOGENS AND THEIR RESISTANCE AGAINST ANTIMICROBIAL AGENTS IN AWASSI SHEEP IN AL-BALQA PROVINCE OF JORDAN

    Directory of Open Access Journals (Sweden)

    Azmi D. Hawari

    2014-01-01

    Full Text Available The primary objective of this study was to establish data on mastitis in Awassi Sheep in Al-Balqa Province of Jordan. Milk samples were collected from 260 lactating ewes that selected randomly from eight flocks. California Mastitis Test (CMT gave result with 220 milk samples; 122 samples (55.5% showed positive CMT. Infection with some bacterial species was associated with positive CMT. About 26% of the ewes revealed clinical signs of mastitis. The highest percentage of bacterial count, which range from 3×102 to <3.0 103 cfu mL-1 was founded in the milk samples. The most predominant bacteria isolated were Staphylococcus aureus, Streptococcus agalactiae, Streptococcus spp., Escherichia coli, Corynebacterium spp. and Coagulase negative Staphylococci. Sensitivity tests were applied to different isolated strains., Gentamycim, Ampicillin and Tetracycline were the most effective antimicrobial agents against the bacterial isolates.

  10. Chronic proliferative rhinitis associated with Salmonella enterica subspecies diarizonae serovar 61:k:1, 5, (7) in sheep in Spain.

    Science.gov (United States)

    Lacasta, D; Ferrer, L M; Ramos, J J; Bueso, J P; Borobia, M; Ruiz de Arcaute, M; Figueras, L; González-Sainz, J M; De Las Heras, M

    2012-11-01

    A chronic proliferative rhinitis in sheep associated with Salmonella enterica subspecies diarizonae serovar 61:k:1, 5, (7) is described. Ten adult sheep from eight traditionally managed Rasa Aragonesa flocks located in Aragon (Spain) were studied. Clinical signs began with bilateral thick mucus nasal discharge, wheezing and snoring and progressed to partial or complete obstruction of the nostrils. Necropsy examination revealed swollen ventral nasal turbinates with a roughened mucosal surface partially covered by small polyps. Histopathology revealed chronic proliferative rhinitis with a predominant population of neutrophils that infiltrated the mucosal epithelium. Plasma cells and macrophages were present in the lamina propria. Organisms expressing Salmonella antigen immunohistochemically were detected within epithelial cells. Salmonella enterica subspecies diarizonae serovar 61:k:1, 5, (7) was isolated as a sole microorganism from nasal swabs taken from five animals. The implication of finding this bacterium in various diseases in sheep and its role as a potential zoonosis are discussed.

  11. Herd risk factors associated with sero-prevalence of Maedi-Visna in the Manitoba sheep population.

    Science.gov (United States)

    Shuaib, Muhammad; Green, Chris; Rashid, Mamoon; Duizer, Glen; Whiting, Terry L

    2010-04-01

    Disease associated with Maedi-Visna infection results in substantial economic losses in affected sheep producing areas of the world. A survey was conducted to estimate herd and individual seroprevalence in the province of Manitoba and evaluate risk factors for seropositive herds. Of 2207 sheep sampled from 77 selected sheep flocks, the animal level seroprevalence was 2.47% and herd level seroprevalence was 25.10%. The herd-level factors of presence of clinical skin disease, herd size of > 70, history of musculoskeletal/lameness abnormalities, and the purchase of new stock (> 50) in the last 1 to 5 y, showed significant associations with seropositive herd status. The study documented a remarkable stability of low seroprevalence in the province over a 20-year period in the absence of a systematic disease control program.

  12. Organic Turkey Flocks: A Reservoir of Streptococcus gallolyticus subspecies gallolyticus.

    Directory of Open Access Journals (Sweden)

    Jochen Schulz

    Full Text Available Streptococcus gallolyticus subspecies gallolyticus (S. gallolyticus can colonise the gastrointestinal tract of humans and animals and is known to cause similar infections in both humans and animals. Data about the spread or prevalence in farm animals are missing. In this study, Trypton Soya Agar was modified to a selective medium enabling the isolation and quantification of S. gallolyticus from faecal samples. The bacterium was observed in 82 out of 91 faecal samples obtained from 18 different organic turkey flocks. The prevalence of shedding birds was estimated by the number of positive fresh droppings and reached up to 100% on most farms. Furthermore, for the first time S. gallolyticus was quantified in faeces from poultry flocks. The median of colony forming units (CFU per gramme faeces was 3.6 x 10(5 CFU/g. Typing of one isolate from each positive faecal sample by multilocus sequence typing delivered 24 sequence types (STs. Most of the isolates belonged to the clonal complex CC58. The same STs of this complex were detected in up to six different flocks. Partly, these flocks were located in various regions and stocked with varying breeding lines. Regarding the biochemical profiles of the same STs from different farms, the results did not contradict a spread of specific STs in the organic turkey production. Moreover, checking the pubMLST database revealed that STs found in this study were also found in other animal species and in humans. The high detection rate and the number of S. gallolyticus in turkey faeces indicate that this bacterium probably belongs to the common microbiota of the gastrointestinal tract of turkeys from organic flocks. Furthermore, the findings of this study support the suggestion of a possible interspecies transmission.

  13. Cyclic and Coherent States in Flocks with Topological Distance

    Directory of Open Access Journals (Sweden)

    Biplab eBhattacherjee

    2014-01-01

    Full Text Available A simple model of the two dimensional collective motion of a group of mobile agents have been studied. Like birds, these agents travel in open free space where each of them interacts with the first $n$ neighbors determined by the topological distance with a free boundary condition. Using the same prescription for interactions used in the Vicsek model with scalar noise it has been observed that the flock, in absence of the noise, arrives at a number of interesting stationary states. One of the two most prominent states is the `single sink state' where the entire flock travels along the same direction maintaining perfect cohesion and coherence. The other state is the `cyclic state' where every individual agent executes a uniform circular motion, and the correlation among the agents guarantees that the entire flock executes a pulsating dynamics i.e., expands and contracts periodically between a minimum and a maximum size of the flock. We have studied another limiting situation when refreshing rate of the interaction zone is the fastest. In this case the entire flock gets fragmented into smaller clusters of different sizes. On introduction of scalar noise a crossover is observed when the agents cross over from a ballistic motion to a diffusive motion. Expectedly the crossover time is dependent on the strength of the noise $eta$ and diverges as $eta to 0$. An even more simpler version of this model has been studied by suppressing the translational degrees of freedom of the agents but retaining their angular motion. Here agents are the spins, placed at the sites of a square lattice with periodic boundary condition. Every spin interacts with its $n$ = 2, 3 or 4 nearest neighbors. In the stationary state the entire spin pattern moves as a whole when interactions are anisotropic with $n$ = 2 and 3; but it is completely frozen when the interaction is isotropic with $n=4$. These spin configu

  14. Prion protein gene frequencies in three Sicilian dairy sheep populations

    Directory of Open Access Journals (Sweden)

    Santo Caracappa

    2010-01-01

    Full Text Available The objective of this paper was to investigate the prion protein (PrP genotype and haplotype frequencies in three Sicilian dairy sheep populations. The three populations were: (1 1096 Valle del Belice animals, (2 1143 Comisana animals, and (3 1771 individuals from 5 flocks with scrapie outbreaks, in which the animals were crossbreds derived from indigenous Sicilian dairy breeds. PrP genotypes are described for the three codons 136 (Alanine or Valine; A, V, 154 (Histidine or Arginine; H, R, and 171 (Glutamine, Arginine or Histidine; Q, R, H which represent polymorphisms known to be linked with scrapie susceptibility. The Valle del Belice haplotype frequencies were 32.3% ARR, 6.5% AHQ, 1.0% ARH, 58.8% ARQ, and 1.4% VRQ. The Comisana frequencies were 39.4% ARR, 2.9% AHQ, 2.9% ARH, 50.9% ARQ, and 3.9% VRQ. In the flocks with scrapie outbreaks the frequencies were 32.8% ARR, 2.4% AHQ, 1.7% ARH, 59.1% ARQ, and 3.9% VRQ. In all three populations ARQ and ARR were the most frequent haplotypes. Multiple generations of strong selection will be needed to fixate the most resistant ARR haplotype.

  15. Effects of stocking density, flock size and management on the welfare of laying hens in single-tier aviaries.

    Science.gov (United States)

    Nicol, C J; Brown, S N; Glen, E; Pope, S J; Short, F J; Warriss, P D; Zimmerman, P H; Wilkins, L J

    2006-04-01

    Management practices, stocking rate and flock size may affect laying hen welfare but there have been few replicated studies in commercial non-cage systems that investigate this. This study used a broad range of physical and physiological indicators to assess the welfare of hens in 36 commercial flocks. Six laying period treatments were examined with each treatment replicated 6 times. It was not possible to randomly allocate treatments to houses, so treatment and house were largely confounded. Three stocking rates were compared: 7 birds/m(2) (n = 2450), 9 birds/m(2) (n = 3150) and 12 birds/m(2) in either small (n = 2450) or large (n = 4200) flocks. In addition, at 12 birds/m(2), in both small and large flocks, birds were subjected to either standard (SM) or modified (MM) management. MM flocks had nipple drinkers and no nest-box lights. Bone strength, fracture incidence, heterophil:lymphocyte (H:L) ratio, live weight, organ weights, serum creatine, serum osmolality, muscle pH and faecal corticosterone were measured on samples of birds at the end of the rearing period and at the end of lay. During the laying period, mortality, production and integument condition were recorded at regular intervals. Birds housed at 9 birds/m(2) had higher mortality than birds housed at 12 birds/m(2) by the end of lay, but not higher than birds housed at 7 birds/m(2). Birds housed at 7 and 9 birds/m(2) had lower percent liver weight, and worse plumage condition than most of the 12 bird/m(2) treatments. Modified management tended to improve plumage condition. There were no clear effects of flock size on the welfare indicators recorded. At the end of the rearing period fracture incidence was almost negligible and H:L ratio was within a normal range. By the end of lay fracture incidence was 60% and H:L ratio was high, with no treatment effect for either measure. This, together with information on faecal corticosterone, feather loss and mortality, suggests that the welfare of birds in all

  16. Polymorphism of the PrP prion protein gene in Polish Merino and old-type Polish Merino from Brylewo flock

    Directory of Open Access Journals (Sweden)

    Niżnikowski Roman

    2015-06-01

    Full Text Available The study was conducted on Polish Merino (143♀ and 39♂ and old-type Polish Merino sheep (176♀ and 61♂ in Brylewo flock (Wielkopolskie Province. The examined sheep were at the age of one year. Prion protein (PrP genotype was determined in all animals. In both breeds four alleles (ARR, ARQ, AHQ, VRQ were found. Highly significant effect of breed and insignificant impact of gender within breed was observed in regard to the frequency of occurrence of alleles and genotypes susceptible to classical scrapie in the sheep. Eight different PrP genotypes in Polish Merino and nine genotypes in old-type Polish Merino were identified. Very high frequency of ARR/ARR genotype in old-type Polish Merino and high frequency of ARR/ARQ genotype in Polish Merino were found, with relatively significant frequency of occurrence of the genotypes containing VRQ allele. In old-type Polish Merino, three animals (of both genders had VRQ/VRQ genotype. Breeding work involving elimination of animals encoding valine at codon 136, and introduction of rams with ARR allele to the population increased the frequency of occurrence of ARR/ARR genotype and ARR allele in the population of old-type Polish Merino. To improve the distribution of the genotypes genetically resistant to scrapie in the flock of Polish Merino only rams with ARR/ARR genotype were left. This guarantees an increase in the frequency of occurrence of genotypes genetically resistant to scrapie in the offspring.

  17. Erysipelothrix rhusiopathiae contamination in the poultry house environment during erysipelas outbreaks in organic laying hen flocks.

    Science.gov (United States)

    Eriksson, Helena; Bagge, Elisabeth; Båverud, Viveca; Fellström, Claes; Jansson, Désirée S

    2014-01-01

    This study investigated organic laying hen farms for the presence of Erysipelothrix rhusiopathiae in the house environment and from potential carriers (i.e. insects and mice) during ongoing erysipelas outbreaks, and compared the obtained isolates with those from laying hens. The samples were investigated by selective culture followed by species-specific polymerase chain reaction on cultures. E. rhusiopathiae was isolated from the spleen, jejunal contents, manure, dust and swabs from water nipples. Three more samples from the house environment tested positive by polymerase chain reaction compared with selective culture alone. Selected isolates were investigated by pulsed-field gel electrophoresis (PFGE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). One farm was represented by isolates from laying hens only, and one of these isolates differed in one PFGE band from the others. Different banding patterns were observed for isolates from laying hens and manure on one farm. On the remaining two farms, the isolates from the house environment and laying hens were identical but differed between farms. Outbreaks reoccurred in the next flock on two of the farms, and different PFGE types were isolated from consecutive flocks. Our results suggest an external source of infection, which would explain the previously reported increased risk of outbreaks in free-range flocks. Contaminated manure and dust may represent sources of transmission. For the isolates, MALDI-TOF MS and biochemical typing results were in agreement but, since the type strain of Erysipelothrix tonsillarum was typed as E. rhusiopathiae using MALDI-TOF MS, further studies into this method are needed.

  18. The dynamics of Salmonella occurrence in commercial laying hen flocks throughout a laying period

    DEFF Research Database (Denmark)

    Schulz, J.; Van Hoorebeke, S.; Hald, Birthe

    2011-01-01

    of a laying period. The total of 41 laying hen flocks*18 in Belgium, six in Denmark and 17 in Germany*were followed during an entire laying period. Samples taken from the empty cleaned and disinfected poultry houses were all negative for Salmonella. After hens arrived on the farms, five pooled faecal samples......, one pooled dust sample and 40 cloacal swabs (Belgium and Germany) or 40 swabs from fresh droppings (Denmark) were taken four times from 18 flocks, three times from 21 flocks and two times from two flocks in the course of the laying period. Ten flocks (two Belgian and eight German flocks) tested up...... to three times positive for Salmonella. Forty-three out of 50 positive samples contained Salmonella Enteritidis phage type 4 (29 isolates) or phage type 8 (14 isolates). The probability of subsequent Salmonella-positive findings increased significantly in Salmonella-positive flocks (PB0.05, odds ratio6...

  19. Surveillance of Campylobacter ssp. in broiler flocks by PCR on boot sock samples

    DEFF Research Database (Denmark)

    Nordentoft, Steen; Lund, Marianne; Hald, Birthe

    Detection of Campylobacter in feces is traditionally based on microbiological culture from caecum or cloacal swabs at the abattoir, but due to long time for analysis no intervention can be taken. By knowing the status of the flock before it reaches the abattoir, logistic slaughter becomes possible......, i. e. to allocate negative flocks before positive to slaughter, as well as channeling negative flocks to the fresh market and use positive flocks for freeze or marinated products. To know the status of the broiler flock before arriving at the abattoir, a Campylobacter surveillance system based...... before DNA purification, corresponding to 103 / gram feces. To evaluate the capability of the sock sample to predict the flock status at slaughter the same flocks were also tested at slaughter by pooling 10 cloacal swabs and analysed using the same PCR method. The accordance of the two sampling method...

  20. Large-Scale Patterns in a Minimal Cognitive Flocking Model: Incidental Leaders, Nematic Patterns, and Aggregates

    Science.gov (United States)

    Barberis, Lucas; Peruani, Fernando

    2016-12-01

    We study a minimal cognitive flocking model, which assumes that the moving entities navigate using the available instantaneous visual information exclusively. The model consists of active particles, with no memory, that interact by a short-ranged, position-based, attractive force, which acts inside a vision cone (VC), and lack velocity-velocity alignment. We show that this active system can exhibit—due to the VC that breaks Newton's third law—various complex, large-scale, self-organized patterns. Depending on parameter values, we observe the emergence of aggregates or millinglike patterns, the formation of moving—locally polar—files with particles at the front of these structures acting as effective leaders, and the self-organization of particles into macroscopic nematic structures leading to long-ranged nematic order. Combining simulations and nonlinear field equations, we show that position-based active models, as the one analyzed here, represent a new class of active systems fundamentally different from other active systems, including velocity-alignment-based flocking systems. The reported results are of prime importance in the study, interpretation, and modeling of collective motion patterns in living and nonliving active systems.

  1. Genetic Testing for TMEM154 Mutations Associated with Lentivirus Susceptibility in Sheep

    Science.gov (United States)

    Petrik, Dustin T.; Simpson, Barry; Kijas, James W.; Clawson, Michael L.; Chitko-McKown, Carol G.; Harhay, Gregory P.; Leymaster, Kreg A.

    2013-01-01

    In sheep, small ruminant lentiviruses cause an incurable, progressive, lymphoproliferative disease that affects millions of animals worldwide. Known as ovine progressive pneumonia virus (OPPV) in the U.S., and Visna/Maedi virus (VMV) elsewhere, these viruses reduce an animal’s health, productivity, and lifespan. Genetic variation in the ovine transmembrane protein 154 gene (TMEM154) has been previously associated with OPPV infection in U.S. sheep. Sheep with the ancestral TMEM154 haplotype encoding glutamate (E) at position 35, and either form of an N70I variant, were highly-susceptible compared to sheep homozygous for the K35 missense mutation. Our current overall aim was to characterize TMEM154 in sheep from around the world to develop an efficient genetic test for reduced susceptibility. The average frequency of TMEM154 E35 among 74 breeds was 0.51 and indicated that highly-susceptible alleles were present in most breeds around the world. Analysis of whole genome sequences from an international panel of 75 sheep revealed more than 1,300 previously unreported polymorphisms in a 62 kb region containing TMEM154 and confirmed that the most susceptible haplotypes were distributed worldwide. Novel missense mutations were discovered in the signal peptide (A13V) and the extracellular domains (E31Q, I74F, and I102T) of TMEM154. A matrix-assisted laser desorption/ionization–time-of flight mass spectrometry (MALDI-TOF MS) assay was developed to detect these and six previously reported missense and two deletion mutations in TMEM154. In blinded trials, the call rate for the eight most common coding polymorphisms was 99.4% for 499 sheep tested and 96.0% of the animals were assigned paired TMEM154 haplotypes (i.e., diplotypes). The widespread distribution of highly-susceptible TMEM154 alleles suggests that genetic testing and selection may improve the health and productivity of infected flocks. PMID:23408992

  2. Genetic testing for TMEM154 mutations associated with lentivirus susceptibility in sheep.

    Directory of Open Access Journals (Sweden)

    Michael P Heaton

    Full Text Available In sheep, small ruminant lentiviruses cause an incurable, progressive, lymphoproliferative disease that affects millions of animals worldwide. Known as ovine progressive pneumonia virus (OPPV in the U.S., and Visna/Maedi virus (VMV elsewhere, these viruses reduce an animal's health, productivity, and lifespan. Genetic variation in the ovine transmembrane protein 154 gene (TMEM154 has been previously associated with OPPV infection in U.S. sheep. Sheep with the ancestral TMEM154 haplotype encoding glutamate (E at position 35, and either form of an N70I variant, were highly-susceptible compared to sheep homozygous for the K35 missense mutation. Our current overall aim was to characterize TMEM154 in sheep from around the world to develop an efficient genetic test for reduced susceptibility. The average frequency of TMEM154 E35 among 74 breeds was 0.51 and indicated that highly-susceptible alleles were present in most breeds around the world. Analysis of whole genome sequences from an international panel of 75 sheep revealed more than 1,300 previously unreported polymorphisms in a 62 kb region containing TMEM154 and confirmed that the most susceptible haplotypes were distributed worldwide. Novel missense mutations were discovered in the signal peptide (A13V and the extracellular domains (E31Q, I74F, and I102T of TMEM154. A matrix-assisted laser desorption/ionization-time-of flight mass spectrometry (MALDI-TOF MS assay was developed to detect these and six previously reported missense and two deletion mutations in TMEM154. In blinded trials, the call rate for the eight most common coding polymorphisms was 99.4% for 499 sheep tested and 96.0% of the animals were assigned paired TMEM154 haplotypes (i.e., diplotypes. The widespread distribution of highly-susceptible TMEM154 alleles suggests that genetic testing and selection may improve the health and productivity of infected flocks.

  3. Scrapie diagnosis in a goat and four Santa Inês sheep from the same herd in Brazil

    Directory of Open Access Journals (Sweden)

    J.S. Leal

    2015-12-01

    Full Text Available Scrapie is a fatal and progressive transmissible spongiform encephalopathy (TSE of natural occurrence in sheep and goats. The suspicion of scrapie may be based on clinical signs; however, the detection of pathological features of the prionic protein (PrP in target tissues is necessary to diagnose the disease. The presence of an abnormal protein form (PrPSc in lymphoreticular and nervous tissues is an important characteristic in diagnosis. This paper reports a case of scrapie in a flock of 55 Suffolk crossbred sheep, 19 Santa Inês sheep and 21 goats in the Mato Grosso state, midwestern Brazil. The animals were euthanized after the confirmation of a scrapie case with clinical signs in a Suffolk sheep in the same farm. Samples of brainstem at the level of the obex and lymphoid issues like palatine tonsils, mesenteric lymph nodes, third eyelid fixed in formalin 10% were processed for histological examination. Histological examination with hematoxylin and eosin did not show any microscopic changes in samples. Immunohistochemistry (IHC examination to detect anti-prion PrPSc was performed in lymphoid tissues. Scrapie diagnosis was confirmed based on IHC positive results for PrPSc in lymphoid tissues of a crossbreed goat and four Santa Inês sheep, without any clinical scrapie signs. IHC showed positive staining in at least three lymphoid germinal centers in goat mesenteric lymph node, palatine tonsil, and third eyelid samples. The mesenteric lymph node, and tonsil samples of all sheep showed positive immunostaining, and only one sheep showed positive staining in lymphoid follicles in the third eyelid. Scrapie diagnosis using IHC in fixed samples of lymphoreticular tissue is technically feasible to detect the disease in both goats and sheep, as a form of pre-clinical diagnosis. The results indicate that the herd was infected by a sheep coming from another herd where scrapie had been diagnosed before.

  4. Reduced lentivirus susceptibility in sheep with TMEM154 mutations.

    Directory of Open Access Journals (Sweden)

    Michael P Heaton

    2012-01-01

    Full Text Available Visna/Maedi, or ovine progressive pneumonia (OPP as it is known in the United States, is an incurable slow-acting disease of sheep caused by persistent lentivirus infection. This disease affects multiple tissues, including those of the respiratory and central nervous systems. Our aim was to identify ovine genetic risk factors for lentivirus infection. Sixty-nine matched pairs of infected cases and uninfected controls were identified among 736 naturally exposed sheep older than five years of age. These pairs were used in a genome-wide association study with 50,614 markers. A single SNP was identified in the ovine transmembrane protein (TMEM154 that exceeded genome-wide significance (unadjusted p-value 3×10(-9. Sanger sequencing of the ovine TMEM154 coding region identified six missense and two frameshift deletion mutations in the predicted signal peptide and extracellular domain. Two TMEM154 haplotypes encoding glutamate (E at position 35 were associated with infection while a third haplotype with lysine (K at position 35 was not. Haplotypes encoding full-length E35 isoforms were analyzed together as genetic risk factors in a multi-breed, matched case-control design, with 61 pairs of 4-year-old ewes. The odds of infection for ewes with one copy of a full-length TMEM154 E35 allele were 28 times greater than the odds for those without (p-value<0.0001, 95% CI 5-1,100. In a combined analysis of nine cohorts with 2,705 sheep from Nebraska, Idaho, and Iowa, the relative risk of infection was 2.85 times greater for sheep with a full-length TMEM154 E35 allele (p-value<0.0001, 95% CI 2.36-3.43. Although rare, some sheep were homozygous for TMEM154 deletion mutations and remained uninfected despite a lifetime of significant exposure. Together, these findings indicate that TMEM154 may play a central role in ovine lentivirus infection and removing sheep with the most susceptible genotypes may help eradicate OPP and protect flocks from reinfection.

  5. Genetic differentiation and gene flow among six sheep breeds of Mongolian group in China

    Institute of Scientific and Technical Information of China (English)

    Yan GENG; Zhangping YANG; Hong CHANG; Yongjiang MAO; Wei SUN; Xiaoya GUO; Dongyan QU

    2008-01-01

    The level of genetic differentiation,gene flow and the relationship between geographical distance and genetic differentiation among six sheep populations of Mongolian group in China (Tong sheep,small-tailed Han sheep,Hu sheep,Tan sheep,Ujumuqin sheep and Bayinbuluk sheep) were analyzed using seven microsatellites.The trees were constructed from diversity coefficient (DC) distances among the six sheep populations.The overall heterozygote deficit across all the populations (Fit) was between 0.167 (OarAE101) and 0.044 (MAF33).The overall significant deficit of heterozygote,because of inbreeding within breeds,(Fis) was between 0.089 (OarFCB304) and 0.005 (MAF33).The coefficient of genetic differentiation (Fst) was between 0.100 (OarAE101) and 0.022 (Oar-FCB48).It indicated that 3.9% of the total genetic variation could be explained by breed differences and the remaining 96.1% by differences among individuals for each population.This illustrated that most variations existed within breeds and genetic differentiation level were very low among sheep breeds of the Mongolian Group in China.The average number of effective migrants exchanged per generation (Nem) ranged from 2.7369 (Tan sheep and Bayinbuluk sheep) to 44.3928 (Tong sheep and Hu sheep),and the mean value was 11.25213.Significantly positive relationships between the level of genetic differentiation and geographical distance and genetic distances were detected.It is concluded that genetic differentiation of sheep breeds of Mongolian group in China is mainly the result of natural selection (different living conditions).

  6. Evaluating and improving terminal hygiene practices on broiler farms to prevent Campylobacter cross-contamination between flocks.

    Science.gov (United States)

    Battersby, Tara; Walsh, D; Whyte, P; Bolton, D

    2017-06-01

    The objectives of this study were to evaluate current cleaning practices in broiler houses by testing a range of sites after cleaning and disinfection and to test the efficacy of the most commonly used methods in a commercial broiler house after flock harvesting. Cleaning procedures on 20 broiler houses (10 separate farms) were examined by testing a range of sampling points (feeders, drinkers, walls, etc.) for total viable count (TVC), total Enterobacteriaceae count (TEC) and Campylobacter spp. after cleaning and disinfection, using culture based methods. In a second experiment, the six most commonly used commercially available disinfectants and/or detergent products were evaluated. The results of the first study demonstrated that critical areas in 12 of the 20 broiler houses were not effectively cleaned and disinfected between flocks as the tarmac apron, ante-room, house door, feeders, drinkers, walls, columns, barriers and/or bird weighs were Campylobacter positive. Thermal fogging with the combination of potassium peroxymonosulfate, sulfamic acid and sodium chloride (5%, v/v) or the glutaraldehyde and quaternary ammonium complex (0.3%, v/v) were the most effective treatments while other disinfectant treatments were considerably less effective. It was therefore concluded that farmers should review their broiler house cleaning and disinfection procedures if Campylobacter cross-contamination between successive flocks is to be prevented. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Susceptibility of phagocytes from elk, deer, bighorn sheep, and domestic sheep to Pasteurella haemolytica cytotoxins.

    Science.gov (United States)

    Silflow, R M; Foreyt, W J

    1994-10-01

    Alveolar macrophages and peripheral blood neutrophils from elk (Cervus elaphus), bighorn sheep (Ovis canadensis canadensis), and domestic sheep were exposed to culture supernatants from Pasteurella haemolytica isolated from bighorn sheep and domestic sheep. In a second experiment, peripheral blood neutrophils from mule deer (Odocoileus hemionus), elk, and bighorn sheep were exposed to culture supernatants from P. haemolytica isolated from elk, bighorn sheep and domestic sheep. Alveolar macrophages from elk, bighorn sheep and domestic sheep were resistant to killing by P. haemolytica supernatants from bighorn sheep and domestic sheep; susceptibility of neutrophils to cell death, as measured by release of lactate dehydrogenase, differed significantly (P sheep and domestic sheep neutrophils were susceptible to cytotoxin damage by the P. haemolytica isolates used; bighorn sheep neutrophils were four- to eight-fold more susceptible to cytotoxin damage than domestic sheep neutrophils. Neutrophils from deer and elk were resistant to killing by P. haemolytica cytotoxins from any species tested.

  8. Fatal pneumonia of bighorn sheep following association with domestic sheep.

    Science.gov (United States)

    Foreyt, W J; Jessup, D A

    1982-04-01

    During 1979-1980 acute fibrinopurulent bronchopneumonia resulted in high mortality or total loss of herds of bighorn sheep (Ovis canadensis) in California and Washington. Contact with domestic sheep occurred shortly before the onset of disease in each case. Circumstantial evidence indicated that the apparently healthy domestic sheep transmitted pathogenic bacteria to the bighorns, resulting in mortality. Pasteurella multocida and Corynebacterium pyogenes were isolated from pulmonary tissue of dead bighorns. The presence of domestic sheep may have been an important stress which initiated or compounded the disease.

  9. Salmonellosis and Related Risk Factors in Broiler Flocks in Mazandaran Province, Northern Iran

    Directory of Open Access Journals (Sweden)

    Seifi

    2016-05-01

    Full Text Available Background Prevention of foodborne pathogens is essential to control infectious diseases; Salmonella spp. is referred to as the most common causative agent of foodborne illnesses. Objectives The current study aimed to determine the prevalence of Salmonella enterica subsp. enterica in broiler flocks in Mazandaran province, north of Iran and find the potential risk factors including: age, size of flock, strain, season, vaccination program and use of antibiotics. Materials and Methods From March 2012 to December 2013, a total of 50 flocks were selected in slaughterhouse and 20 cloacal samples were collected from each flock. Every five samples were pooled and investigated for Salmonella spp. using polymerase chain reaction (PCR. Results Thirteen flocks out of 50 (26% were positive for Salmonella species. Chances of Salmonella spp. detection was higher in flocks with lower age (P = 0.41. Increasing flock population was associated with increased chance of Salmonella spp. isolation (P = 0.21. The risk of salmonellosis in broiler flocks was increased when no antibiotics were given to day-old chicks. There was no significant difference (P = 0.30 in the prevalence of salmonellosis among different broiler strains. Conclusions In the current study, six risk factors were assessed for Salmonella spp. contamination in broiler flocks. Some of these factors contributed to the risk of salmonellosis in broiler flocks.

  10. Topology-preserving flocking of nonlinear agents using optimistic planning

    Institute of Scientific and Technical Information of China (English)

    Lucian BU SONIU; Irinel-Constantin MORARESCU

    2015-01-01

    We consider the generalized flocking problem in multiagent systems, where the agents must drive a subset of their state variables to common values, while communication is constrained by a proximity relationship in terms of another subset of variables. We build a flocking method for general nonlinear agent dynamics, by using at each agent a near-optimal control technique from artificial intelligence called optimistic planning. By defining the rewards to be optimized in a well-chosen way, the preservation of the interconnection topology is guaranteed, under a controllability assumption. We also give a practical variant of the algorithm that does not require to know the details of this assumption, and show that it works well in experiments on nonlinear agents.

  11. Detection of avian nephritis virus in Australian chicken flocks.

    Science.gov (United States)

    Hewson, Kylie A; O'Rourke, Denise; Noormohammadi, Amir H

    2010-09-01

    Avian nephritis virus (ANV) is thought to infect poultry flocks worldwide, but no confirmed case has been reported in Australia. The first such case is described in this study. Cases of young chickens with clinical signs of dehydration and diarrhea were submitted to our laboratory and histopathology detected interstitial nephritis. Vaccine strains of infectious bronchitis virus were detected in some of these cases but were not considered to be the causative agent. A total of seven fresh submissions from broiler chicken flocks were collected at 8-11 days of age. Degenerate PCR primers were designed based on published ANV polymerase gene sequences and used to analyze historic cases as well as the fresh submissions. Six of the seven fresh submissions, and one historic case, were positive for ANV with nucleotide sequencing confirming these results. These results establish ANV as an infectious pathogen circulating in Australian poultry.

  12. A phenomenological model for the collective landing of bird flocks.

    Science.gov (United States)

    Daruka, István

    2009-03-07

    A three-dimensional phenomenological model was developed to describe the collective landing of bird flocks. The employed individual based model included the landscape (as an external field) and a continuous internal variable G, to characterize the landing intent of the birds. The birds' interaction with the landscape was coupled adaptively to their landing intent. During the flight, a sharp crossover is observed in the dynamics of the landing intent, i.e. from the initial, non-landing state (small G) to the landing state (large G) that was terminated by the landing of the flock. In the model, the landing process appears to be a highly concerted, collective motion of the birds, in agreement with the field observations.

  13. Salmonella in Sheep in Iceland

    Directory of Open Access Journals (Sweden)

    Gunnarsson E

    2002-03-01

    Full Text Available In 1995 several outbreaks of food poisoning in humans occurred in Iceland, that were traced to salmonella contamination of singed sheep heads. This prompted us to study the prevalence of salmonella infection in sheep and to trace where and how infection might have occurred. Faecal, intestinal contents and tonsillar samples were collected in the spring and autumn from sheep on 50 farms in the southwestern part of the country, where salmonellosis had been detected and from 5 farms in the northwestern part of the country. All faecal samples from the southwest were negative, whereas samples from 3 farms obtained in the autumn in the northwest were positive. Tonsillae taken in the autumn were positive in sheep from 3 farms in the southwest and 2 in the northwest. Our results show that salmonella infection is rare in Icelandic sheep but healthy carriers may harbour the bacteria in tonsillae. Salmonella was not detected in drainage from slaughterhouses nor in singed sheep heads.

  14. Uncertainty Quantification in Control Problems for Flocking Models

    Directory of Open Access Journals (Sweden)

    Giacomo Albi

    2015-01-01

    Full Text Available The optimal control of flocking models with random inputs is investigated from a numerical point of view. The effect of uncertainty in the interaction parameters is studied for a Cucker-Smale type model using a generalized polynomial chaos (gPC approach. Numerical evidence of threshold effects in the alignment dynamic due to the random parameters is given. The use of a selective model predictive control permits steering of the system towards the desired state even in unstable regimes.

  15. Popular Backyard Flock program reduces biosecurity risks of amateur production

    OpenAIRE

    Stinson, Sarah; Mete, Asli

    2013-01-01

    The California Animal Health and Food Safety laboratories provide free necropsy (postmortem examination) services to owners of backyard poultry through the Backyard Flock program funded by the California Department of Food and Agriculture. We collected and analyzed data on the number of poultry submissions to the program between 2007 and 2012, the lab totals by location and the diseases diagnosed. During those 6 years, submissions increased 383%, with chickens representing 91% of them, and th...

  16. Field efficacy of four anthelmintics and confirmation of drug-resistant nematodes by controlled efficacy test and pyrosequencing on a sheep and goat farm in Denmark.

    Science.gov (United States)

    Peña-Espinoza, Miguel; Thamsborg, Stig M; Demeler, Janina; Enemark, Heidi L

    2014-12-15

    We describe a case of anthelmintic resistance on one of the largest organic small ruminant farms in Denmark. The flock was established in 2007 by purchase of animals from other Danish farms and had history of clinical parasitism, high mortality of young stock and anthelmintic treatment failure. In October 2011, 40 lambs and 40 kids were selected for a faecal egg count reduction test (FECRT) with fenbendazole (FBZ), ivermectin (IVM), moxidectin (MOX) and levamisole (LEV). Lambs were treated with the recommended sheep dose of each product while kids received the sheep dose of IVM, 1.5× sheep dose of MOX and 2× sheep dose of FBZ and LEV. Untreated lambs and kids were also included and three methods for calculating faecal egg count (FEC) reduction were compared. In a subsequent investigation, a controlled efficacy test (CET) with FBZ and IVM was performed in lambs infected with Haemonchus contortus and Trichostrongylus colubriformis isolated from adult goats on the farm. Recovered specimens of H. contortus were subjected to pyrosequencing for detection of single nucleotide polymorphisms (SNPs) related to benzimidazole (BZ) resistance. During the FECRT, FECs in untreated lambs dropped significantly by 47%. No FEC reduction was detected in untreated kids. After FBZ treatments, FEC reductions in lambs and kids ranged from 15 to 54% and 49-56%, respectively, according to the different calculation methods. Post IVM treatments, FEC reductions in lambs and kids varied between 71-90% and 81-83%, correspondingly. LEV and MOX reduced FECs by 98-100% in both species. In the CET, FBZ reduced H. contortus worm counts by 52-56% and no reduction in T. colubriformis counts were detected after treatment. IVM eliminated 100% of H. contortus and reduced T. colubriformis counts by 84-92%, according to different calculation methods. Pyrosequencing of isolated H. contortus revealed increased frequencies of the BZ resistance-related SNP in codon 200 of the β-tubulin isotype 1 gene

  17. Monitoring the on-farm welfare of sheep and goats

    Directory of Open Access Journals (Sweden)

    Agostino Sevi

    2010-01-01

    Full Text Available Schemes for on-farm welfare assessment in sheep and goats are not yet available. Factors responsible for this lack of availability are discussed in the first part of this review. Requisites for reliable methods of welfare assessment to be used in sheep and goat farms are discussed, taking into account the peculiarities of the small ruminant production systems in terms of flock management and farm location. Some housing parameters related to structures, design and micro-environment are reviewed and could be included in schemes of welfare assessment on farm. Human-animal interaction, health status of the animals in terms of body condition scoring, skin and hair conditions, lameness and injuries, and management practices in relation to cleanliness, animal handling and moving, milking procedures and abnormal behaviours, are proposed as potential animal-based indicators. When available, validity, reliability and feasibility of the proposed parameters are discussed. The voluntary adhesion to welfare standards in Sardinia and the application of a scientifically validated protocol in Basilicata are reported as examples of practical experiences.

  18. Economic sustainability of organic dairy sheep systems in Central Spain

    Directory of Open Access Journals (Sweden)

    Paula Toro-Mujica

    2015-05-01

    Full Text Available Sheep production systems in regions with a Mediterranean climate are important in social, economic and environmental terms. Modeling these systems allows, among others, evaluation of the costs efficiencies which in turn permits assessing the expected effects of changes in production variables. This paper presents a prototype analysis of the economic sustainability of ecological dairy sheep systems of Castilla-La Mancha, Central Spain evaluated through the estimation of costs efficiencies. Costs functions were developed using data from 31 farms. Rate of supplementary feeding, labour use, and flock size were used to measure the cost efficiency. On average, cost efficiency was 61.7±15.5%, with significant differences among typological groups. High efficiency was found in only 29% of the farms. The economic analyses performed suggest that the continued existence of economically unsustainably farms is explained by the available subsidies, lack of amortization of fixed assets leading to progressive decapitalization, and subsistence incomes by family groups (gross family income.

  19. Spontaneous fluctuations in a zero-noise model of flocking

    Science.gov (United States)

    Chakraborty, Abhijit; Bhattacharya, Kunal

    2016-11-01

    Investigations into the complex structure and dynamics of collectively moving groups of living organisms have provided valuable insights. Understanding the emergent features, especially, the origin of fluctuations, appears to be challenging in the current scheme of models. It has been argued that flocks are poised at criticality. We present a two-dimensional self-propelled particle model where neighbourhoods and forces are defined through topology-based rules. The attractive forces are modeled in order to maintain cohesion in the flock in open-boundary conditions. We find that fluctuations occur spontaneously in the absence of any external noise. For certain values of the parameters the flock shows a high degree of order as well as scale-free decay of spatial correlations in velocity and speed. We characterize the dynamical behaviour of the system using the Lyapunov spectrum. Largest exponents being positive but small in magnitude suggest that the apparent high susceptibility may result from the system operating near the borderline of order and chaos.

  20. Flocking behavior with multiple leaders and global trajectory

    Institute of Scientific and Technical Information of China (English)

    李猛; 梁加红; 李石磊

    2014-01-01

    Aiming at the group of autonomous agents consisting of multiple leader agents and multiple follower ones, a flocking behavior method with multiple leaders and a global trajectory was proposed. In this flocking method, the group leaders can attain the information of the global trajectory, while each follower can communicate with its neighbors and corresponding leader but does not have global knowledge. Being to a distributed control method, the proposed method firstly sets a movable imaginary point on the global trajectory to ensure that the center and average velocity of the leader agents satisfy the constraints of the global trajectory. Secondly, a two-stage strategy was proposed to make the whole group satisfy the constraints of the global trajectory. Moreover, the distance between the center of the group and the desired trajectory was analyzed in detail according to the number ratio of the followers to the leaders. In this way, on one hand, the agents of the group emerge a basic flocking behavior; on the other hand, the center of the group satisfies the constraints of global trajectory. Simulation results demonstrate the effectiveness of the proposed method.

  1. Genetic correlations between ewe reproduction and carcass and meat quality traits in Merino sheep.

    Science.gov (United States)

    Safari, E; Fogarty, N M; Hopkins, D L; Greeff, J C; Brien, F D; Atkins, K D; Mortimer, S I; Taylor, P J; van der Werf, J H J

    2008-12-01

    Genetic correlations between reproduction traits in ewes and carcass and meat quality traits in Merino rams were obtained using restricted maximum likelihood procedures. The carcass data were from 5870 Merino rams slaughtered at approximately 18 months of age that were the progeny of 543 sires from three research resource flocks over 7 years. The carcass traits included ultrasound scan fat and eye muscle depth (EMDUS) measured on live animals, dressing percentage and carcass tissue depth (at the GR site FATGR and C site FATC), eye muscle depth, width and area and the meat quality indicator traits of muscle final pH and colour (L*, a*, b*). The reproduction data consisted of 13 464 ewe joining records for number of lambs born and weaned and 9015 records for LS. The genetic correlations between reproduction and fat measurements were negative (range -0.06 +/- 0.12 to -0.37 +/- 0.12), with smaller correlations for live measurement than carcass traits. There were small favourable genetic correlations between reproduction traits and muscle depth in live rams (EMDUS, 0.10 +/- 0.12 to 0.20 +/- 0.12), although those with carcass muscle traits were close to zero. The reproduction traits were independent of meat colour L* (relative brightness), but tended to be favourably correlated with meat colour a* (relative redness, 0.12 +/- 0.17 to 0.19 +/- 0.16). There was a tendency for meat final pH to have small negative favourable genetic correlations with reproduction traits (0.05 +/- 0.11 to -0.17 +/- 0.12). This study indicates that there is no antagonism between reproduction traits and carcass and meat quality indicator traits, with scope for joint improvement of reproduction, carcass and meat quality traits in Merino sheep.

  2. Becoming Sheep, Becoming Animal..

    DEFF Research Database (Denmark)

    Grum, Charlotte; Svabo, Connie

    As a part of a 2015 group exhibition exploring the history and local myths of a woman living in a Danish heath landscape 150 years ago, artist Charlotte Grum connected herself to a live sheep for 4 hours a day, 5 days a week, for 5 weeks, turning the two into a hybrid relational assemblage, intra...... of posthuman performance.Engaging with matter and producing knowledge on mattering itself seems to call for multiple mediated modes of dissemination, embodying the complexities of becoming...

  3. Sheep botfly: ophthalmomyiasis externa.

    Science.gov (United States)

    Harvey, J T

    1986-04-01

    Sheep botfly (Oestrus ovis) conjunctival infestation is rare in North America but is common in other parts of the world. The author treated 30 patients with this type of conjunctivitis in Jerusalem in 1981 and 1982. The conjunctivitis may vary from mild to severe (pseudo-orbital cellulitis). Features of the conjunctivitis include pale edema, linear superficial punctate keratopathy and the presence of larvae in the conjunctival sac. Conjunctival scrapings revealed a preponderance of polymorphonucleocytes.

  4. SHEEP TEMPORAL BONE

    Directory of Open Access Journals (Sweden)

    Kesavan

    2016-03-01

    Full Text Available INTRODUCTION Human temporal bones are difficult to procure now a days due to various ethical issues. Sheep temporal bone is a good alternative due to morphological similarities, easy to procure and less cost. Many middle ear exercises can be done easily and handling of instruments is done in the procedures like myringoplasty, tympanoplasty, stapedotomy, facial nerve dissection and some middle ear implants. This is useful for resident training programme.

  5. Diagnosis and PrP genotype target of scrapie in clinically healthy sheep of Massese breed in the framework of a scrapie eradication programme.

    Science.gov (United States)

    Vascellari, M; Aufiero, G M; Nonno, R; Agrimi, U; Vaccari, G; Basilicata, L; Falcaro, C; Mancin, M; Marcon, S; Mutinelli, F

    2005-10-01

    The application of a selective culling programme in two scrapie affected flocks of Massese breed sheep is described. The genetic susceptibility of this breed and the sensitivity of different diagnostic methods in the pre-clinical diagnosis of scrapie were also investigated. Overall, 2,068 clinically healthy sheep underwent PrP genotyping, providing the basis for selective culling. The prevalence of scrapie infection was investigated in susceptible sheep by two independent diagnostic methods. All the sheep older than 18 months (n = 620) were tested by Prionics Check Western rapid test on the obex, with a prevalence of infection of 3.9%. Furthermore, 385 sheep underwent immunohistochemistry (IHC) on retropharyngeal lymph node (RPLN), with a prevalence of infection of 5.2%. Overall, 32 sheep were diagnosed with pre-clinical scrapie. Of these, 31 were positive by Western blot on the spleen, 29 by IHC on the RPLN and tonsil, 28 by IHC on the obex, 24 by rapid test, and only 18 by IHC on the third eyelid. All the scrapie positive sheep were of the ARQ/ARQ, ARQ/AHQ or ARQ/VRQ genotypes. No significant differences in scrapie prevalence were observed among these genotypes. The estimated risk of the three targeted alleles was also similar, suggesting that in this breed the VRQ allele was not at higher risk for scrapie, compared to the ARQ and AHQ alleles.

  6. Linear response to leadership, effective temperature, and decision making in flocks

    Science.gov (United States)

    Pearce, Daniel J. G.; Giomi, Luca

    2016-08-01

    Large collections of autonomously moving agents, such as animals or micro-organisms, are able to flock coherently in space even in the absence of a central control mechanism. While the direction of the flock resulting from this critical behavior is random, this can be controlled by a small subset of informed individuals acting as leaders of the group. In this article we use the Vicsek model to investigate how flocks respond to leadership and make decisions. Using a combination of numerical simulations and continuous modeling we demonstrate that flocks display a linear response to leadership that can be cast in the framework of the fluctuation-dissipation theorem, identifying an effective temperature reflecting how promptly the flock reacts to the initiative of the leaders. The linear response to leadership also holds in the presence of two groups of informed individuals with competing interests, indicating that the flock's behavioral decision is determined by both the number of leaders and their degree of influence.

  7. Pigeon interaction mode switch-based UAV distributed flocking control under obstacle environments.

    Science.gov (United States)

    Qiu, Huaxin; Duan, Haibin

    2017-07-28

    Unmanned aerial vehicle (UAV) flocking control is a serious and challenging problem due to local interactions and changing environments. In this paper, a pigeon flocking model and a pigeon coordinated obstacle-avoiding model are proposed based on a behavior that pigeon flocks will switch between hierarchical and egalitarian interaction mode at different flight phases. Owning to the similarity between bird flocks and UAV swarms in essence, a distributed flocking control algorithm based on the proposed pigeon flocking and coordinated obstacle-avoiding models is designed to coordinate a heterogeneous UAV swarm to fly though obstacle environments with few informed individuals. The comparative simulation results are elaborated to show the feasibility, validity and superiority of our proposed algorithm. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  8. Analysis of factors important for the occurrence of Campylobacter in Danish broiler flocks

    DEFF Research Database (Denmark)

    Sommer, Helle Mølgaard; Heuer, Ole Eske; Sørensen, Anna Irene Vedel

    2013-01-01

    of Campylobacter in Danish broiler flocks. The study was based on a large data set consisting of Campylobacter positive status for nearly 6000 broiler flocks and 43 explanatory variables. Data were obtained from the Danish Campylobacter surveillance programme in poultry and from the responses to a standardized...... of positive flocks/total number of flocks delivered over the 2-year period).The following factors were found to be significantly associated with the occurrence of Campylobacter in the broiler flocks: old broiler houses, late introduction of whole wheat in the feed, relatively high broiler age at slaughter....... The results concerning chimneys may be explained by the easier access that flies have to the broiler houses, which seems in agreement with recent Danish studies on the significance of fly-screens to reduce Campylobacter in broiler flocks. The results of this study may be used in identification of effective...

  9. Efficacy of an anthelmintic combination in sheep infected with Fasciola hepatica resistant to albendazole and clorsulon.

    Science.gov (United States)

    Martínez-Valladares, M; Cordero-Pérez, C; Rojo-Vázquez, F A

    2014-01-01

    In the current study, we identified five sheep flocks with fasciolosis in the province of León (northwestern Spain) in order to determine the anthelmintic resistance status to three commonly used anthelmintics, namely albendazole (ABZ), triclabendazole (TCBZ) and clorsulon (CLOR). The identification of one flock resistant to ABZ and CLOR was shown after the faecal egg count reduction test (FECRT). The reductions in eggs per gram values were -17.6% and -68% against immature and adult flukes, respectively, after ABZ treatment; 85.15% and 44.91% against immature and adult flukes, respectively, after CLOR treatment; and 97.06% against both stages, after the administration of TCBZ. As an alternative to control the infection, two combinations of ABZ and CLOR were tested. In the first, both drugs were administered at the recommended dose of each; in this case, the efficiency reached values above 95% against both immature and adult flukes. However, when the combined drugs were administered at half the recommended dose of each, the efficiency of the combination was very low, i.e. 16.67% and -11.11% against mature and immature flukes, respectively. In conclusion, this preliminary report suggests a possible interaction between ABZ and CLOR after their joint administration. However, these results should be confirmed in other flocks.

  10. Potential disease agents in domestic goats and relevance to bighorn sheep (Ovis canadensis) management.

    Science.gov (United States)

    Drew, Mark L; Weiser, Glen C

    2017-01-01

    Domestic goats are raised for meat, milk and hair production, in herds for rangeland weed control, and as pack animals. Domestic sheep, goats and wild bighorn sheep are all susceptible to a multifactorial pneumonia. We sampled 43 herd goats from 7 herds and 48 pack goats from 11 herds for viral and bacterial serology, parasitology, and Pasteurellaceae microbiology. The goats in this study were in generally good health, although most goats did harbor various pathogens and parasites including several bacteria, specifically Pasteurellaceae, which have been associated with pneumonia in free-ranging bighorn sheep. It is not known if domestic goats can transmit the Pasteurellaceae or other pathogens found in this study readily to wild bighorn sheep. However, due the possibility of transmission, domestic goats in areas in or near bighorn sheep habitat should be managed to minimize the risk of spreading disease agents to bighorn sheep.

  11. Identification, genetic diversity and prevalence of Theileria and Babesia species in a sheep population from Northern Spain.

    Science.gov (United States)

    Nagore, Daniel; García-Sanmartín, Josune; García-Pérez, Ana L; Juste, Ramón A; Hurtado, Ana

    2004-08-01

    The genetic diversity and prevalence of virtually all Theileria and Babesia species in a sheep population were studied using a specifically designed reverse line blot macroarray. The amplified hypervariable V4 region of the 18S rRNA gene was hybridised against generic and species-specific probes. In a first screening (Study I), 320 apparently healthy animals corresponding to 32 flocks located in the Basque Country (Northern Spain) were analysed. The survey demonstrated a high prevalence of subclinical infections (64.7%). Three Theileria genotypes were identified, sharing 96.7-97.0% similarity between their 18S rRNA gene sequences: Theileria ovis, Theileria sp. OT1 (99.6% similarity with the recently described pathogenic piroplasm Theileria sp. China 1), and Theileria sp. OT3. Two Babesia species sharing 91.5% similarity were also detected: Babesia ovis and Babesia motasi. The complete 18S rRNA gene sequences of these and other piroplasm species were phylogenetically analysed. Prevalence of piroplasms was also investigated in a second group of 80 sheep from 16 flocks reared in mountain areas that had been heavily exposed to ticks and had suffered a recent abortion episode (Study II). The screening revealed a significantly higher (P distribution of Theileria spp. in the studied sheep population suggests that the parasites involved are of relatively low pathogenicity, in contrast to what has been reported for Theileria sp. China 1 in other countries.

  12. Development of 316v antibody enzyme-linked immunosorbent assay for detection of paratuberculosis in sheep.

    Science.gov (United States)

    Gurung, R B; Begg, D J; Purdie, A C; Eamens, G J; Whittington, R J

    2015-12-01

    An enzyme-linked immunosorbent assay (ELISA) was developed and optimised using a Mycobacterium avium subspecies paratuberculosis (MAP) antigen prepared from a C strain (316v) passed through a French press. The optimised assay was evaluated with a panel of sera from MAP infected (n = 66) and uninfected (n = 1,092) sheep. Animals in the MAP infected category were positive on either tissue culture or histopathology but were of unknown serum antibody status. The diagnostic performance and cost of the assay were compared with those of a commercial ELISA (IDEXX). At 99.8% diagnostic specificity the assay showed a diagnostic sensitivity of 23% (95% CI: 15.1-35.8) compared with 36.4% (95% CI: 25.8-48.4) for the commercial ELISA (McNemar's test: chi-square 5.82, p ELISA for an equivalent number of tests, the multiple depending on the number of plates processed per run. For flock-level surveillance, to account for the lower sensitivity of the 316v ELISA compared with the commercial ELISA, sample sizes would be increased but the test cost would still be lower. The 316v assay will be useful for diagnosis of Johne's disease in sheep flocks, particularly in developing countries where labour costs are low relative to the cost of consumables.

  13. BIOCHEMICAL POLYMORPHISMS IN SHEEP AND THEIR POTENTIAL USE FOR PATERNITY TESTS

    Directory of Open Access Journals (Sweden)

    Luiz Ernani Henkes

    1994-12-01

    Full Text Available The genetic variability of 22 protein loci was investigated in two sheep flocks: 22 females Romney Marsh and 124 animals derived from crossbreeding between Romney Marsh and Merino Booroola, reared by the Brazilian Agricultural Research Corporation (Empresa Brasileira de Pesquisa Agropecuária -EMBRAPA, Bagé, RS, Brazil. Eight loci were polymorphic; the others showed no variation. The usefulness of the eight plymorphic systems (Cat, DIA I, EP-1, EsA, HbB, ME, Tf, and X Prot. in parentage tests was analyzed. The probability to find two random identical animals in each breed was estimated as 1:1000. The efficiency of these proteins for exclusion of one of two possible sires in parentage tests was about 77% both for Romney Marsh and Romney/ Booroola flocks. Although parentage tests in sheep have not been enforced in Brazil up to now, the establishment of this technique is important for the prevention of non-paternity on the excellent rams.

  14. Fatal Pasteurella haemolytica pneumonia in bighorn sheep after direct contact with clinically normal domestic sheep.

    Science.gov (United States)

    Foreyt, W J

    1989-03-01

    Six Rocky Mountain bighorn sheep were raised in captivity from birth (n = 5) or taken from the wild as a lamb (n = 1). After the bighorn sheep were in captivity for over a year, 6 clinically normal domestic sheep were placed on the 2 ha of pasture on which the bighorn sheep were kept. Nasal swab specimens were obtained from all sheep at the time the domestic sheep were introduced. Pasteurella haemolytica was isolated from swab specimens obtained from 4 of 6 domestic sheep, but not from specimens obtained from the bighorn sheep. All 6 bighorn sheep died of acute hemorrhagic pneumonia after exposure to domestic sheep. Death in the bighorn sheep occurred on days 4, 27, 27, 29, 36, or 71 after initial exposure to domestic sheep. Pasteurella haemolytica was isolated from respiratory tract tissue specimens of all bighorn sheep at the time of death. None of the domestic sheep were clinically ill during the study. At the end of the study, 3 of 6 domestic sheep were euthanatized, and at necropsy, P haemolytica was isolated from 2 of them. The most common serotypes in bighorn and domestic sheep were P haemolytica T-3 and A-2. Other serotypes isolated included P haemolytica A-1, A-9, and A-11 in bighorn sheep and A-1 in domestic sheep. On the basis of results of this study and of other reports, domestic sheep and bighorn sheep should not be managed in proximity to each other because of the potential fatal consequences in bighorn sheep.

  15. [Suppression of cycling activity in sheep using parenteral progestagen treatment].

    Science.gov (United States)

    Janett, F; Camponovo, L; Lanker, U; Hässig, M; Thun, R

    2004-03-01

    The objective of this study was to evaluate the effect of two synthetic progestagen preparations Chlormadinone acetate (CAP, Chronosyn, Veterinaria AG Zürich) and Medroxyprogesterone acetate (MPA, Nadigest, G Streuli & Co. Uznach) on cycling activity and fertility in sheep. A flock of 28 non pregnant white alpine sheep was randomly divided into three groups, A (n = 10), B (n = 9) and C (n = 9). During a period of 4 weeks the cycling activity was confirmed by blood progesterone analysis. Thereafter, the animals of group A were treated with 50 mg CAP, those of group B with 140 mg MPA and those of group C with physiological saline solution. All injections were given intramuscularly. Suppression of endogenous progesterone secretion lasted from 28 to 49 days (mean = 39 days) in group A and from 42 to 70 days (mean = 50 days) in group B. The synchronization effect of both preparations was unsatisfactory as the occurrence of first estrus was distributed over a period of 3 weeks in group A and 4 weeks in group B. These findings could also be confirmed by the lambing period which lasted 52 days in group A and 36 days in group B. Control animals lambed within 9 days due to the synchronizing effect of the ram. The first fertile estrus was observed 36 days (group A) and 45 days (group B) after the treatment. In group A all 10 animals and in groups B and C 8 of 9 ewes each became pregnant. Parenteral progestagen application with CAP and MPA is a simple, safe and reversible method of estrus suppression in the sheep. The minimal suppressive duration of 4 (CAP) and 5 weeks (MPA) is not sufficient when a period of 3 months (alpine pasture period) is desired.

  16. Assessment of flukicide efficacy against Fasciola hepatica in sheep in Sweden in the absence of a standardised test

    Directory of Open Access Journals (Sweden)

    Adam Novobilský

    2016-12-01

    Full Text Available Anthelmintic resistance (AR to Fasciola hepatica is emerging worldwide. Recently, AR to the adulticide compound albendazole (ABZ was shown in Argentina and Spain. In Sweden, ABZ treatment failure against F. hepatica was first reported in sheep in 2012. The present study tested the efficacy of ABZ and triclabendazole (TCBZ in sheep naturally infected with F. hepatica using a combination of three different diagnostic methods: faecal egg counts (FEC, coproantigen ELISA (cELISA and Fasciola egg hatch test (FEHT. Two deworming trials, in November 2014 and January 2015, were performed on two sheep farms (farms A and B in south-western Sweden. Except ABZ in November, treatment with ABZ or TCBZ achieved sufficient efficacy (97–100% against adult F. hepatica on farm A. In contrast, ABZ treatment failed in the sheep flock on farm B, despite low initial faecal egg output. On farm B, ABZ efficacy based on FEC was 67% (95% CI: 35–84 and four of eight ewes tested were coproantigen-positive 21 days post-treatment. Ovicidal activity of ABZ against Fasciola eggs in isolates from both farms and one additional bovine isolate were tested by FEHT to exclude the presence of juvenile flukes and other factors such as dosing failure and poor quality of drug product. Irrespective of drug trial, data from FEHT showed significantly lower ovicidal activity of ABZ for the ovine farm B isolate than for the isolate from farm A. This confirms that the low efficacy of ABZ in sheep flock B was associated with ABZ resistance. Overall, the usefulness of three complementary methods for detection of ABZ resistance in the field was demonstrated.

  17. Behaviour of confined sheep fed with different concentrate sources

    Directory of Open Access Journals (Sweden)

    A.H.H. Minervino

    2014-08-01

    Full Text Available In this study we examined the effects of different feed concentrates on sheep behaviour. Our hypothesis was that citric pulp would stimulate rumination and be capable of replacing other concentrates traditionally used for feeding in confinement, to reduce the risk of urolithiasis. Ten adult Santa Inês sheep were distributed in a Latin square with five different diets, one control diet with 80% hay and 20% commercial feed and four diets containing 30% coast-cross hay and 70% of the following concentrates: pelleted citrus pulp, citrus pulp meal, cornmeal or wheat bran. After 21d of adaptation to each one of the five diets, the sheep were visually monitored for 24 h at 3 min intervals to record the time spent ruminating, time spent eating and time spent resting; the animals' positions (standing or lying down were also noted. Daytime was considered to be from 06:00h to 18:00h. The data were evaluated using ANOVA, with Tukey post-hoc test or throughout Two-sample T test for circadian and position assessment. Citrus pulp diets resulted in time spent ruminating similar to the control diet (601, 590 and 669 min, respectively, but greater (P<0.05 than the cornmeal group (421min, which showed that citrus pulp generated effective rumination. The estimated saliva production in the control diet (26L was greater than in the other groups, and was greater in the citrus pulp groups (24L/d than cornmeal (21L/d. Feeding with cornmeal led to shorter time spent eating and time spent ruminating than all other diets. The sheep had higher time spent resting at night when fed concentrates (P<0.05. For all diets, about 90% of the time spent ruminating occurred with the animals lying down. Pelleted citrus pulp, citrus pulp meal and to a lesser degree wheat bran, led to adequate time spent ruminating. The use of citrus pulp can act as a preventive management measure to reduce the incidence of urolithiasis in sheep flocks.

  18. Role of batch depletion of broiler houses on the occurrence of Campylobacter spp. in chicken flocks

    DEFF Research Database (Denmark)

    Hald, Birthe; Rattenborg, Erik; Madsen, Mogens

    2001-01-01

    Aims: The effect of batch depletion of broiler houses for campylobacter occurrence in broiler flocks was estimated in 10 flocks, each comprising a separate female and male batch. Methods and Results: The chicks were sampled first bq; cloacal swabs in the broiler houses before the start...... that batch depletion of broiler houses increased the prevalence of Campylobacter spp.-infected broilers in the flocks, that the introduction occurred a hen catching the first batch, and that campylobacter spreads through the entire flock within a week. Significance and Impact of the Study: The results from...

  19. Derivation of multivariate indices of milk composition, coagulation properties, and individual cheese yield in dairy sheep.

    Science.gov (United States)

    Manca, M G; Serdino, J; Gaspa, G; Urgeghe, P; Ibba, I; Contu, M; Fresi, P; Macciotta, N P P

    2016-06-01

    Milk composition and its technological properties are traits of interest for the dairy sheep industry because almost all milk produced is processed into cheese. However, several variables define milk technological properties and a complex correlation pattern exists among them. In the present work, we measured milk composition, coagulation properties, and individual cheese yields in a sample of 991 Sarda breed ewes in 47 flocks. The work aimed to study the correlation pattern among measured variables and to obtain new synthetic indicators of milk composition and cheese-making properties. Multivariate factor analysis was carried out on individual measures of milk coagulation parameters; cheese yield; fat, protein, and lactose percentages; somatic cell score; casein percentage; NaCl content; pH; and freezing point. Four factors that were able to explain about 76% of the original variance were extracted. They were clearly interpretable: the first was associated with composition and cheese yield, the second with udder health status, the third with coagulation, and the fourth with curd characteristics. Factor scores were then analyzed by using a mixed linear model that included the fixed effect of parity, lambing month, and lactation stage, and the random effect of flock-test date. The patterns of factor scores along lactation stages were coherent with their technical meaning. A relevant effect of flock-test date was detected, especially on the 2 factors related to milk coagulation properties. Results of the present study suggest the existence of a simpler latent structure that regulates relationships between variables defining milk composition and coagulation properties in sheep. Heritability estimates for the 4 extracted factors were from low to moderate, suggesting potential use of these new variables as breeding goals.

  20. Comparative evaluation of eight serological assays for diagnosing Chlamydophila abortus infection in sheep.

    Science.gov (United States)

    Wilson, Kim; Livingstone, Morag; Longbottom, David

    2009-03-16

    Chlamydophila abortus is one of the principal causes of late-term abortion (enzootic abortion of ewes or EAE) in sheep across Europe. Serological diagnosis of EAE is routinely carried out by the complement fixation test, although the interpretation of results can often be difficult because of cross reaction with Chlamydophila pecorum, which also commonly infects sheep. The purpose of this study was to evaluate and compare four ELISAs developed at Moredun Research Institute and based on whole C. abortus elementary bodies (EBs), an outer membrane preparation of the whole organism (SolPr) and two recombinant polymorphic outer membrane protein fragments (rOMP90-3 and rOMP90-4), with 3 commercial tests, the CHEKIT Chlamydophila Abortus, Pourquier ELISA Chlamydophila abortus and ImmunoComb Ovine Chlamydophila Antibody tests. The tests were evaluated using a panel of 202 sera from experimentally and naturally infected animals, as well as from EAE-free flocks. The EB, SolPr and CHEKIT ELISAs performed similarly to the CFT, all lacking in specificity by cross reacting with sera from C. pecorum infected animals. The ImmunoComb also lacked specificity with C. pecorum sera, but also badly cross reacted with sera from EAE-free flocks. The rOMP90-3, rOMP90-4 and Pourquier ELISAs were the most specific, although the Pourquier test appeared less sensitive with sera from naturally infected animals. Overall, the rOMP90-3 ELISA performed the best, with high sensitivity (96.8%) and no cross reaction with sera from C. pecorum infected animals or from EAE-free flocks (100% specificity) and so would be a suitable alternative to the CFT for the serological diagnosis of EAE.

  1. Production objectives and breeding practices of urban goat and sheep keepers in West Africa: regional analysis and implications for the development of supportive breeding programs.

    Science.gov (United States)

    Dossa, Luc Hippolyte; Sangaré, Mamadou; Buerkert, Andreas; Schlecht, Eva

    2015-01-01

    To better understand the relative importance of the multi-purpose functions of small ruminants for their urban owners and related breeding practices including selection criteria, we undertook a comparative analysis across the West African cities of Kano (Nigeria), Bobo Dioulasso (Burkina Faso) and Sikasso (Mali). Semi-structured questionnaires were used to collect the required information from 301 sheep farmers (100, 102 and 99 in Kano, Bobo Dioulasso and Sikasso) and 306 goat farmers (100, 99 and 107 in Kano, Bobo Dioulasso and Sikasso). Sheep and goats were kept for a variety of reasons including income generation, insurance (sale for cash to meet unexpected expenditures) and economic security (sale for cash to support foreseeable expenses), social/religious functions and prestige in ownership. The relative importance given by respondents to the different functions varied significantly (p record keeping and selection criteria), the emphasis put on each selection criteria varied across cities and between species. Irrespective of city, most of the goats were of the indigenous type while keeping crossbred animals and/or maintaining more than one genotype in the same flock was more commonly practiced by sheep keepers. This points to a higher motivation for strategic breeding among sheep than goat keepers and indicates that the former might be interested in joining carefully designed participatory flock improvement programs.

  2. Breeding Practices in Sheep Farming

    Directory of Open Access Journals (Sweden)

    M.A. Shejal

    2009-02-01

    Full Text Available The sheep is an important economic livestock species, contributing greatly to the Indian economy, especially in arid, semi arid and mountain areas. The current population in world is 1110.78 millions, around 44.85 millions (1987 sheeps in India (ICAR., 2002. Sheeps are mostly reared for meat and wool. The average annual wool production per sheep is between 3.5 to 5.5 kg of fine quality wool in Australia, New Zealand and U.S.S.R., where as in India except Magra sheep which annually yield more than 2 kg wool having staple length 5.8 cm, the average of rest of the wool produced is less than 1.0 kg per sheep of inferior quality (Banerjee G.C., 1998. Therefore many farmers in southern India adapted sheep rearing for meat production than for wool production. For yielding more production from sheep farming one should have sound knowledge of general information related to the reproduction and different breeding practices. [Vet. World 2009; 2(1.000: 43-44

  3. Resistance of gastrointestinal nematodes to the most commonly used anthelmintics in sheep, cattle and horses in Spain.

    Science.gov (United States)

    Martínez-Valladares, M; Geurden, T; Bartram, D J; Martínez-Pérez, J M; Robles-Pérez, D; Bohórquez, A; Florez, E; Meana, A; Rojo-Vázquez, F A

    2015-07-30

    The objective of this study was to evaluate the status of anthelmintic resistance (AR) in ruminants and horses in Spain. The efficacy of commonly used macrocyclic lactones (MLs) - ivermectin (IVM) and moxidectin (MOX) - was measured in sheep, cattle and horses. In addition, albendazole (ABZ) and levamisole (LEV) were evaluated in sheep and oxibendazole (OXI) and pyrantel (PYR) in horses. Efficacy was evaluated based on the difference between the arithmetic mean pre- and post-treatment faecal egg count (in cattle and horses), or compared to an untreated control group (in sheep). AR was present when the percentage reduction in egg count was <95% and the lower 95% confidence interval (CI) was <90%; if only one of these two criteria was met, the finding was recorded as suspected AR (SAR). In horses, AR-PYR and OXI was considered when the percentage reduction in egg count was ≤ 90% and the lower 95% CI was ≤ 80%. For each animal species, at least 10 study sites were selected. AR to at least one of the drugs was detected in all 10 sheep flocks; the main parasite identified after treatment was Teladorsagia circumcincta. Moreover, in 5 flocks multidrug resistance was identified, on 4 farms to drugs from different families, on one farm to both MOX and IVM and on another farm to all drugs tested. In cattle, the efficacy of both MOX and IVM was 100% on 4 and 3 farms, respectively, and therefore 60% of these farms were considered to have AR or SAR to both MLs. The most frequent parasite identified after treatment was Trichostrongylus spp., although Ostertagia ostertagi was also identified after treatment on one farm. In contrast to ruminants, the 4 drugs evaluated in horses were highly efficacious against strongyles, with efficacies for the MLs and OXI between 95 and 100% and between 94 and 100% for PYR, although 3 herds were SAR against PYR. In conclusion, AR to at least one of the commonly used drugs was identified on all sheep flocks investigated in the northwest of

  4. Genotype-dependent molecular evolution of sheep bovine spongiform encephalopathy (BSE) prions in vitro affects their zoonotic potential.

    Science.gov (United States)

    Krejciova, Zuzana; Barria, Marcelo A; Jones, Michael; Ironside, James W; Jeffrey, Martin; González, Lorenzo; Head, Mark W

    2014-09-19

    Prion diseases are rare fatal neurological conditions of humans and animals, one of which (variant Creutzfeldt-Jakob disease) is known to be a zoonotic form of the cattle disease bovine spongiform encephalopathy (BSE). What makes one animal prion disease zoonotic and others not is poorly understood, but it appears to involve compatibility between the prion strain and the host prion protein sequence. Concerns have been raised that the United Kingdom sheep flock may have been exposed to BSE early in the cattle BSE epidemic and that serial BSE transmission in sheep might have resulted in adaptation of the agent, which may have come to phenotypically resemble scrapie while maintaining its pathogenicity for humans. We have modeled this scenario in vitro. Extrapolation from our results suggests that if BSE were to infect sheep in the field it may, with time and in some sheep genotypes, become scrapie-like at the molecular level. However, the results also suggest that if BSE in sheep were to come to resemble scrapie it would lose its ability to affect humans.

  5. Some risk factors for reproductive failures and contribution of Toxoplasma gondii infection in sheep and goats of Central Ethiopia: a cross-sectional study.

    Science.gov (United States)

    Gebremedhin, Endrias Zewdu; Agonafir, Abebe; Tessema, Tesfaye Sisay; Tilahun, Getachew; Medhin, Girmay; Vitale, Maria; Di Marco, Vincenzo

    2013-12-01

    Reproductive failure has a negative impact on animal production, health and welfare and ultimately rural economies. In Ethiopia, the factors affecting small ruminant reproductive efficiency are inadequately investigated. A cross-sectional survey was done from November, 2010 to May, 2011 to investigate risk factors of reproductive failures including Toxoplasma gondii infection. Analysis of 1372 sera (787 sheep and 585 goats) from 409 flocks using ELISA showed high flock (59.7%) and animal (31.8%) level T. gondii seroprevalence. An overall 24.9% (341/1372) annual abortion rate (19.6% in sheep and 32.0% in goats) was recorded. Animal level T. gondii seroprevalence was significantly associated with abortion in Ambo and Ada'a-Liben districts (Odds ratio [OR] = 2.31, 95% confidence interval [CI]: 1.42, 3.76; P = 0.001). Questionnaire survey on 199 households of Ambo, Ada'a-Liben and Fentale districts revealed high flock level abortion (57.5%), still birth (28.9%) and neonatal losses (47.9%), which are significantly different between study districts (Pabortions was significantly higher in goat than in sheep flocks (Incidence risk ratio [IRR] = 1.42, 95% CI: 1.08, 1.87; P = 0.012). It is also significantly higher in pastoral (IRR = 1.81, 95% CI: 1.16, 2.83; P = 0.008) and agro-pastoral production systems (IRR = 1.94, 95% CI: 1.32, 2.86; P = 0.001) than in sedentary production system. Prevention of toxoplasmosis, improved husbandry practices and further epidemiological studies to identify causes of reproductive failures are recommended.

  6. Participatory definition of breeding objectives for sheep breeds under pastoral systems--the case of Red Maasai and Dorper sheep in Kenya.

    Science.gov (United States)

    König, Emelie Zonabend; Mirkena, Tadele; Strandberg, Erling; Audho, James; Ojango, Julie; Malmfors, Birgitta; Okeyo, Ally Mwai; Philipsson, Jan

    2016-01-01

    Crossing local breeds with exotic breeds may be an option for increased livestock productivity. However, there is a risk for endangerment of the local breeds. One such case is in Kenya where the imported Dorper breed is used for crossbreeding with Red Maasai sheep. The aim of this study was to investigate farmers' trait preferences as a basis for determination of breeding objectives for Red Maasai and Dorper sheep at two sites, Amboseli and Isinya, in Kenya. Within their own flock, each farmer identified three ewes representing the best, average and poorest within each breed group: Red Maasai, Dorper and Crosses. Farmers gave reasons for their ranking. Body measurements and weights were also taken. At the harshest site, Amboseli, differences between breed groups in body weight were small and breeds were equally preferred. In Isinya, where environmental conditions are better and farmers are more market oriented, Dorper and Crosses had significantly higher body weights and market prices and were thus preferred by the farmers. Red Maasai were preferred for their maternal and adaptive traits. Breeding objectives should emphasize growth traits and milk production in both breeds at both sites. Body condition needs to be specifically considered in the breeding objectives for sheep in Amboseli, whereas adaptive traits need to be generally emphasized in Dorper.

  7. Flocking of multi-agent systems with multiple groups

    Science.gov (United States)

    Jing, Gangshan; Zheng, Yuanshi; Wang, Long

    2014-12-01

    In this paper, we consider the flocking problem of multi-agent systems with multiple groups. First, some algorithms using local information are designed to divide the agents into any pre-assigned number of groups in fixed and switching heterogeneous networks, respectively. Based on algebraic graph theory and Barbalat's lemma, convergence criteria are established to ensure velocity alignment and cohesion of each subgroup as well as collision avoidance between any agents in the whole group. Second, an algorithm for homogeneous networks is studied. Simulation examples are finally presented to verify the effectiveness of our theoretical results.

  8. Brachygnathia, cardiomegaly and renal hypoplasia syndrome (BCRHS) in Merino sheep maps to a 1.1-megabase region on ovine chromosome OAR2.

    Science.gov (United States)

    Shariflou, M R; Wade, C M; Kijas, J; McCulloch, R; Windsor, P A; Tammen, I; Nicholas, F W

    2013-04-01

    A genome scan was conducted to map the autosomal recessive lethal disorder brachygnathia, cardiomegaly and renal hypoplasia syndrome (BCRHS) in Poll Merino sheep. The scan involved 10 affected and 27 unaffected animals from a single Poll Merino/Merino sheep flock, which were genotyped with the Illumina Ovine SNP50 BeadChip. Association and homozygosity mapping analyses located the disorder in a region comprising 20 consecutive SNPs spanning 1.1 Mb towards the distal end of chromosome OAR2. All affected animals and none of the unaffected animals were homozygous for the associated haplotype in this region. These results provide the basis for identifying the causative mutation(s) and should enable the development of a DNA test to identify carriers in the Poll Merino sheep population. Understanding the molecular control of BCRHS may provide insight into the fundamental genetic control and regulation of the affected organ systems.

  9. The enzyme-linked immunosorbent assay (ELISA) as a serological test for detecting antibodies against Leptospira interrogans serovar hardjo in sheep.

    Science.gov (United States)

    Adler, B; Faine, S; Gordon, L M

    1981-09-01

    The enzyme-liked immunosorbent assay (ELISA) was compared with the standard microscopic agglutination test (MAT) as a method for detecting antibodies against Leptospira interrogans serovar hardjo in sheep. Peak antibody levels detected by the 2 tests occurred at different times following experimental infection of sheep. In serums from flocks of sheep with naturally acquired infection there was a 95% correlation between MAT and ELISA with respect to the presence or absence of antibody to serovar hardjo, although the levels of correlation of the titres of the 2 tests was low. The 2 tests appeared to measure different antigen-antibody systems. The ELISA would be a useful test for screening large numbers of serums for antibodies to L. interrogans serovar hardjo.

  10. in a Western Cape Dohne Merino nucleus flock

    African Journals Online (AJOL)

    The Dohne Merino breed is a synthetic breed developed in South Africa from the ... stage it is uncertain if such effects would also exist in Dohne Merino sheep ..... recent studies reported maternal additive effects for 2-tooth live weight and ...

  11. Awassi sheep reproduction and milk production: review.

    Science.gov (United States)

    Talafha, Abdelsalam Q; Ababneh, Mohammed M

    2011-10-01

    Awassi is the local breed of sheep in Jordan and is the most important breed in the semi-arid regions of the near east countries. Awassi ram and ewe lambs reach puberty at around 8 and 9 months of age, respectively. The breeding season of Awassi ewes starts as early as April and lasts through September. After puberty, Awassi rams are sexually active throughout the year. The normal estrous cycle in Awassi ewes is 15-20 days (average 17 days). Estrus ranges from 16-59 h (average 29 h) during the breeding season. The reproductive performance of unimproved Awassi sheep has been low while improved Awassi has the highest fertility and milk production and are the heaviest among all Awassi populations. The gestation length varies from 149 to 155 days (average 152 days). Hormones that are commonly used for induction and synchronization of estrus in Awassi ewes include progestins, gonadotropins and PGF2α. An Awassi ewe produces 40-60 and 70-80 kg of milk per 150-day lactation period under traditional and improved production systems, respectively, in addition to the suckled milk left for lambs until weaning. The improved Awassi has the highest milk production among all Awassi populations and may reach 506 L over 214-day lactation period. The objective of this review is to summarize the reproductive pattern and milk production of Awassi sheep in the Middle East region.

  12. ANTIPARASITICAL PROTECTION IN SHEEP FARMS

    Directory of Open Access Journals (Sweden)

    DOINA ARDELEANU

    2013-12-01

    Full Text Available Through our researches were carried out at ICDCOC- Palas, Constantza, we proposed ourselves to establish the poly-parasitism structure on sheep, as well as elaborating efficientical methods for anti-parasitical prophylaxis and fighting in sheep populations and pasture sourfaces, in order to ensuring anti-parasitical protection in sheep exploitations The copro-parasitological examinations was carried ovoscopicaly (flotation - by Willis and Mc. Master methods; sediment – by polyvalent method and larvoscopicaly – by Baermann method. The parasitological examination of coprological smears which were harvested on sheep showed the presence of polyparasitism phenomenon with protozoans (coccidiae: Eimeria spp. and helmints (cestodae: Moniesia expansa; gastro-intestinal nemathodes: Trichostrongylus spp., Nematodirus spp., Strongyloides papillosus and pulmonary nemathodes: Müellerius capillaris, Protostrongylus rufescens, Dictyocaulus filaria. Also, we proposed ourselves to study the paresites and their intermediary stages on pastures which were exploited with sheep, comparatively with mowed pastures. In the ansamble of research activities a special place is occupied by testing differents methods, in order to prevention and fighting of parasitical infestations on sheep and pasture in sheep farms.

  13. Leadership of Winter Mixed-Species Flocks by Tufted Titmice (Baeolophus bicolor: Are Titmice Passive Nuclear Species?

    Directory of Open Access Journals (Sweden)

    Thomas A. Contreras

    2011-01-01

    Full Text Available The tufted titmouse (Baeolophus bicolor, TUTI is a nuclear species in winter foraging flocks whose antipredator calls are used to manage predation risk by diverse heterospecifics. We hypothesized that satellite species in mixed flocks follow TUTI (not vice versa, thereby defining the role of TUTI as a “passive” nuclear species. We followed 20 winter mixed-species flocks in North-Central Florida and assessed angular-angular correlations between overall flock, TUTI, and satellite species movement directions. We observed significant correlations between overall flock movement directions and those of TUTI, confirming our central prediction. Within flocks, however, fine-scale movement directions of satellite species were often more highly correlated with those of other satellites than with TUTI movements. We conclude that TUTI are passive nuclear species whose movements define flock paths, but within flocks, TUTI movements may have less influence on satellite movements than do other factors.

  14. Prevalence and distribution of gastrointestinal nematodes on 32 organic and conventional commercial sheep farms in Ontario and Quebec, Canada (2006-2008).

    Science.gov (United States)

    Mederos, A; Fernández, S; VanLeeuwen, J; Peregrine, A S; Kelton, D; Menzies, P; LeBoeuf, A; Martin, R

    2010-06-24

    In order to characterize the epidemiology of sheep gastrointestinal nematodes in organic and conventional flocks in Canada, a longitudinal study was carried out from May 2006 to March 2008 on 32 purposively selected farms in Ontario (ON) and Quebec (QC): 8 certified organic (CO), 16 non-certified organic (NCO), and 8 conventional (C) farms. On each farm, 10 ewes and 10 female lambs were selected. Farm visits were undertaken monthly during the grazing season, and twice in the winter. At each visit, individual fecal samples were taken, and pasture samples were obtained during the grazing season. In addition, body condition score was recorded for all sheep. Fecal egg counts per gram of feces (EPGs) were determined for all fecal samples, and infective larvae (L(3)) were identified in fecal samples (lambs and ewes separately) and pasture samples from farms. Necropsies of 14 lambs from 7 of the 23 Ontario farms were performed at the end of the grazing season in 2006. The mean EPG for year 1 (May 2006 to March 2007) was 181 (range=0-9840) and 351 (range=0-18,940) for the ewes in ON and QC, respectively, and for the lambs was 509 (range=0-25,020) and 147 (range=0-3060) for ON and QC, respectively. During year 2 (April 2007 to March 2008), the mean EPG was 303 (range=0-21,160) and 512 (range=0-22,340) for the ewes in ON and QC, respectively, and for lambs was 460 (range=0-26,180) and 232 (range=0-8280) for ON and QC, respectively. Although the overall mean EPGs were not remarkably high, there were months of higher EPG such as May-June for ewes and July-August for lambs in both provinces. Pasture infectivity was highest in May-June and September. There was a general trend for the CO farms to have lower mean EPG than NCO and C farms. Fecal cultures demonstrated that the most predominant nematode genera were Teladorsagia sp., Haemonchus sp. and Trichostrongylus spp. Pasture infectivity was highest during June-July (984 L3/kg DM) in ON farms and September (mean=436 L3/kg DM) in

  15. Reproductive Performance of Balochi Sheep in Different Ecological Zones of Balochistan, Pakistan

    Directory of Open Access Journals (Sweden)

    Mudassar Jahan1,3, Mohammad Masood Tariq2*, Muhammad Azam Kakar3 and Abdul Waheed4

    2013-01-01

    Full Text Available The data on reproductive performance of Balochi sheep (n=150 kept at three Government sheep farms in Balochistan, Quetta (KSBFM (n=50, Loralai (SRCY (n=50 and Usta Mohammad (UMSF (n=50, under semi-intensive management system, were analyzed. General linear model was used for analyzing the data. The fixed effects in the model included location of flock, age, type of birth, sex of lamb and their interactions. The overall findings of reproductive traits such as fertility, prolificacy, single lambing, twinning rate, lambs born alive and sex ratio (male: female were 92.67, 101.33, 89.86, 10.14, 96.33% and 50.33:49.67, respectively. The highest value for twinning rate was recorded in UMSF (13.04% and the lowest in KSBFM (6.52%. All traits were significantly different (P0.05 between flocks. The overall results revealed that age of dam, age at first service (AFS, service period (SP, age at first lambing (AFL and lambing interval (LI were 1078±2.2, 579.61±0.6, 206.25±0.2, 731.67±0.3 and 256.60±0.3 days, respectively. The results of ANOVA showed that locations had significant effect (P<0.05 on AFS and SP; however lambing interval and age at first lambing were not affected. Age of ewe, type of birth, sex of lamb(s born and interaction between these factors did not influence the traits significantly. It was concluded that reproductive performance of Balochi sheep was modest so it is vital to improve management, nutritional and breeding practices at the farm.

  16. Risk factors associated with Salmonella enterica serovar typhimurium infection in Danish broiler flocks

    DEFF Research Database (Denmark)

    Skov, M. N.; Angen, Øystein; Chriel, M.;

    1999-01-01

    , breed of the laying flock, animal density, size of the flock, area of the house, age of the house, geographical location of the farm, observation of beetles, number of days between disinfection and replacement, visual appearance of the bedding, and age of the chickens when they were tasted...

  17. Serotype and genotype diversity and hatchery transmission of Campylobacter jejuni in commercial poultry flocks

    DEFF Research Database (Denmark)

    Petersen, L.; Nielsen, E.M.; On, Stephen L.W.

    2001-01-01

    We investigated the genotype and serotype diversity of Campylobacter coli and C jejuni in two parent flocks of adult hens and their offspring over two rotations in order to evaluate the role of hatchery mediated transmission and/or vertical transmission of campylobacters in broiler flocks. In tot...

  18. 9 CFR 145.83 - Terminology and classification; flocks and products.

    Science.gov (United States)

    2010-01-01

    ... POULTRY Special Provisions for Primary Meat-Type Chicken Breeding Flocks and Products § 145.83 Terminology... for primary meat-type breeders wishing to assure their customers that the chicks produced are... flock collected and cultured as described in § 147.12(a)(5) of this subchapter; or (B) A sample of chick...

  19. Who Is Spreading Avian Influenza in the Moving Duck Flock Farming Network of Indonesia?

    Directory of Open Access Journals (Sweden)

    Joerg Henning

    Full Text Available Duck populations are considered to be a reservoir of Highly pathogenic avian influenza (HPAI virus H5N1 in some agricultural production systems, as they are able to shed the virus for several days without clinical signs. Countries endemically affected with HPAI in Asia are characterised by production systems where ducks are fed on post-harvest spilled rice. During this scavenging process it is common for ducks to come into contact with other duck flocks or wild birds, thereby providing opportunities for virus spread. Effective risk management for HPAI has been significantly compromised by a limited understanding of management of moving duck flocks in these countries, despite of a small number of recent investigations. Here, for the first time, we described the management of moving duck flocks and the structure of the moving duck flock network in quantitative terms so that factors influencing the risk of HPAIV transmission can be identified. By following moving duck flock farmers over a period of 6 months in Java, Indonesia, we were able to describe the movement of flocks and to characterise the network of various types of actors associated with the production system. We used these data to estimate the basic reproductive number for HPAI virus spread. Our results suggest that focussing HPAI prevention measures on duck flocks alone will not be sufficient. Instead, the role of transporters of moving duck flocks, hatcheries and rice paddy owners, in the spread of the HPAI virus needs to be recognised.

  20. Who Is Spreading Avian Influenza in the Moving Duck Flock Farming Network of Indonesia?

    Science.gov (United States)

    Henning, Joerg; Pfeiffer, Dirk U; Stevenson, Mark; Yulianto, Didik; Priyono, Walujo; Meers, Joanne

    2016-01-01

    Duck populations are considered to be a reservoir of Highly pathogenic avian influenza (HPAI) virus H5N1 in some agricultural production systems, as they are able to shed the virus for several days without clinical signs. Countries endemically affected with HPAI in Asia are characterised by production systems where ducks are fed on post-harvest spilled rice. During this scavenging process it is common for ducks to come into contact with other duck flocks or wild birds, thereby providing opportunities for virus spread. Effective risk management for HPAI has been significantly compromised by a limited understanding of management of moving duck flocks in these countries, despite of a small number of recent investigations. Here, for the first time, we described the management of moving duck flocks and the structure of the moving duck flock network in quantitative terms so that factors influencing the risk of HPAIV transmission can be identified. By following moving duck flock farmers over a period of 6 months in Java, Indonesia, we were able to describe the movement of flocks and to characterise the network of various types of actors associated with the production system. We used these data to estimate the basic reproductive number for HPAI virus spread. Our results suggest that focussing HPAI prevention measures on duck flocks alone will not be sufficient. Instead, the role of transporters of moving duck flocks, hatcheries and rice paddy owners, in the spread of the HPAI virus needs to be recognised.

  1. Reduction of campylobacter infections in broiler flocks by application of hygiene measures

    NARCIS (Netherlands)

    Giessen, A.W. van de; Tilburg, J.J.H.C.; Ritmeester, W.S.; Plas, J. van der

    1998-01-01

    Transmission routes of Campylobacter spp. in broilers and possibilities for prevention of infections were studied on two Dutch broiler farms. The occurrence of Campylobacter spp. was studied in successive broiler flocks, in the environment of the farms and in some of the parent flocks involved.

  2. Questionnaire study and postmortem findings in backyard chicken flocks in Finland

    OpenAIRE

    2015-01-01

    Abstract Background Although modern commercial poultry production today is based on large farms and intensive husbandry, keeping backyard poultry has regained popularity in industrialized countries. However, the health status of backyard flocks is still relatively poorly documented. A questionnaire was sent to the owners of 376 backyard poultry flocks (<500 birds) in order to ...

  3. Prevalence and risk factors of Campylobacter infection in broiler flocks from southern Spain.

    Science.gov (United States)

    Torralbo, Alicia; Borge, Carmen; Allepuz, Alberto; García-Bocanegra, Ignacio; Sheppard, Samuel K; Perea, Anselmo; Carbonero, Alfonso

    2014-05-01

    An extensive epidemiological study was performed to determine the prevalence and risk factors of Campylobacter infection in broiler farms in Andalusia (southern Spain). A total of 2221 cloacal swabs and 747 environmental swabs from 291 broiler flocks were screened between April 2010 and May 2012. The prevalence of Campylobacter in individual animals was 38.1%, and the flock prevalence was 62.9%. Flocks were predominantly infected by C. jejuni and C. coli but were also infected by untyped Campylobacter spp., and mixed-species infection could be found. Risk factors for Campylobacter infection were assessed from direct interview of the farmers. The number of positive samples by flock was modelled assuming a binomial distribution. Analysis indicated five factors associated with increased intra-flock prevalence: presence of dogs or cats on the farm, older age of the broiler flock, the application of thinning of flocks, the presence of windows with canvas blinds, and the presence of rodents in the poultry house. Two factors were associated with decreased intra-flock prevalence: the treatment of drinking water and having an entrance room for access into the poultry house. This is the first study performed on broilers farms from Spain reporting the risk factors of Campylobacter infection and is the largest study on the prevalence of Campylobacter infection.

  4. Reduction of campylobacter infections in broiler flocks by application of hygiene measures

    NARCIS (Netherlands)

    Giessen, A.W. van de; Tilburg, J.J.H.C.; Ritmeester, W.S.; Plas, J. van der

    1998-01-01

    Transmission routes of Campylobacter spp. in broilers and possibilities for prevention of infections were studied on two Dutch broiler farms. The occurrence of Campylobacter spp. was studied in successive broiler flocks, in the environment of the farms and in some of the parent flocks involved. Isol

  5. 9 CFR 146.23 - Terminology and classification; flocks and products.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Terminology and classification; flocks and products. 146.23 Section 146.23 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... POULTRY Special Provisions for Commercial Table-Egg Layer Flocks § 146.23 Terminology and...

  6. 9 CFR 145.10 - Terminology and classification; flocks, products, and States.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Terminology and classification; flocks, products, and States. 145.10 Section 145.10 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... POULTRY General Provisions § 145.10 Terminology and classification; flocks, products, and...

  7. 9 CFR 145.43 - Terminology and classification; flocks and products.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Terminology and classification; flocks and products. 145.43 Section 145.43 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... POULTRY Special Provisions for Turkey Breeding Flocks and Products § 145.43 Terminology and...

  8. 9 CFR 146.9 - Terminology and classification; flocks, products, and States.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Terminology and classification; flocks, products, and States. 146.9 Section 146.9 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... POULTRY General Provisions § 146.9 Terminology and classification; flocks, products, and...

  9. Footpad dermatitis in Dutch broiler flocks: Prevalence and factors of influence

    NARCIS (Netherlands)

    Jong, de I.C.; Harn, van J.; Gunnink, H.; Hindle, V.A.; Lourens, A.

    2012-01-01

    In some European countries, footpad dermatitis (FPD) is measured as an indicator of broiler welfare. Prevalence and seasonal variation of FPD was determined within broiler flocks (fast-growing breeds) in the Netherlands. Samples were taken from 386 Dutch flocks at 8 slaughterhouses during a period o

  10. Mobile Sensing of Pedestrian Flocks in Indoor Environments using WiFi Signals

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun; Wirz, Martin; Roggen, Daniel

    2012-01-01

    a cohesive whole - specifically flocks - with clustering approaches operating on three different feature sets derived from WiFi signals which are comparatively analysed. Automatic detection of flocks has several important applications, including social and psychological sensing and emergency research studies...

  11. 2D Hand Tracking Based on Flocking with Obstacle Avoidance

    Directory of Open Access Journals (Sweden)

    Zihong Chen

    2014-02-01

    Full Text Available Hand gesture-based interaction provides a natural and powerful means for human-computer interaction. It is also a good interface for human-robot interaction. However, most of the existing proposals are likely to fail when they meet some skin-coloured objects, especially the face region. In this paper, we present a novel hand tracking method which can track the features of the hand based on the obstacle avoidance flocking behaviour model to overcome skin-coloured distractions. It allows features to be split into two groups under severe distractions and merge later. The experiment results show that our method can track the hand in a cluttered background or when passing the face, while the Flocking of Features (FoF and the Mean Shift Embedded Particle Filter (MSEPF methods may fail. These results suggest that our method has better performance in comparison with the previous methods. It may therefore be helpful to promote the use of the hand gesture-based human-robot interaction method.

  12. Information transfer and behavioural inertia in starling flocks

    Science.gov (United States)

    Attanasi, Alessandro; Cavagna, Andrea; Del Castello, Lorenzo; Giardina, Irene; Grigera, Tomas S.; Jelić, Asja; Melillo, Stefania; Parisi, Leonardo; Pohl, Oliver; Shen, Edward; Viale, Massimiliano

    2014-09-01

    Collective decision-making in biological systems requires all individuals in the group to go through a behavioural change of state. During this transition fast and robust transfer of information is essential to prevent cohesion loss. The mechanism by which natural groups achieve such robustness, however, is not clear. Here we present an experimental study of starling flocks performing collective turns. We find that information about direction changes propagates across the flock with a linear dispersion law and negligible attenuation, hence minimizing group decoherence. These results contrast starkly with present models of collective motion, which predict diffusive transport of information. Building on spontaneous symmetry breaking and conservation-law arguments, we formulate a theory that correctly reproduces linear and undamped propagation. Essential to this framework is the inclusion of the birds' behavioural inertia. The theory not only explains the data, but also predicts that information transfer must be faster the stronger the group's orientational order, a prediction accurately verified by the data. Our results suggest that swift decision-making may be the adaptive drive for the strong behavioural polarization observed in many living groups.

  13. A Distributed Flocking Approach for Information Stream Clustering Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xiaohui [ORNL; Potok, Thomas E [ORNL

    2006-01-01

    Intelligence analysts are currently overwhelmed with the amount of information streams generated everyday. There is a lack of comprehensive tool that can real-time analyze the information streams. Document clustering analysis plays an important role in improving the accuracy of information retrieval. However, most clustering technologies can only be applied for analyzing the static document collection because they normally require a large amount of computation resource and long time to get accurate result. It is very difficult to cluster a dynamic changed text information streams on an individual computer. Our early research has resulted in a dynamic reactive flock clustering algorithm which can continually refine the clustering result and quickly react to the change of document contents. This character makes the algorithm suitable for cluster analyzing dynamic changed document information, such as text information stream. Because of the decentralized character of this algorithm, a distributed approach is a very natural way to increase the clustering speed of the algorithm. In this paper, we present a distributed multi-agent flocking approach for the text information stream clustering and discuss the decentralized architectures and communication schemes for load balance and status information synchronization in this approach.

  14. 2D Hand Tracking Based on Flocking with Obstacle Avoidance

    Directory of Open Access Journals (Sweden)

    Zihong Chen

    2014-02-01

    Full Text Available Hand gesture-based interaction provides a natural and powerful means for human-computer interaction. It is also a good interface for human-robot interaction. However, most of the existing proposals are likely to fail when they meet some skin-coloured objects, especially the face region. In this paper, we present a novel hand tracking method which can track the features of the hand based on the obstacle avoidance flocking behaviour model to overcome skin-coloured distractions. It allows features to be split into two groups under severe distractions and merge later. The experiment results show that our method can track the hand in a cluttered background or when passing the face, while the Flocking of Features (FoF and the Mean Shift Embedded Particle Filter (MSEPF methods may fail. These results suggest that our method has better performance in comparison with the previous methods. It may therefore be helpful to promote the use of the hand gesture-based human-robot interaction method.

  15. Mic Flocks in the Cloud: Harnessing Mobile Ubiquitous Sensor Networks

    Science.gov (United States)

    Garces, M. A.; Christe, A.

    2015-12-01

    Smartphones provide a commercial, off-the-shelf solution to capture, store, analyze, and distribute infrasound using on-board or external microphones (mics) as well as on-board barometers. Free iOS infrasound apps can be readily downloaded from the Apple App Store, and Android versions are in progress. Infrasound propagates for great distances, has low sample rates, and provides a tractable pilot study scenario for open distributed sensor networks at regional and global scales using one of the most ubiquitous sensors on Earth - microphones. Data collection is no longer limited to selected vendors at exclusive prices: anybody on Earth can record and stream infrasound, and the diversity of recording systems and environments is rapidly expanding. Global deployment may be fast and easy (www.redvox.io), but comes with the cost of increasing data volume, velocity, variety, and complexity. Flocking - the collective motion of mobile agents - is a natural human response to threats or events of interest. Anticipating, modeling and harnessing flocking sensor topologies will be necessary for adaptive array and network processing. The increasing data quantity and complexity will exceed the processing capacity of human analysts and most research servers. We anticipate practical real-time applications will require the on-demand adaptive scalability and resources of the Cloud. Cloud architectures for such heterogeneous sensor networks will consider eventual integration into the Global Earth Observation System of Systems (GEOSS).

  16. Chronic arsenic toxicity in sheep of Kurdistan province, western Iran.

    Science.gov (United States)

    Keshavarzi, Behnam; Seradj, Afsaneh; Akbari, Zahra; Moore, Farid; Shahraki, Alireza Rahmani; Pourjafar, Mehrdad

    2015-07-01

    After the detection of arsenic (As) toxicity in sheep from Ebrahim-abad and Babanazar villages in Kurdistan province, the concentration of this element in drinking water, cultivated soil, alfalfa hay, wool, and blood samples was evaluated. Total As concentrations ranged from 119 to 310 μg/L in drinking water, 46.70-819.20 mg/kg in soil 1.90-6.90 mg/kg in vegetation 1.56-10.79 mg/kg in sheep's wool, and 86.30-656 μg/L in blood samples. These very high As contents, in all parts of the biogeochemical cycle, exceed the recommended normal range for this element compared with a control area. Results indicate that As has moved through all compartments of the biogeochemical cycle by way of direct or indirect pathways. The present investigation illustrated decreased packed cell volume and hemoglobin in sheep from the As-contaminated zone. It was concluded that sheep from the contaminated areas suffer from anemia. Chronic As exposure of the liver was determined by liver function tests. For this purpose, blood aspartate transaminase (AST) and alanine transaminase (ALT) were measured. The results show that serum ALT and AST activities are increased significantly (p < 0.01) in the sheep population exposed to As in the contaminated zone. Moreover, chronic As exposure causes injury to hepatocytes and damages the liver.

  17. Preliminary investigation of bird and human movements and disease-management practices in noncommercial poultry flocks in southwestern British Columbia.

    Science.gov (United States)

    Burns, Theresa E; Kelton, David; Ribble, Carl; Stephen, Craig

    2011-09-01

    Understanding normal movement patterns and husbandry practices of poultry production systems is important for understanding the dynamics of disease spread, and for controlling outbreaks of highly infectious diseases, such as highly pathogenic avian influenza. To learn about these patterns in the noncommercial or "backyard" poultry-keeping sector, an open-ended questionnaire was administered to 18 backyard-flock owners in British Columbia, Canada, and responses were analyzed descriptively. Six participants reported that they visited premises that were part of the commercial poultry system in the last year; however, bird movements between commercial and noncommercial farms were always unidirectional, from commercial to backyard. Bird movements into and out of participants' flocks occurred multiple times per month (two flocks), three times per year (five flocks), once or twice a year (nine flocks) and every 3-5 yr (two flocks). Visitors had direct contact with three participants' flocks multiple times per week; for other flocks, visitors had direct contact three times or less per year. Fourteen participants rarely had direct contact with other backyard flocks, three had contact more than once per week, and one had contact every 3 mo. Participants stated that the health of their birds was excellent (7), very good (3), good (6), O.K. (1), and all right (1), and used a median of two biosecurity practices to maintain health in their flock. Our findings suggest that bird movements are not likely to transmit disease from backyard to commercial flocks; however, human movements between backyard and commercial premises could transmit diseases. Within the backyard-flock sector, the majority of small flocks appear to pose little risk of disease transmission because they are maintained in semi-isolation from other flocks; however, a minority of flocks has high contact levels with other flocks and could be important in disease spread.

  18. [National Bison Range: Annual narrative report 1924

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report summarizes conditions on the National Bison Range during 1924. Wildlife- including buffalo, elk, deer, mountain sheep, predators, rodents, and...

  19. Fighting the flow: the stability of model flocks in a vortical flow

    CERN Document Server

    Baggaley, Andrew W

    2016-01-01

    We investigate the stability of self-propelled particle flocks in the Taylor-Green vortex, a steady vortical flow. We consider a model where particles align themselves to a combination of the orientation and the acceleration of particles within a critical radius. We identify two distinct regimes, if alignment with orientation is dominant the particles tend to be expelled from regions of high vorticity. In contrast if anticipation is dominant the particles accumulate in areas of large vorticity. In both regimes the relative order of the flock is reduced. However we show that there can be a critical balance of the two effects which stabilises the flock in the presence of external fluid forcing. This strategy could provide a mechanism for animal flocks to remain globally ordered in the presence of fluid forcing, and may also have applications in the design of flocking autonomous drones and artificial microswimmers.

  20. Reductive Effect of Fly Screens on the Campylobacter Prevalence of Broiler Flocks in Summer

    DEFF Research Database (Denmark)

    Hald, Birthe; Sommer, Helle M.; Skovgård, Henrik

    Flies act as vectors in the introduction of Campylobacter from the environment to broiler flocks. We conducted a case-control study to evaluate the effect of fly screens on the prevalence of Campylobacter in broiler flocks. Cases were 52 broiler flocks reared in 20 houses on 11 farms between June...... and November 2006, where houses were equipped with fly screens made of glass fibre mesh. The controls consisted of 70 broiler flocks reared in 25 matched houses on 13 farms without screens. Other bio-security and management routines were strictly as before the study. All broiler houses were ventilated through...... wall inlets and roof outlets. The broiler flocks were sampled at days 21, 28, and 35 and at slaughter (on day 35 to 42). Samples were tested for Campylobacter by PCR. Campylobacter prevalence data were analyzed using SAS (SAS Institute). In fly screened houses, the Campylobacter prevalence was 15.4% (8...

  1. Effect of climate and farm environment on Campylobacter spp. colonisation in Norwegian broiler flocks

    DEFF Research Database (Denmark)

    Jonsson, Malin E.; Chriél, Mariann; Norström, Madelaine

    2012-01-01

    of Campylobacter spp. in Norwegian broiler flocks and factors related to the climate and the farm environment. Data from 18,488 broiler flocks from 623 different farms during 2002–2007 were included in the study. A logistic regression analysis was conducted where Campylobacter spp. status of a broiler flock...... at the time of slaughter was defined as the dependent variable and farm was modelled as a random effect. The following factors were found to increase the probability for a broiler flock to test positive for Campylobacter spp.: daily mean temperature above 6°C during the rearing period, private water supply......, presence of other livestock farms within a distance of 2km, presence of other broiler farms within a distance of 4km with flocks positive for Campylobacter spp. within 30 days prior to slaughter, heavy rainfall 11–30 days prior to slaughter, region and year. Daily mean temperature below 0°C reduced...

  2. Risk factors associated with Salmonella enterica serovar typhimurium infection in Danish broiler flocks

    DEFF Research Database (Denmark)

    Skov, M. N.; Angen, Øystein; Chriel, M.

    1999-01-01

    A retrospective longitudinal study was conducted to identify risk factors associated with Salmonella enterica serovar typhimurium (S. typhimurium) infection in Danish broiler flocks. The data included all broiler flocks slaughtered in 1995, and the epidemiological unit was the individual broiler...... flock. The S. typhimurium status was determined by microbiological examination of 60 fresh fecal samples. This procedure should detect an infected flock with a probability above 95%, if the prevalence is above 5%, and given that the sensitivity of the test is 100%. Nineteen variables were selected...... for analysis. Five factors and an interaction term were found significant by multivariate logistic regression analysis. An increased risk for S, typhimurium infection was associated with two parent flocks, one confirmed infected and one suspected of being infected with S. typhimurium, with two...

  3. Pre-harvest surveillance of Campylobacter and Salmonella in Danish broiler flocks: a 2-year study

    DEFF Research Database (Denmark)

    Wedderkopp, A.; Gradel, K.O.; Jorgensen, J.C.

    2001-01-01

    In national surveillance programmes of broiler flocks carried out in Denmark during 1998 and 1999, 89,110 samples for Campylobacter representing 8911 broiler flocks were taken at 10 different abattoirs, and 44,550 samples for Salmonella were taken from the same flocks in the broiler houses...... at the farms. Of the swabs, 42.5% were Campylobacter positive. Most positive samples were found during July, August and September, while the lowest number of positive samples were found during January, February, March and April. Of the flocks, 5.5% were Salmonella positive, but no seasonal variation...... was observed. For each flock, the presence of Campylobacter and Salmonella was recorded in order to estimate the possible correlation between colonisation with the two pathogens. In conclusion, no significant effects on intensive cleaning and disinfection procedures on Campylobacter occurrence could...

  4. 9 CFR 54.8 - Requirements for flock plans and post-exposure management and monitoring plans.

    Science.gov (United States)

    2010-01-01

    ... determine, the following: sire, dam, and offspring of the animal; (3) Date of acquisition and previous flock... cause of death, if known, or date of removal from the flock and name and address of the person to whom... choose to maintain, the date and cause of death, if known, or date of removal from the flock and name...

  5. 9 CFR 147.10 - Laboratory procedure recommended for the bacteriological examination of egg-type breeding flocks...

    Science.gov (United States)

    2010-01-01

    ... the bacteriological examination of egg-type breeding flocks with salmonella enteritidis positive... examination of egg-type breeding flocks with salmonella enteritidis positive environments. Birds selected for bacteriological examination from egg-type breeding flocks positive for Salmonella enteritidis after...

  6. Combined Campylobacter jejuni and Campylobacter coli Rapid Testing and Molecular Epidemiology in Conventional Broiler Flocks.

    Science.gov (United States)

    Schallegger, G; Muri-Klinger, S; Brugger, K; Lindhardt, C; John, L; Glatzl, M; Wagner, M; Stessl, B

    2016-12-01

    Campylobacter spp. are important causes of bacterial zoonosis, most often transmitted by contaminated poultry meat. From an epidemiological and risk assessment perspective, further knowledge should be obtained on Campylobacter prevalence and genotype distribution in primary production. Consequently, 15 Austrian broiler flocks were surveyed in summer for their thermophilic Campylobacter spp. contamination status. Chicken droppings, dust and drinking water samples were collected from each flock at three separate sampling periods. Isolates were confirmed by PCR and subtyped. We also compared three alternative methods (culture-based enrichment in Bolton broth, culture-independent real-time PCR and a lateral-flow test) for their applicability in chicken droppings. Twelve flocks were found to be positive for thermophilic Campylobacter spp. during the entire sampling period. Seven flocks (46.6%) were contaminated with both, C. jejuni and C. coli, five flocks harboured solely one species. We observed to a majority flock-specific C. jejuni and C. coli genotypes, which dominated the respective flock. Flocks within a distance jejuni genotypes indicating a cross-contamination event via the environment or personnel vectors. Multilocus sequence typing (MLST) of C. jejuni revealed that the majority of isolates were assigned to globally distributed clonal complexes or had a strong link to the human interface (CC ST-446 and ST4373). The combination of techniques poses an advantage over risk assessment studies based on cultures alone, as, in the case of Campylobacter, occurrence of a high variety of genotypes might be present among a broiler flock. We suggest applying the lateral-flow test under field conditions to identify 'high-shedding' broiler flocks at the farm level. Consequently, poultry farmers and veterinarians could improve hygiene measurements and direct sanitation activities, especially during the thinning period. Ultimately, real-time PCR could be applied to quantify

  7. QUINOLONE- AND ETA-LACTAM- RESISTANCE IN Escherichia coli FROM DANISH AND ITALIAN BROILER FLOCKS

    Directory of Open Access Journals (Sweden)

    M. Trevisani

    2009-03-01

    Full Text Available The prevalence of quinolone- and -lactam-resistant E. coli was investigated among healthy broiler flocks in Denmark and Italy. In Denmark, sock samples were collected from 10 parent flocks and 10 offspring flocks, according to the procedure currently used for the surveillance of Salmonella in the EU. Samples were enriched in McConkey broth and streaked on McConkey agar plates added with nalidixic acid (32 g/ml, ciprofloxacin (2 g/ml, ampicillin (32 g/ml, cefotaxime (2 g/ml or ceftiofur (8 g/ml. The -glucuronidase test was performed for verification of presumptive E. coli. The same methods were used to analyse sock samples collected from 6 Italian broiler flocks. PCR with primers for the CTX-M-type extended-spectrum -lactamases (ESBLs was performed on cephalosporin-resistant isolates. While resistance to ampicillin and nalidixic acid was widespread in both countries, resistance to ciprofloxacin and cephalosporins was more common among Italian flocks. In Denmark, ciprofloxacin resistance was only detected in 1 parent flock without any history of quinolone usage and none of the flocks was positive for cephalosporin-resistant E. coli. In Italy, resistance to ciprofloxacin was detected in all flocks and resistance to ceftiofur and cefotaxime were detected in 5 flocks. Primers specific for the CTX-M-type ESBLs generated PCR amplicons from isolates from 3 of these flocks. In industrialized countries, the poultry production system is highly standardized, and therefore comparable. However, the use of broad-spectrum antimicrobials is particularly limited in Danish poultry production. Accordingly, the results of this study could reflect the different policies in antimicrobial usage between the two countries.

  8. Isolation and immunological detection of Mycoplasma ovipneumoniae in sheep with atypical pneumonia, and lack of a role for Mycoplasma arginini.

    Science.gov (United States)

    Lin, Y-C; Miles, R J; Nicholas, R A J; Kelly, D P; Wood, A P

    2008-06-01

    Mycoplasma ovipneumoniae NCTC 10151(T) and four new isolates from UK sheep flocks were compared. Only glucose and pyruvate were used as energy sources by the five strains: glucose was the best energy source for the type strain, pyruvate supported better growth of the new strains. Whole cell protein patterns and antigenic profiles showed high similarity between all five strains. The new isolates fell into two groups in ELISA tests. Serum samples from 30 pneumonic sheep were assessed for M. ovipneumoniae infection and Mycoplasma arginini co-infection. Fourteen (out of 30) serum samples were positive for M. ovipneumoniae both by ELISA and immunoblotting. Twelve antigenic proteins of M. ovipneumoniae were detected in infected serum samples: the antigen patterns were unique, with between one and at least seven occurring in any one sample. All serum samples were designated as negative for M. arginini antibodies by both ELISA and immunoblotting.

  9. The Koundoum sheep breed in Niger: morpho-biometric study and description of the production system

    Directory of Open Access Journals (Sweden)

    Issa Hamadou

    2015-05-01

    Full Text Available The diffusion of highly productive breeds across developing countries goes along with a neglect of indigenous breeds, which are well suited to their environment but often show low yields. Thus, in Niger, the flock of Koundoum sheep are rapidly decreasing. The Koundoum is one of the few wool sheep breeds of Africa and shows important adaptive feature to its native environment, i.e. the humid pastures on the banks of the Niger River. To characterise the breed and to understand its production context, a survey has been conducted in 104 herds in four communes along the Niger River (Kollo, Tillabery, Say and Tera. Nine body measurements, including live weight, were taken on 180 adult sheep (101 females and 79 males. The herds varied from 2 to 60 heads, with a median size of eight animals and two thirds of the herds having less than 10 animals. Mainly fed on natural pastures, 85.6% of the herds received crop residues. Only natural mating was practiced. Veterinary care was restricted to anti-helminthic and some indigenous treatments. The frequent affiliation of breeders to professional unions appeared as favourable to the implementation of a collective conservation program. The Koundoum sheep were white or black coated, with the black colour being most frequent (75.6 %. Wattles were present in both sexes at similar frequencies of around 14 %. All biometric variables were significantly and positively correlated between them. The thoracic perimeter showed the best correlation with live weight in both males and females. Three variables were selected for live weight prediction: thoracic perimeter, height at withers and rump length. From the present study, it is expected that the in situ conservation of the Koundoum sheep will be highly problematic, due to lack of market opportunities for wool and the willingness of smallholders to get involved in pure Koundoum rearing.

  10. The effects of food abundance and disturbance on foraging flock patterns of the wintering Hooded Crane(Grus monacha)

    Institute of Scientific and Technical Information of China (English)

    Ling Yang; Lizhi Zhou; Yunwei Song

    2015-01-01

    Background:Food abundance and availability affect flock patterns of foraging birds.Cost and risk tradeoffs are especially critical for flocks of wintering waterbirds foraging in lake wetlands.Waterbirds losing suitable habitats face insufficient food supplies and high levels of disturbance,affecting their foraging activities.Our objective was to study the effects of food abundance and disturbances on flock size and the structure of Hooded Crane flocks wintering at Shengjin Lake and,as well,to understand the response of wintering waterbirds to habitat degradation for future management decisions and protection of the population.Methods:We investigated food abundance,disturbances and flock foraging activities of the wintering Hooded Crane in several foraging habitats of Shengjin Lake from November 2013 to April 2014.Flock size and structure were observed by scan sampling.Data on food abundance and disturbances were collected by sampling.Flock size and structure were compared among three wintering stages.The relationship between food resources,disturbances and flock size were illustrated using a generalized linear model.Results:In the early and middle wintering periods,the Hooded Crane used paddy fields as its major foraging habitat,where the number of foraging birds and flocks were the highest.During the late period,the cranes took to meadows as their major foraging habitat.The variation among foraging flock was mainly embodied in the size of the flocks,while the age composition of these flocks did not change perceptibly.Family flocks were notably different from flock groups in size and age composition.The results of a generalized linear model showed that the food abundance had a marked effect on foraging flock size and age composition,while disturbances had a significant effect only on flock size.From our analysis,it appeared that the combined effect of the two variables was significant on the size of the foraging flock,but had less impact on age composition

  11. The effects of food abundance and disturbance on foraging flock patterns of the wintering Hooded Crane (Grus monacha)

    Institute of Scientific and Technical Information of China (English)

    Ling Yang; Lizhi Zhou; Yunwei Song

    2015-01-01

    Background:Food abundance and availability affect flock patterns of foraging birds. Cost and risk tradeoffs are especially critical for flocks of wintering waterbirds foraging in lake wetlands. Waterbirds losing suitable habitats face insufficient food supplies and high levels of disturbance, affecting their foraging activities. Our objective was to study the effects of food abundance and disturbances on flock size and the structure of Hooded Crane flocks wintering at Shengjin Lake and, as well, to understand the response of wintering waterbirds to habitat degradation for future management decisions and protection of the population. Methods:We investigated food abundance, disturbances and flock foraging activities of the wintering Hooded Crane in several foraging habitats of Shengjin Lake from November 2013 to April 2014. Flock size and structure were observed by scan sampling. Data on food abundance and disturbances were collected by sampling. Flock size and structure were compared among three wintering stages. The relationship between food resources, disturbances and flock size were illustrated using a generalized linear model. Results:In the early and middle wintering periods, the Hooded Crane used paddy fields as its major foraging habitat, where the number of foraging birds and flocks were the highest. During the late period, the cranes took to meadows as their major foraging habitat. The variation among foraging flock was mainly embodied in the size of the flocks, while the age composition of these flocks did not change perceptibly. Family flocks were notably different from flock groups in size and age composition. The results of a generalized linear model showed that the food abundance had a marked effect on foraging flock size and age composition, while disturbances had a significant effect only on flock size. From our analysis, it appeared that the combined effect of the two variables was significant on the size of the foraging flock, but had less impact

  12. Husbandry Practices and Outbreak Features of Natural Highly Pathogenic Avian Influenza H5N1 in Turkey Flocks in Nigeria 2006-2008

    Directory of Open Access Journals (Sweden)

    Olatunde Babatunde Akanbi

    2015-12-01

    Full Text Available The Highly Pathogenic Avian Influenza (HPAI outbreaks in Nigeria that occurred during 2006-2008, affected 80 farms that kept subsistence indigenous chicken, duck, turkey, guinea fowl and geese in 15 states of the country including the capital, Abuja resulting in a total loss of more than 14,000 birds in backyard, semi-intensive or free-ranged flocks. The rearing of rural poultry in free-range, multispecies, multiage holdings that have low biosecurity levels have shown to expose them to many contact risks. In order to sustain turkey production in the country in view of the ongoing resurgent HPAI outbreaks, it is necessary to assess the impact of HPAI on this species and to evaluate the husbandry and outbreak features of affected flocks. Spatial data confirmed the presence of HPAI virus in both domestic and commercial poultry farms from 25 States and the Federal Capital Territory (FCT in Nigeria were added to a Geographical Information System (GIS using ESRI ArcGIS 10.3 (ESRI®, USA and QGIS 2.8.2 Desktop (OSGeo and visualized using QGIS. Post mortem examinations of submitted carcasses were carried out and swabs and tissues were analyzed by virus isolation (VI and reverse transcriptase polymerase chain reaction (RT-PCR. HPAI in turkey flocks were mostly in northern part of the country where most poultry mainly subsistence are domiciled and are more in the densely cities of the north. The poultry management systems employed by the subsistence turkey farmers were mainly semi-intensive backyard and free-ranged system of poultry. HPAI introduction sources vary from the introduction of new poultry species (geese and turkey from LBM, to the death of neighborhood poultry and extension to turkey flocks and/or contact with free-ranging local chickens. It is obvious that the husbandry and the management system had influenced on the introduction of the virus and the course of the disease.

  13. Identification of Natural Infections in Sheep/Goats with HoBi-like Pestiviruses in China.

    Science.gov (United States)

    Shi, H; Kan, Y; Yao, L; Leng, C; Tang, Q; Ji, J; Sun, S

    2016-10-01

    The natural infections of HoBi-like pestiviruses in cattle have been reported in South America, Europe and Asia. In China, although the detections of HoBi-like pestivirus have been reported, the epidemiological investigation was limited. From January 2014 to October 2015, several flocks of sheep/goats in Henan province in central China suffered respiratory diseases which were recovered slowly after antibiotics treatment. To test whether it is the HoBi-like pestivirus caused this symptom, 49 serum samples and 22 nasal swabs were then collected for analysis by serology and RT-PCR. Serological result revealed that prevalence of pestivirus in small ruminants was 12.2% (6/49) in central China. Sequence analysis of partial 5'-UTR nucleotides of pestivirus-positive samples suggested that HoBi-like pestivirus might have circulated in sheep/goats of China for a period and have evolved into new genotype clusters. It is apparent that the study provides the molecular evidence of natural infections in goat/sheep species with HoBi-like pestiviruses in China.

  14. Economic values for production traits for different sheep breeds in Kosovo

    Directory of Open Access Journals (Sweden)

    Hysen Bytyqi

    2015-10-01

    Full Text Available Generally, all traits of economic importance should be included in the breeding goal of livestock breeding programmes. The main aim of this study was to examine economic values for a combination of dairy and meat traits of the dual purpose Bardhoka (BAR, Balusha (BAL, Sharri (SHA and Kosova (KOS sheep breeds in Kosovo. The underlying herd model is based on a deterministic approach considering a sheep flock with milk production, lamb fattening and replacement stock. In order to examine the economic impact for different sheep breeds, the production traits considered were milk (milk yield and fattening (daily gain. For each lactation cycle among the breeds the main revenues resulted from selling milk (€ 61.82/46.03/26.37/27.22 and fattened lambs (€ 34.06/39.88/35.42/33.92 for BAR/BAL/ SHA/KOS, respectively. For BAR and BAL the economic value per average ewe place and year was € 37.7 for both breeds, while for SHA and KOS it was € 35.1 and € 32.5, respectively. For lamb fattening, daily gain was found to have the highest economic value at € 7.00 for BAL, SHA and KOS, while for BAR it was € 6.67. The relative economic values for milk yield and daily gain for BAR, BAL, SHA and KOS were 84.96:15.04, 84.42:15.58, 83.45:16.55, and 82.36:17.64, respectively.

  15. The isolation of multiple strains of Mycoplasma ovipneumoniae from individual pneumonic sheep lungs.

    Science.gov (United States)

    Ionas, G; Clarke, J K; Marshall, R B

    1991-11-01

    The heterogeneity of Mycoplasma ovipneumoniae isolates from the lungs of sheep with chronic non-progressive pneumonia (CNP) from the same flock raised the possibility that multiple isolates derived from one lung were not all identical. To test this hypothesis, thirty isolates were obtained from each of six pneumonic sheep lungs at slaughter. Four lungs had relatively severe lesions and from each of these, three or four strains of M. ovipneumonia, distinguishable by REA and in most cases by SDS-PAGE, were detected. From the lungs of each of two sheep with mild lesions, two strains of M. ovipneumoniae were detected. Four isolates from one lung were further examined by restriction endonuclease analysis (REA) using many restriction endonucleases. Those which differed with EcoRI also differed when other restriction endonucleases were used. However, partial digests occurred mainly with those restriction endonucleases which recognise cytosine-rich sequences. The presence of multiple strains of one species of microorganism in individual lesions is an unusual concept which may not be limited to one disease or to one host.

  16. Genetic parameters for resistance to the Salmonella abortusovis vaccinal strain Rv6 in sheep

    Directory of Open Access Journals (Sweden)

    Bouix Jacques

    2003-03-01

    Full Text Available Abstract An experimental population (1216 lambs from 30 sires of the Inra401 sheep was created in an Inra flock to allow QTL detection for susceptibility to Salmonella infection, wool and carcass traits. The Inra401 is a sheep composite line developed from two breeds: Berrichon du Cher and Romanov. At 113 days of age on average, the lambs were inoculated intravenously with 108 Salmonella abortusovis Rv6 (vaccinal strain. They were slaughtered 10 days after the inoculation. Several traits were measured at inoculation and/or slaughtering to estimate the genetic resistance of the lambs to Salmonella infection: specific IgM and IgG1 antibody titres, body weight loss, spleen and pre-scapular node weights and counts of viable Salmonella persisting in these organs. This paper presents a quantitative analysis of the genetic variability of the traits related to salmonellosis susceptibility. The heritabilities of the traits varied between 0.10 and 0.64 (significantly different from zero. Thus, in sheep as well as in other species, the determinism of resistance to Salmonella infection is under genetic control. Moreover, the correlations between the traits are in agreement with the known immune mechanisms. The genetic variability observed should help QTL detection.

  17. Production trials involving use of the FAMACHA© system for haemonchosis in sheep : preliminary results

    Directory of Open Access Journals (Sweden)

    J.A. Van Wyk

    2008-09-01

    Full Text Available In three trials conducted on two separate farms the production of sheep treated for naturally acquired haemonchosis using the FAMACHA© system of targeted selective treatment (TST (i.e. to treat only those animals unable to manage unaided in the face of heavy Haemonchus challenge was compared to that of suppressively drenched sheep in the same flock. As expected by the research team who developed and evaluated the FAMACHA© system, TST did result in some loss in production. However, despite high levels of worm challenge in two of the trials and the fact that the comparison was with suppressive drenching which is not sustainable, the total effect was relatively small in relation to the important advantage of using the TST as regards reduced selection for anthelmintic resistance (AR. Concerning the sustainability of worm control, it is concluded that the development of drug resistance to anthelmintics leaves sheep and goat farmers in South Africa no choice but to use methods of TST such as FAMACHA©. The FAMACHA© system can also be a useful clinical aid for early on-farm detection of AR by farmers; the degree of improvement in the colour of the ocular mucous membrane from pale to red in individually drenched anaemic animals over a period of 7-14 days can give a good indication of the efficacy of the compound(s used.

  18. Implications of Genotype by Environment Interactions in Dairy Sheep Welfare

    Directory of Open Access Journals (Sweden)

    Dinu Gavojdian

    2014-05-01

    Full Text Available Small ruminants are the most extensively farmed livestock species in Europe, as a result being extremely exposed to natural hazards which leads to strong interactions between genotype and environment. Aim of the current review was to outline and discuss the main welfare issues and economic implications with regards to the genotype by environment interactions in dairy sheep. Researches concerning the additive genetic effect on milk yield, shown that this accounts only for 10%, while the milk production is 90% influenced by environmental factors, highlighting the major role that management and nutrition play in the dairy production of sheep. Nowadays, dairy sheep breeds (e.g. Eastern Friesian and Lacaune, are being introduced and reared in various countries under an extremely wide range of rearing conditions, without adequate knowledge on their acclimatization to the new specific conditions. It was concluded that a welfare assessment protocol for dairy sheep does not exist up today, moreover, there is a serious lack of data concerning the genetic and environmental factors affecting the welfare status of dairy sheep at farm level under different production systems.

  19. Potential risk factors associated with contact dermatitis, lameness, negative emotional state, and fear of humans in broiler chicken flocks.

    Science.gov (United States)

    Bassler, A W; Arnould, C; Butterworth, A; Colin, L; De Jong, I C; Ferrante, V; Ferrari, P; Haslam, S; Wemelsfelder, F; Blokhuis, H J

    2013-11-01

    The objectives of this study were to 1) identify determinants of poor welfare in commercial broiler chicken flocks by studying the associations between selected resource-based measures (RBM, potential risk factors), such as litter quality and dark period, and animal-based welfare indicators (ABM), such as foot pad dermatitis and lameness, and 2) establish the breadth of effect of a risk factor by determining the range of animal welfare indicators associated with each of the risk factors (i.e., the number of ABM related to a specific RBM). Eighty-nine broiler flocks were inspected in 4 European countries (France, Italy, the United Kingdom, and the Netherlands) in a cross-sectional study. The ABM were contact dermatitis (measured using scores of foot-pad dermatitis and hock burn, respectively), lameness (measured as gait score), fear of humans (measured by the avoidance distance test and the touch test), and negative emotional state (measured using qualitative behavior assessment, QBA). In a first step, risk factors were identified by building a multiple linear regression model for each ABM. Litter quality was identified as a risk factor for contact dermatitis. Length of dark period at 3 wk old (DARK3) was a risk factor for the touch test result. DARK3 and flock age were risk factors for lameness, and the number of different stockmen and DARK3 were risk factors for QBA results. Next, the ABM were grouped according to risk factor and counted. Then, in a second step, associations between the ABM were investigated using common factor analysis. The breadth of a risk factor's effect was judged by combining the number (count) of ABM related to this factor and the strength of association between these ABM. Flock age and DARK3 appeared to affect several weakly correlated ABM, thus indicating a broad range of effects. Our findings suggest that manipulation of the predominant risk factors identified in this study (DARK3, litter quality, and slaughter age) could generate

  20. The dynamics of Salmonella occurrence in commercial laying hen flocks throughout a laying period.

    Science.gov (United States)

    Schulz, J; Van Hoorebeke, S; Hald, B; Hartung, J; Van Immerseel, F; Radtke, I; Kabell, S; Dewulf, J

    2011-06-01

    Contaminated eggs and egg products have been recognized for many years as an important source of Salmonella infections in humans in the European Union and in the United States. Longitudinal studies can help to increase our knowledge about the dynamics of the occurrence of Salmonella in the course of a laying period. The total of 41 laying hen flocks-18 in Belgium, six in Denmark and 17 in Germany-were followed during an entire laying period. Samples taken from the empty cleaned and disinfected poultry houses were all negative for Salmonella. After hens arrived on the farms, five pooled faecal samples, one pooled dust sample and 40 cloacal swabs (Belgium and Germany) or 40 swabs from fresh droppings (Denmark) were taken four times from 18 flocks, three times from 21 flocks and two times from two flocks in the course of the laying period. Ten flocks (two Belgian and eight German flocks) tested up to three times positive for Salmonella. Forty-three out of 50 positive samples contained Salmonella Enteritidis phage type 4 (29 isolates) or phage type 8 (14 isolates). The probability of subsequent Salmonella-positive findings increased significantly in Salmonella-positive flocks (Playing period or the season.

  1. Climatic factors and prevalence of Campylobacter in commercial broiler flocks in Thailand.

    Science.gov (United States)

    Prachantasena, S; Charununtakorn, P; Muangnoicharoen, S; Hankla, L; Techawal, N; Chaveerach, P; Tuitemwong, P; Chokesajjawatee, N; Williams, N; Humphrey, T; Luangtongkum, T

    2017-04-01

    Campylobacter are bacteria associated with human foodborne disease worldwide. Poultry and poultry products are generally considered as a main source of these organisms. Compared to temperate zones, baseline information on Campylobacter in tropical regions is limited. Thus, the objectives of the present study were 1) to determine the prevalence of Campylobacter in Thai broiler flocks and 2) to investigate the association between climatic factors (i.e., rainfall, ambient temperature, and relative humidity) and Campylobacter colonization status of broiler flocks in Thailand. A total of 442 commercial broiler flocks reared in the central and northeastern regions of Thailand during 2012 to 2014 were investigated. Campylobacter positive status was identified in 252 examined flocks (57.01%; 95% CI 52.39 to 61.63%). Prevalence of Campylobacter in the northeastern region (54.46%; 95% CI 44.76 to 63.83%) was slightly lower than that of the central region (57.77%; 95% CI 52.47 to 62.90%). More than 65% of Campylobacter positive flocks in the central and northeastern regions had within-flock prevalence higher than 75%. Generalized estimating equations (GEE) revealed that the increased rainfall and relative humidity were associated with the increase of Campylobacter colonization in broiler flocks (P ≤ 0.05), while no relationship between ambient temperature and Campylobacter colonization status was identified. © 2016 Poultry Science Association Inc.

  2. Enhanced biochemical and biomechanical properties of scaffolds generated by flock technology for cartilage tissue engineering.

    Science.gov (United States)

    Steck, Eric; Bertram, Helge; Walther, Anja; Brohm, Kathrin; Mrozik, Birgit; Rathmann, Maxi; Merle, Christian; Gelinsky, Michael; Richter, Wiltrud

    2010-12-01

    Natural cartilage shows column orientation of cells and anisotropic direction of collagen fibers. However, matrices presently used in matrix-assisted autologous chondrocyte implantation do not show any fiber orientation. Our aim was to develop anisotropic scaffolds with parallel fiber orientation that were capable to support a cellular cartilaginous phenotype in vitro. Scaffolds were created by flock technology and consisted of a membrane of mineralized collagen type I as substrate, gelatine as adhesive, and parallel-oriented polyamide flock fibers vertically to the substrate. Confocal laser scan microscopy demonstrated that mesenchymal stem cells (MSCs) adhered and proliferated well in the scaffolds and cell vitality remained high over time. Articular chondrocytes seeded in a collagen type I gel into flock scaffolds deposited increasing amounts of proteoglycans and collagen type II over time. MSC-seeded flock scaffold constructs under chondrogenic conditions deposited significantly more proteoglycans and collagen type II than MSC collagen type I gel constructs only. Biomechanical testing revealed higher initial hardness of flock scaffolds than that of a clinically applied collagen type I/III scaffold combined with superior relaxation and an increasing hardness in MSC-loaded flock biocomposites during chondrogenesis. In conclusion, flock technology allows fabrication of scaffolds with anisotropic fiber orientation that mediates superior biomechanical and biochemical composition of tissue engineering constructs for cartilage repair.

  3. Flocking of multiple mobile robots based on backstepping.

    Science.gov (United States)

    Dong, Wenjie

    2011-04-01

    This paper considers the flocking of multiple nonholonomic wheeled mobile robots. Distributed controllers are proposed with the aid of backstepping techniques, results from graph theory, and singular perturbation theory. The proposed controllers can make the states of a group of robots converge to a desired geometric pattern whose centroid moves along a desired trajectory under the condition that the desired trajectory is available to a portion of the group of robots. Since communication delay is inevitable in distributed control, its effect on the performance of the closed-loop systems is analyzed. It is shown that the proposed controllers work well if communication delays are constant. To show effectiveness of the proposed controllers, simulation results are included.

  4. Enteric viruses in turkey flocks: a historic review

    Directory of Open Access Journals (Sweden)

    JM Alavarez

    2014-09-01

    Full Text Available In this review, diagnostic techniques and viral agents involved in enteric diseases affecting turkeys are described. Data from field observations and laboratory researches have been reported in turkey flocks for over 70 years, and several viruses have been identified. After a period of 30 years of inoculation experiments and neutralization studies, adequate visualization of the viruses was achieved using electronic microscopy. During the following years, several studies were then conducted to isolate and classify those viruses using cell-culture, embryo-propagation, serological tests, genome electropherotyping by polyacrylamide gel electrophoresis of double-stranded RNA viruses, and recently, nucleic acid studies. Thus, since the 1990s, the nucleic-acid technology has focused on genomic surveys and on the detection of specific segments of the genome of each virus using the polymerase-chain reaction, resulting in several prevalence studies and phylogenetic analyses of different isolates and proper classification of the viruses.

  5. A genome resource to address mechanisms of developmental programming: determination of the fetal sheep heart transcriptome.

    Science.gov (United States)

    Cox, Laura A; Glenn, Jeremy P; Spradling, Kimberly D; Nijland, Mark J; Garcia, Roy; Nathanielsz, Peter W; Ford, Stephen P

    2012-06-15

    The pregnant sheep has provided seminal insights into reproduction related to animal and human development (ovarian function, fertility, implantation, fetal growth, parturition and lactation). Fetal sheep physiology has been extensively studied since 1950, contributing significantly to the basis for our understanding of many aspects of fetal development and behaviour that remain in use in clinical practice today. Understanding mechanisms requires the combination of systems approaches uniquely available in fetal sheep with the power of genomic studies. Absence of the full range of sheep genomic resources has limited the full realization of the power of this model, impeding progress in emerging areas of pregnancy biology such as developmental programming. We have examined the expressed fetal sheep heart transcriptome using high-throughput sequencing technologies. In so doing we identified 36,737 novel transcripts and describe genes, gene variants and pathways relevant to fundamental developmental mechanisms. Genes with the highest expression levels and with novel exons in the fetal heart transcriptome are known to play central roles in muscle development. We show that high-throughput sequencing methods can generate extensive transcriptome information in the absence of an assembled and annotated genome for that species. The gene sequence data obtained provide a unique genomic resource for sheep specific genetic technology development and, combined with the polymorphism data, augment annotation and assembly of the sheep genome. In addition, identification and pathway analysis of novel fetal sheep heart transcriptome splice variants is a first step towards revealing mechanisms of genetic variation and gene environment interactions during fetal heart development.

  6. Transmission of lungworms (Muellerius capillaris) from domestic goats to bighorn sheep on common pasture.

    Science.gov (United States)

    Foreyt, William J; Jenkins, E J; Appleyard, G D

    2009-04-01

    Four domestic goats (Capra hircus) that were passing first-stage dorsal-spined larvae of Muellerius capillaris were copastured on a 0.82-ha pasture for 11 mo from May 2003 to April 2004 with seven Rocky Mountain bighorn sheep (Ovis canadensis) that were not passing dorsal-spined larvae. During the 11-mo experiment, two bighorn sheep died from pneumonia caused by Mannheimia (Pasteurella) haemolytica biotype A, serotype 2. The remaining five bighorn sheep and the four domestic goats remained healthy throughout the experiment. Muellerius larvae were detected from all domestic goats on a monthly basis throughout the experiment and were first detected from all five surviving bighorn sheep approximately 5 mo after the copasturing began. Once the bighorn sheep began passing Muellerius larvae, larvae were detected in low numbers from all bighorn sheep every month thereafter for the 6 mo the goats were still in the enclosure and continued to pass larvae for more than 3 yr after the goats were removed from the experiment. Six bighorn sheep in two similar enclosures that did not contain goats did not pass Muellerius larvae before, during, or after the experimental period. Results of this experiment indicate that M. capillaris from domestic goats is capable of infecting bighorn sheep when animals are copastured together on a common range.

  7. Epizootic pneumonia of bighorn sheep following experimental exposure to Mycoplasma ovipneumoniae.

    Science.gov (United States)

    Besser, Thomas E; Cassirer, E Frances; Potter, Kathleen A; Lahmers, Kevin; Oaks, J Lindsay; Shanthalingam, Sudarvili; Srikumaran, Subramaniam; Foreyt, William J

    2014-01-01

    Bronchopneumonia is a population limiting disease of bighorn sheep (Ovis canadensis). The cause of this disease has been a subject of debate. Leukotoxin expressing Mannheimia haemolytica and Bibersteinia trehalosi produce acute pneumonia after experimental challenge but are infrequently isolated from animals in natural outbreaks. Mycoplasma ovipneumoniae, epidemiologically implicated in naturally occurring outbreaks, has received little experimental evaluation as a primary agent of bighorn sheep pneumonia. In two experiments, bighorn sheep housed in multiple pens 7.6 to 12 m apart were exposed to M. ovipneumoniae by introduction of a single infected or challenged animal to a single pen. Respiratory disease was monitored by observation of clinical signs and confirmed by necropsy. Bacterial involvement in the pneumonic lungs was evaluated by conventional aerobic bacteriology and by culture-independent methods. In both experiments the challenge strain of M. ovipneumoniae was transmitted to all animals both within and between pens and all infected bighorn sheep developed bronchopneumonia. In six bighorn sheep in which the disease was allowed to run its course, three died with bronchopneumonia 34, 65, and 109 days after M. ovipneumoniae introduction. Diverse bacterial populations, predominantly including multiple obligate anaerobic species, were present in pneumonic lung tissues at necropsy. Exposure to a single M. ovipneumoniae infected animal resulted in transmission of infection to all bighorn sheep both within the pen and in adjacent pens, and all infected sheep developed bronchopneumonia. The epidemiologic, pathologic and microbiologic findings in these experimental animals resembled those seen in naturally occurring pneumonia outbreaks in free ranging bighorn sheep.

  8. Quinolone- and ß-lactam-resistance in Escherichia coli from Danish and Italian broiler flocks

    DEFF Research Database (Denmark)

    Bortolaia, Valeria; Guardabassi, Luca; Bisgaard, Magne

    , sock samples were collected from 10 parent flocks and 10 offspring flocks, according to the procedure currently used for the surveillance of Salmonella in the EU. Samples were enriched in McConkey broth and streaked on McConkey agar plates added with nalidixic acid (32 µg/ml), ciprofloxacin (2 µg...... on cephalosporin-resistant isolates. While resistance to ampicillin and nalidixic acid was widespread in both countries, resistance to ciprofloxacin and cephalosporins was more common among Italian flocks. In Denmark, ciprofloxacin resistance was only detected in one parent flock without any history of quinolone...... usage and none of the flocks was positive for cephalosporin-resistant E. coli. In Italy, resistance to ciprofloxacin was detected in all flocks and resistances to ceftiofur and cefotaxime were detected in five flocks. Primers specific for the CTX-M-type ESBLs generated PCR amplicons from isolates from...

  9. Farmer reported prevalence and factors associated with contagious ovine digital dermatitis in Wales: A questionnaire of 511 sheep farmers.

    Science.gov (United States)

    Angell, J W; Duncan, J S; Carter, S D; Grove-White, D H

    2014-01-01

    In 2012, 2000 questionnaires were sent to a random sample of Welsh sheep farmers. The questionnaire investigated farmers' knowledge and views on contagious ovine digital dermatitis (CODD) - an emerging disease of sheep responsible for causing severe lameness, welfare and production problems. The overall response rate was 28.3% with a usable response rate of 25.6%. The between farm prevalence of CODD was 35.0% and the median farmer estimated prevalence of CODD was 2.0%. The disease now appears endemic and widespread in Wales. Furthermore, there has been a rapid increase in reports of CODD arriving on farms since the year 2000. Risk factors for CODD identified in this study include the presence of bovine digital dermatitis (BDD) in cattle on the farm and larger flocks. Farmers also consider concurrent footrot/interdigital dermatitis, buying in sheep, adult sheep, time of year and housing to be associated with CODD. Further experimental research is necessary to establish whether these observations are true associations.

  10. Impacts of animal science research on United States sheep production and predictions for the future.

    Science.gov (United States)

    Lupton, C J

    2008-11-01

    One hundred years ago, there were more than 48 million sheep in the United States. In 1910, they were valued at $4/head, with 43% of income coming from the sale of sheep, lambs, and meat and 57% coming from wool. Over the years, fluctuations in this ratio have challenged the breeder and researcher alike. By 2007, sheep numbers had declined to 6.2 million, with the average sheep shearing 3.4 kg of wool (representing animal science research has made little impact on sheep production in the United States. On the contrary, lamb crops in the new millennium (range = 109 to 115%) are greater than those recorded in the 1920s (85 to 89%) and dressed lamb weights increased from 18 to 32 kg from 1940 to the present. In the past century, researchers conducted thousands of investigations, with progress reported in new, existing, and crossbreed evaluations, quantitative and molecular genetics, selection, nutrition, fiber, meat, hides, milk, growth, physiology, reproduction, endocrinology, management, behavior, the environment, disease, pharmacology, toxicology, and range, pasture, and forage utilization such that a vast amount of new information was accrued. Our understanding of sheep has benefited also from research conducted on other species, and vice versa. Many factors that have contributed to the decline in the sheep industry are not influenced easily by academic research (e.g., low per capita consumption of lamb meat, predation, reluctance to adopt new technologies, cost and availability of laborers with sheep-related skills, and fewer young people pursuing careers in agriculture). The size of the US sheep industry is expected to remain stable, with possible slow growth in the foreseeable future. To remain profitable, producers will take advantage of new (or previously unused) technologies, the desire of the public for things natural, domestic niche and international fiber markets, and the ability of the sheep to control noxious weeds and thrive in suboptimal ecosystems.

  11. The Prevalence of Sheep Traumatic Myiasis in Three Counties from the West Side of Romania and Bacteria Isolated from the Insects Maggots

    Directory of Open Access Journals (Sweden)

    Daniela Marina Mot

    2013-10-01

    Full Text Available Myiasis represents an infestation of animals and humans caused by the maggots of certain fly species of Diptera order, Insecta class, which feed on the hosts' living or dead tissues or body fluids. In sheep, myiasis is a major animal welfare issue developing serious pain, suffering and in untreated cases may result in tissue injuries, reproduction and productivity losses and even death. There are two most important fly species which cause traumatic cutaneous myiasis of sheep in Europe: Wohlfahrtia magnifica (Sarcophagidae implicated in etiology of wound myiasis in southern and eastern Europe and Lucilia sericata (Calliphoridae, implicated in etiology of sheep strike, mainly in the middle latitudes of Europe continent. A few farmers from Timiş, Arad and Caraş-Severin counties were been asked to response to a questionnaire on the prevalence of traumatic myiasis which evolved in their sheep flock in April-September period of year 2012. From a total number of 2206 sheep taken into study were been discovered 1658 healthy sheep (75.16% and 548 sheep with myiasis (24.84%. From identified lesions with myiasis were been collected insects maggots from all three stages of development and were been prepared in Microbiology laboratory in the view to obtain data on the culturable bacteria isolated under aerobic conditions. Bacteria detected from maggots samples were: Staphylococcus aureus, Bacillus subtilis, Proteus vulgaris, Micrococcus luteus and Escherichia coli. The myasis insects maggots in sheep infestation can acquire many bacteria from their host or from their surroundings, all these can, together another bacteria, complicate the lesions and without treatment may lead to animals death.

  12. Detection of Leptospira spp. in semen and vaginal fluids of goats and sheep by polymerase chain reaction.

    Science.gov (United States)

    Lilenbaum, W; Varges, R; Brandão, F Z; Cortez, A; de Souza, S O; Brandão, P E; Richtzenhain, L J; Vasconcellos, S A

    2008-04-15

    Thirteen goat herds and seven sheep flocks in the state of Rio de Janeiro, Brazil were screened for leptospirosis. From the three herds and three flocks with greatest seroreactivity, 19 goats (16 females and three bucks) and 40 sheep (26 ewes and 14 rams) that were seropositive (specific anti-Leptospira titres > or =400, based on a microscopic agglutination test), were selected for more detailed studies. From those animals, samples of vaginal fluids or semen were collected for bacteriological and molecular assays. For both species of animals, the most prevalent reactions were to serovars Hardjo, Shermani, and Grippotyphosa. Although leptospires were detected by darkfield microscopy in three vaginal fluid samples (from two goats and one ewe), pure isolates were not obtained by bacteriological culture of vaginal fluids or semen. However, seven vaginal fluid samples (from four goats and three ewes) and six semen samples (all from rams) were positive on polymerase chain reaction (PCR). Based on these findings, in addition to analogous findings in cattle, we inferred that there is potential for venereal transmission of leptospirosis in small ruminants.

  13. Feasibility of a linear scoring method of udder morphology for the selection scheme of Sardinian sheep.

    Science.gov (United States)

    Casu, Sara; Pernazza, I; Carta, A

    2006-06-01

    Breeders are increasingly interested in improving the machine milkability of Sardinian dairy sheep by selection for udder morphology. Nine-point linear scales were developed to appraise teat placement, degree of suspension of the udder, udder depth, and degree of separation of the 2 halves. Repeatabilities within and across lactation were estimated on an experimental flock. Ewes were scored at least 3 times a year from 1999 to 2003. Within-lactation repeatabilities were greater than 0.70 for all linear traits, whereas across-lactation repeatabilities ranged from 0.59 to 0.66. The first linear combination of basic traits, obtained by principal component analysis, was highly correlated with teat placement, degree of suspension of the udder, and udder depth and showed an across-lactation repeatability of 0.76. These results indicate that an accurate evaluation of animals is possible by a single, early lifetime score. Genetic parameters of linear udder traits were estimated using a REML method applied to a sire model. Data were selected from 76,984 scores of Sardinian yearling ewes collected by 31 classifiers from 1999 to 2004. Two models were compared, one fitting the contemporary group effect as fixed and the other as random. Heritabilities of udder traits ranged from 0.19 to 0.31. The model with the random contemporary group effect produced slightly higher heritabilities and higher correlations between the sires' estimated breeding values and the daughters' average scores. As a whole, the genetic correlations between udder traits were favorable, indicating that selection for one trait will produce a positive evolution of the overall udder conformation. In particular, the degree of suspension of the udder was highly correlated with udder depth (0.82). Genetic correlations with milk yield were unfavorable but generally low, with the exception of udder depth (-0.48). Genetic trends were estimated using an animal model. Only udder depth showed a negative constant

  14. Becoming Sheep, Becoming Animal

    DEFF Research Database (Denmark)

    Grum, Charlotte; Svabo, Connie

    2016-01-01

    Proposal for Performance Research, in response to the call Turning Animal: As a part of a 2015 group exhibition exploring the history and local myths of a woman living in a Danish heath landscape 150 years ago, artist Charlotte Grum connected herself to a live sheep for 4 hours a day, 5 days a we...... support the written account – together with graphic figurations of the many human and non-human actors playing a part of the mattering of “Becoming Sheep”, with an equal intention of performing multiple positions within and through the text......., for 5 weeks, turning the two into a hybrid relational assemblage, intra-acting and becoming with the heath habitat, the other by-passing human and non-human animals, the changing weather and their fluctuating biological needs. She wanted to explore the discursive and material effects of a site......-specific human-nonhuman animal intra-action, to challenge the gendered and anthropocentric reading of a particular historical subject and to explore the messy constituents of the very categories of women and animals. In general she is occupied with how to animate and perform the intra-active entanglement...

  15. Sheep-related Culture of Guizhou

    Institute of Scientific and Technical Information of China (English)

    WuZhengguang

    2003-01-01

    Sheep and goats, major livestock in Guizhou Steppe of southwest China, are of both practical and social value for local dwellers. As sheep is pronounced similar as "auspicious" in Chinese, its image is widely applied to every aspect of local society, including religious rites, calendar calculation, arts creation and architecture. Thus a sheep-related culture has been developed and prospered.

  16. Predator avoidance as a function of flocking in the sexually dichromatic Hawaii akepa

    Science.gov (United States)

    Hart, P.J.; Freed, L.A.

    2005-01-01

    Hypotheses for joining a mixed-species bird flock consider each species as a single unit. In sexually dichromatic birds, differential conspicuousness between the sexes may result in differences in vigilance for predators. Aspects of the predator avoidance and foraging enhancement hypotheses for the selective value of joining a mixed-species flock were assessed for the strongly sexually dichromatic Hawaii akepa (Loxops coccineus coccineus). There was support for the primary predictions of the predator avoidance hypothesis: vigilance levels decreased with increasing group size, and with membership in a flock, but only for brightly colored adult males. There was little support for the hypothesis that the primary benefit of joining a mixed-species flock is to enhance foraging efficiency through "local enhancement".

  17. Fixed-wing UAVs Flock Control through Cohesion and Repulsion Behaviours Combined with a Leadership

    Directory of Open Access Journals (Sweden)

    Cezary Kownacki

    2016-02-01

    Full Text Available The aim of this paper is to present a novel approach to swarm control of small fixed-wing UAVs, which combines only two flocking behaviours with a leadership feature. In the presented approach, two fundamental rules of Reynolds flocking are applied, i.e., cohesion and repulsion, as the base of a decentralized control of self-organization of the flock. These rules are combined with a leadership feature, which is responsible for a global behaviour of guidance, as in the case of animals. Such a bio-inspired combination allows the achievement of a coherent collective flight of a flock of fixed-wing UAVs without applying formal behaviours of migration and alignment. This highly simplifies an implementation of the algorithm. The presented results include both numerical simulations and experimental flights, which validate the hardware implementation of the approach.

  18. Atypical velogenic Newcastle disease in a commercial layer flock in Japan.

    Science.gov (United States)

    Umali, Dennis V; Ito, Hiroshi; Shirota, Kazutoshi; Ito, Toshihiro; Katoh, Hiromitsu

    2015-05-01

    In 2002, a commercial layer flock in Japan was initially diagnosed as being infected with infectious bronchitis (IB) based on clinical signs, virus isolation, and serological analysis but was later found to be atypically infected with velogenic Newcastle disease virus (NDV) following molecular diagnosis. The flock had slightly decreased egg production and an increased occurrence of soft-shelled eggs without significant mortality. IB-like viruses were isolated, which caused dwarfing and curling in 12-day-old chicken embryos. Ten years after this case, retrospective genetic analyses showed that apart from IB virus (IBV), the flock was also infected with NDV. Mean death time (MDT), intracerebral pathogenicity index (ICPI), and deduced amino acid sequence of the cleavage site of the fusion (F)-protein gene revealed that the NDV isolate was velogenic ((112)RRQKR(116)). These results indicate that poultry clinicians should look out for atypical velogenic ND, especially in vaccinated commercial chicken flocks, which may harbor hidden NDV infection.

  19. Fixed-Wing UAVs Flock Control through Cohesion and Repulsion Behaviours Combined with a Leadership

    Directory of Open Access Journals (Sweden)

    Cezary Kownacki

    2016-02-01

    Full Text Available The aim of this paper is to present a novel approach to swarm control of small fixed-wing UAVs, which combines only two flocking behaviours with a leadership feature. In the presented approach, two fundamental rules of Reynolds flocking are applied, i.e., cohesion and repulsion, as the base of a decentralized control of self-organization of the flock. These rules are combined with a leadership feature, which is responsible for a global behaviour of guidance, as in the case of animals. Such a bio-inspired combination allows the achievement of a coherent collective flight of a flock of fixed-wing UAVs without applying formal behaviours of migration and alignment. This highly simplifies an implementation of the algorithm. The presented results include both numerical simulations and experimental flights, which validate the hardware implementation of the approach.

  20. Risk factors for Campylobacter colonization in Danish broiler flocks, 2010 to 2011

    DEFF Research Database (Denmark)

    Sandberg, M; Sørensen, L L; Steenberg, B

    2015-01-01

    The objectives of the two studies presented were to estimate the prevalence of Campylobacter-positive farms and flocks and to acquire updated knowledge about risk factors for the introduction of Campylobacter in Danish broiler flocks. In the first study, from September 2010 to September 2011...... in the Danish Broiler Production ( KIK: ) database. House- and flock-specific data collected in the surveys were supplemented with information obtained from the KIK database. Data obtained from the two studies were analyzed separately by logistic regression analysis. In both models, the dependent variable...... was "Campylobacter flock status (positive/negative)," which was based on real-time PCR testing of fecal material from the floor of each broiler house that had been collected preslaughter using a pair of tube gauze "socks." This material was pooled into one sample. Of the 25 farms visited, 17 had delivered...

  1. Ranging Behaviour of Commercial Free-Range Laying Hens.

    Science.gov (United States)

    Chielo, Leonard Ikenna; Pike, Tom; Cooper, Jonathan

    2016-04-26

    In this study, the range use and behaviour of laying hens in commercial free-range flocks was explored. Six flocks were each visited on four separate days and data collected from their outdoor area (divided into zones based on distance from shed and available resources). These were: apron (0-10 m from shed normally without cover or other enrichments); enriched belt (10-50 m from shed where resources such as manmade cover, saplings and dust baths were provided); and outer range (beyond 50 m from shed with no cover and mainly grass pasture). Data collection consisted of counting the number of hens in each zone and recording behaviour, feather condition and nearest neighbour distance (NND) of 20 birds per zone on each visit day. In addition, we used techniques derived from ecological surveys to establish four transects perpendicular to the shed, running through the apron, enriched belt and outer range. Number of hens in each 10 m × 10 m quadrat was recorded four times per day as was the temperature and relative humidity of the outer range. On average, 12.5% of hens were found outside. Of these, 5.4% were found in the apron; 4.3% in the enriched zone; and 2.8% were in the outer range. This pattern was supported by data from quadrats, where the density of hens sharply dropped with increasing distance from shed. Consequently, NND was greatest in the outer range, least in the apron and intermediate in the enriched belt. Hens sampled in outer range and enriched belts had better feather condition than those from the apron. Standing, ground pecking, walking and foraging were the most commonly recorded activities with standing and pecking most likely to occur in the apron, and walking and foraging more common in the outer range. Use of the outer range declined with lower temperatures and increasing relative humidity, though use of apron and enriched belt was not affected by variation in these measures. These data support previous findings that outer range areas tend to be

  2. Comparative curative and preventive efficacies of ivermectin and closantel on Oestrus ovis (Linné 1758) in naturally infected sheep.

    Science.gov (United States)

    Dorchies, P; Alzieu, J P; Cadiergues, M C

    1997-10-01

    A field trial was undertaken to assess the efficacy of each of two formulations of ivermectin and of closantel in prevention and treatment of Oestrus ovis in a naturally infected flock grazing on the foothills of the Pyrenees mountains, in south-western France. Within the flock, 875 sheep were randomly divided into four groups, and treated twice during the fly season, with an interval of 60 days between treatments. Group 1 sheep were treated with albendazole (ABZ) at a dose rate of 3.8 mg/kg to maintain control of trichostrongylid parasites without affecting O. ovis; Group 2 received closantel at a dose rate of 10 mg/kg because of its known persistent activity against O. Ovis; Groups 3 and 4 received ivermectin at a dose rate of 200 mcg/kg bodyweight by subcutaneous injection (Isc) and orally (Io), respectively. All sheep were managed as a single group throughout the study. In order to assess the prophylactic effect of each product, immediately prior to the scheduled second treatment on Day 60 (D60), five sheep from each group were chosen at random and necropsied. Similarly, to assess the therapeutic effect, another five sheep from each group were selected on D70 and necropsied for parasite counts. During the 120 days of the trial, a significant number of animals from each group were regularly individually examined to assess their clinical status with regard to O. Ovis infection. Clinical signs of infection had significantly declined in Groups 2, 3 and 4 by 10 days after treatment reaching their lowest level at D30. In the control group during this period, clinical signs increased. Ten days after the second treatment, (D70), there was also evidence of a significant response to treatment. Finally the between-treatment differences in clinical scores of the closantel and ivermectin groups were small, although scores in Group 1 sheep was suggestive of a higher challenge in the second half of the study. On the basis of the postmortem counts and arithmetic means

  3. Failed landings after laying hen flight in a commercial aviary over two flock cycles.

    Science.gov (United States)

    Campbell, D L M; Goodwin, S L; Makagon, M M; Swanson, J C; Siegford, J M

    2016-01-01

    Many egg producers are adopting alternative housing systems such as aviaries that provide hens a tiered cage and a litter-covered open floor area. This larger, more complex environment permits expression of behaviors not seen in space-limited cages, such as flight. Flight is an exercise important for strengthening bones; but domestic hens might display imperfect flight landings due to poor flight control. To assess the potential implications of open space, we evaluated the landing success of Lohmann white laying hens in a commercial aviary. Video recordings of hens were taken from 4 aviary sections at peak lay, mid lay and end lay across two flock cycles. Observations were made in each focal section of all flights throughout the day noting flight origin and landing location (outer perch or litter) and landing success or failure. In Flock 1, 9.1% of all flights failed and 21% failed in Flock 2. The number of flights decreased across the laying cycle for both flocks. Proportionally more failed landings were observed in the double row sections in Flock 2. Collisions with other hens were more common than slipping on the ground or colliding with aviary structures across sections and flocks. More hens slipped on the ground and collided with physical structures at peak lay for Flock 2 than at other time points. More collisions with other hens were seen at mid and end lay than at peak lay for Flock 2. Landings ending on perches failed more often than landings on litter. These results indicate potential for flight-related hen injuries in aviary systems resulting from failed landings, which may have implications for hen welfare and optimal system design and management.

  4. Avian hepatitis E virus infection and possible associated clinical disease in broiler breeder flocks in Hungary.

    Science.gov (United States)

    Morrow, Chris J; Samu, Gyozo; Mátrai, Eszter; Klausz, Akos; Wood, Alasdair M; Richter, Susanne; Jaskulska, Barbara; Hess, Michael

    2008-10-01

    In broiler breeder flocks in one broiler integration in Hungary, a new syndrome appeared in January 2005 with initially four successive post-peak flocks experiencing significant decreases in egg production. Clinically birds became depressed and there was a small increase in the mortality rate. Postmortem examinations revealed enlarged livers in up to 19% of birds dying, and enlarged spleens in some. Also observed were birds with either clotted blood or serosanguineous fluid in the abdomen and subcapsular haemorrhages of the liver. Histopathology and polymerase chain reaction excluded tumours and the presence of common tumour-associated viruses. Chronic bacterial infections (especially causing hepatitis, peritonitis and airsacculitis) were common but many enlarged livers had no obvious bacterial involvement. After a 9-month period during which a majority of flocks became affected, no newly affected flocks occurred. Investigations showed that all tested affected flocks were seropositive in the big liver and spleen (BLS) Agar Gel Immunodiffusion test. Subsequent flocks without post-peak egg-production drops were shown to be seronegative in the BLS AGID test, as were all the parent flocks contributing to the affected flocks. Liver samples and cloacal swabs were positive by polymerase chain reaction (aHEV helicase target), and calicivirus-like particles were demonstrated in bile samples from affected birds. These observations are similar to hepatitis-splenomegaly syndrome as described in North America and BLS syndrome as described in Australia. Histopathological features were a non-specific chronic hepatitis similar to those described in BLS and hepatitis-splenomegaly syndrome. Immunohistochemistry using a BLS-specific monoclonal antibody confirmed the presence of avian hepatitis E virus antigen in livers and spleen.

  5. Temporal genetic variation of Fasciola hepatica from sheep in Galicia (NW Spain).

    Science.gov (United States)

    Vázquez-Prieto, Severo; Vilas, Román; Ubeira, Florencio M; Paniagua, Esperanza

    2015-04-30

    We found low genetic differentiation between two temporal samples of Fasciola hepatica (2006 and 2008) collected from nine sheep of the same flock that shared the same pasture for at least 2 years. However, each sample, represented by four and five infrapopulations respectively, showed strong heterozygote deficits regarding Hardy-Weinberg expectations and a high degree of genetic structure at infrapopulation level. This is an unexpected result since genetic drift should increase temporal variation among years. Our findings are most likely explained by the fact that the parasite can survive many years in the definitive host. Temporal gene flow favored by high longevity probably increases levels of genetic variability of the population but could also contribute to the observed heterozygote deficits within temporal samples and infrapopulations if it favors the Wahlund effect. Despite the homogenizing effect of gene flow, the high genetic divergence observed between infrapopulations is most likely a consequence of strong genetic drift associated to the complexity of the life cycle.

  6. Mastitis in sheep--The last 10 years and the future of research.

    Science.gov (United States)

    Gelasakis, A I; Mavrogianni, V S; Petridis, I G; Vasileiou, N G C; Fthenakis, G C

    2015-12-14

    Bacterial mastitis is a significant welfare and financial problem in sheep flocks. This paper reviews the recently published literature, including publications that highlight the significance and virulence factors of the causal agents, especially Staphylococcus aureus and Mannheimia haemolytica, the primary causes of the disease. Research has also contributed to the understanding of risk factors, including genetic susceptibility of animals to infections, supporting future strategies for sustainable disease control. Pathogenetic mechanisms, including the role of the local defenses in the teat, have also been described and can assist formulation of strategies that induce local immune responses in the teat of ewes. Further to well-established diagnostic techniques, i.e., bacteriological tests and somatic cell counting, advanced methodologies, e.g., proteomics technologies, will likely contribute to more rapid and accurate diagnostics, in turn enhancing mastitis control efforts. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Epidemiological survey for visna-maedi among sheep in northern prefectures of Japan

    Directory of Open Access Journals (Sweden)

    Massimo Giangaspero

    2011-12-01

    Full Text Available Ovine sera collected from the northern Prefectures of Hokkaido, Iwate and Aomori in Japan, were examined for the presence of antibodies against visna-maedi virus using the agar gel immunodiffusion test and enzyme-linked immunosorbent assays. Three animals (1.12%, out of 267 samples tested, were found to be seropositive to the visna-maedi antigens in both tests. Levels of infection were found in flocks from Hokkaido and Iwate Prefectures, but not in the Aomori Prefecture. Nucleic acid detection by polymerase chain reaction on serum samples did not give positive results. Although no diagnostic measures were in place, the infection could not be related to losses in sheep production or to reduced survival rates. The very limited visna-maedi distribution indicates a highly favourable condition for the application of eradication strategies in this area.

  8. Cost structure and profitability of Assaf dairy sheep farms in Spain.

    Science.gov (United States)

    Milán, M J; Frendi, F; González-González, R; Caja, G

    2014-01-01

    Twenty dairy sheep farms of Assaf breed, located in the Spanish autonomous community of Castilla y León and included in a group receiving technical support, were used to study their production cost structure and to assess their economic profitability during 2009. On average, farms had 89.2±38.0 ha (own, 38%), 592±63 ewes, yielded 185.9±21.1×10(3) L/yr (i.e., 316±15 L/ewe), and were attended by 2.3±0.2 annual working units (family, 72%). Total annual income was €194.4±23.0×10(3)/yr (€1.0=$1.3) from milk (78.6%), lamb (13.2%), culled ewes (0.5%), and other sales (0.8%, wool and manure), and completed with the European Union sheep subsidy (6.9%). Total costs were €185.9±19.0×10(3)/yr to attend to feeding (61.6%), labor (18.2%), equipment maintenance and depreciation (7.6%), finances (3.0%), animal health (2.5%), energy, water and milking supplies (2.2%), milk recording (0.5%), and other costs (4.4%; assurances, shearing, association fees, and so on). Mean dairy sheep farm profit was €8.5±5.8×10(3)/yr (€7.4±8.3/ewe) on average, and varied between -€40.6 and €81.1/ewe among farms. Only 60% of farms were able to pay all costs, the rest had negative balances. Nevertheless, net margin was €31.0±6.5×10(3)/yr on average, varying between €0.6 and €108.4×10(3)/yr among farms. In this case, without including the opportunity costs, all farms had positive balances. Total annual cost (TAC; €/ewe) and total annual income (TAI; €/ewe) depended on milk yield (MY; L/ewe) and were TAC=161.6 + 0.502 MY (R(2)=0.50), and TAI=78.13 + 0.790 MY (R(2)=0.88), respectively, with the break-even point being 291 L/ewe. Conversely, farm TAC (€/yr) and farm TAI (€/yr) were also predicted as a function of the number of ewes (NOE) per flock, as TAC=18,401 + 282.8 NOE (R(2)=0.89) and TAI=330.9 NOE (R(2)=0.98), with the break-even point being 383 ewes/flock. Finally, according to the increasing trend expected for agricultural commodity prices, it was

  9. A Case of Contagious Ecthyma (Orf Virus in a Nonmanipulated Laboratory Dorset Sheep (Ovis aries

    Directory of Open Access Journals (Sweden)

    Gwynne E. Kinley

    2013-01-01

    Full Text Available An approximately 5-month-old laboratory wether, originating from a local vendor with a closed flock and maintained on a preventative medicine plan, presented with a continuum of lesions from hemorrhagic papules, vesicles, and pustules, to multifocal necrotic scabs at the commissure of the lips, medial canthus of the left eye, and distal prepuce. A presumptive diagnosis of Orf virus (ORFV was made and the sheep was euthanized. A full necropsy was performed, and histopathological evaluation of affected tissues revealed multifocal-to-coalescing necrotizing and proliferative cheilitis and dermatitis with eosinophilic intracytoplasmic inclusion bodies. Electron microscopy findings revealed degenerate keratinocytes containing numerous typical 200–300 nm wide cytoplasmic parapoxvirus virions, confirming the diagnosis of ORFV. We believe that this animal developed a clinical case of ORFV either due to an adverse reaction to an ORFV vaccine, or this animal had a case of preexisting ORFV which manifested after arrival at our facility.

  10. EPIDEMIOLOGICAL INVESTIGATIONS OF A PESTE DES PETITS RUMINANTS (PPR OUTBREAK IN AFGHAN SHEEP IN PAKISTAN

    Directory of Open Access Journals (Sweden)

    A. B. ZAHUR, A. ULLAH, H. IRSHAD, M. S. FAROOQ, M. HUSSAIN AND M. JAHANGIR

    2009-10-01

    Full Text Available Epidemiological and virological investigations were carried out during an outbreak of Peste des petits ruminants (PPR in Afghan (Bulkhi sheep in Pakistan. The overall morbidity, mortality and case fatality rates were 41.0, 1.2 and 3.0%, respectively. The epidemic curve was plotted and the values for basic reproductive number (R0 and herd immunity threshold (HIT for the affected flock were estimated to be 6.85 and 85.4%, respectively. The morbid material analysis by immuno-capture ELISA (Ic-ELISA and haemagglutination assay (HA revealed the presence of PPR virus. The PPR virus was isolated and identified through cytopathic effects, Ic-ELISA and transmission electron microscopy (TEM.

  11. Norwegian farmers' vigilance in reporting sheep showing scrapie-associated signs

    Directory of Open Access Journals (Sweden)

    Jarp Jorun

    2007-12-01

    Full Text Available Abstract Background Scrapie is a chronic neurodegenerative disease affecting small ruminants and belongs to the transmissible spongiform encephalopathies. Scrapie is considered a serious animal disease and it has been notifiable in Norway since 1965. The clinical signs of scrapie might be vague and the farmers, if familiar with the signs of scrapie, are often in the best position for detecting scrapie suspects. In 2002, an anonymous questionnaire survey was conducted in order to assess Norwegian sheep farmers' vigilance of scrapie. Results Although the potential detection of a scrapie-positive animal would lead to the destruction of the sheep flock concerned, almost all the farmers (97 % expressed their willingness to report scrapie suspects. This was most certainly dependent on the Government taking the economic responsibility for the control programme as nearly all the farmers responded that this was an important condition. Listeriosis is relatively common disease in Norwegian sheep and a differential diagnosis for scrapie. In a multinomial logistic regression the reporting behaviour for non-recovering listeriosis cases, used as a measurement of willingness to report scrapie, was examined. The reporting of non-recovering listeriosis cases increased as the knowledge of scrapie-associated signs increased, and the reporting behaviour was dependent on both economic and non-economic values. Conclusion The results indicate that in 2002 almost all sheep farmers showed willingness to report any scrapie suspects. Nevertheless there is an underreporting of scrapie suspects and the farmers' awareness and hence their vigilance of scrapie could be improved. Furthermore, the results suggest that to ensure the farmers' compliance to control programmes for serious infectious diseases, the farmers' concerns of non-economic as well as economic values should be considered.

  12. Environmental factors and interval from the introduction of rams to estrus in postpartum Saint Croix sheep.

    Science.gov (United States)

    Sánchez Dávila, Fernando; Bernal, Hugo; Colín, Javier; Olivares, Emilio; del Bosque, Alejandro S; Ledezma, Rogelio; Ungerfeld, Rodolfo

    2011-04-01

    The objective of this study was to determine whether season and total rainfall during the breeding season, sheep parity, and/or litter size affect the interval from the introduction of rams to estrus (IRE) in hair Saint Croix sheep in northeastern Mexico. An analysis was made of 874 services performed during 9 years, introducing the rams into the sheep flock after an isolation period of 60 days during the postpartum period. Estrus was recorded twice daily during 35 days. Year and season influenced significantly on the interval between ram introduction and estrus length (P < 0.01). Winter IRE length (7.9 ± 0.1 days) was shorter than in the other three seasons (11.1 ± 0.2, 11.1 ± 0.1, and 16.2 ± 0.2 days in summer, autumn, and spring, respectively) (P < 0.01). An interaction was observed between rainfall and season, then by rainfall between 0 and 100 mm, IRE was shorter (P < 0.05) in winter (6.8 ± 0.3 days), and by rainfall between 100 and 199 mm, IRE was shorter (P < 0.05) in autumn (10.2 ± 0.5 days); however, when rainfall was beyond 200 mm, IRE length was shorter (P < 0.01) in summer (4.8 ± 0.5 days) than in autumn (14.5 ± 0.3 days). The IRE length was also longer in first lambing ewes (P < 0.05) and was not affected by litter size. In the present study, several factors, including the breeding season, rainfall and parity, directly influenced the interval between the male introduction and the onset of estrus by Saint Croix hair sheep.

  13. Natural Immunity of Sheep and Lambs Against the Schmallenberg Virus Infection.

    Science.gov (United States)

    Rodríguez-Prieto, V; Kukielka, D; Mouriño, M; Paradell, H; Plaja, L; Urniza, A; Sánchez-Vizcaíno, J Manuel

    2016-04-01

    Since the first reports of the Schmallenberg disease (SBD) outbreaks in late 2011, the disease has spread across Europe, affecting cattle and sheep farms. While Schmallenberg virus (SBV) causes a mild clinical disease in adults, infection of pregnant females may lead to the production of typical congenital malformations (CMFs) in their offspring. It is speculated that the immunity acquired after a SBV infection is effective in preventing further infections. However, this has not been proven in naturally infected sheep, especially if they are pregnant when reinfected. The aim of this study was to monitor the natural immunity in SBV-infected sheep. Twenty-four ewes from the only Spanish farm with a SBV OIE-notified outbreak were sampled. Subsequently, nine pregnant ewes were inoculated with SBV infectious plasma under controlled conditions. Six of them were euthanized before delivery, and their fetuses were inspected for lesions indicative for the SBV infection. The three remaining ewes were allowed to deliver one lamb each. Inoculation of the lambs was scheduled at approx. 3 months after birth. All samples were analyzed for viral RNA by RT-PCR, and for antibodies by an indirect ELISA and a virus neutralization test (VNT). The majority of the 24 ewes showed a serological reaction against SBV. The three ewes that were allowed to lamb down demonstrated variable degrees of seroconversion which corresponded to the levels of immune reaction observed in their lambs. Moreover, no viral RNA was detected, no lesions were observed in the fetuses, and no clinical signs were detected in the inoculated animals. These findings suggest that the immunity acquired by sheep following a natural SBV infection could be sufficient to stop SBV reinfection. However, vaccination could be a valuable tool to control SBV infections and associated economic losses as it affords a more uniform and predictable protection at the flock/herd level.

  14. Serological and molecular evidence of Q fever among small ruminant flocks in Algeria.

    Science.gov (United States)

    Khaled, H; Sidi-Boumedine, K; Merdja, S; Dufour, P; Dahmani, A; Thiéry, R; Rousset, E; Bouyoucef, A

    2016-08-01

    Q fever, a commonly reported zoonosis worldwide, is caused by infection with Coxiella burnetii, an obligate intracellular bacterium. The infection is often asymptomatic in ruminants, but it can lead to reproductive disorders with bacterial shedding into the environment. Between 2011 and 2013, a study was undertaken in small ruminant flocks in different regions of Algeria. A total of 35 flocks were visited and 227 sera and 267 genital swabs were collected from females after abortions or the lambing period to investigate Q fever infection. Indirect ELISA was used to detect specific antibodies against C. burnetii and real-time PCR for detecting bacterial DNA. Our survey indicated that 58% (95% CI=40-76%) of flocks had at least one positive animal (17 seropositive flocks) and individual seroprevalence was estimated at 14.1% (95% CI=11.8-16.4%) (32 seropositive animals). Bacterial excretion was observed in 21 flocks (60%), and 57 females showed evidence of C. burnetii shedding (21.3%). These results suggest that C. burnetii distribution is high at the flock level and that seropositive and infected (shedder) animals can be found all over the country. Further studies are needed in other regions and on different animal species to better understand the distribution and incidence of Q fever, as well as human exposure, and to develop an adequate prophylaxis program.

  15. Non-commercial poultry industries: surveys of backyard and gamefowl breeder flocks in the United States.

    Science.gov (United States)

    Garber, L; Hill, G; Rodriguez, J; Gregory, G; Voelker, L

    2007-07-16

    The National Animal Health Monitoring System (NAHMS) Poultry '04 study was conducted to better describe non-commercial United States poultry populations, in particular, backyard and gamefowl breeder flocks. To estimate the density of backyard flocks in close proximity to commercial operations, a sample of 350 commercial poultry operations in 18 top poultry producing states was selected from the National Agricultural Statistics Service (NASS) list of poultry operations. A 1 mile radius circle was drawn around each operation, and door-to-door canvassing was conducted within these circles to enumerate premises with all species of birds. Premises with backyard poultry flocks completed a questionnaire focusing on bird health, bird movement, and biosecurity practices. A similar questionnaire, provided in both English and Spanish, was mailed to all members of State affiliates of the United Gamefowl Breeders Association (UGBA) as well as to members of State associations not affiliated with UGBA. An average of 29.4 residences was found within a 1 mile radius of commercial operations, of which 1.9 residences per circle had backyard poultry flocks. Gamefowl breeder flocks were larger, used more health care and biosecurity practices, and moved birds more frequently compared to backyard flocks.

  16. Foraging efficiency of a predator flock for randomly moving prey: A simulation study

    Science.gov (United States)

    Lee, Sang-Hee; Kwon, Ohsung

    2016-03-01

    Flocking behavior of animals is highly advantageous for taking food resources. The degree of the advantage is related to the ability of flock members to detect their prey and the mobility of prey individuals. In this study, to explore the relation, we constructed a model to simulate a predator flock and its randomly moving prey. The predator members have the prey detection ability, which was characterized as sensing distance, R, and a sensing angle, θ. The mobility of the prey individuals was characterized as the maximum traveling distance of an iteration time step, L. The relative flock foraging efficiency, ɛ, was defined as ɛ = 1 - (Td/Tup). Tup and Td represent the spent time for the flock to eat all prey individuals and to uptake the last remaining 10% prey, respectively. Simulation results showed that ɛ increased, maximized, and decreased with the increase of R, regardless of L. As the number of prey, N, increased, the tendency of the increasing and decreasing was diluted. The result was briefly discussed in relation to the flock foraging behavior and the development of the model toward applications for real ecosystems.

  17. An Improved Fast Flocking Algorithm with Obstacle Avoidance for Multiagent Dynamic Systems

    Directory of Open Access Journals (Sweden)

    Jialiang Wang

    2014-01-01

    Full Text Available Flocking behavior is a common phenomenon in nature, such as flocks of birds and groups of fish. In order to make the agents effectively avoid obstacles and fast form flocking towards the direction of destination point, this paper proposes a fast multiagent obstacle avoidance (FMOA algorithm. FMOA is illustrated based on the status of whether the flocking has formed. If flocking has not formed, agents should avoid the obstacles toward the direction of target. If otherwise, these agents have reached the state of lattice and then these agents only need to avoid the obstacles and ignore the direction of target. The experimental results show that the proposed FMOA algorithm has better performance in terms of flocking path length. Furthermore, the proposed FMOA algorithm is applied to the formation flying of quad-rotor helicopters. Compared with other technologies to perform the localization of quad-rotor helicopter, this paper innovatively constructs a smart environment by deploying some wireless sensor network (WSN nodes using the proposed localization algorithm. Finally, the proposed FMOA algorithm is used to conduct the formation flying of these quad-rotor helicopters in the smart environment.

  18. Nitrogen mineralization from sheep faeces can be predicted from the apparent digestibility of the feed

    DEFF Research Database (Denmark)

    Kyvsgaard, P.; Sørensen, P.; Møller, E.

    2000-01-01

    It is difficult to predict plant availability of N in faeces because most faecal N is bound in organic form. In this study the influence of diet and faeces composition on mineralization of sheep faeces in soil were investigated. Net mineralization of C and N from 16 different samples of sheep...... faeces originating from sheep fed different known diets was studied after incubation in a sandy soil. After 4 weeks net mineralization of N ranged from -41 to 9% of faeces N and after 12 weeks -28 to 43% was net mineralized. Mineralization was related to different feed and faeces characteristics...

  19. Genetic diversity and population structure of different varieties of Morada Nova hair sheep from Brazil.

    Science.gov (United States)

    Ferreira, J S B; Paiva, S R; Silva, E C; McManus, C M; Caetano, A R; Façanha, D A E; de Sousa, M A N

    2014-01-01

    The aim of this study was to analyze genetic diversity and population structure among varieties of White (N = 40), Red (N = 32), and Black (N = 31) Morada Nova hair sheep from flocks in the northeastern Brazilian semiarid region. Fifteen nuclear microsatellite markers and two regions of mitochondrial DNA were used. The intra-population analysis demonstrated that the White variety had higher diversity, while the Red variety had the lowest values. The Bayesian analysis to assess the genetic population structure allowed differentiation between White, Red, and Black varieties, and revealed a tendency towards sub-structuring in the White variety flocks from the States of Ceará and Paraíba. The results of analyses of molecular variance showed that the greatest genetic structure was found when comparing flocks rather than varieties (8.59 vs 6.64% of the total variation, P Dtl, both the dendrogram analysis and the principal coordinate analysis showed the formation of two main groups: one composed of White and another of Black and Red individuals. Five and two haplotypes were found for the D-loop region and the ND5 gene, respectively. A haplotype unique to the Red variety was found in the D-loop region and a variety haplotype unique to the Black variety was found in the ND5 gene; however, these frequencies were low and therefore require further validation. These results support the existence of substantial differences between the Red and White varieties and should be used as separate genetic resources and to improve conservation programs.

  20. Genetic variability of six French meat sheep breeds in relation to their genetic management

    Directory of Open Access Journals (Sweden)

    Coralie Danchin-Burge

    2003-11-01

    Full Text Available Abstract Some demographic parameters, the genetic structure and the evolution of the genetic variability of six French meat sheep breeds were analysed in relation with their management. Four of these breeds are submitted to more or less intense selection: the Berrichon du Cher (BCH, Blanc du Massif Central (BMC, Charollais (CHA and Limousin (LIM; the other two breeds are under conservation: the Roussin de La Hague (RLH and Solognot (SOL. Genealogical data of the recorded animals born from 1970 to 2000 and of their known ancestors were used. The most balanced contributions of the different flocks to the sire-daughter path was found in the SOL. In the BCH, a single flock provided 43% of the sire-AI sire path, whereas the contributions of the flocks were more balanced in the BMC and LIM (the only other breeds where AI is used to a substantial amount. The distribution of the expected genetic contribution of the founder animals was found to be unbalanced, especially in the BCH and LIM. The effective numbers of ancestors (founders or not for the ewes born from 1996 to 2000 were equal to 35 (BCH, 144 (BMC, 112 (CHA, 69 (LIM, 40 (RLH and 49 (SOL. Inbreeding was not analysed in the BMC, due to incomplete pedigree information. From 1980 on, the rates of inbreeding, in percentage points per year, were +0.112 (BCH, +0.045 (CHA, +0.036 (LIM, +0.098 (RLH and +0.062 (SOL. The implications of the observed trends on genetic variability are discussed in relation to the genetic management of each breed. The need for a larger selection basis in the BCH, the efficiency of the rules applied in the SOL to preserve the genetic variability and the need for a more collective organisation in the CHA and RLH are outlined.

  1. Milk yield of some Croatian sheep breeds

    OpenAIRE

    Kristijan Pandek; Boro Mioč; Zdravko Barać; Vesna Pavić; Neven Antunac; Zvonimir Prpić

    2005-01-01

    Among the most important breeds of sheep, used for the milk production in Croatia, are the sheep from Pag, Brač, Cres, Istrian and Travnik΄s sheep, different crossbreeds and, recently, East Friesian sheep. The aim of the research was to determine the genotype effect on lactation period, milk yield and protein and fat content, which are important in cheese making. The longest lactation period (213 days) had East Friesian sheep, while the highest total milk production (294 kg) and the highest p...

  2. Estimation of economic values for traits of dairy sheep: I. Model development.

    Science.gov (United States)

    Wolfová, M; Wolf, J; Krupová, Z; Kica, J

    2009-05-01

    A bioeconomic model was developed to estimate effects of change in production and functional traits on profit of dairy or dual-purpose milked sheep under alternative management systems. The flock structure was described in terms of animal categories and probabilities of transitions among them, and a Markov chain approach was used to calculate the stationary state of the resultant ewe flock. The model included both deterministic and stochastic components. Performance for most traits was simulated as the population average, but variation in several traits was taken into account. Management options included lambing intervals, mating system, and culling strategy for ewes, weaning and marketing strategy for progeny, and feeding system. The present value of profit computed as the difference between total revenues and total costs per ewe per year, both discounted to the birth date of the animals, was used as the criterion for economic efficiency of the production system in the stationary state. Economic values (change in system profit per unit change in the trait) of up to 35 milk production, growth, carcass, wool, and functional traits may be estimated.

  3. Genetic correlations among and between wool, growth and reproduction traits in Merino sheep.

    Science.gov (United States)

    Safari, E; Fogarty, N M; Gilmour, A R; Atkins, K D; Mortimer, S I; Swan, A A; Brien, F D; Greeff, J C; van der Werf, J H J

    2007-04-01

    Data from seven research resource flocks across Australia were combined to provide accurate estimates of genetic correlations among production traits in Merino sheep. The flocks represented contemporary Australian Merino fine, medium and broad wool strains over the past 30 years. Over 110,000 records were available for analysis for each of the major wool traits, and 50,000 records for reproduction and growth traits with over 2700 sires and 25,000 dams. Individual models developed from the single trait analyses were extended to the various combinations of two-trait models to obtain genetic correlations among six wool traits [clean fleece weight (CFW), greasy fleece weight, fibre diameter (FD), yield, coefficient of variation of fibre diameter and standard deviation of fibre diameter], four growth traits [birth weight, weaning weight, yearling weight (YWT), and hogget weight] and four reproduction traits [fertility, litter size, lambs born per ewe joined, lambs weaned per ewe joined (LW/EJ)]. This study has provided for the first time a comprehensive matrix of genetic correlations among these 14 wool, growth and reproduction traits. The large size of the data set has also provided estimates with very low standard errors. A moderate positive genetic correlation was observed between CFW and FD (0.29 +/- 0.02). YWT was positively correlated with CFW (0.23 +/- 0.04), FD (0.17 +/- 0.04) and LWEJ (0.58 +/- 0.06), while LW/EJ was negatively correlated with CFW (-0.26 +/- 0.05) and positively correlated with FD (0.06 +/- 0.04) and LS (0.68 +/- 0.04). These genetic correlations, together with the estimates of heritability and other parameters provide the basis for more accurate prediction of outcomes in complex sheep-breeding programmes designed to improve several traits.

  4. The epizootiology of Eimeria infections in commercial broiler chickens where anticoccidial drug programs were employed in six successive flocks to control coccidiosis.

    Science.gov (United States)

    Chapman, H D; Barta, J R; Hafeez, M A; Matsler, P; Rathinam, T; Raccoursier, M

    2016-08-01

    The course of natural Eimeria infections in 6 successive broiler flocks at a commercial farm comprising 4 houses, where different anticoccidial drug programs were employed, was studied by counting the number of oocysts in the litter at weekly intervals. The course of infection in all flocks followed a bell shaped curve in which oocyst numbers, initially low, increased to a peak ranging from 36 × 10(3) to 74 × 10(3) oocysts/g (OPG) of litter around 3 to 4 wk of age. Numbers subsequently declined to 3 × 10(3) to 15 × 10(3) OPG. Oocysts could be detected between flocks when birds were not present. Species of Eimeria identified included E. acervulina, E. maxima, and E. tenella Despite the presence of large numbers of oocysts in the litter, coccidial lesions were not observed in the intestines of the birds. The performance of broilers at the study site was comparable to that of other farms in the area where birds from the same settlement were reared to a similar age using the same drug programs. The results indicate the ubiquitous nature of Eimeria spp. infections in commercial broilers despite prophylactic medication. © 2016 Poultry Science Association Inc.

  5. Critical thresholds in flocking hydrodynamics with non-local alignment.

    Science.gov (United States)

    Tadmor, Eitan; Tan, Changhui

    2014-11-13

    We study the large-time behaviour of Eulerian systems augmented with non-local alignment. Such systems arise as hydrodynamic descriptions of agent-based models for self-organized dynamics, e.g. Cucker & Smale (2007 IEEE Trans. Autom. Control 52, 852-862. (doi:10.1109/TAC.2007.895842)) and Motsch & Tadmor (2011 J. Stat. Phys. 144, 923-947. (doi:10.1007/s10955-011-0285-9)) models. We prove that, in analogy with the agent-based models, the presence of non-local alignment enforces strong solutions to self-organize into a macroscopic flock. This then raises the question of existence of such strong solutions. We address this question in one- and two-dimensional set-ups, proving global regularity for subcritical initial data. Indeed, we show that there exist critical thresholds in the phase space of the initial configuration which dictate the global regularity versus a finite-time blow-up. In particular, we explore the regularity of non-local alignment in the presence of vacuum.

  6. Determination of mechanism of flock sediment formation in tea beverages.

    Science.gov (United States)

    Niino, Hitoshi; Sakane, Iwao; Okanoya, Kazunori; Kuribayashi, Syuhei; Kinugasa, Hitoshi

    2005-05-18

    The mechanism of sediment formation during the storage of green tea beverage was investigated. Green tea extract was separated by Diaion HP-20 column chromatography, and a sediment-formation test was performed. Results showed that at least one compound of the substance causing flock sediment was contained in each of the HP-20 nonadsorbed and adsorbed fractions. From the following fractionations and structure analyses, the substance in the HP-20 adsorbed fraction was determined to be 1-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-beta-D-glucose (strictinin), which is one of the ellagitannins. Strictinin was hydrolyzed to ellagic acid by heat-sterilization processes such as retort sterilization or the ultra-high temperature processing used during the manufacturing of tea beverages. Ellagic acid combined with proteins in the HP-20 nonadsorbed fraction to form an irreversible sediment of green tea beverage; ellagic acid and proteins were confirmed to be present in that sediment. The HP-20 adsorbed fraction contained little strictinin and formed hardly any sediment, suggesting that control of the strictinin content is significant in avoiding sediment formation during the manufacturing process of tea beverages.

  7. Implications for Welfare, Productivity and Sustainability of the Variation in Reported Levels of Mortality for Laying Hen Flocks Kept in Different Housing Systems: A Meta-Analysis of Ten Studies.

    Science.gov (United States)

    Weeks, Claire A; Lambton, Sarah L; Williams, Adrian G

    2016-01-01

    Data from ten sources comprising 3,851 flocks were modelled to identify variation in levels of mortality in laying hens. The predicted increase with age was curvilinear with significant variation between the seven breed categories. Mortality was higher in loose housing systems than in cages and variable within system, confirming previous reports. Cumulative mortality (CM) was higher in flocks with intact beaks (χ2 = 6.03; df 1; p = 0.014) than in those with trimmed beaks. Most data were available for free-range systems (2,823 flocks), where producer recorded CM at 60-80 weeks of age averaged 10% but with a range from 0% to 69.3%. Life cycle assessment showed that the main effect of increased levels of hen mortality is to increase the relative contribution of breeding overheads, so increasing environmental burdens per unit of production. Reducing CM to levels currently achieved by the 1st quartile could reduce flock greenhouse gas emissions by as much as 25%. Concurrently this would enhance hen welfare and better meet the expectation of egg consumers. More research to understand the genetic x environment interaction and detailed records of the causes of mortality is required so that improved genotypes can be developed for different systems and different breeds can be better managed within systems.

  8. Risk factors for Campylobacter colonization in Danish broiler flocks, 2010 to 2011.

    Science.gov (United States)

    Sandberg, M; Sørensen, L L; Steenberg, B; Chowdhury, S; Ersbøll, A K; Alban, L

    2015-03-01

    The objectives of the two studies presented were to estimate the prevalence of Campylobacter-positive farms and flocks and to acquire updated knowledge about risk factors for the introduction of Campylobacter in Danish broiler flocks. In the first study, from September 2010 to September 2011, there were 25 Danish broiler farms visited, and a questionnaire was filled in by a veterinarian/consultant. In the second study, a similar questionnaire was distributed electronically to all Danish broiler farmers (n=164) that were on record with an email address in the Quality Assurance System in the Danish Broiler Production (KIK) database. House- and flock-specific data collected in the surveys were supplemented with information obtained from the KIK database. Data obtained from the two studies were analyzed separately by logistic regression analysis. In both models, the dependent variable was "Campylobacter flock status (positive/negative)," which was based on real-time PCR testing of fecal material from the floor of each broiler house that had been collected preslaughter using a pair of tube gauze "socks." This material was pooled into one sample. Of the 25 farms visited, 17 had delivered Campylobacter-positive flocks during the study period, and eight farms had no Campylobacter-positive flocks. Moreover, the flock prevalence of Campylobacter was 17% (n=418). Data obtained from the electronically distributed survey revealed that 63% (n=71) of the farms were Campylobacter-positive. Further, the flock prevalence of Campylobacter was 14% (n=1,286). The multivariable models from the two sets of data identified the following statistically significant risk factors: summer vs. winter; if the previous flock in the house was positive for Campylobacter vs. if the previous flock in the house was negative; and litter delivered into the house close to the time of arrival of new chickens vs. storing litter on the farm. Furthermore, the data showed that a vertically based ventilation

  9. Poultry flocks as a source of Campylobacter contamination of broiler carcasses.

    Science.gov (United States)

    Wieczorek, K; Osek, J

    2015-01-01

    Campylobacter infection is the leading foodborne bacterial gastroenteritis worldwide and the bacteria are frequently isolated from the intestines of chickens. The broiler meat contamination with C. jejuni or C. coli may occur during slaughter processing. The aim of the study was to investigate the prevalence of Campylobacter in poultry flocks and the corresponding broiler carcasses in 15 districts (voivodeships) all over Poland. A total of 128 samples from broiler flocks and the corresponding carcasses were collected between February 2011 and April 2013. The Campylobacter isolation and species identification were performed according to ISO 10272-1 standard and with PCR. It was found that 112 flock (96.5%) were contaminated with campylobacters, either C. jejuni (77 samples; 68.7%) or C. coli (35 flocks; 31.3%). Analysis of the corresponding chicken carcasses tested after chilling revealed that 77 out of 128 (60.2%) samples were positive for Campylobacter, either C. jejuni (58; 75.3%) or C. coli (19; 24.7%). Most of the carcasses were contaminated with the same Campylobacter species as identified in the corresponding flock before slaughter. As tested by PCR, out of the 77 crops with C. jejuni 58 were positive for the same bacterial species. On the other hand, out of the remaining 35 flocks infected with C. coli, only 19 corresponding carcass samples were contaminated with C. coli. In three cases in the slaughtered flocks C. jejuni was identified but in the same carcasses C. coli was found. The opposite findings (flock positive for C. coli but the corresponding carcasses contaminated with C. jejuni) were seen in six voivodeships. It was also observed that several carcass samples were negative for C. jejuni and C. coli although the original flocks were Campylobacter-positive before slaughter (total 36 of the 77 samples; 46.7%). On the other hand, some carcasses were contaminated with Campylobacter although the flocks were negative for these bacteria (9 samples; 11

  10. Molecular detection of Theileria spp. and Babesia spp. in sheep and ixodid ticks from the northeast of Iran.

    Science.gov (United States)

    Razmi, Gholamreza; Pourhosseini, Moslem; Yaghfouri, Saeed; Rashidi, Ahmad; Seidabadi, Mohsen

    2013-02-01

    Theilerioses and babesioses are important diseases in Iranian sheep. The present study was undertaken to identify and classify/specify Theileria spp. and Babesia spp. in sheep and vector ticks. Investigation was carried out from 2009 to 2011 in the Khorasan Razavi Province, Iran. In total, 302 sheep originating from 60 different flocks were clinically examined and their blood collected. In addition, from the same flocks, ixodid ticks were sampled. Stained blood smears were microscopically examined for the presence of Theileria and Babesia organisms, and a semi-nested PCR was used for subsequent molecular specification. From the ticks, salivary glands and uterus were isolated and subsequently analyzed by semi-nested PCR. Piroplasm organisms were observed in 29% of the blood smears with low parasitemia, whereas 65% of the blood samples yielded positive PCR findings. The presence of Theileria ovis (55.6%), Theileria lestoquardi, and mixed infection with Theileria spp. and Babesia ovis were detected by semi-nested PCR in 0.3%, 5.6%, and 0.99%, respectively. In total, 429 ixodid ticks were collected from different areas of the province. The most prevalent ticks were Rhipicephalus turanicus (n = 376; 87.6% of the total), followed by Hyalomma marginatum turanicum (n = 30; 7.0%), Dermacentor raskemensis (n = 12; 2.8%), Hyalomma anatolicum anatolicum (n = 7; 1.6%), Dermacentor marginatus (n = 2; 0.5%), Rhipicephalus bursa (n = 1; 0.2%), and Haemaphysalis sp. (n = 1; 0.2%). Of the positive R. turanicus samples, 5 (5.7%) were infected with T. ovis and 2 (2.9%) with T. lestoquardi. Neither Babesia ovis nor Babesia motasi infection was detected in salivary glands or uterine samples of the ticks. The results also suggest that R. turanicus could be the vector responsible for transmission of the 2 Theileria species.

  11. Ivermectin pharmacokinetics in lactating sheep

    NARCIS (Netherlands)

    Cerkvenik, V.; Grabnar, V.; Skubic, V.; Doganoc, D.Z.; Beek, W.M.J.; Keukens, H.J.; Kosorok, M.D.; Pogacnik, M.

    2002-01-01

    Ivermectin (IVM) concentrations in plasma and milk were studied in six Istrian Pramenka dairy sheep after a single subcutaneous dose of 0.2 mg/kg b.w. of IVM in the early lactation period to describe IVM disposition in milk and to evaluate the transfer of IVM residues via milk to suckling lambs. Lar

  12. Ventral hernia in the sheep.

    Science.gov (United States)

    Tirgari, M

    1980-01-05

    Between November 1974 and November 1978, 11 sheep with ventral hernia were referred for surgical correction. The anatomy of the area, clinical findings, operative details, surgicopathological observations and postoperative results are described. A comparison of these cases with hernial correction in horses and cattle is made.

  13. Sensitivity and specificity of the FAMACHA(©) system in Suffolk sheep and crossbred Boer goats.

    Science.gov (United States)

    Sotomaior, Cristina Santos; Rosalinski-Moraes, Fernanda; da Costa, Alane Rayana Barbosa; Maia, Dhéri; Monteiro, Alda Lúcia Gomes; van Wyk, Jan A

    2012-11-23

    Sheep and goats are the species of farm animal with the highest growth rate in Paraná State. The main problems facing Paraná State flocks are gastrointestinal parasites and anthelmintic resistance. One of the newest resources used to slow down the development of anthelmintic resistance is the FAMACHA(©) system, a selective method useful for controlling gastrointestinal verminosis in small ruminants. The purpose of the present research was to evaluate the sensitivity and specificity of the FAMACHA(©) system in sheep and goats and to compare the results for both species. The conjunctivae of 83 Suffolk ewes and 60 adult crossbred Boer does were evaluated by the same trained person using the FAMACHA(©) system. The packed cell value (PCV) served as the gold standard for clinical FAMACHA(©) evaluation. To calculate the sensitivity and specificity of the FAMACHA(©) system, different criteria were adopted in turn: animals classified as FAMACHA(©) (F(©)) 4 and 5, or 3, 4 and 5, were considered to be anemic (positive test), and animals classified as F(©)1, 2 and 3, or 1 and 2 were considered to be non-anemic (negative test). Three standard values of PCV, namely ≤19%, ≤18% or ≤15%, were used to confirm anemia. At all cut-off levels, the sensitivity increased if F(©)3 animals were included as being anemic. However, changes in levels of sensitivity were associated with reciprocal changes in specificity. The sensitivity was higher for sheep than for goats, excepting when the criteria included PCV≤18 and F(©)3, F(©)4 and F(©)5 were considered positive. In contrast, the specificity was always lower in sheep for any criteria adopted. Other than in goats, using the ≤15 cut-off level for sheep, it is possible to opt not to drench the animals that were shown to be F(©)3 because the sensitivity is still high, indicating that few animals that should have been drenched were overlooked. In goats, in contrast, the low sensitivity at all cut-off levels made it too

  14. Quantitative trait loci underlying udder morphology traits in dairy sheep.

    Science.gov (United States)

    Gutiérrez-Gil, B; El-Zarei, M F; Alvarez, L; Bayón, Y; de la Fuente, L F; San Primitivo, F; Arranz, J J

    2008-09-01

    A genome scan was conducted on the basis of the daughter design to detect quantitative trait loci (QTL) influencing udder morphology traits in Spanish Churra dairy sheep. A total of 739 ewes belonging to 11 half-sib families were genotyped for 182 microsatellite markers covering 3,248.2 cM (Kosambi) of the ovine autosomal genome. Phenotypic traits included scores for 5 linear udder traits: udder depth, udder attachment, teat placement, teat size, and udder shape. Quantitative measurements for the QTL analysis were calculated for each trait from evaluation scores using within-family yield deviations corrected for fixed environmental effects. Joint analysis of all families using Haley-Knott regression identified 5 regions that exceeded the 5% chromosome-wise significance threshold on chromosomes 7, 14, 15, 20, and 26. Based on the across-family results, a within-family analysis was carried out to identify families segregated according to the QTL and to estimate the QTL effect. The allelic substitution effect for individual families ranged from 0.47 to 1.7 phenotypic standard deviation units for udder shape on chromosome 15 and udder depth on chromosome 14, respectively. These QTL regions provide a starting point for further research aimed at the characterization of genetic variability involved in udder traits in Churra sheep. This paper presents the first report of a sheep genome scan for udder-related traits in a dairy sheep outbred population.

  15. Decay of interspecific avian flock networks along a disturbance gradient in Amazonia

    Science.gov (United States)

    Mokross, Karl; Ryder, Thomas B.; Côrtes, Marina Corrêa; Wolfe, Jared D.; Stouffer, Philip C

    2014-01-01

    Our understanding of how anthropogenic habitat change shapes species interactions is in its infancy. This is in large part because analytical approaches such as network theory have only recently been applied to characterize complex community dynamics. Network models are a powerful tool for quantifying how ecological interactions are affected by habitat modification because they provide metrics that quantify community structure and function. Here, we examine how large-scale habitat alteration has affected ecological interactions among mixed-species flocking birds in Amazonian rainforest. These flocks provide a model system for investigating how habitat heterogeneity influences non-trophic interactions and the subsequent social structure of forest-dependent mixed-species bird flocks. We analyse 21 flock interaction networks throughout a mosaic of primary forest, fragments of varying sizes and secondary forest (SF) at the Biological Dynamics of Forest Fragments Project in central Amazonian Brazil. Habitat type had a strong effect on network structure at the levels of both species and flock. Frequency of associations among species, as summarized by weighted degree, declined with increasing levels of forest fragmentation and SF. At the flock level, clustering coefficients and overall attendance positively correlated with mean vegetation height, indicating a strong effect of habitat structure on flock cohesion and stability. Prior research has shown that trophic interactions are often resilient to large-scale changes in habitat structure because species are ecologically redundant. By contrast, our results suggest that behavioural interactions and the structure of non-trophic networks are highly sensitive to environmental change. Thus, a more nuanced, system-by-system approach may be needed when thinking about the resiliency of ecological networks. PMID:24335983

  16. Does mixed-species flocking influence how birds respond to a gradient of land-use intensity?

    Science.gov (United States)

    Mammides, Christos; Chen, Jin; Goodale, Uromi Manage; Kotagama, Sarath Wimalabandara; Sidhu, Swati; Goodale, Eben

    2015-07-22

    Conservation biology is increasingly concerned with preserving interactions among species such as mutualisms in landscapes facing anthropogenic change. We investigated how one kind of mutualism, mixed-species bird flocks, influences the way in which birds respond to different habitat types of varying land-use intensity. We use data from a well-replicated, large-scale study in Sri Lanka and the Western Ghats of India, in which flocks were observed inside forest reserves, in 'buffer zones' of degraded forest or timber plantations, and in areas of intensive agriculture. We find flocks affected the responses of birds in three ways: (i) species with high propensity to flock were more sensitive to land use; (ii) different flock types, dominated by different flock leaders, varied in their sensitivity to land use and because following species have distinct preferences for leaders, this can have a cascading effect on followers' habitat selection; and (iii) those forest-interior species that remain outside of forests were found more inside flocks than would be expected by chance, as they may use flocks more in suboptimal habitat. We conclude that designing policies to protect flocks and their leading species may be an effective way to conserve multiple bird species in mixed forest and agricultural landscapes. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  17. Improving the Local Sheep in Gansu via Crossing with Introduced Sheep Breeds Dorset and Borderdale

    Institute of Scientific and Technical Information of China (English)

    Sun; Xiaoping; Liu; Jianbin; Zhang; Wanlong; Lang; Xia; Yang; Bohui; Guo; Jian; Feng; Ruilin

    2014-01-01

    In order to improve the meat performance of local sheep in Gansu Province,Dorset and Borderdale were introduced to crossbreed with local sheep which were Tan sheep,Small-tail Han sheep and Mongolia sheep. The offspring under different crossbreeding combinations were sampled randomly at the different growing stage to measure their growth traits so as to select optimize the crossbreeding mode. The results indicated that,for the same crossbreeding mode,the growth rate of progeny was in order F3> F2> F1; for the F3 progeny,the combinations Dorset- Borderdale- Small tail Han sheep and Dorset- Borderdale- Mongolia sheep gave a higher growth rate,with a body weight of 1. 57%,3. 17%,8. 23%,1. 15% higher in male and female individuals than the counterparts of Dorset and Tan sheep and Small tail Han sheep; for the F2 progeny,the combinations Dorset- Borderdale- Small tail Han sheep and Dorset- Borderdale- Mongolia sheep also gave a higher growth rate,with a body weight of 2. 15%,4. 53%,9. 21% and 2. 75% higher in male and female individuals than the counterparts of Dorset and Tan sheep and Small tail Han sheep; for the F1 progeny,the combination Borderdale and Small tail Han sheep assumed a higher growth rate,with a body weight of 3. 23%,6. 07%,7. 42% and 8. 66% higher in male and female individuals than the counterparts of Borderdale- Mongolia sheep and Tan sheep- Small tail Han sheep,respectively. Therefore,in the Small-tail Han sheep and Mongolia sheep producing regions,the F2 or F3progeny bred by using Dorset or Borderdale sheep as male parent to cross with local breeds,or the hybrid lambs of Small-tail Han sheep and Borderdale sheep as highly qualified commodity,would produce significant economic benefit. Moreover,the novel breeds obtained by crossing were the valuable genetic resource for breeding meat sheep.

  18. The Levels of Genetic Differentiation of Small-Tailed Han Sheep and Tan Sheep Populations Using Structural Loci

    Institute of Scientific and Technical Information of China (English)

    LU Sheng-xia; CHANG Hong; JI De-jun; Tsunoda Kenji; REN Zhan-jun; REN Xiang-lian; SUN Wei; YANG Zhang-ping; CHANG Guo-bin

    2006-01-01

    Using the method of "random sampling in typical colonies of the central area of the habitat" and several electrophoresis techniques, the variations of 17 structural loci encoding blood proteins in 60 Small-Tailed Han sheep and 73 Tan sheep were examined and compared with those of 14 other sheep populations in China and other countries to investigate their levels of genetic differentiation. The average heterozygosities of Small-Tailed Han sheep and Tan sheep were 0.2360 and 0.2587, respectively. The average polymorphic information content values were 0.1974 and 0.2102, respectively. The average effective numbers of alleles were 1.5723 and 1.5751, respectively. The coefficients of gene differentiation in the four groups (including 4, 6, 13, and 16 sheep populations, respectively) were 0.049323, 0.059987, 0.1728, and 0.201256,respectively, indicating that the degree of gene differentiation at the structural loci was the least in Hu sheep, Tong sheep,Small-Tailed Han sheep, and Tan sheep; followed by the above-mentioned four sheep populations and two Mongolian sheep populations; and was the highest in sheep populations belonging to the Mongolian sheep group, South Asian sheep, and European sheep. The earlier researchers' conclusions that both Small-Tailed Han sheep and Tan sheep evolved from Mongolian sheep were further verified by the results of this study. Hu sheep, Tong sheep, Small-Tailed Han sheep, and Tan sheep were decreasingly affected by the bloodline of Mongolian sheep to different degrees. The relationships among sheep populations were not closely related to the geographical distances among sheep populations.

  19. Detection of newly produced T and B lymphocytes by digital PCR in blood stored dry on nylon flocked swabs.

    Science.gov (United States)

    Tessitore, Marion Vaglio; Sottini, Ales