Ronald J. Erskine
Full Text Available Enzootic bovine leukosis is a contagious disease of cattle caused by the retrovirus, bovine leukemia virus (BLV and is the most common cause of malignant neoplasm in cattle. In order to facilitate surveillance of this disease in dairy herds, we developed a method to combine ELISA of milk collected during routine production testing with a prescribed sampling of cows that is independent of the proportion of cows within each lactation. In 113 Michigan dairy herds, milk samples from ten cows in each of the 1st, 2nd, 3rd, and ≥4th lactations were analyzed for anti-Bovine Leukemia Virus (BLV antibodies by milk ELISA. For each herd, a BLV herd profile (BHP was calculated as the simple average of the percent of BLV-positive cows within each of the four lactation groups. The mean BHP for all herds was 32.8%, with means of 18.5, 28.8, 39.2, and 44.8% of 1st, 2nd, 3rd, and ≥4th lactation animals infected, respectively. In eight herds, we determined the correlation between the BHP, and true herd prevalence by testing the entire lactating herd (r=0.988, P<0.0001. The BHP allows discrimination of lactation-specific BLV prevalence within a dairy herd, to help identify risk factors and management plans that may be important in transmission of BLV.
Berends, I.M.G.A.; Graat, E.A.M.; Swart, W.A.J.M.; Weber, M.F.; Giessen, van de A.W.; Lam, T.J.G.M.; Heuvelink, A.E.; Weering, H.J.
The aim of this study was to determine the herd prevalence of veal and dairy herds and to identify risk factors for VTEC O157 positive veal herds. The study was based on monitoring data from November 1996 through July 2005 of 1051 dairy herds and 930 veal herds. The herd level prevalence (95% CI) wa
Johanna Vakkamaki; Suvi Taponen; Anna-Maija Heikkila; Satu Pyorala
.... This study addressed pathogen-specific microbiological data and treatment and culling records, in combination with cow and herd characteristics, from the Finnish dairy herd recording system during 2010-2012...
Full Text Available In order to survey the behaviour of choosing the alley area instead of a cubicle as a lying place (cubicle refusal, a questionnaire was sent to the 273 dairy farms in Norway known to keep cows in cubicle housing systems. Sixty-six percent of the farmers contacted were included in the study. The median herd size was 18 cows (range 7–118. More than 85% of the herds had sheds providing one or more cubicles per cow. The mean herd occurrence of cubicle refusal was 6%, but showed great variation (range 0–55%. Regression analysis showed a significant association between rearing heifers in slatted floor pens and an increased cubicle refusal occurrence (p = 0.02, R2 = 0.05, while herd size, use of litter, or cubicle-to-animal ratio were not found to be associated with cubicle refusal. The practice of rearing heifers in slatted floor pens accounted for about one half of the observed cubicle refusal (etiologic fraction = 0.51.
In a multivariable logistic regression analysis, being cross breed .... objective of this dairy system is to sale milk as a means of additional cash income. ... and herd characteristics (such as dairy herd management system, herd size, keeping of ...
Nielsen, Liza Rosenbaum
SUMMARY In this study within-herd prevalence of Salmonella Dublin was investigated in three age groups (calves, young stock, adult cows) during five herd visits at 3-month intervals of 14 endemically infected dairy herds. A total of 10162 paired faecal cultures and antibody measurements were used...... stock and adult cows than in calves. Hierarchical mixed-model results showed that seroprevalence was associated with the bacteriological status in calves and cows, but not in young stock. These results can be used to develop and validate theoretical infection dynamics models and to design effective...... control programmes for Salmonella Dublin in dairy herds....
Rajala-Schultz, P J; Gröhn, Y T; Allore, H G
The purpose of this study was to determine the effect of reproductive performance on profitability and optimal breeding decisions for Finnish dairy herds. We used a dynamic programming model to optimize dairy cow insemination and replacement decisions. This optimization model maximizes the expected net revenues from a given cow and her replacements over a decision horizon. Input values and prices reflecting the situation in 1998 in Finland were used in the study. Reproductive performance was reflected in the model by overall pregnancy rate, which was a function of heat detection and conception rate. Seasonality was included in conception rate. The base run had a pregnancy rate of 0.49 (both heat detection and conception rate of 0.7). Different scenarios were modeled by changing levels of conception rate, heat detection, and seasonality in fertility. Reproductive performance had a considerable impact on profitability of a herd; good heat detection and conception rates provided an opportunity for management control. When heat detection rate decreased from 0.7 to 0.5, and everything else was held constant, net revenues decreased approximately 2.6%. If the conception rate also decreased to 0.5 (resulting in a pregnancy rate of 0.25), net revenues were approximately 5% lower than with a pregnancy rate of 0.49. With lower fertility, replacement percentage was higher and the financial losses were mainly from higher replacement costs. Under Finnish conditions, it is not optimal to start breeding cows calving in spring and early summer immediately after the voluntary waiting period. Instead, it is preferable to allow the calving interval to lengthen for these cows so that their next calving is in the fall. However, cows calving in the fall should be bred immediately after the voluntary waiting period. Across all scenarios, optimal solutions predicted most calvings should occur in fall and the most profitable time to bring a replacement heifer into a herd was in the fall. It
In this thesis, the potential for improvements in surveillance of Mycobacterium avium subsp. paratuberculosis (Map) infection and paratuberculosis in dairy herds was investigated, leading to a reduction in surveillance costs whilst continuing to meet specific quality targets. In particular, differen
Kristensen, Erling Lundager; Østergaard, Søren; Krogh, Mogens Agerbo;
Monte Carlo simulation was used to predict the long-term financial performance related to the technical performance of dairy herds. The indicators addressed were derived from data collected routinely in the herd. They indicated technical performance that can be affected by the farmer or the consu......Monte Carlo simulation was used to predict the long-term financial performance related to the technical performance of dairy herds. The indicators addressed were derived from data collected routinely in the herd. They indicated technical performance that can be affected by the farmer......" that used data extracted from ordinary management software to predict herd-specific financial performance related to major management changes. The metamodel was derived from systematic experiments with a complex simulation model that was used directly for advanced herd-specific decision support. We...
Veling, J.; Barkema, H.W.; Schans, van de J.; Zijderveld, van F.G.; Verhoeff, J.
Herd-level sensitivities of bacteriological and serological methods were compared in 79 bovine dairy herds, recently infected with Salmonella enterica subsp. enterica serovar Dublin. All farms experienced clinical signs of salmonellosis for the first time and had no history of vaccination against sa
Nielsen, S.S.; Weber, M.F.; Kudahl, Anne Margrethe Braad
Stochastic simulation models are widely accepted as a means of assessing the impact of changes in daily management and the control of different diseases, such as paratuberculosis, in dairy herds. This paper summarises and discusses the assumptions of four stochastic simulation models and their use...... the models are somewhat different in their underlying principles and do put slightly different values on the different strategies, their overall findings are similar. Therefore, simulation models may be useful in planning paratuberculosis strategies in dairy herds, although as with all models caution...
Agerholm, J.S.; Willadsen, C. M.; Nielsen, Thomas Krogh
Diagnostic findings in 218 aborted bovine foetuses are reported. The materials were examined in a matched case-control study of 69 Danish dairy herds with a sudden increase in the number of abortions and a corresponding 69 control herds. Foetuses aborted during the subsequent 6-month period were...... examined to identify the cause of abortion if possible. A total of 186 specimens were submitted from case herds and 32 from control herds. A likely cause of abortion was diagnosed in 73 foetuses. The most common cause was bovine viral diarrhoea virus (BVDV: 13%) followed by Neospora caninum infection (10......%), mycosis (5%) and Bacillus licheniformis infection (4%). Foetal and/or placental lesions were found in a further 27 cases. Only BVDV infection and neosporosis were diagnosed in more than one foetus per herd and only protozoal associated abortions occurred significantly more frequently in the case, rather...
Ferguson, James D; Skidmore, Andrew
Sixteen herds were selected from a pool of 64 herds nominated by consultants for participation in a national survey to demonstrate excellence in reproductive performance. For inclusion in the survey, herds had to have comprehensive records in a farm computer database or participate in a Dairy Herd Improvement Association record system and have superior reproductive performance as judged by the herd advisor. Herd managers were asked to fill out a questionnaire to describe their reproductive management practices and provide herd records for data analysis. Reproductive analysis was based on individual cow records for active and cull dairy cows that calved during the calendar year 2010. Breeding records by cow were used to calculate indices for insemination rate (IR), conception rate (CR), pregnancy rate (PR), and culling. Herds ranged in size from 262 to 6,126 lactating and dry cows, with a mean of 1,654 [standard deviation (SD) 1,494] cows. Mean days to first insemination (DFS) was 71.2d (SD 4.7d), and IR for first insemination was 86.9%. Mean days between inseminations were 33.4d (SD 3.1d), and 15.4% of insemination intervals were greater than 48 d (range: 7.2 to 21.5%). First-service conception rate was 44.4% (SD 4.8%) across all herds and ranged from 37.5 to 51.8%. Mean PR was 32.0% (SD 3.9%) with a range of 26.5 to 39.4%. Lactation cull rate was 32.2% (SD 12.4%) with a range from 13.6 to 58.1%. Compared with mean data and SD for herds in the Raleigh Dairy Herd Improvement Association system, mean indices for these herds ranked them in the 99 th percentile for IR (using heat detection rate as comparison), 99 th percentile for PR, the bottom 18.6 percentile for DFS, and around the 50th percentile for CR. This suggests that excellent herd reproductive performance was associated with reproductive management that resulted in high insemination rates combined with average CR.
Johnston, Howard; Beasley, Laura; MacPherson, Neil
Chronic copper toxicity was diagnosed in a Jersey herd in the Waikato region of New Zealand following an investigation into the deaths of six cattle from a herd of 250 dry cows. Clinical signs and post-mortem examination results were consistent with a hepatopathy, and high concentrations of copper in liver and blood samples of clinically affected animals confirmed copper toxicity. Liver copper concentrations and serum gamma-glutamyl transferase activities were both raised in a group of healthy animals sampled at random from the affected herd, indicating an ongoing risk to the remaining cattle; these animals all had serum copper concentrations within normal limits. Serum samples and liver biopsies were also collected and assayed for copper from animals within two other dairy herds on the same farm; combined results from all three herds showed poor correlation between serum and liver copper concentrations. To reduce liver copper concentrations the affected herd was drenched with 0.5 g ammonium molybdate and 1 g sodium sulphate per cow for five days, and the herd was given no supplementary feed or mineral supplements. Liver biopsies were repeated 44 days after the initial biopsies (approximately 1 month after the end of the drenching program); these showed a significant 37.3% decrease in liver copper concentrations (P record keeping, but multiple sources of copper contributed to a long term copper over supplementation of the herd; the biggest source of copper was a mineral supplement. The farmer perceived this herd to have problems with copper deficiency prior to the diagnosis of copper toxicity, so this case demonstrates the importance of monitoring herd copper status regularly. Also the poor correlation between liver and serum copper concentrations in the three herds sampled demonstrates the importance of using liver copper concentration to assess herd copper status.
Parker Gaddis, K L; Cole, J B; Clay, J S; Maltecca, C
Genetic improvement of dairy cattle health through the use of producer-recorded data has been determined to be feasible. Low estimated heritabilities indicate that genetic progress will be slow. Variation observed in lowly heritable traits can largely be attributed to nongenetic factors, such as the environment. More rapid improvement of dairy cattle health may be attainable if herd health programs incorporate environmental and managerial aspects. More than 1,100 herd characteristics are regularly recorded on farm test-days. We combined these data with producer-recorded health event data, and parametric and nonparametric models were used to benchmark herd and cow health status. Health events were grouped into 3 categories for analyses: mastitis, reproductive, and metabolic. Both herd incidence and individual incidence were used as dependent variables. Models implemented included stepwise logistic regression, support vector machines, and random forests. At both the herd and individual levels, random forest models attained the highest accuracy for predicting health status in all health event categories when evaluated with 10-fold cross-validation. Accuracy (SD) ranged from 0.61 (0.04) to 0.63 (0.04) when using random forest models at the herd level. Accuracy of prediction (SD) at the individual cow level ranged from 0.87 (0.06) to 0.93 (0.001) with random forest models. Highly significant variables and key words from logistic regression and random forest models were also investigated. All models identified several of the same key factors for each health event category, including movement out of the herd, size of the herd, and weather-related variables. We concluded that benchmarking health status using routinely collected herd data is feasible. Nonparametric models were better suited to handle this complex data with numerous variables. These data mining techniques were able to perform prediction of health status and could add evidence to personal experience in herd
Rösler, U; Hensel, A
Protothecosis is a severe form of mastitis in dairy cows caused by colorless algae of the genus Prototheca. Since P. zopfii is highly resistant to all known chemotherapeutics, infected cows must be removed from the herd. Eradication measures are difficult since many chronically infected cows may become intermittent shedders. Therefore, cultural methods are insufficient for control measures. In order to eradicate Prototheca zopfii-mastitis in dairy cattle herds, two isotype specific indirect ELISA for detection of IgA and IgG1 in whey were used in a dairy herd highly affected with protothecal mastitis. All cows (n = 313) were tested four times in intervals of six months. Milk specimens were examined in parallel by cultivation and serologically using two indirect ELISA systems for specific IgA and IgG1 in whey. Cows tested Prototheca positive were consequently separated from the herd and slaughtered. At the first examination, 15.6% of the animals were found positive by culture, and 23.3% were positive in at least one of the ELISA systems. Within two years, protothecal prevalence and incidence decreased to zero indicating that the eradication strategy used was successful. In summary, serological identification of P. zopfii-infected lactating cows is an useful tool to eradicate protothecal bovine mastitis in infected herds.
Schewe, R L; Kayitsinga, J; Contreras, G A; Odom, C; Coats, W A; Durst, P; Hovingh, E P; Martinez, R O; Mobley, R; Moore, S; Erskine, R J
The ability to reduce somatic cell counts (SCC) and improve milk quality depends on the effective and consistent application of established mastitis control practices. The US dairy industry continues to rely more on nonfamily labor to perform critical tasks to maintain milk quality. Thus, it is important to understand dairy producer attitudes and beliefs relative to management practices, as well as employee performance, to advance milk quality within the changing structure of the dairy industry. To assess the adoption rate of mastitis control practices in United States dairy herds, as well as assess social variables, including attitudes toward employees relative to mastitis control, a survey was sent to 1,700 dairy farms in Michigan, Pennsylvania, and Florida in January and February of 2013. The survey included questions related to 7 major areas: sociodemographics and farm characteristics, milking proficiency, milking systems, cow environment, infected cow monitoring and treatment, farm labor, and attitudes toward mastitis and related antimicrobial use. The overall response rate was 41% (21% in Florida, 39% in Michigan, and 45% in Pennsylvania). Herd size ranged from 9 to 5,800 cows. Self-reported 3-mo geometric mean bulk tank SCC (BTSCC) for all states was 194,000 cells/mL. Multivariate analysis determined that proven mastitis control practices such as the use of internal teat sealants and blanket dry cow therapy, and not using water during udder preparation before milking, were associated with lower BTSCC. Additionally, farmer and manager beliefs and attitudes, including the perception of mastitis problems and the threshold of concern if BTSCC is above 300,000 cells/mL, were associated with BTSCC. Ensuring strict compliance with milking protocols, giving employees a financial or other penalty if BTSCC increased, and a perceived importance of reducing labor costs were negatively associated with BTSCC in farms with nonfamily employees. These findings highlight the
Agger, Jens F.; Christoffersen, Anna-Bodil; Rattenborg, Erik
During recent years in Denmark higher rates of antibodies to Coxiella burnetii have been detected in animals and humans than previously reported. A study based on bulk tank milk samples from 100 randomly selected dairy herds was performed to estimate the prevalence and geographical distribution o...
Nekouei, Omid; VanLeeuwen, John; Sanchez, Javier; Kelton, David; Tiwari, Ashwani; Keefe, Greg
Enzootic bovine leukosis (EBL) is an economically important infection of dairy cattle worldwide, which is caused by bovine leukemia virus (BLV). The prevalence of infection in Canadian dairy herds is high and continues to increase; however, there has not been a national program to control BLV. This cross-sectional study was conducted to identify potentially important risk factors for BLV infection on Canadian dairy herds, which is a prerequisite to developing an effective control program. During 1998-2003, based on a stratified two-stage random sampling process, 315 dairy farms from seven provinces of Canada were selected. Within each farm, 9-45 cows were bled and tested with a commercial serum ELISA kit for BLV antibodies. A comprehensive questionnaire, targeting potentially important herd-level management indicators, was successfully administered in 272 herds. A zero-inflated negative binomial (ZINB) regression model was fit to the resulting data to assess the potential associations between BLV seropositivity and a variety of herd-level factors. Seventy-eight percent of the herds were identified as BLV-positive (had one or more test positive animals). In the negative-binomial part of the final ZINB model, herds with clinical cases of leukosis during the 12 months prior to sampling, as well as herds which purchased animals with unknown BLV infection status in the last five years, had a significantly larger proportion of BLV positive animals. Based on a significant interaction between two of the risk factors, changing gloves between cows during pregnancy examination was not statistically associated with lower proportion of infected cows compared with not changing gloves, in the western Canadian provinces. In the logistic part of the model, herds from eastern Canadian provinces and those not purchasing cows in the last five years had increased odds of being free from BLV. The high prevalence of infection across Canada should be addressed through the development and
Thysen, Iver; Enevoldsen, Carsten
Two complementary approaches to produce visual information from reproduction records are described and exemplified. The Event Display shows all reproductive events, over a year, for all cows in a herd, by symbols placed in an array with columns representing calendar weeks and rows representing in...
Hancock, A S; Younis, P J; Beggs, D S; Mansell, P D; Pyman, M F
Investigate the presence of infectious reproductive disease pathogens in dairy herd bulls in south-west Victoria, Australia, using a cross-sectional study. Dairy herd bulls from 32 herds were sampled for bovine viral diarrhoea virus (BVDV: 256 bulls, 32 herds) prior to the natural mating period, bovine herpes virus-1 prior to (10 bulls, 5 herds) and after (118 bulls, 19 herds) the natural mating period, and for Campylobacter fetus spp. and Tritrichomonas foetus after the natural mating period (61 bulls, 7 herds). BVDV was detected from an ear-notch sample using a commercially available rapid assay ELISA, bovine herpes virus-1 and T. foetus were screened for by PCR from a penile swab and preputial sample respectively, and C. fetus spp. were screened for by culture of preputial samples. None of the bulls tested positive for BVDV antigen. Campylobacter fetus venerealis (or C. fetus fetus) was cultured in 6.6% (4/61) of bulls, representing 2 of the 7 (28.6%) farms that were not vaccinating bulls against bovine genital campylobacteriosis. Bovine herpes virus-1 was identified in 7.8% (10/128) bulls sampled; T. foetus was not identified in any samples. Bovine genital campylobacteriosis is present in south-western Victoria, despite longstanding recommendations to vaccinate bulls. Screening bulls for persistent infection with BVDV is probably justified, despite the absence of persistently infected bulls in this study. Further research is warranted to investigate the potential reproductive implications of BHV-1, and the presence of T. foetus. © 2015 Australian Veterinary Association.
Burow, Elke; Thomsen, Peter Thorup; Sørensen, Jan Tind;
The effect of summer grazing in large Danish dairy herds and certain management characteristics of grazing were studied for their impact on dairy cow mortality. Mortality data (from the Danish Cattle Database) from 391 Danish dairy herds (>100 cows) were combined with information from a questionn...
Full Text Available Abstract The objective of this study was to investigate the impact of paratuberculosis sero-status on milk yield, fat, protein, somatic cell count and calving interval in Irish dairy herds. Serum from all animals over 12 months of age (n = 2,602 in 34 dairy herds was tested for antibodies to Mycobacterium avium subsp. paratuberculosis using an ELISA. Herds were categorised by sero-status into positive, non-negative and negative, where a positive herd contained two or more positive cows, a non-negative herd contained only one positive cow and a negative herd contained no positive cows. Data at animal, parity and herd-level were analysed by multiple regression using general linear models. Positive herds (mean herd size = 129 cows and non-negative herds (81 cows were larger than negative herds (72 cows (P
Ćaǧlayan, Alper; Yüca, Songül
Herd management requires multidisciplinary practices including animal feeding, gynecology, artificial insemination, immunology, and similar topics. Animal feeding is the most delicate subject as the fodder expense is 70% of the farm cost and as nearly all of the metabolic diseases arising out as health problem are because of misfeeding. However, a business organization's being able to maintain making profit will be possible by taking a healthy calf from breeding herd every year. For this reason, precision registrations of birth and artificial insemination, following-up pregnant state of animals, and making the other animals pregnant as soon as possible should be primary aim. It should not be forgotten that diarrhea and pneumonia in calves are among the most frequently witnessed infection related health problems. Mastitis, metritis and foot diseases take an important place in mature cows. These diseases can be minimized by vaccinations that are done properly and in suitable time, in-service training of staffs, making shelters suitable for animals welfare, and improving the hygienic conditions.
Bradley, A J; Green, M J
Clinical mastitis was monitored in six Somerset dairy herds for one year. The herds all had three-month geometric mean bulk milk somatic cell counts of less than 250,000 cells/ml. Escherichia coli was the predominant pathogen isolated on all the farms and in all months of the year. Environmental pathogens accounted for 61.4 per cent of all cases of clinical mastitis and for 79.3 per cent of the mastitis cases in which an aetiological agent was identified. The mean annual incidence was 41.6 cases per 100 cows (range 14 to 75). Affected cows suffered a mean of 1.5 cases and 16.4 per cent of quarters suffered at least one repeat case. Mastitis due to E. coli was more severe than mastitis due to other causes and it tended to be more severe in early lactation and during the housing period. Mastitis was significantly more severe (grades 2 and 3) in the herd with the lowest bulk milk somatic cell count and in the herd which was kept indoors throughout the year than in the other four herds. Mastitis was fatal in 2.2 per cent of cases and resulted in the death of 0.6 per cent of the lactating cows.
Ersbøll, Annette Kjær; Ersbøll, Bjarne Kjær; Houe, H.
According to the current literature BVDV-infected neighbours probably impose a high risk of infection of susceptible cattle herds. In the present study, the objective was to evaluate the risk of a dairy herd changing infection status (from not having persistently infected (PI) animals to having PI-animals...
Vakkamäki, Johanna; Taponen, Suvi; Heikkilä, Anna-Maija; Pyörälä, Satu
The Finnish dairy herd recording system maintains production and health records of cows and herds. Veterinarians and farmers register veterinary treatments in the system. Milk samples for microbiological analysis are routinely taken from mastitic cows. The laboratory of the largest dairy company in Finland, Valio Ltd., analyzes most samples using real-time PCR. This study addressed pathogen-specific microbiological data and treatment and culling records, in combination with cow and herd characteristics, from the Finnish dairy herd recording system during 2010-2012. The data derived from 240,067 quarter milk samples from 93,529 dairy cows with mastitis; 238,235 cows from the same herds served as the control group. No target pathogen DNA was detected in 12% of the samples. In 49% of the positive samples, only one target species and in 19%, two species with one dominant species were present. The most common species in the samples with a single species only were coagulase-negative staphylococci (CNS) (43%), followed by Staphylococcus aureus (21%), Streptococcus uberis (9%), Streptococcus dysgalactiae (8%), Corynebacterium bovis (7%), and Escherichia coli (5%). On average, 36% of the study cows and 6% of the control cows had recorded mastitis treatments during lactation. The corresponding proportions were 16 and 6% at drying-off. For more than 75% of the treatments during lactation, diagnosis was acute clinical mastitis. In the milk samples from cows with a recorded mastitis treatment during lactation, CNS and S. aureus were most common, followed by streptococci. Altogether, 48% of the cows were culled during the study. Mastitis was reported as the most common reason to cull; 49% of study cows and 18% of control cows were culled because of mastitis. Culling was most likely if S. aureus was detected in the milk sample submitted during the culling year. The PCR test has proven to be an applicable method also for large-scale use in bacterial diagnostics. In the present
Hand, K J; Godkin, M A; Kelton, D F
The objective of this study was to determine the effect of somatic cell count (SCC) monitoring at the cow level through Dairy Herd Improvement (DHI) programs on the risk of bulk tank SCC (BTSCC) penalties. For the year 2009, BTSCC for all producers in Ontario were examined, for a total of 2,898 DHI herds, 1,186 non-DHI herds, and 48,250 BTSCC records. Two penalty levels were examined, where BTSCC exceeded 499,000 (P500) and 399,000 (P400) cells/mL. Data were modeled first to determine the odds of a BTSCC exceeding a set penalty threshold and second to determine the odds of incurring a penalty under the Ontario Milk Act. All data were modeled as a generalized mixed model with a binary link function. Random effects included herd, fixed effects included season of BTSCC (summer, May to September, and winter, October to April), total milk shipped per month (L), fat paid per month (kg), protein paid per month (kg), and participation or not in the DHI program. The likelihood of a BTSCC exceeding a penalty threshold in a non-DHI herd compared with a DHI herd was significantly greater than 1 at both penalty levels, where the odds ratios were estimated to be 1.42 [95% confidence interval (CI): 1.19 to 1.69] and 1.38 (95% CI: 1.25 to 1.54) for P500 and P400, respectively. The likelihood of incurring a BTSCC penalty (where 3 out of 4 consecutive BTSCC exceeded penalty thresholds) was not significantly different at P500; however, it was significantly different for P400, where the odds ratio was estimated to be 1.42 (95% CI: 1.12 to 1.81).
Kristensen, Erling Lundager; Østergaard, Søren; Krogh, Mogens Agerbo
Monte Carlo simulation was used to predict the long-term financial performance related to the technical performance of dairy herds. The indicators addressed were derived from data collected routinely in the herd. They indicated technical performance that can be affected by the farmer......, mortality in cows and calves, dynamics of body condition, and somatic cell counts. Each indicator was defined by 2 or 3 levels, and 2- and 3-factor interactions were included in the simulation experiment, which included 72 scenarios. Each scenario was replicated 200 times, and the resulting gross margin per...... increased the gross margin 2.6 times more than improved reproduction efficiency, which again increased the gross margin 2.6 to 5.9 times more than improved management related to heifers, body condition score, mortality, and somatic cell counts. These results were implemented in a simple "metamodel...
Stevenson, Jeffrey S
Timed artificial insemination (AI) programs are commonly used in the dairy industry for lactating cows, but less so in replacement heifers. Excellent programs using combinations of prostaglandin F2α and gonadotropin-releasing hormone in protocols relying on timed AI without detection of estrus or in protocols that combine timed AI with inseminations performed after detected estrus are able to achieve acceptable pregnancy percentages. In herds with excellent estrus detection, timed AI programs serve as a failsafe system to address cows or heifers not yet inseminated after a defined period of estrus detection.
Hoogendam, K.; Richardson, E.; Mee, J.F.
The objective of this study was to investigate the impact of paratuberculosis sero-status on milk yield, fat, protein, somatic cell count and calving interval in Irish dairy herds. Serum from all animals over 12 months of age (n=2,602) in 34 dairy herds was tested for antibodies to Mycobacterium avi
Tomaszewski, M.A.; Dijkhuizen, A.A.; Huirne, R.B.M.; Otten, A.
Yearly production and performance data were obtained for dairy herd improvement members in Texas to determine whether on-farm use of a management information system (MIS) quantitatively impacted performance. Data from 66 dairy operations for the years 1983–1996 were evaluated. Herds enrolled in an M
The data characteristics of the United States dairy herd related to animals enrolled in milk recording (dairy herd improvement) are the basic foundation and important influencers for the management and genetic progress achieved in a population or animal production unit. The amount, characteristics ...
Vaarst, Mette; Enevoldsen, Carsten
Danish organic dairy production is characterized by a low input of antibiotics for udder treatment and a high input of other mastitis control procedures. A study was conducted in 14 organic dairy herds with the objectives of obtaining a comprehensive description of clinical mastitis cases...... and identifying characteristic patterns in these results. Clinical signs, inflammatory reactions and microbiological identifications were obtained from 367 cases of clinical mastitis occurring over 18 months. Cow characteristics and preincident values such as milk yield and somatic cell count were obtained...... for each cow. Signs of previous udder inflammation were present in two-thirds of the clinical mastitis cases. Severe local inflammatory reactions were found in 21% of the cases and some indication of generalized signs such as fever and reduced appetite were found in 35% of the cases. Logistic regression...
Thomsen, Peter T; Østergaard, Søren; Sørensen, Jan Tind; Houe, Hans
During the last few years, many Danish dairy farmers have expressed increasing concerns regarding a group of cows, which we have chosen to term 'loser cows'. Until now, a loser cow has not been described scientifically. We defined a loser cow on the basis of a clinical examination of the cow. A total of 15,151 clinical examinations were made on 6,451 individual cows from 39 randomly selected, large Danish dairy herds with loose-housing systems using a clinical protocol. Scores for the clinical signs lameness, body condition, hock lesions, other cutaneous lesions, vaginal discharge, condition of hair coat and general condition were converted into a loser cow score. Cows with a loser cow score of 8 or more were classified as loser cows. The overall prevalence of loser cows was 2.15%, 4.50% and 2.98% during the first, second and third round of herd visits, respectively. The associations between the loser cow state and milk production, mortality, morbidity, culling and workload for the farmer were evaluated using data from herd visits and from the Danish Cattle Database and a number of different statistical techniques. It was concluded that the loser cow state has significant negative consequences for both the farmer and the cow. On average, loser cows yielded 0.61 to 2.24 kg energy corrected milk less per day than non-loser cows depending on parity. Hazard ratio for death or euthanasia was 5.69 for loser cows compared to non-loser cows. Incidence rate ratio for disease treatments was 0.69 for non-loser cows compared to loser cows. Loser cows were often culled in an 'unfavourable' way and generally caused extra workload for the farmer. A simplified version of the loser cow score was evaluated and is recommended for future research and use in practice.
Belage, E; Dufour, S; Bauman, C; Jones-Bitton, A; Kelton, D F
Several studies have investigated which management practices have the greatest effect on udder health, but little information is available on how broadly the recommended milking practices are adopted across Canada. The National Dairy Study 2015 was designed to gather dairy cattle health and management data on dairy farms across Canada. The objectives of the present study were to describe the current proportions of adoption of milking practices on Canadian dairy farms, and identify factors associated with their use on farms. A bilingual questionnaire measuring use of various practices, including an udder health-specific section, was developed and sent to all Canadian dairy farms. The questions in the udder health section of the questionnaire were adapted from a bilingual questionnaire previously validated and containing questions regarding general milking hygiene and routine, and on-farm mastitis management. Chi-squared tests were used to investigate simple associations between adoption of practices and various explanatory variables including region, milking system, herd size, and bulk tank somatic cell count. In total, 1,373 dairy producers completed the survey. The regional distribution of the participants was representative of the Canadian dairy farm population, and milk quality was, on average, similar to nonparticipants. Overall, Canadian dairy producers followed the recommendations for milking procedures, but some were more extensively used than others. Fore-stripping, cleaning teats, wiping teats dry, using single-cow towels, and use of postmilking teat disinfectant were widely adopted. Use of gloves and glove hygiene, use of a premilking teat disinfectant, and use of automatic takeoffs were not as extensively implemented. Adoption percentages for several practices, including use of gloves, use of a premilking teat disinfectant, teat drying methods, and use of automatic takeoffs were significantly associated with milking system, herd size, and region. It
Wedderkopp, A.; Stroger, U.; Bitsch, V.;
of being test-negative in the third test round was 0.926 for a herd with 2 previous test-negative results. It was concluded that the investigated ELISA method was in general accordance with the cases of clinical S. Dublin infection recorded. and that the method has a potential for national screening......The usefulness of enzyme-linked immunosorbent assay (ELISA) was investigated as a simple method to screen for Salmonella Dublin infection in dairy herds, examining bulk tank milk samples for lipopolysaccharide (O:1,9,12) antibodies. The cut-off value for the ELISA on bulk tank milk was established...... based on individual milk samples (n = 2887) and bulk tank milk from 52 herds. Bulk tank milk samples (n = 5108) were collected from 1464 dairy herds located in 19 different areas. About 10% of the dairy herds in Denmark participated in the study. The percentage of herds changing from test...
Ott, S L; Johnson, R; Wells, S J
Bovine-leukosis virus (BLV; also termed 'bovine-leukemia virus') is a retrovirus that primarily affects lymphoid tissue of dairy and beef cattle. Our objective was to investigate the association between BLV infection and annual value of production (AVP) on dairy herds within the United States, as part of the USDA National Animal Health Monitoring System's 1996 dairy study. 1006 herds (in 20 states) with at least 30 dairy cows were interviewed during 1996. The agar-gel immunodiffusion test was used to detect serum antibodies to BLV. 10-40 cows from each herd were tested and each tested cow was classified as negative or positive based on results of a single test. A multivariable regression model was used with the 976 herds with complete data for analysis. When compared to herds with no test-positive cows, herds with test-positive cows produced 218 kg per cow (i.e. 3%) less milk. The average reduction in AVP was $59 per cow for test-positive herds relative to test-negative herds. For the dairy industry as a whole, BLV seropositivity was associated with loss to producers of $285 million and $240 million for consumers. Most of this $525 million industry loss was due to reduced milk production in test-positive herds.
Sidibe, M.; Boly, H.; Lakouetené, T.; Leroy, P.; Bosma, R.H.
Peri-urban dairy cattle farms within 50 km of Bobo-Dioulasso were studied to assess herd type, disease incidence, management, feeding and breeding strategy. Out of 417 cattle farmers, 42% had dairy objectives and were studied. Among these peri-urban dairy farmers, 60% were settled, 36% semi-settled,
Burow, E; Rousing, T; Thomsen, P T
studied under different conditions. However, the effect of grazing on welfare, conceptualised as the multidimensional physical and mental state of the animal, has not yet been studied in contemporary cubicle loose-housing systems. The aim of our study was to investigate, based on a Welfare Quality (R......Structural development in the prime sector has led to increasing herd sizes and new barn systems, followed by less summer grazing for dairy cows in Denmark. Effects of grazing on single welfare measures in dairy cows - for example, the presence of integument alterations or mortality - have been......) inspired multidimensional dairy cow welfare assessment protocol, the within-herd effect of summer grazing compared with winter barn housing in Danish dairy herds with cubicle free-stall systems for the lactating cows. Our hypothesis was that cow welfare in dairy herds was better during summer grazing than...
Full Text Available Abstract The decline in dairy herd fertility internationally has highlighted the limited impact of traditional veterinary approaches to bovine fertility management. Three questionnaire surveys were conducted at buiatrics conferences attended by veterinary practitioners on veterinary dairy herd fertility services (HFS in countries with a seasonal (Ireland, 47 respondents and non-seasonal breeding model (The Netherlands, 44 respondents and Portugal, 31 respondents. Of the 122 respondents, 73 (60% provided a HFS and 49 (40% did not. The majority (76% of all practitioners who responded stated that bovine fertility had declined in their practice clients' herds with inadequate cow management, inadequate nutrition and increased milk yield as the most important putative causes. The type of clients who adopted a herd fertility service were deemed more educated than average (70% of respondents, and/or had fertility problems (58% and/or large herds (53%. The main components of this service were routine postpartum examinations (95% of respondents, fertility records analysis (75% and ultrasound pregnancy examinations (69%. The number of planned visits per annum varied between an average of four in Ireland, where breeding is seasonal, and 23 in Portugal, where breeding is year-round. The benefits to both the practitioner and their clients from running a HFS were cited as better fertility, financial rewards and job satisfaction. For practitioners who did not run a HFS the main reasons given were no client demand (55% and lack of fertility records (33%. Better economic evidence to convince clients of the cost-benefit of such a service was seen as a major constraint to adoption of this service by 67% of practitioners.
Waage, S.; Bjorland, J.; Caugant, D. A.
One hundred and seven bovine isolates of penicillin and tetracycline resistant Staphylococcus aureus, recovered from 25 different dairy herds in various parts of Norway, were characterized using antimicrobial susceptibility testing, multilocus enzyme electrophoresis, ribotyping, plasmid analysis...... and serotyping of capsular polysaccharide. Forty-one isolates from one particular herd, 37 isolates from 5 herds that used a common pasture and milking parlour in summer and 21 isolates from 12 herds in 8 different counties belonged to the same strain. The remaining 8 isolates, which originated from herds in 5...
Ohtsuka, Hiromichi; Kohiruimaki, Masayuki; Hayashi, Tomohito; Katsuda, Ken; Matsuda, Kei-ichi; Masui, Machiko; Abe, Ryo; Kawamura, Sei-ichi
To clarify the relationship between cellular immune status and nutritive condition, feeding program, blood profiles, and leukocyte populations were analyzed in two dairy herds experiencing frequent mastitis. Fourteen of the 35 lactating cows in herd A, and 18 of the 50 lactating cows in herd B scored positive on the California Mastitis Test (CMT), and 3 of the 73 lactating cows were CMT positive in herd C, which was the control. All herds were evaluated during five different milking stages, and blood was collected from five cows at each stage. With regard to feed content, the percentages of total digestible nutrients (TDN) and crude protein (CP) were found to be lower in herds A and B than in herd C. Levels of serum total cholesterol and blood urea nitrogen were lower in herds A and B than those in herd C. Neutrophil counts in herds A and B were increased compared to the neutrophil counts in herd C. On the other hand, the numbers of CD3(+) T cells and CD14-MHC class(+) cells were lower in herd A and B than in herd C. A decrease in peripheral lymphocytes and undernourishment were observed in the herds with frequent occurring mastitis.
Silvana Andrea Dieser
Full Text Available The objective of this study was to investigate the prevalence of different mastitis pathogens in Argentinean dairy farms. Composite milk samples were collected of 2296 cows from 51 randomly selected herds in Córdoba, Argentina. Somatic cell count was determined in all samples and bacterial examination of the milk samples with a SCC exceeding 200,000 cells/mL was performed. About 54%of cows were diagnosed with subclinical mastitis (SCC ≥200,000/mL. Bacteria were isolated in 83.1% of milk samples subjected to bacteriological analysis. The most frequently isolated pathogen was coagulase-negative staphylococci (CNS (52.1%, followed by Staphylococcus aureus (21.3%, Corynebacterium spp. (5.2%, Streptococcus agalactiae (4.4% and Streptococcus dysgalactiae (4.4%. This study demonstrates that among the major pathogens isolated, the contagious bacteria caused most of the subclinical infections of dairy cows in Cordoba, Argentina. Moreover, CNS was the most relevant group of minor pathogens causing subclinical mastitis.
Lu, Zhao; Mitchell, Rebecca M; Smith, Rebecca L; Karns, Jeffrey S; van Kessel, Jo Ann S; Wolfgang, David R; Schukken, Ynte H; Grohn, Yrjo T
An outbreak of Salmonella Kentucky followed by a high level of sustained endemic prevalence was recently observed in a US adult dairy herd enrolled in a longitudinal study involving intensive fecal sampling...
Ågren, Estelle C C; Sternberg Lewerin, Susanna; Wahlström, Helene; Emanuelson, Ulf; Frössling, Jenny
Legislated Salmonella control in Sweden has been in place since the 1960s. The purpose of this study was to investigate presence of Salmonella antibodies in dairy cattle herds and to provide a basis for decisions on how surveillance and control can be improved. Bulk milk samples from all Swedish dairy herds (n=4 683) were analysed with two different ELISAs; one detecting antibodies against Salmonella Dublin (Dublin ELISA), and one detecting antibodies against several of the serotypes causing bovine salmonellosis including S. Dublin (Bovine ELISA). Information about herds, i.e. geographical location, local animal density, number of test positive herds within 5km, animal trade and herd size, was based on register data. The results confirm a very low prevalence of Salmonella in Swedish dairy herds throughout the country with the exception of an island in the southeast. The test positive herds split into two groups; 41 herds (1%) positive in the Dublin ELISA, and 101 herds (2%) positive in the Bovine ELISA but negative in the Dublin ELISA. Geographical location of positive herds, and comparison of the results of the screening with serotypes previously isolated from some of the herds, indicated that the first group represents herds presently or previously infected with S. Dublin while the second group represents herds presently or previously infected with other serotypes. Differences in serological status between herds in different regions, of different size, with different animal purchase patterns et cetera, were tested using logistic regression. Presence of positive herds within 5km was significantly associated to testing positive. For herds testing positive in the Dublin ELISA, significant associations were also seen with herd size. Purchase of animals during the last year was not significantly associated with the outcome in the final models. We conclude that for future surveillance, the Bovine ELISA can be used to help in identifying infected herds, and the Dublin
Full Text Available Abstract Background Mastitis is one of the major threats to animal health, in organic farming as well as conventional. Preliminary studies of organic dairy herds have indicated better udder health in such herds, as compared to conventional herds. The aim of this paper was to further study mastitis and management related factors in certified organic dairy herds. Methods An observational study of 26 certified organic dairy herds in mid-eastern Sweden was conducted during one year. A large-animal practitioner visited the herds three times and clinically examined and sampled cows, and collected information about general health and management routines. Data on milk production and disorders treated by a veterinarian in the 26 herds, as well as in 1102 conventional herds, were retrieved from official records. Multivariable logistic regression was used to assess associations between herd type (organic vs. conventional and incidence of disorders. Results The organic herds that took part in the study ranged in size from 12 to 64 cows, in milk production from 3772 to 10334 kg per cow and year, and in bulk milk somatic cell counts from 83000 to 280000 cells/ml. The organic herds were found to have a lower incidence of clinical mastitis, teat injuries, and a lower proportion of cows with a high somatic cell count (as indicated by the UDS, Udder Disease Score compared to conventional herds. The spectrum of udder pathogenic bacteria was similar to that found in other Swedish studies. Treatment of mastitis was found to be similar to what is practised in conventional herds. Homeopathic remedies were not widely used in the treatment of clinical mastitis. The calves in most of these organic herds suckled their dams for only a few days, which were not considered to substantially affect the udder health. The main management factor that was different from conventional herds was the feeding strategy, where organic herds used a larger share of forage. Conclusion Udder
Vargas, B.; Herrero, M.; Arendonk, van J.A.M.
A dynamic performance model was integrated with a model that optimised culling and insemination policies in dairy herds using dynamic programming. The performance model estimated daily feed intake, milk yield and body weight change of dairy cows on the basis of availability and quality of feed and p
Vries, de M.; Bokkers, E.A.M.; Schaik, van G.; Engel, B.; Dijkstra, T.; Boer, de I.J.M.
Routine on-farm assessment of dairy cattle welfare is time consuming and, therefore, expensive. A promising strategy to assess dairy cattle welfare more efficiently is to estimate the level of animal welfare based on herd data available in national databases. Our aim was to explore the value of rout
Recently the number of milking cows has increased substantially in the Dar es Salaam region due to an increasing demand for fresh milk in this densely populated urban centre. It is estimated that there are 1,765 smallholder dairy herds with 8,233 improved dairy animals in and around the Dar es Sala
Recently the number of milking cows has increased substantially in the Dar es Salaam region due to an increasing demand for fresh milk in this densely populated urban centre. It is estimated that there are 1,765 smallholder dairy herds with 8,233 improved dairy animals in and around the Dar es
Gates, M C
National cattle movement databases provide a valuable opportunity to monitor the reproductive performance of breeding cattle on an industry-wide scale. In this analysis, records from the Cattle Tracing System database were used to derive key measures of reproductive efficiency for British beef and dairy herds, including calving spread, age at first calving, calving interval, culling rate and calf mortality rate. At the animal level, only 8.5 per cent of beef heifers and 6.9 per cent of dairy heifers calved by the target age of 24 months. The average calving interval was 394 days for beef dams (median: 371) and 426 days for dairy dams (median: 400). Differences in performance were noted between cattle breeds. An estimated 43.9 per cent calves born in dairy herds were crossbreed beef animals, which may limit the availability of replacement dairy heifers. At the herd level, calving spread and calf mortality rates increased with herd size, while average age at first calving, calving interval, and crossbreeding generally decreased with herd size. Dam age, calving month, breed and twinning were significant risk factors for culling and calf mortality at the animal level. Wide variation in performance between individual herds highlights the potential for improving the efficiency of British cattle production.
Verbeke, Joren; Piepers, Sofie; Supré, Karlien; De Vliegher, Sarne
A one-year survey on clinical mastitis was conducted on 50 randomly selected commercial Flemish dairy herds to estimate the pathogen-specific incidence rate of clinical mastitis (IRCM). The severity of the cases and the potential associations with herd hygiene were studied. Participating producers sampled 845 cases and 692 dairy cows. The mean and median IRCM was estimated at 7.4 and 5.3 quarter cases per 10,000 cow-days at risk, respectively. A large between-herd variation was observed (range of 0-21.3). In general, the IRCM was lower in heifers compared with multiparous cows (2.9 vs. 11.0 quarter cases per 10,000 cow-days at risk). However, the overall IRCM in the first week after calving was higher in heifers compared with cows (43.4 vs. 31.6 quarter cases per 10,000 cow-days at risk). Streptococcus uberis (18.2% of the cases) and Escherichia coli (15.5%) were the most frequently isolated pathogens and no growth was observed in 19.9% of the cases. The majority of the cases (63.1%) were mild (only clots in milk). Moderate (hard quarter without general signs) and severe symptoms (systemic illness) were observed in 29.9 and 7.0% of the cases, respectively. Isolation of E. coli (vs. any other culture result) was more likely in moderate and severe cases compared with mild cases. Overall IRCM and E. coli IRCM were higher in dirty compared with clean herds based on udder hygiene scores (9.0 and 1.7 vs. 6.0 and 0.6 quarter cases per 10,000 cow-days at risk, respectively). This study broadens the knowledge on clinical mastitis in Flemish dairy herds and underlines the high risk of CM in early-lactation heifers, the role of the so-called environmental pathogens, and herd hygiene.
Andersen, H. J.; Pedersen, L. H.; Aarestrup, Frank Møller;
The aim of this study was to evaluate the Danish surveillance program of Streptococcus agalactiae in dairy herds with respect to 1) fluctuation over time of the presence of S. agalactiae in bulk tank milk, 2) sensitivity and specificity of the bacteriological method used, and 3) contamination...... of bulk tank milk samples with milk from other herds. From June to September 1996, bulk tank milk was sampled from 100 Danish dairy herds seven times, with intervals of 2 wk. The samples were examined for the presence of S. agalactiae by four different methods: 1) by the method approved for the program, 2...... the isolates. Streptococcus agalactiae was found in eight of 96 herds in which S. agalactiae had never previously been found during the surveillance program. Streptococcus agalactiae was not found in all seven sampling rounds in any of the eight herds. Comparing the approved method with supplemental findings...
Shahid, M Q; Reneau, J K; Chester-Jones, H; Chebel, R C; Endres, M I
The objectives of this study were to describe on-farm mortality and to investigate cow- and herd-level risk factors associated with on-farm mortality in Midwest US dairy herds using lactation survival analysis. We analyzed a total of approximately 5.9 million DHIA lactation records from 10 Midwest US states from January 2006 to December 2010. The cow-level independent variables used in the models were first test-day milk yield, milk fat percent, milk protein percent, fat-to-protein ratio, milk urea nitrogen, somatic cell score, previous dry period, previous calving interval, stillbirth, calf sex, twinning, calving difficulty, season of calving, parity, and breed. The herd-level variables included herd size, calving interval, somatic cell score, 305-d mature-equivalent milk yield, and herd stillbirth percentage. Descriptive analysis showed that overall cow-level mortality rate was 6.4 per 100 cow-years and it increased from 5.9 in 2006 to 6.8 in 2010. Mortality was the primary reason of leaving the herd (19.4% of total culls) followed by reproduction (14.6%), injuries and other (14.0%), low production (12.3%), and mastitis (10.5%). Risk factor analysis showed that increased hazard for mortality was associated with higher fat-to-protein ratio (>1.6 vs. 1 to 1.6), higher milk fat percent, lower milk protein percent, cows with male calves, cows carrying multiple calves, higher milk urea nitrogen, increasing parity, longer previous calving interval, higher first test-day somatic cell score, increased calving difficulty score, and breed (Holstein vs. others). Decreased hazard for mortality was associated with higher first test-day milk yield, higher milk protein, and shorter dry period. For herd-level factors, increased hazard for mortality was associated with increased herd size, increased percentage of stillbirths, higher somatic cell score, and increased herd calving interval. Cows in herds with higher milk yield had lower mortality hazard. Results of the study
Jensen, Anette Møllegaard; Bjorkman, C.; Kjeldsen, A.M.;
The prevalence and distribution of seropositivity towards the protozoan parasite Neospora caninum were studied in single blood samples from 1561 cows from 31 Danish dairy herds. Blood samples were analysed by an indirect enzyme-linked immunoassay and an indirect fluorescent-antibody test......, Seroprevalence in 15 herds with previous abortions assigned to neosporosis ranged from I% to 58%, with a mean frequency of 22%. In eight out of 16 herds without a history of N. caninum related abortions, no seroreactors were found. In the remaining eight herds, the seroprevalence ranged from 6% to 59...
Burgu, I; Alkan, F; Karaoglu, T; Bilge-Dagalp, S; Can-Sahna, K; Güngör, B; Demir, B
Serum samples of 15,909 cattle from 31 dairy herds located in various regions of Turkey were tested for the presence of antibodies against bovine leucosis virus (BLV) using Agar Gel Immuno-diffusion technique (AGID). 48.3% (15/31) of the herds had seropositive animals and positivity rates were detected from 0.5-34.4% in these herds. In an EBL control/eradication programme all seropositive animals were culled in the infected herds. Thereafter, a total of 74,347 sera were tested for the presence of BLV specific antibodies. The serological results and detail of EBL control/eradication programme were shown in this paper.
Ranjbar, S; Rabiee, A R; Gunn, A; House, J K
Lameness is a significant welfare concern for dairy farmers and a major contributing economic loss to the dairy industry. Information is limited on environmental and managerial risk factors associated with lameness in Australian dairy herds. The objective of this study was to explore and quantify the environmental and management risk factors associated with lameness in pasture-based dairy herds. A cross-sectional study was conducted in 63 pasture-based dairy herds between 2011 and 2014, where all lactating cows were locomotion scored (scale 1-4) during a single visit. Environmental and management variables, such as length of main track and animal handling practices, were recorded during the visit. The prevalence of lameness was measured for each farm and associated risk factors were analyzed using a Generalized Linear Model, where farm was the unit of analysis. Estimated average prevalence of lameness was 18.9% (range 5 to 44.5%). The prevalence of lameness was associated with the amount of rainfall during the 30 d before the farm assessment, smoothness of concrete surface and available space per cow in the holding yard, and length of feed-pad available per cow. Inappropriate handling of cows on the track (e.g., causing sideways pushing among cows) was also a contributing risk factor to high prevalence of lameness in these dairy herds. The findings of this study suggest that by managing several environmental and farming practices, producers can reduce the prevalence of lameness, leading to improved productivity of their herds.
Hancock, A S; Younis, P J; Beggs, D S; Mansell, P D; Stevenson, M A; Pyman, M F
In the pasture-based, seasonally calving dairy herds of southern Australia, the mating period usually consists of an initial artificial insemination period followed by a period of natural service using herd bulls. Bull breeding soundness evaluations (BBSE) were performed on 256 bulls from 32 dairy herds in southwest Victoria, using guidelines produced by the Australian Cattle Veterinarians, before and immediately after a single natural mating period. At the same time, herd managers were questioned regarding the management of the bulls. The objectives of this study were to describe the management practices of dairy herd bulls; to describe the causes of increased risk of reduced fertility in dairy herd bulls, as measured by a standard BBSE; and to describe the reasons for bull removal by herd managers during mating. At the premating BBSE, 19.5% of bulls were classified as high risk of reduced fertility, mostly due to physical abnormalities and reduced semen quality. At the postmating BBSE, 36.5% of bulls were classified as high risk of reduced fertility, mostly due to physical abnormalities, primarily lameness. Of the bulls used, 15.9% were removed from normal mating use by the herd manager, predominantly due to lameness and injuries. A premating BBSE is recommended in dairy herd bulls to identify bulls at risk of reduced fertility. Lameness is the most common problem in dairy herd bulls during the natural mating period, and risk factors associated with lameness in these bulls should be identified to better manage herd bulls.
Boutet, Philippe; Detilleux, Johann; Motkin, Michel; Deliege, M.; PIRAUX, E.; Depinois, A.; Debliquy, P.; Mainil, Jacques; Czaplicki, G.; Lekeux, Pierre
A comparison of somatic cell count and antimicrobial susceptibility of subclinical mastitis pathogens in organic and conventional dairy herds.Bovine subclinical mastitis is the most important disease affecting dairy cows. The fluctuating increase in somatic cell count (SCC) that occurs causes major economic losses in dairy industry. This comparative study between conventional and organic dairy herds was conducted in the aim to better characterize which consequences might have different manage...
Staněk, S; Zink, V; Doležal, O; Štolc, L
It is important to describe weaknesses in rearing calves not only to improve their welfare, but also to detect areas where current scientific knowledge is poorly integrated into practice. A survey of preweaning calf-rearing practices was conducted using a farmer questionnaire. The survey included 136 farms, representing 11.9% of all dairy cows in the Czech Republic. Mean herd size (± standard deviation) was 326 ± 131.4 cows, and mean milk production 7,413 ± 1,389.5 kg per cow per year. We evaluated 59 farms with Holsteins (H) and 77 with the Czech Fleckvieh breed (C). The survey revealed that (1) calving in group pens predominated (67.6% of farms); (2) no disinfection of calf navels occurred on 11.8% of herds; (3) pooled colostrum was fed on 15.4% of farms; (4) colostrum quality was controlled on only 44.1% of farms, and only 73.5% of farms had reserve colostrum stocks; (5) nonmarket waste milk was fed in 64.7% of herds but it was pasteurized in only in 6.8% of herds and acidified in 35.2% of herds; (6) milk replacer was mixed with nonmarket waste milk on 52.9% of farms; (7) 58.8% of farms enabled calves to obtain milk by sucking and 41.2% by drinking from a bucket; (8) the main criterion in weaning was calf age (61.7%), followed by acceptance of starter and concentrated feed (19.9%) and lack of housing capacity (18.4%); and (9) newborn calves were individually housed on 96.7% of farms and group-housed on 3.3% of farms. The most marked differences in calf-rearing management between Holstein and Czech Fleckvieh farms were (1) a higher proportion of operations calving in tie-stalls or stanchions in C (6.5%) versus H (1.7%) farms; (2) a higher proportion of untreated navels on C (15.6%) versus H (6.8%) farms; (3) a lower proportion of C (11.7%) versus H (20.4%) farms feeding pooled colostrum; (4) a lower proportion of C (39%) versus H (50.9%) farms monitoring colostrum quality; (5) sucking milk from nipple buckets predominated (61%) on C farms, whereas drinking
de Vries, M; Bokkers, E A M; van Schaik, G; Engel, B; Dijkstra, T; de Boer, I J M
Routine on-farm assessment of dairy cattle welfare is time consuming and, therefore, expensive. A promising strategy to assess dairy cattle welfare more efficiently is to estimate the level of animal welfare based on herd data available in national databases. Our aim was to explore the value of routine herd data (RHD) for estimating dairy cattle welfare at the herd level. From November 2009 through March 2010, 7 trained observers collected data for 41 welfare indicators in a selected sample of 183 loose-housed and 13 tethered Dutch dairy herds (herd size: 10 to 211 cows) using the Welfare Quality protocol for cattle. For the same herds, RHD relating to identification and registration, management, milk production and composition, and fertility were extracted from several national databases. The RHD were used as potential predictors for each welfare indicator in logistic regression at the herd level. Nineteen welfare indicators were excluded from the predictions, because they showed a prevalence below 5% (15 indicators), or were already listed as RHD (4 indicators). Predictions were less accurate for 7 welfare indicators, moderately accurate for 14 indicators, and highly accurate for 1 indicator. By forcing to detect almost all herds with a welfare problem (sensitivity of at least 97.5%), specificity ranged from 0 to 81%. By forcing almost no herds to be incorrectly classified as having a welfare problem (specificity of at least 97.5%), sensitivity ranged from 0 to 67%. Overall, the best-performing prediction models were those for the indicators access to at least 2 drinkers (resource based), percentage of very lean cows, cows lying outside the supposed lying area, and cows with vulvar discharge (animal based). The most frequently included predictors in final models were percentages of on-farm mortality in different lactation stages. It was concluded that, for most welfare indicators, RHD have value for estimating dairy cattle welfare. The RHD can serve as a
ELISA (Rønsholt et al., 1997; Bitsch et al., 1997) and the SVANOVIR ELISA (Juntti at al., 1987; Niskanen, 1993) were compared on milk and serum samples. The prevalence of antibody positive milking cows, which can be detected by each of those tests, was estimated by diluting positive individual milk...... dairy herds (e.g. after import of infected cattle) could be more difficult to detect compared to the past, due to the lower prevalence of antibody positive milking cows and the (expected) higher dilution of antibodies in bigger milk containers. Therefore, an evaluation and an eventual optimization...... of the BVD surveillance system in Danish dairy herds were considered necessary by the Danish Cattle Federation. In study I, we verified how the BVD herd prevalence, the herd size and the dilution of individual milk within the bulk tank milk (BTM) changed, between 2003 and 2010. Moreover, the Danish blocking...
Kowalczyk, Sławomir J; Czopowicz, Michał; Weber, Corinna N; Müller, Elisabeth; Witkowski, Lucjan; Kaba, Jarosław
A serosurvey was carried out to estimate the herd-level seroprevalence of Neospora caninum infection in cattle in central and northeastern Poland. Ninety seven dairy cattle herds from 2 provinces of Poland (Podlaskie, 47 herds and Łodzkie, 50 herds) were randomly enrolled in the study using two-stage cluster method. A simple random selection was applied within each herd to select a sample of adult cows (≥18 month-old). A total number of 734 cows were enrolled in the study. The animals were screened with a commercial competitive ELISA (Bio-X Diagnostics, Belgium). To calculate true herd-level seroprevalence test sensitivity and specificity were adjusted from an individual- to a herd-level using FreeCalc method. The true overall herd-level seroprevalence of N. caninum infection was 56.7% (95% CI: 47.5%, 65.9%). The true herd-level seroprevalence in Podlaskie was 63.3% (95% CI: 43.0%, 83.6%) and 50.5% (95% CI: 32.8%, 68.2%) in Łodzkie province and these figures did not differ significantly between the two provinces (chi2 test p = 0.238). One hundred forty three of 734 cows (19.5%) were seropositive which gave the true overall individual-level seroprevalence of 20.1% (95% CI: 17.4%, 23.2%). Percentage of seropositive cows in each herd varied from 6% to 80%. This study is the first epidemiological investigation of herd-level seroprevalence of N. caninum infection in Polish dairy cattle population. In conclusion, the result of the study confirmed previous data that N. caninum infection is widespread in the Polish cattle population and thus should be considered as a potential cause of spontaneous abortions.
Jørgensen, H J; Nordstoga, A B; Sviland, S; Zadoks, R N; Sølverød, L; Kvitle, B; Mørk, T
Many free-stall bovine dairy herds in Norway fail to eradicate Streptococcus agalactiae despite long-term control measures. In a longitudinal study of 4 free-stall herds with automatic milking systems (AMS), milk and extramammary sites were sampled 4 times with 1-2 month intervals. Composite milk, rectal- and vaginal swabs were collected from dairy cows; rectal swabs from heifers and young stock; rectal- and tonsillar swabs from calves; and environmental swabs from the AMS, the floors, cow beds, watering and feeding equipment. A cross sectional study of 37 herds was also conducted, with 1 visit for environmental sampling. Fifteen of the herds were known to be infected with S. agalactiae while the remaining 22 had not had evidence of S. agalactiae mastitis in the preceding 2 years. All samples were cultured for S. agalactiae, and selected isolates (n=54) from positive herds were genotyped by Multi Locus Sequence Typing (MLST). Results show that the bovine gastrointestinal tract and the dairy cow environment are reservoirs of S. agalactiae, and point to the existence of 2 transmission cycles; a contagious transmission cycle via the milking machine and an oro-fecal transmission cycle, with drinking water as the most likely vehicle for transmission. Ten sequence types were identified, and results suggest that strains differ in their ability to survive in the environment and transmit within dairy herds. Measures to eradicate S. agalactiae from bovine dairy herds should take into account the extra-mammary reservoirs and the potential for environmental transmission of this supposedly exclusively contagious pathogen.
Monti, G.E.; Frankena, K.; Jong, de, F.
In Argentina, bovine leukaemia virus (BLV) infection is common in dairy herds. The country currently has a National Voluntary Control Programme but relatively few farms have enrolled. However, there is increased interest from authorities and farmers to implement regional compulsory programmes but there is scarce quantitative information of the transmission of BLV in cattle herds. This information is a prerequisite to develop effective BLV control strategies. Mathematical modelling offers ways...
Jalvingh, A.W.; Arendonk, van J.A.M.; Dijkhuizen, A.A.
A dynamic probabilistic model has been designed to determine the technical and economic consequences of various biological variables and management strategies concerning reproduction, replacement and calving patterns in dairy herds. The Markov chain approach is used to simulate herd dynamics. Herds
van den Borne, Bart H P; Graber, Hans U; Voelk, Verena; Sartori, Carlotta; Steiner, Adrian; Haerdi-Landerer, M Christina; Bodmer, Michèle
Staphylococcus aureus is a common mastitis causing pathogen of dairy cattle. Several S. aureus genotypes exist, of which genotype B (GTB) is highly prevalent in Swiss dairy herds. Dairy farming in mountainous regions of Switzerland is characterised by the movement of dairy cattle to communal pasture-based operations at higher altitudes. Cows from different herds of origin share pastures and milking equipment for a period of 2 to 3 months during summer. The aim of this longitudinal observational study was to quantify transmission of S. aureus GTB in communal dairy operations. Cows (n=551) belonging to 7 communal operations were sampled at the beginning and end of the communal period. Transmission parameter β was estimated using a Susceptible-Infectious-Susceptible (SIS) model. The basic reproduction ratio R0 was subsequently derived using previously published information about the duration of infection. Mean transmission parameter β was estimated to be 0.0232 (95% CI: 0.0197-0.0274). R0 was 2.6 (95% CI: 2.2-3.0), indicating that S. aureus GTB is capable of causing major outbreaks in Swiss communal dairy operations. This study emphasized the contagious behaviour of S. aureus GTB. Mastitis management in communal dairy operations should be optimized to reduce S. aureus GTB transmission between cows and back to their herds of origin.
Kristensen, Erling Lundager; Østergaard, Søren; Krogh, Mogens Agerbo
The manager of a dairy herd and the affiliated consultants constantly need to judge whether financial performance of the production system is satisfactory and whether financial performance relates to real (systematic) effects of changes in management. This is no easy task because the dairy herd...... is a very complex system. Thus, it is difficult to obtain empirical data that allows a valid estimation of the random (within-herd) variation in financial performance corrected for management changes. Thus, simulation seems to be the only option. This study suggests that much caution must be recommended...... when claming effect of changes in herd management because the link between management changes (cause) and effect (measured as improvement of gross margin per cow year) is extensively blurred by a large within-herd variation in available real life accounting data and differences between herds in time...
Heuer, C; Healy, A; Zerbini, C
The economic loss to dairy farmers associated with bovine viral diarrhea virus (BVDV) is believed to be high in New Zealand, but no estimates are yet available. The aim was therefore to estimate the economic loss associated with BVDV in dairy herds in New Zealand. Bulk tank milk (BTM) from a random sample of 590 herds from the Northland, Bay of Plenty, and Waikato regions was tested for antibody against BVDV. The inhibition percentage (sample to positive ratio), based on a threshold validated in an earlier study, was used to indicate herd-level infection. Herd reproductive indices, herd lactation-average somatic cell counts, and herd average production of milk solids were regressed on BTM inhibition percentage. Herd averages of the overall annual culling rate, the rate of culling because of failure to conceive, the proportion of physiological inter-service intervals, the first-service conception rate, the pregnancy rate at the end of mating, and somatic cell counts were not associated with BVDV antibody in BTM. Abortion rates, rates of calving induction, the time from calving to conception, and the number of services per conception increased, however, whereas milk production decreased with increasing BVDV antibody in BTM. The results indicated significant reproductive and production loss associated with the amount of BVDV antibody in BTM. Total loss attributable to infection with BVDV was similar to reports from other countries and estimated as NZ$87 per cow and year in affected herds, and NZ$44.5 million per year for the New Zealand dairy industry based on an estimated 14.6% affected herds. The loss estimate excludes added cost and negative consequences with respect to animal welfare attributable to increased induction rates, and a greater incidence of production disease because of BVD-induced immune suppression.
Burow, E; Rousing, T; Thomsen, P T; Otten, N D; Sørensen, J T
Structural development in the prime sector has led to increasing herd sizes and new barn systems, followed by less summer grazing for dairy cows in Denmark. Effects of grazing on single welfare measures in dairy cows - for example, the presence of integument alterations or mortality - have been studied under different conditions. However, the effect of grazing on welfare, conceptualised as the multidimensional physical and mental state of the animal, has not yet been studied in contemporary cubicle loose-housing systems. The aim of our study was to investigate, based on a Welfare Quality® inspired multidimensional dairy cow welfare assessment protocol, the within-herd effect of summer grazing compared with winter barn housing in Danish dairy herds with cubicle free-stall systems for the lactating cows. Our hypothesis was that cow welfare in dairy herds was better during summer grazing than during full-time winter housing. Furthermore, we expected improved welfare with an increase in daily summer grazing hours. In total, 41 herds have been visited once in the winter and once in the summer of 2010 to assess their welfare status with 17 different animal- and resource-based welfare measures. A panel of 20 experts on cattle welfare and husbandry evaluated the relative weight of the 17 welfare measures in a multidimensional assessment scheme. They estimated exact weights for a priori constituted severe compared with moderate scores of welfare impairment concerning each measure, as well as relevance of the measures in relation to each other. A welfare index (WI; possible range 0 to 5400) was calculated for each herd and season with a higher index indicating poorer welfare. The within-herd comparison of summer grazing v. winter housing considered all the 17 measures. The mean WI in summer was significantly lower (better) than in winter (mean 2926 v. 3330; paired t-test P = 0.0001) based on a better state of the integument, claw conformation and better access to water and
Mee John F
Full Text Available Irish dairy herd fertility has been declining since the 1980s. The extent, nature and causes of this decline in fertility and the current status of Irish dairy herd fertility were described. An increase in calving interval of approximately one day per year has been recorded. The principal components of this trend have been an increased incidence of postpartum endocrinopathies, reduced expression of oestrus and a fall in conception rate. Both submission rate and calving-to-service interval have increased slightly over time. Significant risk factors associated with these trends have been strain substitution within the Holstein-Friesian breed and single trait selection for milk production. Critically, these changes have been reflected in loss of body condition. Contributory factors included increased herd size and possibly increased use of DIYAI. The most recent Irish study showed that 48% of cows conceived to first service and 14% of cows were not pregnant at the end of the industry-average 15-week spring breeding season. However, the top quartile of herds achieved a first-service conception rate of 59%, illustrating the wide variation between herds. These phenotypic trends were attributed to both genetic and environmental factors and their interactions. Recent Irish dairy herd fertility performance falls short of the targets set for seasonal compact calving.
Bihrmann, Kristine; Nielsen, Søren Saxmose; Toft, Nils
Paratuberculosis is a chronic infection of economic importance to the cattle industry and a voluntary control programme is offered to Danish dairy farmers. Our objective was to evaluate spatial differences in both control programme participation and paratuberculosis prevalence in Denmark. The study...... included 4414 dairy herds: 1249 were participating in the control programme, and 1503 were tested for antibodies to Mycobacterium avium subsp. paratuberculosis (MAP). Spatial differences were evaluated by kernel smoothing, kriging, and cluster analysis. Participation was lowest among herds on the island...
Bennedsgaard, Torben Werner; Klaas, Ilka Christine; Vaarst, Mette
With the aim of phasing out the use of antimicrobials 23 Danish organic dairy producers from the same organic dairy company participated in Stable School farmer groups from February 2004 to March 2005 in order to go through a common learning and development process towards their common goal. Data...... the project period though the reduction of the incidence rates in the project herds was not statistically significant. It is concluded that the farmers participating in the Stable Schools managed to reduce the use of antimicrobials in their herds also after the project period without apparent negative effects...
Full Text Available A cross-sectional study with a random cluster sampling design was carried out to estimate the seroprevalence of bovine herpesvirus type 1 (BHV-1 in non-vaccinated dairy herds in Hamedan province, west of Iran. Simple random sampling was used for selection of cattle in each herd. Informative data about each herd and selected animals were recorded by the farm manager in a provided questionnaire. Blood samples were collected from 492 animals in 41 industrial herds. A commercial indirect ELISA test was used to determine the seropositivity against BHV-1. The individual and herd seroprevalence for BHV-1 were 58.74% and 82.93%, respectively. The intra-herd prevalences were ranged from 16.70% to 100%. Geographical characteristics of Hamedan province may explain the high sero- prevalence rates found in this study compared to those of others obtained from different parts of the country. The proportion of seropositive cows were increased with age (p <0.05. Animals from large and moderate sized herds had higher odds of seropositivity than those of small size herds. These findings could be related to the presence of a considerable number of BHV-1 carriers in this region. The high herd and animal prevalence found in the present study suggested necessity of implementing an intensive control program for reducing BHV-1 infection rates.
Full Text Available The need of increasing the daily milk yield often has negative backup on herd fertility (Westwood et al., 2002. Culling because of reproductive failure is a cost in dairy breeding. The reproductive efficiency is often expressed as days open (DOPN or calving interval. However, these indexes are a function of the pregnancy rate (PR which is calculated as the heat detection rate (HDR times the conception rate (CR (Ferguson, 1991. Thus, the herd reproductive performance is affected by HDR and CR (Maatje et al., 1997; Nir, 1996, Ferguson, 1996. This work was conducted to estimate reproductive efficiency of cows from thirty herds of the Po valley.........
An observational study of Corynebacterium bovis was conducted in 74 Ontario dairy herds. The levels of infection with C. bovis were 19.9, 36.2 and 85.6% at the quarter, cow and herd level, respectively. Teat disinfection was found to be the variable best able to distinguish between herds with a high or low C. bovis quarter infection rate. Mean total milk somatic cell counts for 1103 quarters and 107 cows infected with only C. bovis ranged between 150,000 and 200,000/mL and were significantly ...
Enevoldsen, Carsten; Sørensen, J.T.; Thysen, Iver;
A computer program framework was established to enable a dairy herd production consultant to perform whole-herd analysis. The diagnostic process was an extensive data analysis 1) to derive key parameters related to production, reproduction, and health and 2) to produce input to a prognostic process....... The prognostic process synthesized the obtained information into short- or long-term prognoses for the herd through a complex herd simulation model. Site specificity of parameter estimation and forecasting and explorability of assumptions and results were major characteristics of the approach. A user acceptance...... problem related to the simulation was addressed through a simultaneous process of development and validation during the introduction of the program framework into veterinary practices. The generally slow adoption of herd simulation models in extension work could be due to lack of credibility of the models...
Nielsen, Lennarth Ravn; Warnick, L. D.; Greiner, M.
A surveillance program in which all cattle herds in Denmark are classified into Salmonella infection categories has been in place since 2002. Dairy herds were considered test negative and thus most likely free of infection if Salmonella antibody measurements were consistently low in bulk tank milk...... samples collected every 3 mo. Herds were considered test positive and thus most likely infected if the 4-quarter moving average bulk tank milk antibody concentration was high or if there was a large increase in the most recent measurement compared with the average value from the previous 3 samples....... The objective of this study was to evaluate risk factors for changing from test negative to positive, which was indicative of herds becoming infected from one quarter of the year to the next, and risk factors for changing from test positive to negative, which was indicative of herds recovering from infection...
Enevoldsen, Carsten; Sørensen, J.T.; Thysen, Iver
A computer program framework was established to enable a dairy herd production consultant to perform whole-herd analysis. The diagnostic process was an extensive data analysis 1) to derive key parameters related to production, reproduction, and health and 2) to produce input to a prognostic process....... The prognostic process synthesized the obtained information into short- or long-term prognoses for the herd through a complex herd simulation model. Site specificity of parameter estimation and forecasting and explorability of assumptions and results were major characteristics of the approach. A user acceptance...... problem related to the simulation was addressed through a simultaneous process of development and validation during the introduction of the program framework into veterinary practices. The generally slow adoption of herd simulation models in extension work could be due to lack of credibility of the models...
Full Text Available Bulk milk samples from 220 dairy herds were collected at 9 public milk collection centres in the northeastern and northern Thailand, and a subset of 11 herds was selected for individual testing. The samples were tested for presence of antibodies to BVDV and BHV-1 using an indirect ELISA. The results from the bulk milk testing demonstrated a moderate level of exposure to BVDV and BHV-1 (73% and 67%, respectively. However, the low proportion of herds with high BVDV antibody-levels (13% and the low within-herd seroprevalence of BVDV and BHV-1 in the 11 herds (24% and 5%, respectively, particularly among the young stock (15% and 0%, respectively, demonstrated a low prevalence of active BVDV infection and a low rate of reactivation of latent BHV-1. The presence of a self-clearance process was also indicated by the results from the individual testing. Moreover, a surprisingly low prevalence of BVDV and BHV-1 antibody-positive herds at one of the milk centres was found. This centre was established 5–10 years before the others. Our impression is that this reflects the self-clearance process, where consecutive replacement of imported infected animals without further spread has resulted in a nearly total elimination of the infections. Based on our experiences and on these results we are convinced that this process can continue if there is awareness of herd biosecurity. This is especially important in the context of a future intensification of the dairy production.
Zárate Rendón, Daniel; Laboratorio de Parasitología, Departamento Académico de Nutrición, Facultad de Zootecnia, Universidad Nacional Agraria La Molina, Lima; Rojas Flores, Julio; Laboratorio de Parasitología, Departamento Académico de Nutrición, Facultad de Zootecnia, Universidad Nacional Agraria La Molina, Lima; Segura Hong, Alan; Laboratorio de Parasitología, Departamento Académico de Nutrición, Facultad de Zootecnia, Universidad Nacional Agraria La Molina, Lima
A study in goats was carried out in the central coast of Peru to validate the FAMACHA© method for selective anthelmintic treatment in dairy goat herds. Blood and fecal samples were taken from 120 adult goats in five dairy goat farms. The micro haematocrit and the McMaster techniques plus faecal culture were used to evaluate the haematocrit, faecal nematode egg count (EPG) and to identify major nematode species, respectively. Spearman correlation coefficients were obtained. Two FAMACHA© criter...
Frankena, K; Noordhuizen, J P; Stassen, E N
Data bases of herd health programs concern data from individual animals mainly. Several parameters that determine herd performance can be calculated from these programs, and by comparing actual values with standard values, areas for further improvement of health (and production) can be advised. However, such advice is usually not backed up by the proper statistical analyses. Moreover, data concerning the environment of the animals are not present and hence advice concerning multifactorial diseases are based on common knowledge and experience. Veterinary epidemiology offers methods that might improve the value of herd health programs by identification and quantification of factors and conditions contributing to multifactorial disease occurrence. Implementation of these methods within herd health programs will lead to more scientifically sound advice.
Talafha, Abdelsalam Q; Ababneh, Mohammed M; Ababneh, Mustafa M; Al-Majali, Ahmad M
A cross-sectional study was carried out to determine seroprevalence and to identify risk factors associated with Chlamydophila abortus infection in 62 nonvaccinated dairy herds (671 cows) in Jordan between January and June 2007. Information regarding herd management was recorded through a personal interview with farmers. Antibodies against C. abortus were detected using an ELISA test kit. Chi-square analysis and multivariable logistic regression model were used to identify risk factors associated with C. abortus seropositivity. The true prevalence of antibodies against C. abortus in individual cows and cattle herds were 19.9 % and 66.3 %, respectively. Univariable Chi-square analysis revealed three variables with P ≤ 0.25 that were further offered to multivariable logistic regression analysis. Small-sized herds were identified as a risk factor for seropositivity to C. abortus, while sweeping followed by water hosing and using disinfectants were identified as protective factors. Cows in the age groups of >8 and ≤ 10 years old and >2 and ≤ 6 years old had the highest and lowest significant seroprevalence to C. abortus, respectively. Results of this study indicated that C. abortus is highly prevalent in Jordan's dairy herds and Chlamydophila infection could be controlled by applying strict biosecurity measures in the dairy farms.
Al-Mamun, Mohammad A; Smith, Rebecca L; Schukken, Ynte H; Gröhn, Yrjö T
In the dairy industry, Johne's disease (JD), caused by Mycobacterium avium subsp. paratuberculosis (MAP) is one of the major investigated diseases. To date, researchers have suggested some control strategies for JD, such as test-and-cull based herd management, isolated calf rearing management, and v
Conflicting reports of the quantities of biologically active compounds present in milk from organic grass-fed and conventional herds show that more research is required, especially as these compounds are linked to human health benefits and can improve the health value consumers place on dairy produc...
Dank, M.; Holzhauer, M.; Veldhuis, A.; Frankena, K.
The objective of this study was to estimate the association between Dictyocaulus viviparus bulk tank milk (BTM) test results and milk production and milk composition parameters in adult Dutch dairy cattle herds. Bulk tank milk samples were collected in August and November 2013, and ELISA tests were
Monti, G.E.; Frankena, K.; Jong, de M.C.M.
In Argentina, bovine leukaemia virus (BLV) infection is common in dairy herds. The country currently has a National Voluntary Control Programme but relatively few farms have enrolled. However, there is increased interest from authorities and farmers to implement regional compulsory programmes but th
Frequency of abortions recorded through Dairy Herd Improvement (DHI) testing was summarized for cows with lactations completed from 2001 through 2009. Reported abortions were 1.3% for 8.5 million DHI lactations of cows with recorded breeding dates and that were >151 d pregnant at lactation terminati...
Antimicrobial resistance in bacterial pathogens is an increasing public health concern. The objective of this study was to examine antimicrobial resistance in Salmonella and E. coli isolates from Pennsylvania dairy herds. Manure composite samples were collected from 76 farms: on each farm one sample...
Sekiya, Mary; Zintl, Annetta; Doherty, Michael L
The bulk milk enzyme-linked immune sorbent assay (ELISA) is a rapid and inexpensive method of assessing herd exposure to pathogens that is increasingly being used for the diagnosis of parasite infections in dairy herds. In this paper, with the dairy herd health veterinarian in mind, we review the principles of the assay and the recent literature on the potential role of bulk milk ELISA for the diagnosis of ostertagiosis, fasciolosis, parasitic bronchitis due to cattle lung worm and neosporosis. It is generally accepted that assay results reflect exposure to the parasite rather than the presence of active infection. Bulk milk ELISA can be a useful tool for the veterinary practitioner as a component of a herd health monitoring programme or in the context of a herd health investigation. It can also play a role in regional or national surveillance programmes. However, the results need to be interpreted within the context of the herd-specific health management, the milk production pattern and the parasite life cycle.
Mweu, Marshal M.; Nielsen, Søren S.; Hisham Beshara Halasa, Tariq;
-level incidence rates and apparent prevalences of Streptococcus agalactiae (S. agalactiae) in the population of Danish dairy cattle herds over a 10-year period from 2000 to 2009 inclusive and (2) to estimate the herd-level entry and exit rates (demographic parameters), the transmission parameter, β, and recovery......Contagious mastitis pathogens continue to pose an economic threat to the dairy industry. An understanding of their frequency and transmission dynamics is central to evaluating the effectiveness of control programmes. The objectives of this study were twofold: (1) to estimate the annual herd...... rate for S. agalactiae infection. Data covering the specified period, on bacteriological culture of all bulk tank milk samples collected annually as part of the mandatory Danish S. agalactiae surveillance scheme, were extracted from the Danish Cattle Database and subsequently analysed...
Thomsen, Peter; Sørensen, Jan Tind; Ersbøll, Annette Kjær
Digital dermatitis is a serious problem in dairy production in many countries. Footbaths have been used extensively for the prevention and cure of digital dermatitis. But there is a lack of scientific evidence regarding the effectiveness of hoof-care products used in footbaths. The objective...... was to evaluate 3 commercial hoof-care products in 12 Danish dairy herds (testing each product in 4 herds) using a controlled clinical trial. One-half of the herds were conventional and the other half was organically managed. The hoof-care products represented the 3 main groups of active compounds currently legal...... new infections). Percentage cured ranged from 13.6 to 100, and percentage new infections ranged from 0 to 35.5. For all hoof-care products, the difference between treatment and control sides was not statistically significant. Overall, there was no effect on percentage cured or percentage new...
Chapagain, Prem; van Kessel, Jo Ann; Karns, Jeffrey; Wolfgang, David; Schukken, Ynte; Grohn, Yrjo
Salmonellosis has been one of the major causes of human foodborne illness in the US. The high prevalence of infections makes transmission dynamics of Salmonella in a farm environment of interest both from animal and human health perspectives. Mathematical modeling approaches are increasingly being applied to understand the dynamics of various infectious diseases in dairy herds. Here, we describe the transmission dynamics of Salmonella infection in a dairy herd with a set of non-linear differential equations. Although the infection dynamics of different serotypes of Salmonella in cattle are likely to be different, we find that a relatively simple SIR-type model can describe the observed dynamics of the Salmonella enterica serotype Cerro infection in the herd.
Romero, J J; Perez, E; Dolz, G; Frankena, K
Twenty-five specialised Costa Rican dairy farms (located in the Poás area) were used to determine neosporosis seroprevalence and the association of seropositivity with environmental and management factors. The farms involved were selected intentionally and all of them use VAMPP 5.1 (Veterinary Automated Management and Production Control Programme) as management-information system. Holstein-Friesian, Jersey and crosses between them were the most-frequent breeds in these herds. The number of females per farm varied from 41 to 296. Our cross-sectional study had two phases. In the first phase, we determined the presence or absence of seropositivity at herd level. For the second phase, all females in 20 seropositive farms were bled. Serum samples were tested for antibodies to Neospora caninum using an indirect enzyme-linked immunosorbent assay (ELISA). A questionnaire with factors mentioned in the literature was administered to the farmers. Logistic regression (LR with herd as random effect) was used to assess the relationships of the serostatus at the individual level with characteristics of the cows and environmental factors. In the first phase all herds had >20% seropositive females; therefore, all herds were eligible for the second phase. In the second phase, the overall prevalence was 39.7% (1191/3002), and within-herd prevalences were between 25.0 and 70.5%. Age 3-6 years, parity < or =2 of the dam of the cow, Jersey breed and lack of purposive sampling to diagnose abortive infectious disease were associated with positive serostatus; other management and environmental factors did not show significant associations. The lack of association between management and environmental factors with serostatus might be because all farms were exposed to a considerable number of potential factors. That all herds of this study were seropositive for neosporosis and the within-herd prevalence was considerable raises questions about how far the infection is spread in other dairy
Nilnont, Theerakul; Aiumlamai, Suneerat; Kanistanont, Kwankate; Inchaisri, Chaidate; Kampa, Jaruwan
Bovine viral diarrhea virus causes a wide range of clinical manifestation with subsequent economic losses in dairy production worldwide. Our study of a population of dairy cattle in Thailand based on 933 bulk tank milk samples from nine public milk collection centers aimed to monitor infective status and to evaluate the effect of the infection in cows as well as to examine the reproductive performance of heifers to provide effective recommendations for disease control in Thailand. The results showed a moderate antibody-positive prevalence in the herd (62.5 %), with the proportion of class-3 herd, actively infected stage, being 17.3 %. Fourteen persistently infected (PI) animals were identified among 1196 young animals from the class-3 herds. Most of the identified PI animals, 11/14, were born in one sub-area where bovine viral diarrhea virus (BVDV) investigation has not been performed to date. With respect to reproductive performance, class-3 herds also showed higher median values of reproductive indices than those of class-0 herds. Cows and heifers in class-3 herds had higher odds ratio of calving interval (CI) and age at first service (AFS) above the median, respectively, compared to class-0 herds (OR = 1.29; P = 0.02 and OR = 1.63; P = 0.02). Our study showed that PI animals were still in the area that was previously studied. Furthermore, a newly studied area had a high prevalence of BVDV infection and the infection affected the reproductive performance of cows and heifers. Although 37.5 % of the population was free of BVDV, the lack of official disease prevention and less awareness of herd biosecurity may have resulted in continuing viral spread and silent economic losses have potentially occurred due to BVDV. We found that BVDV is still circulating in the region and, hence, a national control program is required.
Weber Nielsen, M S; Domecq, J J; Davis, L E; Beede, D K; Budine, M; Martsolf, F
The Dairy Challenge contest allows undergraduate students to apply knowledge gained in the classroom in an evaluation of the management practices of commercial dairy farms. University faculty partnered with industry representatives to develop the competition. Participants in the Dairy Challenge do the following: 1) critically evaluate dairy herd management practices and make recommendations for improvements; 2) visit local dairy farms and gain knowledge of different farms' management practices; 3) meet and interact with potential employers from the dairy industry during the contest; 4) evaluate herd records and utilize knowledge of dairy herd management software and computer presentation tools; 5) test their speaking, presentation, and problem-solving skills; and 6) work as a team to build consensus and tag-team speaking formats. Teams of four undergraduate students critically evaluate a commercial dairy farm using herd records, a description of farm operations, and tour of the farm facilities. The farmer answers questions pertaining to management of the farm in a group interview with all teams and in a separate interview with each individual team. Teams give a 20-min presentation that is scored on the description and assessment of the management practices and recommendations for improvements in management and facilities. Additionally, scoring is based on apparent level of preparation, speaking, presentation skills, and responses to judges' questions. The judges are university specialists and dairy industry professionals. This capstone experience allows students to interact with dairy farmers and representatives from the dairy industry and expands their knowledge and skills gained during their academic career.
Berends, I M G A; Swart, W A J M; Frankena, K; Muskens, J; Lam, T J G M; van Schaik, G
The aim of the study was to investigate the effect of BVDV-free certification of dairy herds on fertility and udder health. Cases were defined as dairy herds that had at least one BVDV-antigen positive animal, subsequently gained the BVDV-free status by participating in the BVDV-control programme of the Animal Health Service (AHS) and maintained this status for at least 2 years. Controls had an unknown status for BVDV and two controls were matched to one case by region and herd size. Data concerning fertility and milk production of all herds were provided by The Dutch Royal Cattle Syndicate (NRS). After validation, data of 79,607 cows of 392 case herds and 124,831 cows of 730 control herds were analysed on ten fertility and three udder health parameters. For the analyses all observations were aggregated at herd level. To account for the matching, differences for fertility parameters were calculated between each of the two pairs of case-control within a matching code. The analyses were performed with these differences as dependent variables. Mixed models and GEE models were used for the statistical analyses of fertility and udder health. Case herds had a significantly lower abortion rate in the BVDV-free period than controls herds (10.3% versus 11.6%, P<0.01) while there was no significant difference for the other fertility parameters. There was no effect on mastitis prevalence or bulk-milk SCC but the mastitis incidence significantly decreased for case herds in the BVDV-free period (cases 0.6 % lower than controls, P<0.05). In our study the effect of getting the BVDV-free status may have been underestimated for several reasons like an unknown status for control herds, not knowing when an acute infection occurred in case herds and not knowing the management for both cases and controls. Interestingly, both significant variables, being abortions and mastitis incidence, are parameters that are more difficult to influence by the farmer than the other parameters (e
Full Text Available Abstract Background Several management and environmental factors are known as contributory causes of clinical mastitis in dairy herd. The study objectives were to describe the structure of herd-specific mastitis management and environmental factors and to assess the relevance of these herd-specific indicators to mastitis incidence rate. Methods Disease reports from the Danish Cattle Data Base and a management questionnaire from 2,146 herds in three Danish regions were analyzed to identify and characterize risk factors of clinical mastitis. A total of 94 (18 continuous and 76 discrete management and production variables were screened in separate bivariate regression models. Variables associated with mastitis incidence rate at a p-value Results Three latent factors (quality of labor, region of Denmark and claw trimming, and quality of outdoor holding area were identified from 14 variables. Daily milk production per cow, claw disease, quality of labor and region of Denmark were found to be significantly associated with mastitis incidence rate. A common multiple regression analysis with backward and forward selection procedures indicated there were 9 herd-specific risk factors. Conclusion Though risk factors ascertained by farmer-completed surveys explained a small percentage of the among-herd variability in crude herd-specific mastitis rates, the study suggested that farmer attitudes toward mastitis and lameness treatment were important determinants for mastitis incidence rate. Our factor analysis identified one significant latent factor, which was related to labor quality on the farm.
Morton, John M; Penry, John F; Malmo, Jakob; Mein, Graeme A
A controlled trial was conducted in 5 pasture-grazed commercial dairy herds in Australia in 2012 to determine whether premilking teat disinfection and drying of teats reduces clinical mastitis incidence during early lactation by at least 50%. A 50% reduction was estimated to be the minimum required to justify additional costs of labor, disinfectants, and other resources if premilking teat disinfection was implemented in a 500-cow herd averaging 8 clinical cases per 100 cow-months. A secondary aim was to determine whether this premilking teat disinfection routine reduces incidence of new udder infections. Treatment was applied in each herd for approximately 60 d (range of 59.5 to 61 d), commencing in each herd soon after the start of the herd's main or only calving period. Within each herd, cows were allocated to either the treatment (premilking disinfection) or the control (no premilking disinfection) group based on their herd identity number. During the trial period, any cow having a new case of clinical mastitis or an individual cow cell count greater than 250,000 cells/mL of milk (when preceded by individual cow cell counts of 250,000 cells/mL of milk or below) was deemed to have had a new infection. Overall, neither clinical mastitis incidence nor new infection rate differed significantly between treatment and control groups. Over the whole study period, 98 of the 1,029 cows in the premilking disinfection group and 97 of the 1,025 cows in the control group had clinical mastitis. Total cow-days at risk of clinical mastitis were similar in each group. However, clinical incidence rates were markedly lower in treatment cows in one herd (herd 3; incidence rate ratio=0.34) and there was some evidence that new infection incidence rates were lower in treated cows in this herd (incidence rate ratio=0.42). Rainfall during the study period was below long-term district average in all 5 study herds. Cows' teats were less dirty than in previous, wetter years for the 4 herds
Pedersen, Louise Dybdahl; Jørgensen, Hanne Birgitte Hede; Kargo, Morten
Following the recent years' increase in herd size, the awareness of a group of cows with a generally lowered health and production level, the “loser cows,” has arisen in Denmark. The aim of this study was to estimate genetic correlations between the loser cow score, 305d protein yield and realize...
Van Wuijckhuise, L; Bosch, J; Franken, P; Frankena, K; Elbers, A R
Samples of bulk milk were taken from all 33,636 Dutch dairy herds in November 1994 and tested for the presence of bovine herpesvirus 1 (BHV-1) antibodies with a gB-blocking ELISA. Sixteen per cent of the herds had a negative BHV-1 status in the bulk milk. Farms with only dairy cows were 1.9 times more likely to have a negative or weakly positive BHV-1 status than herds which also had beef/veal animals. Farms in areas containing less than one herd/km2 were 1.5 times more likely to have a negative or weakly positive BHV-1 status than herds in areas with more than three herds/km2. Differences in numbers of animals per unit area were not significantly associated with BHV-1 status. The probability of herds having a negative or weakly positive BHV-1 status decreased linearly with herd size by a factor of 1.2 per 10 animals. The purchase of stock was significantly associated with a negative or weakly positive BHV-1 status, but there was an interaction between farm type and purchase of stock. For farms with both dairy and beef/veal animals there was a weak association between the purchase of stock and BHV-1 status. For pure dairy herds the probability of having a negative or weakly positive BHV-1 status decreased linearly with the numbers of purchased stock by a factor of 1.3 per 10 animals purchased.
Full Text Available In November 2008, a total of 19,910 bulk tank milk (BTM samples were obtained from dairy farms from all over Germany, corresponding to about 20% of all German dairy herds, and analysed for antibodies against the bovine lungworm Dictyocaulus viviparus by use of the recombinant MSP-ELISA. A total number of 3,397 (17.1%; n = 19,910 BTM samples tested seropositive. The prevalences in individual German federal states varied between 0.0% and 31.2% positive herds. A geospatial map was drawn to show the distribution of seropositive and seronegative herds per postal code area. ELISA results were further analysed for associations with land-use and climate data. Bivariate statistical analysis was used to identify potential spatial risk factors for dictyocaulosis. Statistically significant positive associations were found between lungworm seropositive herds and the proportion of water bodies and grassed area per postal code area. Variables that showed a statistically significant association with a positive BTM test were included in a logistic regression model, which was further refined by controlled stepwise selection of variables. The low Pseudo R(2 values (0.08 for the full model and 0.06 for the final model and further evaluation of the model by ROC analysis indicate that additional, unrecorded factors (e.g. management factors or random effects may substantially contribute to lungworm infections in dairy cows. Veterinarians should include lungworms in the differential diagnosis of respiratory disease in dairy cattle, particularly those at pasture. Monitoring of herds through BTM screening for antibodies can help farmers and veterinarians plan and implement appropriate control measures.
Full Text Available Abstract Background Overall reproductive performance of dairy herds is monitored by various indicators. Most of them do not consider all eligible animals and do not consider different management strategies at farm level. This problem can be alleviated by measuring the proportion of pregnant cows by specific intervals after their calving date or after a fixed time period, such as the voluntary waiting period. The aim of this study was to evaluate two reproductive performance indicators that consider the voluntary waiting period at the herd. The two indicators were: percentage of pregnant cows in the herd after the voluntary waiting period plus 30 days (PV30 and percentage of inseminated cows in the herd after the voluntary waiting period plus 30 days (IV30. We wanted to assess how PV30 and IV30 perform in a simulation of herds with different reproductive management and physiology and to compare them to indicators of reproductive performance that do not consider the herd voluntary waiting period. Methods To evaluate the reproductive indicators we used the SimHerd-program, a stochastic simulation model, and 18 scenarios were simulated. The scenarios were designed by altering the reproductive management efficiency and the status of reproductive physiology of the herd. Logistic regression models, together with receiver operating characteristics (ROC, were used to examine how well the reproductive performance indicators could discriminate between herds of different levels of reproductive management efficiency or reproductive physiology. Results The logistic regression models with the ROC analysis showed that IV30 was the indicator that best discriminated between different levels of management efficiency followed by PV30, calving interval, 200-days not-in calf-rate (NotIC200, in calf rate at100-days (IC100 and a fertility index. For reproductive physiology the ROC analysis showed that the fertility index was the indicator that best discriminated
Anastácio, S; Carolino, N; Sidi-Boumedine, K; da Silva, G J
Ruminants are recognized as the main reservoirs of Coxiella burnetii. EFSA highlighted the lack of knowledge about Q fever prevalence in many European countries. A cross-sectional study was carried out in randomly selected dairy herds (n = 109) from central Portugal to screen for C. burnetii infection and to correlate it with herd factors. Bulk tank milk (BTM) samples from cattle (n = 45) and small ruminant (n = 64) herds were tested by ELISA and PCR. The apparent seroprevalence of Q fever was estimated in 45.9% (95% CI: 36.3-55.7) being higher in small ruminants (51.6; 95% CI: 39.6-63.4) than in cattle (37.8; 95% CI: 25.1-52.4). The shedding of C. burnetii in BTM was detected in 11.9% (95% CI: 7.1-19.4) of BTM, and it was higher in cattle (20%; 95% CI: 10.9-33.8) than in sheep and mixed herds (6.3%; 95% CI: 2.5-15). A high bacterial load (≥ 3 × 10(3) bacteria/ml) was observed in 85% of PCR-positive BTM. A significant correlation was found between the bacterial load and positive samples on ELISA (P < 0.001). Antibody positivity was significantly associated with the increased herd size (P < 0.01) and the occurrence of abortion (P < 0.05), whereas the shedding of C. burnetii was significantly associated with the report of infertility (P < 0.05). The results highlight that serological and molecular methods in combination are a useful tool to screen for Q fever and to clarify the herd infection status. The shedding of C. burnetii through milk is important, especially in dairy cattle, and thus, the role of milk as a potential source of infection among dairy workers should not be neglected. To our knowledge, this is the first study reporting C. burnetii infection in dairy livestock in Portugal showing that Q fever is significant in dairy herds, leading to economic losses and being a risk for public health, which highlights the need of implementation of control measures. © 2014 Blackwell Verlag GmbH.
Stockmarr, Anders; Bødker, Rene; Nielsen, Liza Rosenbaum
Salmonella Dublin (S. Dublin) is a costly infection for dairy cows, potentially lethal to humans. Surveillance is based on bulk tank milk (BTM) antibody measurements, taken each quarter of the year. Herds are classified as Status 1- likely free of S. Dublin, or Status 2 – likely infected with S....... Dublin, based on present /recent characteristics, but not actual S. Dublin detection. We develop a predictive model based on characteristics from last quarter, using on registry data for 2001-2007 for 9387 herds in Denmark . Only 2004-2007 data modeled due to data contamination....
Enevoldsen, Carsten; Sørensen, J.T.
Collaboration with practicing veterinarians was established in a research project and has resulted in several epidemiologic tools to assist them in their work. Simultaneously, the research group obtained continuous access to valid and precise data and obtained first-hand knowledge about real......-life problems for the dairy farmer and the practicing veterinarian. The veterinarian was able to supply detailed information concerning managerial routines applied on the farm. Epidemiologic analyses of the collected data produced input for herd-specific modelling of herd dynamic and economic effects...
Smith, R L; Schukken, Y H; Pradhan, A K; Smith, J M; Whitlock, R H; Van Kessel, J S; Wolfgang, D R; Grohn, Y T
Environmental contamination with Mycobacterium avium subsp. paratuberculosis (MAP) is thought to be one of the primary sources of infection for dairy cattle. The exact link between fecal shedding of MAP by individual cows and environmental contamination levels at the herd level was explored with a cross-sectional analysis of longitudinally collected samples on 3 dairy farms. Composite samples from multiple environmental sites in 3 commercial dairy herds in the Northeast US were cultured quarterly for MAP, providing 1131 samples (133 (11.8%) were culture-positive), and all adult animals in the herds were tested biannually by fecal culture (FC), for 6 years. Of the environmental sites sampled, manure storage areas and shared alleyways were most likely to be culture-positive. Environmental sample results were compared to FC results from either the concurrent or previous sampling date at both the herd and the pen level. At the herd level, a 1 log unit increase in average fecal shedding increased the odds of a positive non-pen environmental sample by a factor of 6 and increased the average amount of MAP in non-pen samples by 2.9 cfu/g. At the pen level, a 1 log unit increase in average fecal shedding in the pen increased the odds of a positive environment by a factor of 2.4 and the average amount of MAP was increased by 3.5 cfu/g. We were not able to model the relationship between non-pen environmental sample status and the distance between shedding animals and the sample's location, and neighboring pens did not significantly affect the results of the pen-level analysis. The amount of MAP in pen-level samples and the probability of a pen testing positive for MAP were both positively but non-significantly correlated with the number of animals in the pen shedding >30 cfu/g of MAP. At least 6 environmental samples met the criteria for the U.S. Voluntary Bovine Johne's Disease Control Program on 47 of the 72 sampling dates; of these, 19 of the 47 FC-positive sampling dates
Pandit, Pranav; Hoch, Thierry; Ezanno, Pauline; Beaudeau, François; Vergu, Elisabeta
Q fever, a worldwide zoonotic disease caused by Coxiella burnetii, is a looming concern for livestock and public health. Epidemiological features of inter-herd transmission of C. burnetii in cattle herds by wind and trade of cows are poorly understood. We present a novel dynamic spatial model describing the inter-herd regional spread of C. burnetii in dairy cattle herds, quantifying the ability of airborne transmission and animal trade in C. burnetii propagation in an enzootic region. Among all the new herd infections, 92% were attributed to airborne transmission and the rest to cattle trade. Infections acquired following airborne transmission were shown to cause relatively small and ephemeral intra-herd outbreaks. On the contrary, disease-free herds purchasing an infectious cow experienced significantly higher intra-herd prevalence. The results also indicated that, for short duration, both transmission routes were independent from each other without any synergistic effect. The model outputs applied to the Finistère department in western France showed satisfactory sensitivity (0.71) and specificity (0.80) in predicting herd infection statuses at the end of one year in a neighbourhood of 3 km around expected incident herds, when compared with data. The model developed here thus provides important insights into the spread of C. burnetii between dairy cattle herds and paves the way for implementation and assessment of control strategies.
Sørensen, J.T.; Enevoldsen, Carsten; Kristensen, T.
A range of preplanned dry period lengths in a dairy herd was evaluated, at different culling strategies and feeding regimes, by means of a dynamic stochastic model simulating the production at herd level. Dry period lengths were studied in the range of 4 to 10 weeks. The culling strategies exhibi...
Agger, Jens Frederik; Paul, Suman; Christoffersen, Anna-Bodil
The aim was to identify risk factors associated with Coxiella burnetii antibody positivity in bulk tank milk (BTM) samples from 100 randomly selected Danish dairy cattle herds. Antibody levels were measured by an enzyme-linked immuno-sorbent assay. Before testing the herds, the farm managers were...
García-Vázquez, Z; Cruz-Vázquez, C; Medina-Espinoza, L; García-Tapia, D; Chavarria-Martinez, B
A serological survey for antibody activity to Neospora caninum was carried out in Aguascalientes, a state in the central part of Mexico. One-hundred and eighty-seven serum samples from 13 dairy herds were tested by the ELISA test. The herd prevalence was 100% and the overall prevalence was 59% (n=110). Seventy-six of 97 seropositive cows had previous records of abortion. There was a statistically significant difference between the groups (P<0.05). However, the odds ratio was 1.4, suggesting an association between abortion and seropositivity. Neosporosis in dairy cattle appears to be widespread in Mexico, warranting more epidemiological studies to determine the distribution of the causative protozoan.
Yeruham, I; Shlosberg, A; Hanji, V; Bellaiche, M; Marcus, M; Liberboim, M
Four cases of rarely reported nitrate toxicosis due to contamination of drinking water or whey were recorded in 2 beef and 2 dairy cattle herds. In the cases associated with water contamination, water containing ammonium nitrate as a fertilizer for irrigating orchards accidentally entered drinking water troughs for cattle through malfunctioning 1-way valves. The whey contamination in 1 instance was caused by transportation in containers which contained traces of concentrated ammonium nitrate; the 2nd case was induced by whey derived from the production of a specialty cheese produced by the incorporation of nitrate. Mortality occurred in 2 herds and abortions in the 2 other herds. Affected cows responded well to treatment, but some animals remained in a deteriorated physical condition for several months.
K?stenberger, Kerstin; Tichy, Alexander; Bauer, Karl; Pless, Peter; Wittek, Thomas
Liver fluke is a ubiquitous parasite that causes extensive production losses in cattle and is a zoonosis. The aims of this study were to determine the prevalence of fasciolosis in 178 dairy cattle herds in Styria (federal state of Austria) and its influence on production, to detect the risk factors for infection, and to explore effective strategies in management and control. A questionnaire on farm management, prophylaxis, and therapy was developed and applied. Furthermore, production paramet...
Escamilla, H. Patricia; Martínez, M. José Juan; Medina, C. Mario; Morales, S. Elizabeth
The objective of this study was to determine the frequency of infectious bovine abortion and to identify some of its causes, specifically brucellosis, leptospirosis, bovine viral diarrhea, infectious bovine rhinotracheitis, and neosporosis. The study was carried out in a dairy herd in the state of Queretaro, Mexico, between September 2002 and March 2003. At the beginning of the study, blood samples were taken from a random 33% of the 300 lactating or pregnant cows; antibodies against Leptospi...
Full Text Available Fasciolosis is generally a subclinical infection of dairy cows and can cause marked economic losses. This study investigated the prevalence and spatial distribution of fasciolosis in dairy cow herds in Ireland using an in-house antibodydetection enzyme-linked immunosorbent assay applied to bulk tank milk (BTM samples collected during the autumn of 2012. A total of 5,116 BTM samples were collected from 4,602 different herds, with 514 farmers submitting BTM samples in two consecutive months. Analysis of the BTM samples showed that 82% (n = 3,764 of the dairy herds had been exposed to Fasciola hepatica. A total of 108 variables, including averaged climatic data for the period 1981-2010 and contemporary meteorological data for the year 2012, such as soil, subsoil, land cover and habitat maps, were investigated for a possible role as predictor of fasciolosis. Using mainly climatic variables as the major predictors, a model of the predicted risk of fasciolosis was created by Random Forest modelling that had 95% sensitivity and 100% specificity. The most important predictors in descending order of importance were: average of annual total number of rain-days for the period 1981-2010, total rainfall during September, winter and autumn of 2012, average of annual total number of wet-days for the period 1981- 2010 and annual mean temperature of 2012. The findings of this study confirm the high prevalence of fasciolosis in Irish dairy herds and suggest that specific weather and environmental risk factors support a robust and precise distribution model.
Maillard, R.; Grimard, B; Chastant-Maillard, S; Chomel, B.; Delcroix, T.; Gandoin, C.; Bouillin, C.; Halos, L.; Vayssier-Taussat, M.; Boulouis, H.-J.
Bartonella spp. are small hemotropic bacteria infecting mammals. Four Bartonella species have been recently described in cattle and wild ruminants. To date, the biology and possible pathogenic role of Bartonella species isolated from ruminants are poorly understood. Therefore, a dairy herd of 448 cows and heifers was surveyed in order to establish the prevalence of Bartonella bovis and B. chomelii infections, the level of bacteremia, and the relationship between bacteremia and age or pregnanc...
Howell, Alison; Baylis, Matthew; Smith, Rob; Pinchbeck, Gina; Williams, Diana
The liver fluke Fasciola hepatica is a trematode parasite with a worldwide distribution and is the cause of important production losses in the dairy industry. The aim of this observational study was to assess the prevalence of exposure to F. hepatica in a group of high yielding dairy herds, to determine the risk factors and investigate their associations with production and fertility parameters. Bulk milk tank samples from 606 herds that supply a single retailer with liquid milk were tested with an antibody ELISA for F. hepatica. Multivariable linear regression was used to investigate the effect of farm management and environmental risk factors on F. hepatica exposure. Higher rainfall, grazing boggy pasture, presence of beef cattle on farm, access to a stream or pond and smaller herd size were associated with an increased risk of exposure. Univariable regression was used to look for associations between fluke exposure and production-related variables including milk yield, composition, somatic cell count and calving index. Although causation cannot be assumed, a significant (phepatica exposure and estimated milk yield at the herd level, representing a 15% decrease in yield for an increase in F. hepatica exposure from the 25th to the 75th percentile. This remained significant when fertility, farm management and environmental factors were controlled for. No associations were found between F. hepatica exposure and any of the other production, disease or fertility variables.
Toni, F; Vincenti, L; Ricci, A; Schukken, Y H
The objective of this study was to describe the incidence and the impact of postpartum uterine diseases in postpartum cows on future uterine status and reproductive performance in large Italian dairy herds. This study provides an important quantitative estimate of uterine and postpartum diseases incidence that afflict high-producing Italian dairy cows. The total number of cows included in the study was 1498 on three farms; all cows were followed from the dry period until 300 days postpartum. All farms used high-quality data collection systems and standard operating procedures: weekly herd health visits, monthly Dairy Herd Improvement Association visits, and, due to cheese-making milk quality requirements, a supplementary milk sample collected at 7 ± 3 days postpartum evaluated for milk components. Clinical metritis in primiparous cows did not change the time to the first artificial insemination (AI) or days open; conversely, clinical metritis in multiparous cows had impact on the time to first AI (hazard ratio: 0.66, P cows and had a strong negative effect on the proportion of pregnant cows at 300 days (P parameters, and understanding the immune response in first-lactation cows may be of value for developing alternative intervention protocols for older-lactation cows.
Full Text Available The present study was designed to analyse the causes for culling in dairy herds with different Mycobacterium avium subsp. paratuberculosis infection status and to compare these causes with those observed over the general dairy cattle population. During 2009, causes for culling were registered in two different groups of farms: (1 farms with seropositive cows for three consecutive years (2007-2009 but where Mycobacterium avium subsp. paratuberculosis has not been isolated from any of the fecal samples collected and (2 farms with Mycobacterium avium subsp. paratuberculosis seropositive cows for three consecutive years (2007-2009 and where the bacteria has been isolated from at least one fecal sample. Causes for animal loss were compared between both groups and between them and the general dairy cattle population by means of regression analysis. The distribution of culling reasons was different between infected herds (both bacteriologically positive and negative and the general population. The percentage of losses seemed to be higher in infected herds from the first parity on. The most remarkable difference among groups was observed in losses due to "death/urgent slaughter".
Sergeant, E.S.G.; Nielsen, Søren S.; Toft, Nils
. Using this model, five herd-testing strategies were evaluated: (1) milk-ELISA on all lactating cows; (2) milk-ELISA on lactating cows 4 years old; (4) faecal culture on all lactating cows; and (5) milk-ELISA plus faecal culture in series on all lactating cows. The five testing strategies were evaluated...... using observed milk-ELISA results from 19 Danish dairy herds as well as for simulated results from the same herds assuming that they were uninfected. Whole-herd milk-ELISA was the preferred strategy, and considered the most cost-effective strategy of the five alternatives. The five strategies were all...... efficient in detecting infection, i.e. estimating a low Pr-Low in infected herds, however, Pr-Low estimates for milk-ELISA on age-cohorts were too low in simulated uninfected herds and the strategies involving faecal culture were too expensive to be of practical interest. For simulated uninfected herds...
M. M. Hossain
Full Text Available Aim: The present study was conducted to find out the causes and factors affecting the dairy cattle mortality. Materials and Methods: A retrospective study of dairy cattle mortality on the Central Cattle Breeding and Dairy Farm (CCBDF in Bangladesh was carried out between 1992 and 2007. Sixteen years of data on mortality of dairy cattle were analyzed for the effects of year, season, age, sex, breed, and etiology on mortality rate. Results: The average overall mortality rate was 5.60% and on average, female cattle (55.71% were found to die more than males (44.29%. Mortality was more in crossbred cattle than in indigenous breed. Higher mortality of cattle was observed in rainy season (37.98% followed by winter (33.03% and summer (28.99%. The major causes of death were diseases of the respiratory tract, mainly pneumonia (39.91%. Tuberculosis was the second most common cause of mortality accounting for 20.58% of deaths. The other major cause of death was disease of the alimentary tract, mainly enteritis (15.58%. Other causes of death occurred in the following frequencies: malnutrition (5.91%, debility (4.43%, hairball (3.35%, tympanitis (2.56%, babesiosis (2.27%, internal haemorrhage (2.16%, black quarter (1.76%, and foot and mouth disease (1.48%. Conclusions: Of the four potential risk factors investigated, age was the most important factor and significantly associated with mortality. During the first month of life, calves had a higher risk of mortality than adults.
Albuquerque, Pedro; Ribeiro, Niza; Almeida, Alexandre; Panschin, Irena; Porfirio, Afonso; Vales, Marta; Diniz, Francisca; Madeira, Helena; Tavares, Fernando
Streptococcus uberis is considered one of the most important pathogens associated with bovine mastitis. While traditionally acknowledged as an environmental pathogen, S. uberis has been shown to adopt a contagious epidemiological pattern in several dairy herds. Since different control strategies are employed depending on the mode of transmission, in-depth studies of S. uberis populations are essential to determine the best practices to control this pathogen. In this work, we optimized and validated a dot blot platform, combined with automatic image analysis, to rapidly assess the population structure of infective S. uberis, and evaluated its efficiency when compared to multilocus sequence analysis (MLSA) genotyping. Two dairy herds with prevalent S. uberis infections were followed in a 6 month period, in order to collect and characterize isolates from cows with persistent infections. These herds, located in Portugal (Barcelos and Maia regions), had similar management practices, with the herd from Barcelos being smaller and having a better milking parlor management, since infected cow segregation was immediate. A total of 54 S. uberis isolates were obtained from 24 different cows from the two herds. To overcome operator-dependent analysis of the dot blots and increase the technique's consistency and reliability, the hybridization signals were converted into probability values, with average probabilities higher than 0.5 being considered positive results. These data allowed to confirm the isolates' identity as S. uberis using taxa-specific markers and to determine the presence of virulence- and antibiotic resistance-related genes. In addition, MLSA allowed to disclose the most prevalent S. uberis clonal lineages in both herds. Seven different clusters were identified, with Barcelos showing a high clonal diversity and Maia a dominant lineage infecting most cows, suggesting distinct epidemiological patterns, with S. uberis displaying an environmental or contagious
Relun, A; Lehebel, A; Bruggink, M; Bareille, N; Guatteo, R
The purpose of this study was to concurrently estimate the effect of different digital dermatitis (DD) treatment regimens and herd management practices on the occurrence of a new DD lesion. A controlled clinical trial was conducted and involved 4678 dairy cows from 52 French dairy farms where DD was endemic. Farms were allocated by minimisation to one of 4 treatment regimens, varying through the mode (footbath or collective spraying) and the frequency of application (2 days every 4 weeks or fortnightly). They were visited 7 times every 4 weeks by 14 trained investigators. Frailty Cox proportional hazards models were used to estimate the relative effect of potential risk factors and treatment practices on the time until the first occurrence of a DD lesion. At herd level, high initial DD prevalence strongly increased the risk for DD occurrence (HR=1.93, CI 1.23-3.04), as well as absence of hoof-trimming (HR=1.75, CI 1.36-2.27) and poor leg cleanliness (HR=2.44, CI 1.80-3.31). At animal level, Holstein breed (HR=1.92, CI 1.35-3.57) and high-productive cows (HR=1.26, CI 1.01-1.56) were identified to be at higher risk for DD compared to Normande breed and low-productive cows, respectively. Compared to individual topical antibiotic treatments alone, collective treatments tended to decrease the risk of DD occurrence only when applied over 2 days at least every fortnight (HR range=0.64-0.73). Copyright © 2013 Elsevier B.V. All rights reserved.
Dank, M; Holzhauer, M; Veldhuis, A; Frankena, K
The objective of this study was to estimate the association between Dictyocaulus viviparus bulk tank milk (BTM) test results and milk production and milk composition parameters in adult Dutch dairy cattle herds. Bulk tank milk samples were collected in August and November 2013, and ELISA tests were performed. Two hundred BTM positive (BTM+) and 200 BTM negative (BTM-) herds were selected based on their BTM test result of November 2013, obtained from a list of farms that participated in the Dutch GD Animal Health voluntary monitoring program for controlling nematode infections. The relationship between D. viviparus BTM status and 3 production parameters (milk production, milk fat %, and milk protein %) in summer (June to August 2013) and autumn (September and October 2013) was investigated using generalized linear mixed models. Production data were available for 126 BTM- herds and 109 BTM+ herds. Results showed that a positive D. viviparus status was associated with decreased milk production (June: -1.01, July: -1.19, August: -1.68, September and October: -1.33kg/cow per d). Milk fat percentage was 0.14% and 0.08% lower during summer and autumn, respectively, in BTM+ herds. No significant association was demonstrated between a positive BTM test result and milk protein percentage. Because a strong correlation was present between the BTM status for D. viviparus and that for Ostertagia ostertagi, these losses cannot be attributed to one of the two parasites. However, it is clear that these parasite infections have a considerable effect on production.
Kalantari, A S; Mehrabani-Yeganeh, H; Moradi, M; Sanders, A H; De Vries, A
The objective of this study was to determine the optimum replacement policy for Holstein dairy herds in Iran using a dynamic programming model. Cows were described in terms of state variables that included milk production class, parity, pregnancy status, and month in milk with a 1-mo stage length. The objective function maximized the net present value of cows over a 15-yr planning horizon. Markov simulation was used to estimate expected herd dynamics under the optimal decision plan determined by dynamic programming. Stochastic elements included probabilities of pregnancy and abortion, production level, and involuntary culling. The optimum annual culling rate was estimated to be 31.4%, and cows had an expected herd life (time from first calving until culling) of 3.18 yr. High replacement cost and low carcass value resulted in only 2.87% voluntary culling (i.e., optimal model-based replacement). Assuming a heat detection rate of 0.4, cows averaged 2.8 services per lactation under the optimal policy. Sensitivity analyses were carried out to evaluate the effect of milk price, herd-average production, feed cost, heifer price, and carcass value on optimum replacement decisions. Herd-average production, replacement cost, and risk of involuntary culling were important factors affecting the optimal culling policy. Changes in the price of feed, calves, and milk and the probability of pregnancy had no considerable effect on the optimal policy considering the market situation in Iran during 2008.
Knappe-Poindecker, M.; Gilhuus, M.; Jensen, Tim Kåre
wanted to compare diseased and healthy cows in all herds. The study included 14 dairy herds with a total of 633 cows. Eight herds had a history of ID and E, and 6 were control herds. All cows were scored for lameness, and infectious foot diseases on the hind feet were recorded after trimming. Swabs...... and biopsies were taken from the skin of 10 cows in each herd for bacterial analyses. In total, samples were taken from 34 cows with ID, 11 with E, 40 with both ID and E, and 8 with digital dermatitis (DD), and from 47 cows with healthy feet. Swabs were analyzed for identification and characterization of D...... with DD, and in 66.0% of cows with healthy feet. All serogroups of D. nodosus except F and M were detected, and all isolates were defined as benign by the gelatin gel test. Treponema spp. were detected in 50.0% of the cows with ID, in 9.1% with E, in 67.5% with ID and E, in all cows with DD, and in 6...
Full Text Available A questionnaire was sent to 1500 randomly selected dairy herds in Sweden, asking for general information about the herds, including routines from birth to first calving and also routines at breeding, calving and during the grazing period. Fifty-eight percent of the questionnaires were returned. The preweaned calves were kept in individual calf pens in 68% and in group housing systems in 28% of the herds. Pens with slatted floors were the main housing system for replacement heifers from weaning to breeding, and tie stalls from breeding to first calving. Whole milk was used in 44% and milk replacements in 42% of the herds. The calves received, as a median, 2.5 litres of milk per meal and 2 meals per day. The median age at weaning was 8 weeks. Age was the single most common criteria used for deciding both weaning and breeding time. The median age when the heifers were first turned out to pasture was 6 months. Prophylactic anthelmintic treatment was used by 65% of the herds. The most common diet for replacement heifers before calving was a combination of grain, hay and silage.
Monti, G E; Frankena, K; De Jong, M C M
In Argentina, bovine leukaemia virus (BLV) infection is common in dairy herds. The country currently has a National Voluntary Control Programme but relatively few farms have enrolled. However, there is increased interest from authorities and farmers to implement regional compulsory programmes but there is scarce quantitative information of the transmission of BLV in cattle herds. This information is a prerequisite to develop effective BLV control strategies. Mathematical modelling offers ways of integrating population-level knowledge and epidemiological data to predict the outcomes of intervention scenarios. The purpose of the current paper is to gain understanding about the dynamics of the transmission of BLV in dairy herds from Argentina by simulation and to compare various BLV transmission models and select the one that is most appropriate. The hypothetical herd is conceptually described in terms of BLV status as a population of individuals that are protected by maternal antibodies (M), that are susceptible (S), that are in the latent period (E) or that are infectious (I). BLV is spread by horizontal and vertical transmission. We used an age-structured population model and within-herd transmission was simulated by Monte Carlo techniques. The next-generation approach has been used for the systematic computation of the basic reproduction ratio (R0). Parameter values for disease transmission were derived from previously published data; rates of entry, exit or transition between age groups were calculated based on our previous study, observational data, expert opinions and literature. With these parameter values the probability of a minor outbreak was estimated to be 10%, the probability of extinction was estimated as <0.001% and the expected time to extinction as more than 80 years. The probability of a minor outbreak and changes in prevalence were different when the index case was an adult cow compared to introduction by a heifer. Prediction of prevalences from
Ostergaard, S; Sørensen, J T; Kristensen, A R
A dynamic, stochastic, and mechanistic Monte Carlo model, simulating a dairy herd with focus on the feeding-health-production complex is presented. By specifying biological parameters at cow level and a management strategy at herd level, the model can simulate the technical and economic consequences of scenarios at herd level. The representation of the feeding-health-production complex is aimed to be sufficiently detailed, to include relationships likely to cause significant herd effects, and to be sufficiently simple to enable a feasible parameterization of the model and interpretation of the results from the model. Consequently, diseases are defined as four disease types: two metabolic disease types, an udder disease type, and a reproductive disease type. Risk factors for the diseases were defined as parity, yield capacity, disease recurrence, disease interrelationships, lactation stage, and season. Direct effects of the diseases were defined according to milk yield, feed intake, feed utilization, conception, culling, involuntary removal, and death. Scenarios differing in base risks of milk fever and ketosis, heat detection rate, and culling strategy were simulated for describing the model behavior. Annual milk yield per cow was decreased by increased risk of ketosis and by increased risk of milk fever, even though no direct effect of milk fever on milk yield was modeled at the cow level. The indirect effect from milk fever is a consequence of increased replacement rate (relatively lower milk yield from younger cows). By ignoring the history of milk fever in insemination and replacement decisions, a significantly reduced net income per cow was found in some herds. We concluded that important benefits from using such a herd model are the capability of accounting for herd management factors and the advantage of avoiding to double count the indirect effects from disease, such as increased risk of other diseases, poorer reproduction results, and increased risk of
Beekhuis-Gibbon, Lies; Whyte, Paul; O'Grady, Luke; More, Simon J; Doherty, Michael L
Hazard Analysis and Critical Control Points (HACCP) systems are a risk based preventive approach developed to increase levels of food safety assurance. This is part 1 of a pilot study on the development, implementation and evaluation of a HACCP-based approach for the control of good udder health in dairy cows. The paper describes the use of a novel approach based on a deconstruction of the infectious process in mastitis to identify Critical Control Points (CCPs) and develop a HACCP-based system to prevent and control mastitis in dairy herds. The approach involved the creation of an Infectious Process Flow Diagram, which was then cross-referenced to two production process flow diagrams of the milking process and cow management cycle. The HACCP plan developed, may be suitable for customisation and implementation on dairy farms. This is a logical, systematic approach to the development of a mastitis control programme that could be used as a template for the development of control programmes for other infectious diseases in the dairy herd.
Full Text Available Abstract Hazard Analysis and Critical Control Points (HACCP systems are a risk based preventive approach developed to increase levels of food safety assurance. This is part 1 of a pilot study on the development, implementation and evaluation of a HACCP-based approach for the control of good udder health in dairy cows. The paper describes the use of a novel approach based on a deconstruction of the infectious process in mastitis to identify Critical Control Points (CCPs and develop a HACCP-based system to prevent and control mastitis in dairy herds. The approach involved the creation of an Infectious Process Flow Diagram, which was then cross-referenced to two production process flow diagrams of the milking process and cow management cycle. The HACCP plan developed, may be suitable for customisation and implementation on dairy farms. This is a logical, systematic approach to the development of a mastitis control programme that could be used as a template for the development of control programmes for other infectious diseases in the dairy herd.
Full Text Available Background and objectives: Leptospirosis is an important zoonotic disease caused by Leptospira interrogans. Leptospirosis leads to economical losses in dairy farm industry. The objective of this study was to evaluate the pathogenic serovars of Leptospira interrogans in dairy cattle herds of Shahrekord by PCR.Materials and Methods: Two hundred samples (100 urine and 100 blood were collected from 100 cows randomly and delivered to the laboratory. Samples were stored at -20 °C. DNA was extracted and purified from the plasma and urine samples and concentrated on diatoms in the presence of guanidine thiocyanate (GuSCN. PCR products were detected and identified as Leptospira by ilumination of the expected size of DNA bands after staining of the agarose gel with ethidium bromide gels. PCR products were purified and sequenced.Results: The results showed that 28% of urine samples and 23% of plasma samples were contaminated. The major serotypes were Icterohaemorrhagiae (50% and Pomona (37.5%. The urine samples of 17 cows were positive for Leptospira without positive plasma samples. This indicated that these cows are reservoirs in dairy herds of Shahrekord and dangerous for human health. The plasma samples of twelve cows were positive for Leptospira without positive urine samples.Conclusions: Leptospira serotypes can be maintained in relatively dry regions and must be considered when dealing with leptospirosis in dairy farms of Shahrekord and human health.
Warnick, L.D.; Nielsen, L.R.; Nielsen, Jens
antibody measurements for infected and noninfected herds were determined from field study data. Herd infection was defined as having either >= 1 Salmonella culture-positive fecal sample or >= 5% within-herd prevalence based on antibody measurements in serum or milk from individual animals. No distinction......The Danish government and cattle industry instituted a Salmonella surveillance program in October 2002 to help reduce Salmonella enterica subsp. enterica serotype Dublin (S. Dublin) infections. All dairy herds are tested by measuring antibodies in bulk tank milk at 3-month intervals. The program...... is based on a well-established ELISA, but the overall test program accuracy and misclassification was not previously investigated. We developed a model to simulate repeated bulk tank milk antibody measurements for dairy herds conditional on true infection status. The distributions of bulk tank milk...
Gutiérrez, Gerónimo; Lomonaco, Marina; Alvarez, Irene; Fernandez, Fernando; Trono, Karina
Bovine Leukemia Virus (BLV) is endemic in Argentina, where the individual prevalence is higher than 80% in dairy farms. The aim of this work was to find preliminary evidence to know if the high level of infection of the dam would implicate a higher challenge to her own offspring. We collected 65 sets of samples consisting of dam's blood and colostrum from two heavily infected dairy farms, and investigated the correlation between the dam's blood proviral load and the presence of provirus in colostrum. We also described the dual antibody/provirus profile in the colostrum. Provirus was detected in 69.23% of the colostrum samples, mostly from dams with a high proviral load, 36/45 (80%). Colostrum proviral load was significantly higher in dams with high blood proviral load (pcolostrum samples all along the antibody distribution, even in those with a low amount of antibodies. These results show that even when high blood proviral load dams offer higher levels of infected cells to their offspring through colostrum they also offer higher levels of protection of antibodies. On the contrary, low blood proviral load dams also offer infected cells but a poor content of antibodies, suggesting that these animals could play an important role in the epidemiological cycle of transmission.
Cláudio E. F. Cruz
Full Text Available Over the last decades, the emphasis on the health of dairy cows has changed from an individual to a herd level. In this scenario, the role played by the recording system and its interpretation by veterinarians has gained primordial importance. The records of productive and reproductive performance and of sanitary status from a southern Brazilian dairy cattle herd have been presented and discussed. The period of study was 2000-2009. Mean values per lactation period were 349D 8436M 290F 275P 201SCS (D: days in lactation, M: kg of milk yield, F: kg of fat, P: kg of protein and SCS: somatic cell score in 1000 cells/ml of milk. Major indexes of reproductive efficiency included age at first calving (31 months, services per conception (2.1, intercalving interval (428 days, calving to conception interval (146 days, mean annual rates of parturitions (76.2%, fetal losses (9.8-19.0%, and stillbirths (3.6%, apart of voluntary waiting period (94 days. Main information on sanitary status of the herd was associated with the mean prevalence of common disorders of dairy cattle such as anaplasmosis (29.8%, mastitis (27.8%, digital diseases (26.3%, ovarian cysts (21.3%, placental retention (19.7%, postpartum uterine infections (10.6%, and calf diarrhea (23.7% and pneumonia (16.8%, among others. In addition, culling reasons (low reproductive performance [56.3%] and udder/mastitis problems [33.6%], causes of cattle deaths (anaplasmosis [16.4%] and leukosis [11.4], and the impact of cattle diseases such as tuberculosis, leukosis, and neosporosis on the herd have also been presented and succinctly discussed. Numbers between brackets represent rates accumulated in the 10-year period.
Lu, Zhao; Gröhn, Yrjö T; Smith, Rebecca L; Karns, Jeffrey S; Hovingh, Ernest; Schukken, Ynte H
Salmonella is a major cause of bacterial foodborne disease. Human salmonellosis results in significant public health concerns and a considerable economic burden. Dairy cattle are recognized as a key source of several Salmonella serovars that are a threat to human health. To lower the risk of Salmonella infection, reduction of Salmonella prevalence in dairy cattle is important. Vaccination as a control measure has been applied for reduction of preharvest Salmonella prevalence on dairy farms. Salmonella vaccines are usually imperfect (i.e., vaccines may provide a partial protection for susceptible animals, reduce the infectiousness and shedding level, shorten the infectious period of infected animals, and/or curb the number of clinical cases), and evaluation of the potential impacts of imperfect Salmonella vaccines at the farm level is valuable to design effective intervention strategies. The objective of this study was to investigate the impact of imperfect Salmonella vaccines on the stochastic transmission dynamics in an adult dairy herd. To this end, we developed a semi-stochastic and individual-based continuous time Markov chain (CTMC) vaccination model with both direct and indirect transmission, and applied the CTMC vaccination model to Salmonella Cerro transmission in an adult dairy herd. Our results show that vaccines shortening the infectious period are most effective in reducing prevalence, and vaccines decreasing host susceptibility are most effective in reducing the outbreak size. Vaccines with multiple moderate efficacies may have the same effectiveness as vaccines with a single high efficacy in reducing prevalence, time to extinction, and outbreak size. Although the environment component has negligible contributions to the prevalence, time to extinction, and outbreak size for Salmonella Cerro in the herd, the relative importance of environment component was not assessed. This study indicates that an effective vaccination program against Salmonella Cerro
Full Text Available Abstract The relationship between bulk tank somatic cell count (SCC and farm management and infrastructure was examined using data from 398 randomly selected, yet representative, Irish dairy farms where the basal diet is grazed grass. Median bulk tank SCC for the farms was 282,887 cells/ml ranging from 82,209 to 773,028 cells/ml. Two questionnaires were administered through face-to-face contact with each farmer. Herd-level factors associated with bulk tank SCC were determined using linear models with annual somatic cell score (i.e., arithmetic mean of the natural logarithm of bulk tank SCC included as the dependent variable. All herd level factors were analysed individually in separate regression models, which included an adjustment for geographical location of the farm; a multiple regression model was subsequently developed. Management practices associated with low SCC included the use of dry cow therapy, participation in a milk recording scheme and the use of teat disinfection post-milking. There was an association between low SCC and an increased level of hygiene and frequency of cleaning of the holding yard, passageways and cubicles. Herd management factors associated with bulk tank SCC in Irish grazing herds are generally in agreement with most previous studies from confinement systems of milk production.
The relationship between bulk tank somatic cell count (SCC) and farm management and infrastructure was examined using data from 398 randomly selected, yet representative, Irish dairy farms where the basal diet is grazed grass. Median bulk tank SCC for the farms was 282,887 cells/ml ranging from 82,209 to 773,028 cells/ml. Two questionnaires were administered through face-to-face contact with each farmer. Herd-level factors associated with bulk tank SCC were determined using linear models with annual somatic cell score (i.e., arithmetic mean of the natural logarithm of bulk tank SCC) included as the dependent variable. All herd level factors were analysed individually in separate regression models, which included an adjustment for geographical location of the farm; a multiple regression model was subsequently developed. Management practices associated with low SCC included the use of dry cow therapy, participation in a milk recording scheme and the use of teat disinfection post-milking. There was an association between low SCC and an increased level of hygiene and frequency of cleaning of the holding yard, passageways and cubicles. Herd management factors associated with bulk tank SCC in Irish grazing herds are generally in agreement with most previous studies from confinement systems of milk production. PMID:22081962
Full Text Available This study was carried out to study the inbreeding coefficient and its effect on reproductive performance of dairy cows (age at first calving, calving interval and open days in Isfahan province. Records of 31,977 (primiparous cows, 36,982 and 51,423 (multiparous cows for age at first calving, calving interval and open days were used, respectively. The inbreeding coefficients of animals were calculated using pedigree information of 78,425 females and 8,056 males, which were born from 1963 to 2009. The overall mean and maximum inbreeding coefficients in Holstein cows were 2.33% and 31.30%, respectively. The results showed that 57,234 animals were inbred with 3.57% inbreeding coefficient. Regression coefficients on inbreeding coefficient for age at first calving, calving interval and open days were 0.589±0.21, 1.08±0.15 and 0.27±12, respectively. Estimated inbreeding indicated significantly negative effect on the reproductive traits in different parturition periods. The results revealed that the average inbreeding trend was increased in the dairy herds. The increased inbreeding was due to close mating systems between the candidates, and it showed negative effects on the reproductive traits in Isfahan dairy herds.
Anibal Eugênio Vercesi Filho
Full Text Available The Zebu breeds were introduced in Brazil mainly in the last century by imports from the Indian subcontinent. When the Zebu cattle arrived, the national herd suffered a significative change by backcrossing the national cows of taurine origin with Zebu sires. These processes created a polymorphism in the mitochondrial DNA (mtDNA in the Zebu animals with are in a major part derived from backcrossing and sharing mtDNA of taurine origin. To verify the maternal origin of cows belonging to the Dairy Gyr herd of APTA, Mococa 60 females were analyzed and 33 presented mtDNA from Bos taurus origin and 27 presented mtDNA from Bos indicus origin. None of these animals presented patterns of both mtDNA origins, indicating absence of heteroplasmy for these mitochondrial genotypes.
Blum, S; Mazuz, M; Brenner, J; Friedgut, O; Koren, O; Goshen, T; Elad, D
Bovine necrotic vulvovaginitis (BNVV) is characterized by the development of a necrotic vulvovaginal lesion, almost exclusively in post-parturient first-lactation cows, associated with Porphyromonas levii. The scope of this survey was to evaluate the impact of BNVV on herd productivity as a means to rationally evaluate the resources that should be allocated in dealing with the syndrome. During an outbreak of BNVV in a dairy herd, following the introduction of a large number of cows from another farm, the impact of the animals' origin (local or transferred) and BNVV (positive or negative) upon involuntary culling rate, milk yield and days between pregnancies were assessed. The results indicated that the number of days between pregnancies was significantly higher in first-lactation cows with BNVV but was not influenced by the other independent variables. None of the other variables included in this survey had any effect on the involuntary culling rate and milk yield.
L. Cerqueira, Joaquim; Araújo, José P P; Blanco-Penedo, Isabel
We studied the relationship between behavior during milking with milking parlor management, measuring the occurrence of steps and kicks, and cow-related factors. We also investigated the link between stepping and kicking during milking and udder health. A total of 2,903 direct observations...... of milking behavior were collected in 44 dairy herds in the north of Portugal. The results showed great variability in the occurrence of stepping and kicking among herds during milking. Mixed linear and logistic regression models for factors associated with stepping and kicking were developed. Cows in tandem...... of the visit also showed a trend toward higher kicking frequency. The results suggest that animal welfare measures, like kicking and stepping, are suitable for epidemiologic studies. Significant interactions were observed when animals were affected by challenging health and welfare situations....
de Vries, M; Bokkers, E A M; Dijkstra, T; van Schaik, G; de Boer, I J M
As farm animal welfare is high on the political and societal agendas of many countries, considerable pressure exists to establish audit programs in which farm animal welfare is routinely monitored. On-farm assessment of animal welfare, however, is time-consuming and costly. A promising strategy to monitor animal welfare more efficiently is to first estimate the level of animal welfare on a farm based on routine herd data that are available in national databases. It is not currently known which variables of routine herd data (VRHD) are associated with dairy cattle welfare indicators (WI). Our aim was to identify VRHD that are associated with WI in a literature review. The 27 VRHD used in this review included the main types of data that are currently collected in national herd databases of developed countries, and related to identification and registration, management, milk production, and reproduction of dairy herds. The 34 WI used in this review were based on the Welfare Quality Assessment Protocol for Cattle. The search yielded associations in 146 studies. Twenty-three VRHD were associated with 16 WI. The VRHD that related to milk yield, culling, and reproduction were associated with the largest number of WI. Few associations were found for WI that referred to behavioral aspects of animal welfare, nonspecific disease symptoms, or resources-based indicators. For 18 WI, associations with VRHD were not significant (n=5 WI) or no studies were found that investigated associations with VRHD (n=13 WI). It was concluded that many VRHD have potential to estimate the level of animal welfare on dairy farms. As strengths of associations were not considered in this review, however, the true value of these VRHD should be further explored. Moreover, associations found at the animal level and in an experimental setting might not appear at the farm level and in common practice and should be investigated. Cross-sectional studies using integrated welfare scores at the farm level are
Mohammad Khalili; Ehsanollah Sakhaee; Mohammad Reza Aflatoonian; Naser Shahabi-Nejad
Objective: To determine the prevalence of Coxiella burnetii (C. burnetii) antibody positive randomly selected dairy herds in southeast Iran (Kerman). Methods: Bulk tank milk samples were collected randomly from 44 sufficiently large commercial dairy herds, included near 12 000 dairy cattle, in Kerman (The largest province of Iran), southeast Iran. The samples were tested for antibodies against C. burnetii using the commercial CHEKIT® Q fever antibody ELISA Test Kit (Idexx, Liebefeld-Bern, Switzerland). Results: The prevalence of positive, negative and intermediate herds were 45.4%, 43.2% and 11.4%, respectively. Conclusions: The result supports the hypothesis of high prevalence and endemic pattern of Q fever in Iran. This investigation highlights the importance of further studies on Q fever in Iran.
Arede, Margarida; Nielsen, Per Kantsø; Ahmed, Syed Sayeem Uddin;
, using the indirect BIO K 302 M. bovis enzyme-linked immunosorbent assay (ELISA) (Bio-X, Belgium) in bulk tank milk from all dairy herds between June 2013 and July 2014. The objective of this study was to investigate the evolution of the spatial distribution of M. bovis in the Danish dairy herd...
Græsbøll, Kaare; Kirkeby, Carsten; Nielsen, Søren Saxmose; Halasa, Tariq; Toft, Nils; Christiansen, Lasse Engbo
The future value of an individual dairy cow depends greatly on its projected milk yield. In developed countries with developed dairy industry infrastructures, facilities exist to record individual cow production and reproduction outcomes consistently and accurately. Accurate prediction of the future value of a dairy cow requires further detailed knowledge of the costs associated with feed, management practices, production systems, and disease. Here, we present a method to predict the future value of the milk production of a dairy cow based on herd recording data only. The method consists of several steps to evaluate lifetime milk production and individual cow somatic cell counts and to finally predict the average production for each day that the cow is alive. Herd recording data from 610 Danish Holstein herds were used to train and test a model predicting milk production (including factors associated with milk yield, somatic cell count, and the survival of individual cows). All estimated parameters were either herd- or cow-specific. The model prediction deviated, on average, less than 0.5 kg from the future average milk production of dairy cows in multiple herds after adjusting for the effect of somatic cell count. We conclude that estimates of future average production can be used on a day-to-day basis to rank cows for culling, or can be implemented in simulation models of within-herd disease spread to make operational decisions, such as culling versus treatment. An advantage of the approach presented in this paper is that it requires no specific knowledge of disease status or any other information beyond herd recorded milk yields, somatic cell counts, and reproductive status. PMID:28261585
Sørensen, J.T.; Enevoldsen, Carsten; Houe, H.
A dynamic, stochastic model simulating the technical and economic consequences of bovine virus diarrhoea virus (BVDV) infections for a dairy cattle herd for use on a personal computer was developed. The production and state changes of the herd were simulated by state changes of the individual cows...... modelling principle. The validation problem in relation to the model was discussed. A comparison between real and simulated data using data from a published case report was shown to illustrate how user acceptance can be obtained....
Cho, J; Tauer, L W; Schukken, Y H; Gómez, M I; Smith, R L; Lu, Z; Grohn, Y T
Johne's disease, or paratuberculosis, is a chronic infectious enteric disease of ruminants, caused by infection with Mycobacterium avium ssp. paratuberculosis (MAP). Given the absence of a fail-safe method of prevention or a cure, Johne's disease can inflict significant economic loss on the US dairy industry, with an estimated annual cost of over $200 million. Currently available MAP control strategies include management measures to improve hygiene, culling MAP serologic- or fecal-positive adult cows, and vaccination. Although the 2 first control strategies have been reported to be effective in reducing the incidence of MAP infection, the changes in herd management needed to conduct these control strategies require significant effort on the part of the dairy producer. On the other hand, vaccination is relatively simple to apply and requires minor changes in herd management. Despite these advantages, only 5% of US dairy operations use vaccination to control MAP. This low level of adoption of this technology is due to limited information on its cost-effectiveness and efficacy and some important inherent drawbacks associated with current MAP vaccines. This study investigates the epidemiological effect and economic values of MAP vaccines in various stages of development. We create scenarios for the potential epidemiological effects of MAP vaccines, and then estimate economically justifiable monetary values at which vaccines become economically beneficial to dairy producers such that a net present value (NPV) of a farm's net cash flow can be higher than the NPV of a farm using no control or alternative nonvaccine controls. Any vaccination with either low or high efficacy considered in this study yielded a higher NPV compared with a no MAP control. Moreover, high-efficacy vaccines generated an even higher NPV compared with alternative controls, making vaccination economically attractive. Two high-efficacy vaccines were particularly effective in MAP control and NPV
McAloon, Conor G; Doherty, Michael L; Whyte, Paul; O'Grady, Luke; More, Simon J; Messam, Locksley L McV; Good, Margaret; Mullowney, Peter; Strain, Sam; Green, Martin J
Bovine paratuberculosis is a disease characterised by chronic granulomatous enteritis which manifests clinically as a protein-losing enteropathy causing diarrhoea, hypoproteinaemia, emaciation and, eventually death. Some evidence exists to suggest a possible zoonotic link and a national voluntary Johne's Disease Control Programme was initiated by Animal Health Ireland in 2013. The objective of this study was to estimate herd-level true prevalence (HTP) and animal-level true prevalence (ATP) of paratuberculosis in Irish herds enrolled in the national voluntary JD control programme during 2013-14. Two datasets were used in this study. The first dataset had been collected in Ireland during 2005 (5822 animals from 119 herds), and was used to construct model priors. Model priors were updated with a primary (2013-14) dataset which included test records from 99,101 animals in 1039 dairy herds and was generated as part of the national voluntary JD control programme. The posterior estimate of HTP from the final Bayesian model was 0.23-0.34 with a 95% probability. Across all herds, the median ATP was found to be 0.032 (0.009, 0.145). This study represents the first use of Bayesian methodology to estimate the prevalence of paratuberculosis in Irish dairy herds. The HTP estimate was higher than previous Irish estimates but still lower than estimates from other major dairy producing countries.
Nielsen, Liza Rosenbaum; Dohoo, Ian
-quarters (YQs), either at the start of the study period or after recovery from infection. Survival analysis was performed on a dataset including 6931 dairy herds with 118969 YQs at risk, in which 1523 failures (new infection events) occurred. Predictors obtained from register data were tested in a multivariable......A national surveillance programme for Salmonella Dublin, based on regular bulk-tank milk antibody screening and movements of cattle, was initiated in Denmark in 2002. From 2002 to end of 2009 the prevalence of test-positive dairy herds was reduced from 26% to 10%. However, new infections and spread...
Ettema, Jehan F.; Østergaard, Søren; Sørensen, Morten Kargo
The objective of this study was to explore the importance of including genetic progress in milk yield when evaluating different reproductive strategies in a dairy herd by simulation modeling. The model used in this study was SimHerd V, a dynamic and mechanistic Monte Carlo simulation model...... effect with regard to postponing first insemination. This study has proven that it is important to include genetic progress in decisions on reproduction strategies in a dairy herd....
Bihrmann, Kristine; Nielsen, Søren Saxmose; Ersbøll, Annette Kjaer
Paratuberculosis is a chronic infection of economic importance to the dairy industry. The infection may be latent for years, which makes diagnostic misclassification a general challenge. The objective of this study was to identify the spatial pattern in infection prevalence, when results were...... adjusted for covariate information and diagnostic misclassification. Furthermore, we compared the estimated spatial pattern with the spatial pattern obtained without adjustment for misclassification. The study included 1242 herds in 2009 and 979 herds in 2013. The within-herd prevalence was modelled using...... results suggested that the estimated range of influence and the overall location of areas with increased prevalence are not very sensitive to diagnostic misclassification....
Nielsen, T D; Green, L E; Kudahl, Anne Margrethe Braad;
The effect of Salmonella on milk production is not well established in cattle. The objective of this study was to investigate whether introduction of Salmonella into dairy cattle herds was associated with reduced milk yield and determine the duration of any such effect. Longitudinal data from 2005...... through 2009 were used, with data from 12 mo before until 18 mo after the estimated date of infection. Twenty-eight case herds were selected based on an increase in the level of Salmonella-specific antibodies in bulk-tank milk from ... was randomly allocated to the control herds. Hierarchical mixed effect models with the outcome test-day yield of energy-corrected milk (ECM)/cow were used to investigate daily milk yield before and after the estimated herd infection date for cows in parities 1, 2, and 3+. Control herds were used to evaluate...
Græsbøll, Kaare; Kirkeby, Carsten Thure; Nielsen, Søren Saxmose
The future value of an individual dairy cow depends greatly on its projected milk yield. In developed countries with developed dairy industry infrastructures, facilities exist to record individual cow production and reproduction outcomes consistently and accurately. Accurate prediction...... of the future value of a dairy cow requires further detailed knowledge of the costs associated with feed, management practices, production systems, and disease. Here, we present a method to predict the future value of the milk production of a dairy cow based on herd recording data only. The method consists...... presented in this paper is that it requires no specific knowledge of disease status or any other information beyond herd recorded milk yields, somatic cell counts, and reproductive status....
Foddai, Alessandro; Boklund, Anette; Stockmarr, Anders
A quantitative risk assessment was carried out to estimate the likelihood of introduc-ing bovine viral diarrhea virus (BVDV) in Danish dairy herds per year and per trimester,respectively. The present study gives important information on the impact of risk mitiga-tion measures and sources of uncer......A quantitative risk assessment was carried out to estimate the likelihood of introduc-ing bovine viral diarrhea virus (BVDV) in Danish dairy herds per year and per trimester,respectively. The present study gives important information on the impact of risk mitiga-tion measures and sources...... of uncertainty due to lack of data. As suggested in the Agreementon the Application of Sanitary and Phytosanitary Measures (SPS Agreement), the OIE Ter-restrial Animal Health Code was followed for a transparent science-based risk assessment.Data from 2010 on imports of live cattle, semen, and embryos, exports...... of live cattle, aswell as use of vaccines were analyzed. Information regarding the application of biosecuritymeasures, by veterinarians and hoof trimmers practicing in Denmark and in other countries,was obtained by contacting several stakeholders, public institutions and experts. Stochas-tic scenario...
Lassen, Brian; Viltrop, Arvo; Järvis, Toivo
Cryptosporidium and Eimeria are intestinal parasites which are sensitive to the surroundings, behaviour and well-being of their host. In the present study, a range of factors related to farm management systems, environment, housing and herd characteristics were investigated with regard to alterations in oocyst excretion in cattle, using a mixed-effects model. Information and samples for three age categories were obtained from 45 Estonian dairy farms, located in 15 counties. Leaving the calf with the mother after birth reduced the risk of shedding higher levels of Cryptosporidium (OR = 0.20) and Eimeria (OR = 0.68) oocysts in all animals. The calves younger than 3 months kept on farms housing at least 150 animals had less risk (OR = 0.39) of producing higher numbers of Cryptosporidium oocysts. A somewhat lower infection level was observed in 3- to 12-month-old animals housed in separate buildings (OR = 0.64). The chance of shedding higher levels of Eimeria doubled (OR = 2.27) in cattle older than a year in case a vacancy period was used before replacing animals in pens and tripled (OR = 2.94) when the relative humidity exceeded 75% in the cowshed. Winter reduced the odds (OR = 0.25) of shedding Eimeria oocysts in the oldest animals compared to the fall season. Simple changes in handling and housing of cattle may produce a positive effect on controlling coccidian infections in Estonian dairy herds.
Hall, J; Wapenaar, W
The objective was to compare farm veterinary surgeons' and dairy farmers' opinions on herd health plans and herd health and production management with the aim of discovering and better understanding the differences. Two comparable questionnaires, one for farm veterinarians and one for dairy farmers, were distributed throughout the UK. While listing the 'major roles' of the veterinarian on the farm, veterinarians considered 'optimising milk production', 'decreasing overall cost' and 'being an independent adviser' as important roles, but these were not seem to be perceived as such by the farmers. In addition, when presenting themselves to clients, veterinarians seemed to favour the 'friend of the farmer' approach; a much smaller proportion of farmers seemed to prefer this approach. The majority of farm respondents (98 of 121; 81 per cent) valued the discussions with their veterinarian, and it was apparent from the relatively small proportion of veterinarians instigating a discussion on farm (33 of 125; 26 per cent) that there is the opportunity for a more proactive approach from veterinarians. The study underlines that 'demonstrating cost-effectiveness' is still a main concern for veterinarians and farmers and identifies areas that can be improved by more training and effective communication.
Full Text Available Abstract Q fever is a worldwide zoonosis caused by the bacterium Coxiella burnetii. The control of this infection in cattle is crucial: infected ruminants can indeed encounter reproductive disorders and represent the most important source of human infection. In the field, vaccination is currently advised in infected herds but the comparative effectiveness of different vaccination protocols has never been explored: the duration of the vaccination programme and the category of animals to be vaccinated have to be determined. Our objective was to compare, by simulation, the effectiveness over 10 years of three different vaccination strategies in a recently infected dairy cattle herd. A stochastic individual-based epidemic model coupled with a model of herd demography was developed to simulate three temporal outputs (shedder prevalence, environmental bacterial load and number of abortions and to calculate the extinction rate of the infection. For all strategies, the temporal outputs were predicted to strongly decrease with time at least in the first years of vaccination. However, vaccinating only three years was predicted inadequate to stabilize these dynamic outputs at a low level. Vaccination of both cows and heifers was predicted as being slightly more effective than vaccinating heifers only. Although the simulated extinction rate of the infection was high for both scenarios, the outputs decreased slower when only heifers were vaccinated. Our findings shed new light on vaccination effectiveness related to Q fever. Moreover, the model can be further modified for simulating and assessing various Q fever control strategies such as environmental and hygienic measures.
Full Text Available A longitudinal study was performed in a Swedish dairy herd where Neospora caninum had been isolated from a stillborn calf. Starting in autumn 1994, blood samples from all female animals in the herd were collected once yearly until 1999. The sera were analysed for presence of IgG1 antibodies to N. caninum by the iscom ELISA, and by an avidity ELISA to establish the timing of infection. In addition, data on reproductive performance were compiled. During the study the percentage of seropositive female animals increased from 63% to 87%. In 1994 a large number of young animals tested seropositive although their dams were seronegative, indicating that a transmission of the parasite other than the vertical had recently occurred. Low avidity values supported this assumption. The annual abortion rate increased from a mean of 2% before the initiation of the study to 9% in 1994–1998. During the same time, as judged by the avidity data, a large proportion of the animals shifted from being recently to being chronically infected. The source of the external infection in the herd could not be identified.
Full Text Available An outbreak of coliform mastitis is described in a dairy herd from the State of Rio de Janeiro, Brazil. During a four-month period 14 fatal cases of Klebsiella pneumoniae-related mastitis were observed in a herd of 104 lactating cows. The symptoms included peracute enterotoxemia in which the cows died 6 to 12 h after the detection of mastitis by CMT. Staphylococcus aureus and Streptococcus agalactiae Streptococcus agalactiae were also isolated although could not be associated with cases of acute fatal mastitis. Milking practices were also evaluated. The milking machine was being used correctly and adequate precautions for hygiene and pre-milking and post-milking teat dipping were used. The organism was sensitive to gentamicin. Therapy for acute toxic mastitis required early action for the treatment of infections, involving corticosteroids and fluid therapy. The use of a Klebsiella vaccine produced from the microorganisms isolated from the herd, associated with hygiene measures, resulted in the control of the outbreak.
Chebel, R C; Demétrio, D G B; Metzger, J
Our objective was to evaluate factors that affected the success of embryo transfer programs in large dairy herds. Non-lactating donor cows produced a larger number of ova/embryos (Pcows. The interaction between season and donor class was correlated with the proportion of ova/embryos classified as fertilized (P=0.03), because lactating donors had fewer fertilized ova in the summer. There was no correlation between 305-day mature equivalent milk yield and response to superstimulation. Although the interval between superstimulation protocols was correlated with the number of ova/embryos (P=0.03), there was no correlation with the number of viable embryos. Pregnancy per embryo transfer (P/ET) in heifer recipients was correlated with embryo quality grade (Pcows tended to have a lower rate of P/ET during the summer (P=0.12 to P=0.08). Synchronization protocols tended to be (P=0.06; Herd 1) or were (P=0.02; Herd 2) correlated with P/ET. Lactating cows receiving vitrified IVF embryos had a lower (P=0.01) P/ET than those receiving fresh IVF embryos, especially in the summer (P=0.09). Milk yield was not correlated with P/ET. The use of heat abatement systems is critical to improve embryo production and P/ET. Synchronization protocols that optimized synchrony of ovulation may increase fertility of recipient cows and eliminate the need for estrous detection.
Król, Jarosław; Twardoń, Jan; Mrowiec, Jacek; Podkowik, Magdalena; Dejneka, Grzegorz; Dębski, Bogdan; Nowicki, Tadeusz; Zalewski, Wojciech
Bovine mastitis caused by Streptococcus canis is relatively rare. Consequently, many epidemiologic aspects of the infection, including factors that mediate crossing of host species barriers by the pathogen, infectiousness of the microorganism to the mammary gland, and the course of the disease within a herd, are still not elucidated. Therefore, the aim of the present study was to describe results of a 15-mo observation of subclinical Strep. canis mastitis on a dairy farm housing 76 lactating Holstein-Friesian cows. Upon 3 visits to the farm during a period between April 2013 and June 2014, Strep. canis was cultured from milk samples of 17 (22.4% of the herd), 7 (9.6%), and 8 (11.3%) cows, respectively. The isolates obtained were characterized phenotypically by means of the API Strep identification kit (bioMérieux, Marcy l'Etoile, France), as well as genetically by using random amplified polymorphic DNA and macrorestriction analysis of the chromosomal DNA by pulsed-field gel electrophoresis. All strains displayed the same biochemical features, and the molecular methods revealed that the isolates belonged to a single clone or were very closely related. Results of the study indicate that Strep. canis is capable of causing intramammary infections of long duration, behaving in a contagious manner. Because a persistently infected cow may serve as the source of Strep. canis infection for other animals, effective control of this type of udder infection within a herd may require similar measures to those adopted in Streptococcus agalactiae eradication programs.
Full Text Available Abstract Background Body condition score and blood profiles have been used to monitor management and herd health in dairy cows. The aim of this study was to examine BCS and extended metabolic profiles, reflecting both energy metabolism and liver status around calving in high-producing herds with a high incidence of abomasal displacement and ketosis and to evaluate if such profiles can be used at herd level to pinpoint specific herd problems. Methods Body condition score and metabolic profiles around calving in five high-producing herds with high incidences of abomasal displacement and ketosis were assessed using linear mixed models (94 cows, 326 examinations. Cows were examined and blood sampled every three weeks from four weeks ante partum (ap to nine weeks postpartum (pp. Blood parameters studied were glucose, fructosamine, non-esterified fatty acids (NEFA, insulin, β-hydroxybutyrate, aspartate aminotransferase, glutamate dehydrogenase, haptoglobin and cholesterol. Results All herds had overconditioned dry cows that lost body condition substantially the first 4–6 weeks pp. Two herds had elevated levels of NEFA ap and three herds had elevated levels pp. One herd had low levels of insulin ap and low levels of cholesterol pp. Haptoglobin was detected pp in all herds and its usefulness is discussed. Conclusion NEFA was the parameter that most closely reflected the body condition losses while these losses were not seen in glucose and fructosamine levels. Insulin and cholesterol were potentially useful in herd profiles but need further investigation. Increased glutamate dehydrogenase suggested liver cell damage in all herds.
Wall, E; Coffey, M P; Pollott, G E
Many governments have signed up to greenhouse gas emission (GHGE) reduction programmes under their national climate change obligations. Recently, it has been suggested that the use of extended lactations in dairy herds could result in reduced GHGE. Dairy GHGE were modelled on a national basis and the model was used to compare emissions from lactations of three different lengths (305, 370 and 440 days), and a current 'base' scenario on the basis of maintaining current milk production levels. In addition to comparing GHGE from the average 'National Herd' under these scenarios, results were used to investigate how accounting for lactations of different lengths might alter the estimation of emissions calculated from the National Inventory methodology currently recommended by Intergovernmental Panel on Climate Change. Data for the three lactation length scenarios were derived from nationally recorded dairy performance information and used in the GHGE model. Long lactations required fewer milking cows and replacements to maintain current milk yield levels than short ones, but GHGEs were found to rise from 1214 t of CO2 equivalent (CE)/farm per year for lactations of 305 days to 1371 t CE/farm per year for 440-day lactations. This apparent anomaly can be explained by the less efficient milk production (kg milk produced per kg cow weight) found in later lactation, a more pronounced effect in longer lactations. The sensitivity of the model to changes in replacement rate, persistency and level of milk yield was investigated. Changes in the replacement rate from 25% to 20% and in persistency by −10% to +20% resulted in very small changes in GHGE. Differences in GHGE due to the level of milk yield were much more dramatic with animals in the top 10% for yield, producing about 25% less GHGE/year than the average animal. National Inventory results were investigated using a more realistic spread of lactation lengths than recommended for such calculations using emissions
Bontje, D M; Backer, J A; Hogerwerf, L; Roest, H I J; van Roermund, H J W
Between 2006 and 2009 the largest human Q fever epidemic ever described occurred in the Netherlands. The source of infection was traced back to dairy goat herds with abortion problems due to Q fever. The first aim of control measures taken in these herds was the reduction of human exposure. To analyze Q fever dynamics in goat herds and to study the effect of control measures, a within-herd model of Coxiella burnetii transmission in dairy goat herds was developed. With this individual-based stochastic model we evaluated six control strategies and three herd management styles and studied which strategy leads to a lower Q fever prevalence and/or to disease extinction in a goat herd. Parameter values were based on literature and on experimental work. The model could not be validated with independent data. The results of the epidemiological model were: (1) Vaccination is effective in quickly reducing the prevalence in a dairy goat herd. (2) When taking into account the average time to extinction of the infection and the infection pressure in a goat herd, the most effective control strategy is preventive yearly vaccination, followed by the reactive strategies to vaccinate after an abortion storm or after testing BTM (bulk tank milk) positive. (3) As C. burnetii in dried dust may affect public health, an alternative ranking method is based on the cumulative amount of C. burnetii emitted into the environment (from disease introduction until extinction). Using this criterion, the same control strategies are effective as when based on time to extinction and infection pressure (see 2). (4) As the bulk of pathogen excretion occurs during partus and abortion, culling of pregnant animals during an abortion storm leads to a fast reduction of the amount of C. burnetii emitted into the environment. However, emission is not entirely prevented and Q fever will not be eradicated in the herd by this measure. (5) A search & destroy (i.e. test and cull) method by PCR of individual milk
Mweu, Marshal M.; Nielsen, Søren S.; Hisham Beshara Halasa, Tariq
surveillance scheme as well as live cattle movements into dairy herds during the specified 10-year period. The results indicated that the predicted risk of a herd becoming infected with S. agalactiae varied spatiotemporally; the risk being more homogeneous and higher in the period after 2005. Additionally...... clustering of cases relative to the population of herds at risk nor spatial dependency between herds. Nevertheless, the results signal a need to beef up within-herd biosecurity in order to reduce the risk of new herd infections....
van Dorp, R T; Martin, S W; Shoukri, M M; Noordhuizen, J P; Dekkers, J C
Data recorded in a herd health management system were obtained from 32 registered Holstein dairy herds from British Columbia. Frequencies of disease were described, and the effect of herd, age, year, season, and the interrelationships between diseases within a lactation on the occurrence of disease were evaluated. Lactational incidence rates were computed for diseases with a short period of risk (ie, udder edema, milk fever, retained placenta, metritis, displaced abomasum, and ketosis), whereas for diseases with a longer period of risk (ie, cystic ovaries, mastitis and stable footrot), incidence densities were calculated. Overall, the disease incidence was low and showed an increase in frequency by year, which we attributed to more observing and complete recording by the owner, rather than an actual increase in disease incidence. Most diseases occurred early in lactation and their frequency increased with lactation number; the exception was udder edema, which occurred mainly during the first 2 lactations. An informal path model of disease interrelationships was made conditional on herd. Based on the results we inferred 2 independent pathways: one started by udder edema, and the other by milk fever. Udder edema was directly associated with mastitis occurrence from 0 to 30 d in lactation, metritis, and cystic ovaries. Mastitis from 0-30 d in lactation increased the risk of both mastitis from 31-150 d in lactation and cystic ovaries. Both of these increased the risk of late lactation mastitis. Milk fever was directly related with displaced abomasum, which increased the risk of footrot. In general, diseases that occurred in early lactation tended to increase the risk of other diseases later in lactation.
Lassen, Brian; Ostergaard, Søren
In this study, a stochastic predictive model stimulating a constant infection pressure of Eimeria was used to estimate production outcome, economic, and effects of treatment decisions in a dairy herd of 100 cows. The intestinal parasite cause problems mainly in calves, and is known to have long term effects on the growth rate, and in severe cases can result in mortalities. Due to the inconspicuous nature of the parasite, the clinical signs and sub-clinical manifestations it may produce can be overlooked. Acquired data from literature and Estonian dairy farms were implemented in the SimHerd IV model to simulate three scenarios of symptomatic treatment: no calves treated (NT), default estimate of the current treatment strategy (DT), and all calves treated (AT). Effects of metaphylactic treatment were studied as a lowering of the infection pressure. Delay in the age for beginning of insemination of heifers was the effect with the largest economic impact on the gross margin, followed by calf mortality and reduction in growth rate. Large expenses were associated with the introduction of replacement heifers and feeding of heifers as a result of the delay in reaching a specific body weight at calving. Compared to the control scenarios, with no effects and treatments of Eimeria, dairy farmers were estimated to incur annual losses ranging 8-9% in the balanced income. Providing metaphylactic drugs resulted in an increased gross margin of 6-7%. Purchase of new heifers compensated for some production losses that would otherwise have enhanced expenses related to Eimeria. The simulation illustrates how effects of Eimeria infections can have long lasting impact on interacting management factors. It was concluded that all three simulated symptomatic treatment regimes provided only small economic benefits if they were applied alone and not in combination with lowering of infection pressure.
Merialdi, Giuseppe; Giacometti, Federica; Bardasi, Lia; Stancampiano, Laura; Taddei, Roberta; Serratore, Patrizia; Serraino, Andrea
Factors affecting the fecal shedding of thermophilic Campylobacter in Italian dairy farms were investigated in a 12-month longitudinal study performed on a dairy farm authorized to sell raw milk in Italy. Fifty animals were randomly selected from 140 adult and young animals, and fecal samples were collected six times at 2-month intervals. At each sampling time, three trough water samples and two trough feed samples also were collected for both adult and young animals. Samples were analyzed with real-time PCR assay and culture examination. Overall, 33 samples (9.7%) were positive for thermophilic Campylobacter by real-time PCR: 26 (9.2%) of 280 fecal samples, 6 (16.6%) of 36 water samples, and 1 (4.2%) of 24 feed samples. Campylobacter jejuni was isolated from 6 of 280 samples; no other Campylobacter species was isolated. A higher (but not significantly) number of positive fecal samples were found in younger animals (11.33 versus 6.92% of adult animals), and a significantly higher number of positive water samples were collected from the water troughs of young animals. A distinct temporal trend was observed during the study period for both cows and calves, with two prevalence peaks between November and December and between May and July. Several factors such as calving, housing practices, herd size, management practices forcing together a higher number of animals, and variations in feed or water sources (previously reported as a cause of temporal variation in different farming conditions) were excluded as the cause of the two seasonal peaks in this study. The factors affecting the seasonality of Campylobacter shedding in the dairy herds remain unclear and warrant further investigation. The results of the present study indicate that special attention should be paid to farm hygiene management on farms authorized to produce and sell raw milk, with increased surveillance by the authorities at certain times of the year.
Derks, Marjolein; Hogeveen, Henk; Kooistra, Sake R; van Werven, Tine; Tauer, Loren W
This paper compares farm efficiencies between dairies who were participating in a veterinary herd health management (VHHM) program with dairies not participating in such a program, to determine whether participation has an association with farm efficiency. In 2011, 572 dairy farmers received a questionnaire concerning the participation and execution of a VHHM program on their farms. Data from the questionnaire were combined with farm accountancy data from 2008 through 2012 from farms that used calendar year accounting periods, and were analyzed using Stochastic Frontier Analysis (SFA). Two separate models were specified: model 1 was the basic stochastic frontier model (output: total revenue; input: feed costs, land costs, cattle costs, non-operational costs), without explanatory variables embedded into the efficiency component of the error term. Model 2 was an expansion of model 1 which included explanatory variables (number of FTE; total kg milk delivered; price of concentrate; milk per hectare; cows per FTE; nutritional yield per hectare) inserted into the efficiency component of the joint error term. Both models were estimated with the financial parameters expressed per 100 kg fat and protein corrected milk and per cow. Land costs, cattle costs, feed costs and non-operational costs were statistically significant and positive in all models (P<0.01). Frequency distributions of the efficiency scores for the VHHM dairies and the non-VHHM dairies were plotted in a kernel density plot, and differences were tested using the Kolmogorov-Smirnov two-sample test. VHHM dairies had higher total revenue per cow, but not per 100 kg milk. For all SFA models, the difference in distribution was not statistically different between VHHM dairies and non-VHHM dairies (P values 0.94, 0.35, 0.95 and 0.89 for the basic and complete model per 100 kg fat and protein corrected milk and per cow respectively). Therefore we conclude that with our data farm participation in VHHM is not related
Otten, N D; Toft, N; Houe, H; Thomsen, P T; Sørensen, J T
The elimination of misclassification bias introduced by multiple observers was evaluated and discussed based on an illustrative example using lameness prevalence in 80 Danish dairy herds. Data from 5073 cows from loose-housed cubicle herds larger than 100 cows were included in the analysis. Four trained observers performed clinical scoring on cow level and undertook a calibration test with 39 video sequences. The calibration test served both the purpose of estimating inter-observer agreement (PABAK=0.69) in accordance with previous results and to estimate the sensitivity (Se) and specificity (Sp) for each observer. In the absence of a gold standard for the clinical observations, a latent class analysis (LCA) evaluating the true within-herd lameness prevalence was used. Sensitivity amongst observers was fairly low (0.24-0.81) inducing a general underestimation of the true prevalence. Comparative analyses were made to assess the effect of grazing on the lameness prevalence in order to demonstrate the consequences of using unadjusted apparent prevalences (AP) compared to the true prevalences (TP). Lameness prevalence was higher in grazing herds using AP estimates (19.0% zero-grazing, 20.2% grazing); while the TP estimates showed the expected higher lameness prevalence in zero-grazing herds (42.3% vs. 35.9%). Hence, this study emphasizes the importance of adjusting for observer Se and Sp to obtain true prevalence and avoid false interpretation.
Gädicke, P; Vidal, R; Monti, G
Bovine abortion is a limiting factor for dairy business, as it decreases milk production and the potential, number of herd replacements, increases feeding and medical treatment costs, increases the number of artificial inseminations to obtain a calf as well as culling rates of cows. An estimation of the economic impact of abortion in dairy farms in Chile is not available yet. The aim of this study was to estimate the economic consequences of bovine abortion syndrome (BAS) in dairy cows from Chile. A stochastic model was proposed to evaluate the cost of an abortion on a yearly basis to include variability in cost and income by dairy and by year. The marginal total net revenue (ΔTNR) for a typical, lactation was obtained by the calculating the difference between total revenues (retail milk and calf sales) and total expenses (production cost (cows, feeding, labor, health) plus administrative and, general costs) for lactation with and without abortion. Production data were obtained from a retrospective study of 127 dairy herds located in southern Chile between 2000 and 2006. Milk production from cows with and without abortion was estimated by a mixed model using milk test day data. Production cost and prices paid to farmers were obtained from service company records (TODOAGRO S.A.). Cost and income value was corrected for inflation and expressed in the values from 2006. In addition, a separate analysis for different parities (1, 2, 3 or more) was performed. Distributions for the stochastic variables were obtained by fitting distributions from our database using @Risk. The stochastic variables included in the analysis were all related to income, feeding, depreciation, health, Artificial Insemination and general costs like fuel, salaries, taxes, etc. There was a high probability (89.20%) of a negative ΔTNR in lactations with abortion for overall, parities, with a mean loss of $ -143.32. Stratifying by parity, the predicted mean of the distribution for ΔTNR in each
Rola, J G; Larska, M; Grzeszuk, M; Rola, J
Bovine herpesvirus 1 (BoHV1) is one of the most important pathogens of cattle; however, its effect on somatic cell count and milk components is not completely understood. The aim of the current study was to examine the effect of BoHV1 infection on quality of bovine bulk tank milk (BTM). A total of 1,790 individual blood samples collected at 28 dairy farms were used to determine the BoHV1 infection status of the herds with ELISA tests. The quality parameters of milk were evaluated by instrumental methods with BTM samples collected at monthly intervals from May 2011 to May 2012. The statistical analysis was performed to study the associations between BoHV1 herd status, quality of BTM, and herd-specific parameters. The risk factors influencing bulk milk somatic cell count (BMSCC) were estimated using the multivariable mixed-effects maximum likelihood regression model. The true prevalences of BoHV1 infection at the animal and herd levels were 49.3 and 64.6%, respectively. The average BMSCC differed significantly between the herds grouped accordingly to their BoHV1 infection status. Interestingly, the highest BMSCC was observed in the vaccinated herds (240.3×10(3) cells/mL). Additionally, the BoHV1 herd status had a significant effect on the fat content of BTM. The largest herds that were investigated had a BoHV1 seroprevalence over 30%. The herd status was considerably influenced by the numbers of cows in the herds. Besides, no significant differences in total bacterial count or protein content in milk from BoHV1-infected und uninfected herds were observed. An increase in BMSCC was observed during summer compared with the winter months regardless of the BoHV1 status of the herds. In the final multivariable regression model, the main risk factors associated with BMSCC were BoHV1 herd status, the percentage of BoHV1 infected animals in a herd, the number of cows in a herd, and the season. Our study suggests that BoHV1 infection may influence BMSCC levels, which are key
Foddai, Alessandro; Stockmarr, Anders; Boklund, Anette
The temporal sensitivity of the surveillance system (TemSSe) for Bovine Viral Diarrhea (BVD) in Danish dairy herds was evaluated. Currently, the Danish antibody blocking ELISA is used to test quarterly bulk tank milk (BTM). To optimize the surveillance system as an early warning system, we...
Brouwer, H; Stegeman, J A; Straatsma, J W; Hooijer, G A; Schaik, G van
Dairy cattle health is often assessed during farm visits. However, farm visits are time consuming and cattle health is assessed at only one point in time. Moreover, farm visits are poorly comparable and/or repeatable when inspection is carried out by many different professionals. Many countries register cattle health parameters such as bulk milk somatic cell count (BMSCC) and mortality in central databases. A great advantage of such routinely available data is that they are uniformly gathered and registered throughout time. This makes comparison between dairy cattle herds possible and could result in opportunities to develop reliable tools for assessing cattle health based on routinely available data. In 2005, a monitoring system for the assessment of cattle health in Dutch dairy herds based on routinely available data was developed. This system had to serve as an alternative for the compulsory quarterly farm visits, which were implemented in 2002. However, before implementation of the alternative system for dairy cows, the validity of the data-based monitoring system and the compulsory quarterly visits relative to the real health status of the herd should be known. The aim of this study was to assess the validity of the data-based monitoring system and the compulsory quarterly visits relative to a standardized herd check for detecting dairy herds with health problems. The results showed that routinely available data can be used to develop an effective screening instrument for detecting herds with poor cattle health. Routinely available data such as cattle mortality and BMSCC that were used in this study had a significant association with animal-based measurements such as the general health impression of the dairy cows (including e.g. rumen fill and body condition). Our study supports the view that cattle health parameters based on routinely available data can serve as a tool for detecting herds with a poor cattle health status which can reduce the number of
Diego B. Nóbrega
Full Text Available The objectives of this study were to isolate Klebsiella pneumoniae from different sources in three dairy cattle herds, to use the pulsed-field gel electrophoresis (PFGE to measure genotypic similarities between isolates within a dairy herd, to verify the production of extended-spectrum β-lactamases (ESBLs by the double-disk synergy test (DDST, and to use the PCR to detect the main ESBLs subgroups genes. Three dairy farms were selected based on previous mastitis outbreaks caused by K. pneumoniae. Milk samples were collected from lactating cows and from the bulk tank. Swabs were performed in different locations, including milking parlors, waiting room, soil, animal's hind limbs and rectum. K. pneumoniae was isolated from 27 cases of intramammary infections (IMI and from 41 swabs. For farm A isolates from IMI and bulk tank were considered of the same PGFE subtype. One isolate from a bulk tank, three from IMI cases and four from environmental samples were positive in the DDST test. All eight DDST positive isolates harbored the bla shv gene, one harbored the bla tem gene, and three harbored the bla ctx-m gene, including the bulk tank isolate. Our study confirms that ESBL producing bacteria is present in different locations in dairy farms, and may be responsible for IMI. The detection of ESBLs on dairy herds could be a major concern for both public and animal health.
Kudahl, A B; Nielsen, S S; Ostergaard, S
based on a milk yield criterion the most profitable culling strategy for a longer period (11 to 13 yr). A 20% reduction in heifer price made immediate culling after a positive test the most profitable strategy overall in herds with typical reproduction, and after 9 yr in herd with poor reproduction. To conclude, the ideal culling strategy depends on the aim of intervention, the time horizon, and the reproductive capabilities combined with prices of replacement animals. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Sørensen, Morten Kargo; Andersen, Jakob Voergaard; Pedersen, Louise Dybdahl
with 100 cows each. Each year 50 young bulls (YB), 10 active sires and 215 BD were selected on best linear unbiased prediction estimated breeding values by truncation selection across the simulated population, and the YB were tested within the population. Use of sexed semen alone gave a positive increase......Using stochastic simulation, the effect of using sexed semen to cow dams (CD) in a dairy cattle breeding scheme, with or without use of multiple ovulation and embryo transfer (MOET) to bull dams (BD), on annual genetic gain at the population level was examined. Three levels of sexed semen were...... combined with three levels of MOET: no sexed semen, sexed semen to the best CD and sexed semen to all heifers, combined with no MOET, MOET on all BD and MOET randomly on 20% of the BD. In total, nine scenarios were compared. The simulated population was monitored for 30 years and included 450 herds...
Full Text Available Abstract Since 1994, Irish cattle have been exposed to greater risks of acquiring Mycobacterium avium subspecies paratuberculosis (MAP infection as a consequence of the importation of over 70,000 animals from continental Europe. In recent years, there has been an increase in the number of reported clinical cases of paratuberculosis in Ireland. This study examines the prevalence of factors that promote the introduction and within-herd transmission of Mycobacterium avium subspecies paratuberculosis (MAP on selected Irish dairy farms in the Cork region, and the association between these factors and the results of MAP screening tests on milk sock filter residue (MFR. A total of 59 dairy farms, selected using non-random methods but apparently free of endemic paratuberculosis, were enrolled into the study. A questionnaire was used to collect data about risk factors for MAP introduction and transmission. The MFR was assessed on six occasions over 24 months for the presence of MAP, using culture and immunomagnetic separation prior to polymerase chain reaction (IMS-PCR. Furthermore, blood samples from all entire male and female animals over one year of age in 20 herds were tested by ELISA. Eighteen (31% farms had operated as closed herds since 1994, 28 (47% had purchased from multiple sources and 14 (24% had either direct or indirect (progeny contact with imported animals. Milk and colostrum were mixed on 51% of farms, while 88% of farms fed pooled milk. Thirty (51% herds tested negative to MFR culture and IMS-PCR, 12 (20% were MFR culture positive, 26 (44% were IMS-PCR positive and seven (12% were both culture and IMS-PCR positive. The probability of a positive MFR culture was significantly associated with reduced attendance at calving, and with increased use of individual calf pens and increased (but not significantly if mulitiple suckling was practised. There was poor agreement between MFR culture and MFR IMS-PCR results, but moderate agreement
Full Text Available The prevalence of bovine viral diarrhoea (BVD serologically positive animals in 18 dairy herds with clinical and pathological lesions suggestive of BVD infection, the post-vaccinal seroconversion rates in negative animals vaccinated twice with an inactivated BVD vaccine, and the control measures taken, are described. The pathological and histopathological findings in 6 necropsies performed on animals that died in 5 separate herds closely resembled published descriptions. Positive immunohistochemistry results in 3 cases confirmed the diagnosis in those animals. In 1 herd the prevalence of prevaccinal BVDantibodies was only 36.8 %, while the prevalence varied from 79.85 to 100 % in the remainder. Control measures taken included immunoprophylaxis with an inactivated vaccine, culling animals that were serologically negative after vaccination that were regarded as probably persistently infected (PI and the implementation of additional biosecurity measures. The prevalence of serologically negative PI animals in 10 herds varied from 0.38 to 4.04 %, with 8 herds less than 1 %and 2 herds at 2.79 %and 4.04 %, respectively. Methods based on vaccinating the herd, followed by serological testing and culling cattle that did not develop an antibody titre, are not reliable. The identification of PI animals should be confirmed by isolation of the virus or identification of the antigen.
O' Doherty, E; Sayers, R; O' Grady, L; Shalloo, L
The objective of the current study was to quantify the effects of exposure to Salmonella, Neospora caninum, and Leptospira interrogans serovar Hardjo (L. hardjo) on dairy farm profitability and to simulate the effect of vaccination for Salmonella and L. hardjo on dairy farm profitability. The production effects associated with exposure to each of these pathogens in study herds were defined under 3 categories: (1) milk production effects, (2) reproduction effects (including culling), and (3) mortality effects. The production effects associated with exposure to Salmonella, N. caninum, and L. hardjo were incorporated into the Moorepark Dairy Systems Model. In the analysis, herds negative for exposure to Salmonella, N. caninum, and L. hardjo were assumed baseline herds, with all results presented relative to this base. In simulations examining the effect of vaccination for Salmonella and L. hardjo on farm profitability, vaccinated herds (vaccination costs included) were considered as baseline herds and results were presented relative to this base. Total annual profits in unvaccinated herds were reduced by €77.31, €94.71, and €112.11 per cow at milk prices of €0.24, €0.29, and €0.34/L, respectively, as a result of exposure to Salmonella. In the current study, herds positive for exposure to Salmonella recorded a 316-kg reduction in milk yield, whereas no association was detected between exposure to N. caninum or L. hardjo and milk production. Exposure to both N. caninum and L. hardjo was associated with compromised reproductive performance. Herds positive for exposure to N. caninum and Salmonella had greater rates of adult cow mortality and calf mortality, respectively. Vaccination for both Salmonella and L. hardjo was associated with improved performance in study herds. Exposure to N. caninum resulted in a reduction in annual farm profits of €11.55, €12, and €12.44 per cow at each milk price, whereas exposure to L. hardjo resulted in a reduction in
Smith, R F; Oultram, J; Dobson, H
Fertility performance is intrinsically linked to the quality of the animal environment, overall management and nutrition. This review describes the use of dairy herd records, metabolic profiles and ultrasonographic findings at veterinary fertility examinations to monitor and manage dairy herd fertility. After calving, a cow has to overcome a series of physiological hurdles before establishing a pregnancy. The selection of timely key performance indicators (KPIs) that monitor specific events in the postpartum and service periods is vital to correctly identify problems and their potential causes that hopefully can be rectified. Cumulative sum charts are the timeliest monitors of efficiency of detection of oestrus, insemination outcome and relationship between postpartum events and fertility, with the point of inflection indicating when a change took place. Other KPIs use data from specific cohorts, adding an inherent delay to when change is indicated. Metabolic profiles and milk constituent data allow monitoring of nutritional adequacy and developments to offer new possibilities of on-farm systems for regular measurements of milk constituents (including progesterone) and energy status. Examination of the reproductive tract can be used to indicate individual and herd fertility status but the currently available detail is under used. Recent advances in ultrasonography can improve the diagnosis of reproductive tract pathophysiology still further but the clinical use of these methods in veterinary practice needs further evaluation. Development of new KPIs to exploit research findings are needed to ensure this knowledge is used to improve on-farm performance.
Bennema, Sita C; Vercruysse, Jozef; Morgan, Eric; Stafford, Kathryn; Höglund, Johan; Demeler, Janina; von Samson-Himmelstjerna, Georg; Charlier, Johannes
In this survey, the epidemiology of gastrointestinal (GI) nematodes in dairy herds in five northwestern European countries was studied using a standardized Ostertagia ostertagi ELISA applied on bulk-tank milk, and a common questionnaire. The levels of exposure to GI nematodes were high in Belgium, the UK and Ireland, intermediate in Germany and low in Sweden, with a mean (95% confidence interval) ELISA result (ODR) of 0.83 (0.82-0.84) in Belgium, 0.82 (0.79-0.84) in the UK and 0.80 (0.78-0.83) in Ireland; significantly higher than the mean ODR of 0.66 (0.65-0.68) in Germany and 0.52 (0.51-0.53) in Sweden. Taking into account previous literature, these regional differences are likely to be systematic. Regional variations in exposure were significantly explained by differences in management (grazing time per day, mowing, the months of turnout, housing and anthelmintic treatment). However, after controlling for these factors, significant regional differences in levels of exposure remained, suggesting an importance for climate (temperature, rainfall) and unmeasured management factors. This study emphasizes that GI nematode-induced production losses should be considered on a large percentage of northwest European dairy herds. Proposals are made for the development of region-specific monitoring and control strategies. Further advances in this area are likely to come from intervention studies that investigate the feasibility of control measures and from studies on the potential effects of climatic conditions on shifts in levels of exposure between years and regions.
Nolan, L K; Giddings, C W; Boland, E W; Steffen, D J; Brown, J; Misek, A
Nasal secretions, faecal samples and buffy coats were obtained from 102 cattle from a North Dakota dairy herd with a history of calf scours. Treated buffy coats, faecal samples and nasal secretions were inoculated into tetrathionate broth (TB), incubated at 37 degrees C overnight, and plated onto brilliant green agar medium with novobiocin (BGAN). The TB was left at room temperature for 5 days and then used to inoculate fresh TB. The fresh TB was incubated at 37 degrees C over night and plated onto BGAN medium. All the plates were incubated at 37 degrees C over night and observed for Salmonella-like growth. Suspect colonies were further tested and Salmonella isolates were serotyped by the National Veterinary Services laboratory. Twenty-two of the 36 calves sampled harboured S. typhimurium in their faeces, but no samples from cows were positive. No Salmonella were isolated from the buffy coats, but 4 calves were shown to have Salmonella in their nasal secretions. Extended enrichment of the faecal cultures in TB resulted in a significant increase in Salmonella isolations, although 2 samples were positive following the initial enrichment period and not after secondary enrichment. The typical Salmonella isolate detected from this herd contained a transmissible R-plasmid encoding resistance to tetracycline, kanamycin, sulphisoxazole and ampicillin. This study confirmed that delayed secondary enrichment in TB is superior to primary enrichment for detection of Salmonella from cattle.
Monti, G E; Frankena, K; De Jong, M C M
The purpose of this study was to describe patterns of seroconversion to bovine leukaemia virus and to estimate the main parameters needed for future model building. A longitudinal study was carried out between February 1999 and November 2001 in seven commercial dairy farms in Argentina using 1535 lactating cows. Time-interval parameters were analysed using a parametric survival model with shared frailty, time until infection was analysed using a Bayesian interval-censoring survival model and the infection transmission parameter (beta) was estimated by a generalized linear model. The reproduction ratio (R0) was calculated. In total, 1000 cows tested positive and 494 tested negative. The predicted median age at infection was 4.6 years for seroconverted cows. For infected herds, the proportion of positive calves was as high as for infected cows and showed a large proportion of infected breeding heifers. Peaks in the overall average incidence per season-year were observed during autumn and spring. Results reveal that the period around parturition is a high-risk period. Moreover, heavily infected herds seem to have an increased proportion of young stock infected. The overall beta was estimated as 2.9/year (95% CI 1.9-3.7) and combined with a relatively long infectious period it resulted in a high reproductive ratio (R0=8.9). Therefore, a high effectiveness of control measures needs to be achieved to eradicate the disease.
Clovis Laurindo Silva
Full Text Available Neospora caninum is a coccidian protozoan that affects cattle worldwide causing economic losses. To survey the frequency of anti-N. caninum antibodies in dairy herds in the municipality of Parauapebas, Southeast of Pará, samples of 465 sera from 45 farms were subjected to indirect immunofluorescence assay (cutoff 1:100. Anti-N. caninum antibodies were found with a frequency of 13,33% with the following titer distribution: 27 (43,55% for titer 100; 14 (22,58% for 200; 16 (25,80% for 400, and 5 (8,07% for 800; no serum titers more than 800 was noted, but at least one positive animal was present in most farms. The highest frequency occurred among females, with no significant difference in frequency between the sexes (Fisher exact test = 0,59, P = 0,99; 2-year-old animals had the highest frequency, although their numbers were lesser than those aged >5 years, with no significant difference in frequency between the age groups (?2 = 2,1, P = 0,71. No significant difference was observed between the frequency and occurrence of abortion (?2 = 2,3, P = 0,13 and frequency and presence of dogs in the farms (?2 = 0,26, P = 0,60. Actions toward health monitoring are recommended to prevent the entry of new sources of N. caninum and to control its spread within herds.
Escamilla, H Patricia; Martínez, M José Juan; Medina, C Mario; Morales, S Elizabeth
The objective of this study was to determine the frequency of infectious bovine abortion and to identify some of its causes, specifically brucellosis, leptospirosis, bovine viral diarrhea, infectious bovine rhinotracheitis, and neosporosis. The study was carried out in a dairy herd in the state of Queretaro, Mexico, between September 2002 and March 2003. At the beginning of the study, blood samples were taken from a random 33% of the 300 lactating or pregnant cows; antibodies against Leptospira interrogans were the most commonly identified, in 91% of the 99 samples. Blood samples were also taken 14 to 28 d after the 26 subsequent abortions in the herd in the 6-mo study period, as well as from 22 cows that had not aborted within 5 d after the abortions in the other group. Seroconversion was most frequent for L. hardjo, occurring in 8 (67%) of the 12 dams that aborted after the initial serologic sampling and for which paired serum samples were therefore available. Of the 16 collected fetuses, 10 had histologic lesions suggesting infection in various organs, the features correlating with the serologic results for the dams in 7 cases. Thus, the abortions may have been caused by more than 1 infectious agent.
Shock, D A; LeBlanc, S J; Leslie, K E; Hand, K; Godkin, M A; Coe, J B; Kelton, D F
Regionally aggregated bulk milk somatic cell count (BMSCC) data from around the world shows a repeatable cyclicity, with the highest levels experienced during warm, humid seasons. No studies have evaluated this seasonal phenomenon at the herd level. The objectives of this study were to define summer seasonality in BMSCC on an individual herd basis, and subsequently to describe the characteristics and dynamics of herds with increased BMSCC in the summer. The data used for this analysis were from all dairy farms in Ontario, Canada, between January 2000 and December 2011 (n≈4,000 to 6,000 herds/yr). Bulk milk data were obtained from the milk marketing board and consisted of bulk milk production, components (fat, protein, lactose, other solids), and quality (BMSCC, bacterial count, inhibitor presence, freezing point), total milk quota of the farm, and milk quota and incentive fill percentage. A time-series linear mixed model, with random slopes and intercepts, was constructed using sine and cosine terms as predictors to describe seasonality, with herd as a random effect. For each herd, seasonality was described with reference to 1 cosine function of variable amplitude and phase shift. The predicted months of maximal and minimal BMSCC were then calculated. Herds were assigned as low, medium, and high summer increase (LSI, MSI, and HSI, respectively) based on percentiles of amplitude in BMSCC change for each of the 4 seasons. Using these seasonality classifications, 2 transitional repeated measures logistic regression models were built to assess the characteristics of MSI and HSI herds, using LSI herds as controls. Based on the analyses performed, a history of summer BMSCC increases increased the odds of experiencing a subsequent increase. As herd size decreased, the odds of experiencing HSI to MSI in BMSCC increased. Herds with more variability in daily BMSCC were at higher odds of experiencing MSI and HSI in BMSCC, as were herds with lower annual mean BMSCC. Finally
origen.Paratuberculosis in goats is widely distributed throughout the world. Recently the disease has been officially reported in Chile. The purpose of this study was to determine the infection status of some dairy goat herds under two types of management systems (intensive and extensive in different regions of Chile. Faecal samples were collected from 383 female goats > 2 years old belonging to 8 dairy goat herds located in the Metropolitan Region (2, 9th Region (5 and 10th Region (1. Differences in routine management were not considered when selecting the herds. Faecal samples were collected via rectum, decontaminated with hexadecylpyridinium chloride (HPC and antibiotics, cultured on Herrold’s Egg Yolk Medium with mycobactin J, and incubated at 37ºC for up to nine months. The suspected colonies were confirmed by PCR (IS900 technology using specific primers for this pathogen (P90+ and P91+. Thirty five out of the 383 sampled goats were faecal culture positive (9.1%, all of them belonging to only four herds. These infected herds were generally larger, intensively managed, and they systematically violated most management recommendations for paratuberculosis control, including the routine introduction of animals of unknown paratuberculosis tests status from herds of unknown Map infection status. The remaining four uninfected herds were extensively managed, did not import goats from other herds, and were located in geographical areas where no mixed grazing with other susceptible ruminant species took place, this being a possible risk factor for paratuberculosis. This study reports the presence of caprine paratuberculosis in Chile, in particular in those dairy goat herds that have introduced high producing milk breeds of animals to improve the genetic capacity of milk production. Therefore, any attempt to evaluate the risk of introducing the infection in a paratuberculosisfree area as the result of purchasing animals is worthwhile.
Santman-Berends, I M G A; Gonggrijp, M A; Hage, J J; Heuvelink, A E; Velthuis, A; Lam, T J G M; van Schaik, G
Extended-spectrum β-lactamase and AmpC-producing Escherichia coli (ESBL/AmpC) are an emerging problem and are hypothesized to be associated with antimicrobial use (AMU), and more specifically with the use of third- and fourth-generation cephalosporins. Whether ESBL/AmpC also occur in organic dairy herds, which have restricted AMU, is not known. Additionally, it is unknown whether, in addition to restricted AMU, other factors in organic herd management are associated with ESBL/AmpC herd status. The aim of this study was to estimate the prevalence of ESBL/AmpC in organic dairy herds in the Netherlands. Subsequently, the relationships between the ESBL/AmpC herd status and AMU and between ESBL/AmpC herd status and farmers' management were assessed in organic dairy herds. For this study, 90 randomly selected, officially registered organic dairy herds were included. The ESBL/AmpC herd status was determined based on the bacteriological culture result of a slurry sample. The sensitivity of testing slurry samples for ESBL/AmpC herd status is less than 100% for detecting herds with a low ESBL/AmpC prevalence. For that reason, herds that tested positive for ESBL/AmpC in slurry were defined as positive and herds with negative slurry samples were defined as unsuspected. A comprehensive questionnaire on management practices was conducted and records on specified antimicrobials that were provided to these herds by the veterinary service providers were obtained. From the data on antimicrobial supplies by the veterinarian, the animal daily defined dose of antimicrobials per farm per year (DDDAF) was calculated. Descriptive statistics were used to describe the relation between the ESBL/AmpC herd status and DDDAF. Multivariable logistic regression models were used to evaluate management factors associated with the ESBL/AmpC herd status. We found ESBL/AmpC in 12 of the 90 (13%; 95% confidence interval=7-22%) slurry samples from organic dairy herds. The median DDDAF in organic dairy
Duplessis, M; Pellerin, D; Cue, R I; Girard, C L
Only bacteria can synthesize vitamin B12, and this requires adequate Co supply. The natural source of vitamin B12 in human diets comes from animal products, especially those from ruminants. This study aimed to describe variability regarding vitamin B12 concentration in milk among and within commercial dairy herds in early lactation. A secondary objective was to explore potential causes for this variability such as genetic variation and diet characteristics. In total, 399 dairy cows (135 primiparous and 264 multiparous; 386 Holstein and 13 Jersey cows) in 15 commercial herds were involved. Milk samples were taken at 27.4±4.1 and 55.4±4.1d in milk. Neither parity (primiparous vs. multiparous) nor sampling time affected milk concentrations of vitamin B12. Nevertheless, vitamin B12 concentration in milk was highly variable among and within dairy herds. The lowest vitamin B12 concentration in milk of cows was observed in the Jersey herd. Among herds, vitamin B12 concentration in milk ranged from 2,309 to 3,878 pg/mL; one glass (250mL) of milk from those herds would provide between 23 and 40% of the vitamin B12 recommended daily allowance. Among individual cows, however, this provision varied between 16 and 57% of the recommendation. In spite of the limited size of the studied population, the heritability value was 0.23, suggesting that genetic selection could modify milk vitamin B12 concentration. We observed a positive relationship between milk vitamin B12 concentration and dietary acid detergent fiber content and a negative relationship between milk concentration of vitamin B12 and dietary crude protein content.
Barkallah, Mohamed; Slima, Ahlem Ben; Mallek, Zouhir; Gautier, Michel; Greub, Gilbert; Gdoura, Radhouane; Fendri, Imen
Bovine abortion of unknown infectious etiology still remains a major economic problem. Thus, we investigated whether Brucella spp., Listeria monocytogenes, Salmonella spp., Campylobacter spp. and Coxiella burnetii are associated with abortion and/or stillbirth in Tunisian dairy cattle. Using a pan-Chlamydiales PCR, we also investigated the role of Chlamydiaceae, Waddlia chondrophila, Parachlamydia acanthamoebae and other members of the Chlamydiales order in this setting. Veterinary samples taken from mid to late-term abortions from twenty dairy herds were tested. From a total of 150 abortion cases collected, infectious agents were detected by PCR in 73 (48.66%) cases, 13 (8.66%) of which represented co-infections with two infectious agents. Detected pathogens include Brucella spp (31.3%), Chlamydiaceae (4.66%), Waddlia chondrophila (8%), Parachlamydia acanthamoebae (5.33%), Listeria monocytogenes (4.66%) and Salmonella spp. (3.33%). In contrast, Campylobacter spp. and Coxiella burnetii DNA were not detected among the investigated veterinary samples. This demonstrates that different bacterial agents may cause bovine abortion in Tunisia. This is the first report suggesting the role of Parachlamydia acanthamoebae in bovine abortion in Africa. Further studies with a larger number of samples are necessary to confirm whether this emerging pathogen is directly linked to abortion in cattle. PMID:24662769
Sørensen, J.T.; Enevoldsen, Carsten; Houe, H.
A dynamic, stochastic model simulating the technical and economic consequences of bovine virus diarrhoea virus (BVDV) infections for a dairy cattle herd for use on a personal computer was developed. The production and state changes of the herd were simulated by state changes of the individual cows...... variables describing biologic and management variables including 21 decision variables describing the effect of BVDV infection on the production of the individual animal. Two markedly different scenarios were simulated to demonstrate the behaviour of the developed model and the potentials of the applied...
Norman, H D; Miller, R H; Wright, J R; Hutchison, J L; Olson, K M
Frequency of abortions recorded through Dairy Herd Improvement (DHI) testing was summarized for cows with lactations completed from 2001 through 2009. For 8.5 million DHI lactations of cows that had recorded breeding dates and were >151 d pregnant at lactation termination, the frequency of recorded abortions was 1.31%. Effects of year, herd-year, month, and pregnancy stage at lactation termination; parity; breed; milk yield; herd size; geographic region; and state within region associated with DHI-recorded abortion were examined. Abortions recorded through DHI (minimum gestation of 152 d required) were more frequent during early gestation; least squares means (LSM) were 4.38, 3.27, 1.19, and 0.59% for 152 to 175, 176 to 200, 201 to 225, and 226 to 250 d pregnant, respectively. Frequency of DHI-recorded abortions was 1.40% for parity 1 and 1.01% for parity ≥ 8. Abortion frequency was highest from May through August (1.42 to 1.53%) and lowest from October through February (1.09 to 1.21%). Frequency of DHI-recorded abortions was higher for Holsteins (1.32%) than for Jerseys (1.10%) and other breeds (1.27%). Little relationship was found between DHI-recorded abortions and herd size. Abortion frequencies for effects should be considered to be underestimated because many abortions, especially those caused by genetic recessives, go undetected. Therefore, various nonreturn rates (NRR; 60, 80, …, 200 d) were calculated to document pregnancy loss confirmed by the absence of homozygotes in the population. Breeding records for April 2011 US Department of Agriculture sire conception rate evaluations were analyzed with the model used for official evaluations with the addition of an interaction between carrier status of the service sire (embryo's sire) and cow sire (embryo's maternal grandsire). Over 13 million matings were examined using various NRR for Holstein lethal recessive traits (brachyspina and complex vertebral malformation) and undesirable recessive haplotypes (HH1
Lassen, Brian; Orro, Toomas; Aleksejev, Annely; Raaperi, Kerli; Järvis, Toivo; Viltrop, Arvo
Cows infected with the tissue parasite Neospora caninum (Nc) are more likely to abort or give birth to calves with neurological disorders. The known infection routes are transplacentally and by consumption of oocysts shed by the definitive host, the dog. It has been hypothesised, that dormant stages of persistent Nc infection may be reactivated by immunosuppression mechanisms such as pathogenic invasions as bovine herpes virus 1 (BHV1) and bovine virus diarrhoea virus (BVDV). The study was set to give the first prevalence data on Nc from Estonian dairy herds in both animal as well as herd level. In addition, association between herd size and Nc, and association of Nc with abortion incidence (Ab), stillbirth incidence (Sb), insemination index (II), and calving interval (CaI) in the presence of BHV1 and BVDV was studied. Blood samples from 1973 animals from 100 herds were collected in 2006-2008, and 320 bulk tank milk (BTM) samples were collected in 2007. Antibodies against Nc was found in 2.5 ± 0.4% (95% CI) of the animals and at least one positive animal was found in 37.0 ± 4.7% (95% CI) of the herds. In addition, Nc antibodies were detected in 16.3 ± 2.0% (95% CI) of the tested BTM. Large herds (≥ 200 animals) were less likely to have seropositive animals for Nc. Logistic regression models showed that herds with more than one animal seropositive for Nc had significantly higher odds ratio of abortion incidence (OR: 11.92, 1.18-120.18 95% CI, p=0.036) and tendency of having more stillbirths (OR: 5.52, 0.87-35.02 95% CI, p=0.07). On the other hand one Nc seropostive cow in the herd was associated with lower odds ratio (OR: 0.22, 0.05-0.91 95% CI, p=0.04) of higher calving intervals. Estonian prevalence results reflect observations in the region. No evidence was found of the pathogens were affecting fertility variables through interactions but independently BHV1 and Nc had an impact on the abortion.
Berry, D P; O'Brien, B; O'Callaghan, E J; Sullivan, K O; Meaney, W J
The objective of this study was to document temporal trends in bulk tank somatic cell count (SCC) and total bacterial counts (TBC) in Irish dairy herds during the years 1994 to 2004. Three milk processors participated in the study, providing data on 2,754,270 individual bulk tank SCC and 2,056,992 individual bulk tank TBC records from 9,113 herds. Somatic cell counts decreased during the years 1994 to 2000, followed by an annual increase thereafter of more than 2,000 cells/mL. A tendency existed for TBC to decrease over time. Across all years, bulk tank SCC were the lowest in April and highest in November; TBC were the lowest in May and highest in December. The significant seasonal pattern observed in herd SCC and TBC was an artifact of seasonal calving in Ireland. In general, herds selling more milk had lower bulk tank SCC and TBC. Herds having the highest SCC (i.e., > 450,000 cells/mL) and the lowest SCC (i.e., < or = 150,000 cells/mL) both contributed substantially to the mean SCC of the milk pool collected by the milk processors. Derived transition matrices showed that between adjacent years, herds had the greatest probability of remaining in the same annual mean SCC or TBC category.
Vries, de M.; Bokkers, E.A.M.; Schaik, van G.; Botreau, R.; Engel, B.; Dijkstra, T.; Boer, de I.J.M.
The Welfare Quality multi-criteria evaluation (WQ-ME) model aggregates scores of single welfare measures into an overall assessment for the level of animal welfare in dairy herds. It assigns herds to 4 welfare classes: unacceptable, acceptable, enhanced, or excellent. The aim of this study was to de
Bennedsgaard, Torben W.; Thamsborg, Stig M.; Aarestrup, Frank Møller;
Background: Quarter milk samples from cows with high risk of intramammary infection were examined to determine the prevalence of Staphylococcus aureus (SA) and penicillin resistant SA (SAr) in conventional and organic dairy herds and herds converting to organic farming in a combined longitudinal ...
Chesterton, R N; Pfeiffer, D U; Morris, R S; Tanner, C M
A case-control study of environmental and behavioural factors influencing foot lameness was undertaken on 62 dairy herds comprising an average of 185 milking cows in Taranaki, New Zealand. Thirty two case herds were identified as having had at least 10 per cent of the cows lame during the milking season in which the herd was studied, and thirty control herds were selected on the basis that no more than 3 per cent of cows in these herds had been lame per year for at least two years immediately prior to investigation. Each herd was visited at both a morning and an afternoon milking, and 58 risk factors were measured between the time the farmer began to assemble the cows for milking and the completion of milking. Comparison of single variables between case and control herds identified 24 which showed differences (p<0.10). These variables were then subjected to stepwise multivariate logistic regression, and statistically significant variables in this analysis were used to create a tentative path diagram of possible causal web relationships between the various risk factors and the outcome variable, the lameness prevalence level. Information from a review of the published literature was used to include further variables to the 24 into the initial (or null hypothesis) path model. Logistic path analysis was then used to eliminate non-significant paths from the diagram, leaving 19 arrows joining 13 variables in the final path diagram, compared with 33 joining 20 variables in the initial version. The most influential variables in explaining variation between case and control herds were the average level of maintenance of the track and the degree of patience shown by the farmer in bringing the cows in for milking. Overall, factors associated with the movement of animals to the milking shed explained 40 per cent of the variation (deviance) with regard to the lameness prevalence level. Risk factors associated with characteristics of the milking process explain 24 per cent, and
Full Text Available During the periparturient period, subclinical hypocalcemia (total plasma Ca concentration <2.0 mmol/l is a potential problem for the dairy cow; consequently, its prevention is essential for success of fertility and productive performance. Dietary cation–anion difference (DCAD has been defined as the difference in milliequivalents of cations (Na, K and anions (Cl, S per kilogram of dry matter (DM and has a direct impact on blood acid–base metabolism. Diets rich in K and Na induce metabolic alkalosis, interfering with tissue sensitivity to parathyroid hormone, and diets rich in Cl and S (anionic salts cause metabolic acidosis, reducing the risk of hypocalcemia. Consequently, the use of anionic salts has become a popular method to prevent hypocalcemia in dairy cattle. Monitoring diets with anionic salts can be done by measuring urine pH, with optimal values between 6.2 and 6.8 for Holstein cows. The objective of this report is to present a herd case investigation involving a dairy farm feeding a very low DCAD (−143 mEq/kg DM, expecting improved Ca homeostasis. The diet of −143 mEq/kg (urine pH 5.2–5.8 was changed to a diet with −53 mEq/kg DM (urine pH 6.2–6.8. Blood samples were taken at the time of calving for 10 cows that calved before and then for 10 cows that calved after changing the diet. Cows with extremely low DCAD had Ca concentrations of 2.11 ± 0.22 mmol/l and cows with a more moderated DCAD, 2.11 ± 0.16 mmol/l (P > 0.05. Several other blood metabolites (P, Mg, Na, K, Cl, albumin, globulins, blood urea nitrogen, creatinine, and GGT were also similar between groups. This very low DCAD during the prepartum period may severely compromise animal physiology unnecessarily, with little advantage over normal calcium concentrations at parturition, when compared with a less negative DCAD (−53 mEq/kg DM. Feeding a less negative DCAD ration (−53 mEq/kg DM did not decrease plasma Ca levels right after
Full Text Available Reproductive and economic data were recorded before and one year after the installation of Herd Navigator™ in a dairy farm with AMS (Automatic Milking System located in a mountain area of Northern Italy. Number of days open reduced from 166 to 103 days, number of days between the first and second insemination decreased from 45 to 28 days, and days for identifying an abortion were 80 % less, from 31 to 6 days. The preliminary results highlight the usefulness of the proactive herd management system installed for the reproduction management. A basic economic model is proposed to evaluate the potential economic benefits coming from the introduction of this technology. The model considers the benefits deriving from the reduction of reproduction problems and, consequently, of days open. Considering the effects related to the above mentioned aspects in a case study involving 60 dairy cows, a return on investment over 5 years has been calculated.
de Vries, M; Bokkers, E A M; van Schaik, G; Botreau, R; Engel, B; Dijkstra, T; de Boer, I J M
The Welfare Quality multi-criteria evaluation (WQ-ME) model aggregates scores of single welfare measures into an overall assessment for the level of animal welfare in dairy herds. It assigns herds to 4 welfare classes: unacceptable, acceptable, enhanced, or excellent. The aim of this study was to demonstrate the relative importance of single welfare measures for WQ-ME classification of a selected sample of Dutch dairy herds. Seven trained observers quantified 63 welfare measures of the Welfare Quality protocol in 183 loose housed- and 13 tethered Dutch dairy herds (herd size: 10 to 211 cows). First, values of welfare measures were compared among the 4 welfare classes, using Kruskal-Wallis and Chi-squared tests. Second, observed values of single welfare measures were replaced with a fictitious value, which was the median value of herds classified in the next highest class, to see if improvement of a single measure would enable a herd to reach a higher class. Sixteen herds were classified as unacceptable, 85 as acceptable, 78 as enhanced, and none as excellent. Classification could not be calculated for 17 herds because data were missing (15 herds) or data were deemed invalid because the stockperson disturbed behavioral observations (2 herds). Herds classified as unacceptable showed significantly more very lean cows, more severely lame cows, and more often an insufficient number of drinkers than herds classified as acceptable. Herds classified as acceptable showed significantly more cows with high somatic cell count, with lesions, that could not be approached closer than 1m, colliding with components of the stall while lying down, and lying outside the lying area, and showed fewer cows with diarrhea, more often had an insufficient number of drinkers, and scored lower for the descriptors "relaxed" and "happy" than herds classified as enhanced. Increasing the number of drinkers and reducing the percentage of cows colliding with components of the stall while lying down
Full Text Available Abstract Background The aim of this study was to detect the associations between bovine herpesvirus 1 (BHV-1 status of a herd and respiratory disease (BRD occurrence and reproductive performance in pregnant heifers and cows. The association between management-related factors and higher BRD occurrence was also estimated. Methods Serum samples, collected from cows and youngstock from 103 dairy cattle herds, were analyzed for antibodies against BHV-1, bovine respiratory syncytial virus (BRSV, bovine viral diarrhoea virus (BVDV, and Mycoplasma bovis. A questionnaire was used to collect data concerning herd management factors and reproductive performance, as well as the occurrence of clinical signs of respiratory disease in the last two years, as evaluated by the veterinarian or farm manager. Multiple correspondence analysis (MCA and logistic regression analysis were performed to identify and quantify the risk factors. Results A low to moderate prevalence (1-49% of BRSV antibodies among youngstock was associated with a high occurrence of respiratory disease (OR = 6.2, p = 0.010 in cows and in-calf heifers. Employees of the farm may participate in the spread of such disease. Larger herd size, loose-housing of cows, housing youngstock separately from cows until pregnancy, and purchasing new animals were factors possibly related to a high occurrence of respiratory disease symptoms in pregnant heifers and cows. The highest risk of abortions (> 1.3% and increased insemination index (number of inseminations per pregnancy (> 1.9 occurred in herds with a moderate prevalence of BHV-1 antibodies (1-49% in cows. Conclusions BHV-1 was not associated with acute respiratory disease in adult dairy cattle, however was significantly related to reproductive performance. BRSV possesses the main role in respiratory disease complex in adult dairy cattle.
Abebe, Rahmeto; Hatiya, Hagere; Abera, Mesele; Megersa, Bekele; Asmare, Kassahun
Mastitis is a disease of major economic importance in dairy industry worldwide. It is of particular concern in developing countries like Ethiopia, where milk and milk products are scarce. The objectives of the study were to estimate the prevalence of mastitis, identify the cow-and herd-level potential risk factors and isolate Staphylococcus aureus, one of etiological agents for contagious mastitis, from cows positive for mastitis. A total of 529 lactating cows selected randomly from 95 herds were screened by California mastitis test (CMT) for sub-clinical mastitis. Also 172 milk samples collected from CMT positive cows were cultured for isolation of S. aureus. Based on CMT result and clinical examination, the prevalence of mastitis at herd-level was 74.7% (95% CI: 64.5, 82.8). The corresponding cow-level prevalence was 62.6% (95% CI: 58.3, 66.7), of which 59.2 and 3.4% were sub-clinical and clinical mastitis cases, respectively. S. aureus was isolated from 51.2% of the milk samples cultured and 73.2% of the herds affected with mastitis. In the multivariable logistic regression model, the herd-level factors significantly associated (p mastitis were herd size, bedding material, and milking mastitic cows last, while at cow-level, breed, parity, stage of lactation, udder and leg hygiene, and teat end shape were noted to have a significant effect on mastitis occurrence. The very high prevalence of mastitis, more importantly the sub-clinical one, in the herds examined revealed the huge potential economic loss the sector suffers. Perhaps this was attributed to lack of implementation of the routine mastitis prevention and control practices by all of the herd owners. The findings of this study warrants the need for strategic approach including dairy extension that focus on enhancing dairy farmers' awareness and practice of hygienic milking, regular screening for sub-clinical mastitis, dry cow therapy and culling of chronically infected cows.
reduce the prevalence of clinical and sub-clinical mastitis in dairy herds.
Johnson, R G; Young, A J
A retrospective observational study was conducted using data from Dairy Herd Improvement monthly tests to investigate the association between milk urea nitrogen (MUN) concentration and milk yield, milk protein, milk fat percentage, SCC, and parity for commercial Holstein and Jersey herds in Utah, Idaho, and Montana. Mean MUN for Holstein cows was 15.5 mg/ dl (5.5 mmol/L) MUN and 14.1 mg/dl (5.0 mmol/L) for Jersey cows. Mean MUN, categorized by 30-d increments of days in milk (DIM), paralleled changes in milk values and followed a curvilinear shape. For Holstein cows, concentrations of MUN were different among lactation groups 1, 2, and 3+ for the first 90 DIM for Holsteins. Overall, concentrations of MUN were lower during for the first 30 DIM compared with all other DIM categories for both Holstein and Jersey cows. Multivariate regression models of MUN by milk protein showed that as the milk protein percentage increased, MUN concentration decreased; however, models for Jersey cows showed that MUN did not decrease significantly until above 3.4% milk protein. Milk fat percentage also decreased as MUN increased, but by only 1 mg/dl MUN over the range of 2.2 to 5.8% milk fat. Somatic cell count showed a negative relationship with MUN. Holstein cows with milk protein percentage >3.2% had lower MUN compared with cows having milk protein <3.2% for milk yields from 27.3 to 54.5 kg/d and lower than cows having a milk protein <3.0% for milk yield of 54.5 to 63.6 kg/d. In Jersey cows, MUN concentrations were not different among milk protein percentage categorized by milk yield. This study found that MUN was inversely associated with milk protein percentage and paralleled change in milk yield over time.
Full Text Available The aim of this study was to retrospectively analyse the results of milk samples obtained from South African dairy herds during the period 1996 to April 2007 in order to identify possible trends in isolates of microorganisms and their pathogenicity under field conditions. Milk samples were obtained from 7 of the 9 provinces in South Africa where there are low numbers of dairy cows. Although there is scientific limitation to a country wide survey, such as the variation in herd size, management skills, parity, milk yield, milking frequency and other parameters, the size of this database helps to give a fair indication of general udder health in South Africa. Cytology and routine bacteriology were performed on 379 000 milk samples of lactating cows and bacteriology on 11 946 samples from non-lactating cows. According to the results obtained, mastitis did not decrease in South Africa over the test period. The prevalence of mastitis and teat canal infection was lowest in 2002. Mastitis and teat canal infection increased from 2002 to 2006 from 8.1 % and 24.1 % to 15.4 and 30.0 % respectively. The percentage of mastitogenic pathogens isolated from cows over these years also varied. Previously unknown or almost eradicated mastitogenic pathogens such as αβ haemolytic Staphylococcus aureus which is thought to be of human origin, Streptococcus agalactiae and Enterococcus canis were responsible for numerous mastitis outbreaks seen in the test samples. Coagulase-negative staphylococci were the most frequently isolated bacteria in milk samples from both lactating and dry cows, followed by Staphylococcus aureus and Streptococcus agalactiae. Although Staphylococcus aureus remained the principal mastitogenic pathogen in South Africa, owing to its chronic nature and resultant economic losses, most cases of mastitis were caused by coagulase-negative staphylococci. This finding increases the importance of coagulase-negative staphylococci (formerly described as a
Gelasakis, A I; Angelidis, A S; Giannakou, R; Filioussis, G; Kalamaki, M S; Arsenos, G
The objectives of this study were (1) to record the major pathogens associated with subclinical mastitis (SCM), (2) to calculate their incidence during the milking period, and (3) to estimate the effect of SCM on daily milk yield (DMY) for goats reared under low-input management schemes. Dairy goats (n=590) of Skopelos and indigenous Greek breeds from 4 herds were randomly selected for the study. The study included monthly monitoring, milk yield recording, and bacteriological analyses of milk of individual goats during the course of 2 successive milking periods. Incidence and cumulative incidence were calculated for SCM cases. Moreover, 2 mixed linear regression models were built to assess the effects of (1) SCM and (2) different pathogens isolated from SCM cases, on DMY. The estimated incidence and cumulative incidence of SCM for the first and the second year of the study were 69.5 and 96.4 new cases of SCM/1,000 goat-months, and 24.1 and 31.7%, respectively. A total of 755 milk samples were subjected to microbiological examination, resulting in 661 positive cultures. Coagulase-negative and coagulase-positive staphylococci were isolated from 50.2 and 34.5% of the positive cultures, respectively. The incidence of infections (new infections per 1,000 goat-months) for the first and the second year of the study were 34 and 53 for coagulase-negative staphylococci, 23 and 28 for coagulase-positive staphylococci, 3 and 5 for Streptococcus/Enterococcus spp., and 5.5 and 9.1 for gram-negative bacteria. Goats with SCM had lower DMY when compared with goats without SCM (ca. 47g/d, corresponding to a 5.7% decrease in DMY). In particular, goats with SCM due to coagulase-positive staphylococci infection produced approximately 80g/d less milk (a reduction of ca. 9.7%) compared with uninfected ones, whereas SCM due to gram-negative bacteria resulted in approximately 15% reduction in DMY. Investigating the epidemiology of SCM and its effects on production traits is critical for
Krpálková, L; Cabrera, V E; Kvapilík, J; Burdych, J; Crump, P
The objective of this study was to evaluate the associations of variable intensity in rearing dairy heifers on 33 commercial dairy herds, including 23,008 cows and 18,139 heifers, with age at first calving (AFC), average daily weight gain (ADG), and milk yield (MY) level on reproduction traits and profitability. Milk yield during the production period was analyzed relative to reproduction and economic parameters. Data were collected during a 1-yr period (2011). The farms were located in 12 regions in the Czech Republic. The results show that those herds with more intensive rearing periods had lower conception rates among heifers at first and overall services. The differences in those conception rates between the group with the greatest ADG (≥0.800 kg/d) and the group with the least ADG (≤0.699 kg/d) were approximately 10 percentage points in favor of the least ADG. All the evaluated reproduction traits differed between AFC groups. Conception at first and overall services (cows) was greatest in herds with AFC ≥800 d. The shortest days open (105 d) and calving interval (396 d) were found in the middle AFC group (799 to 750 d). The highest number of completed lactations (2.67) was observed in the group with latest AFC (≥800 d). The earliest AFC group (≤749 d) was characterized by the highest depreciation costs per cow at 8,275 Czech crowns (US$414), and the highest culling rate for cows of 41%. The most profitable rearing approach was reflected in the middle AFC (799 to 750 d) and middle ADG (0.799 to 0.700 kg) groups. The highest MY (≥8,500 kg) occurred with the earliest AFC of 780 d. Higher MY led to lower conception rates in cows, but the highest MY group also had the shortest days open (106 d) and a calving interval of 386 d. The same MY group had the highest cow depreciation costs, net profit, and profitability without subsidies of 2.67%. We conclude that achieving low AFC will not always be the most profitable approach, which will depend upon farm
Olivier B. Kashongwe
Full Text Available On-farm hygienic practices are important in assuring quality and safety of milk for consumers and for reducing losses at production and at post-harvest. This study investigated the relationship between milking practices, mastitis as well as milk somatic cell counts (SCC and the effects of high SCC on milk production and post-harvest losses (PHL in smallholder dairy (n = 64 and pastoral camel (n = 15 herds in Kenya. The collected data included milking practices, mastitis test on udder quarters (n = 1236 and collection of milk samples for laboratory analyses: SCC, detection of Staphylococcus aureus and Streptococcus species. Production losses were computed as a proportion of cows and herds with SCC (>200,000 cells/mL and PHL as quantity of milk exceeding 4 × 105 cells/mL. Practices associated with production herds included hands, udder washing and drying, and milk let down stimulation with calves suckling or manually (p < 0.001. Udder drying was only applied in peri-urban herds (100%. Herd level prevalence of mastitis was lower in smallholder than in pastoral herds (60.7% vs 93.3%. Mastitis positive samples had higher prevalence of S.aureus than of Streptococcus species in both smallholder (57.9% vs 23.7% and pastoral (41.6% vs 36.5% herds. Moreover, SCC was significantly affected by presence of mastitis and S.aureus (p < 0.001. Milk PHL from high SCC was higher in smallholder rural herds (27% compared to peri-urban (7% and in pastoral peri-urban (81% compared to rangelands (76%. Milking practices may have contributed to maintain mastitis pathogens in herds. This has led to substantial pre and postharvest milk losses in smallholder and pastoral herds. Therefore teat dipping, dry cow period and herd level mastitis treatment may complement current practices for lower SCC and milk PHL.
Castro, A.; Pereira, J.M.; Amiama, C.; Bueno, J.
Over the last few years, the adoption of automatic milking systems (AMS) has experienced significant increase. However, hardly any studies have been conducted to investigate the distribution of mastitis pathogens in dairy herds with AMS. Because quick mastitis detection in AMS is very important, the primary objective of this study was to determine operational reliability and sensibility of mastitis detection systems from AMS. Additionally, the frequency of pathogen-specific was determined. For this purpose, 228 cows from ten farms in Galicia (NW Spain) using this system were investigated. The California Mastitis Test (CMT) was considered the gold-standard test for mastitis diagnosis and milk samples were analysed from CMT-positive cows for the bacterial examination. Mean farm prevalence of clinical mastitis was 9% and of 912 milk quarters examined, 23% were positive to the AMS mastitis detection system and 35% were positive to the CMT. The majority of CMT-positive samples had a score of 1 or 2 on a 1 (lowest mastitis severity) to 4 (highest mastitis severity) scale. The average sensitivity and specificity of the AMS mastitis detection system were 58.2% and 94.0% respectively being similar to other previous studies, what could suggest limitations for getting higher values of reliability and sensibility in the current AMSs. The most frequently isolated pathogens were Streptococcus dysgalactiae (8.8%), followed by Streptococcus uberis (8.3%) and Staphylococcus aureus (3.3%). The relatively high prevalence of these pathogens indicates suboptimal cleaning and disinfection of teat dipping cups, brushes and milk liners in dairy farms with AMS in the present study. (Author)
Full Text Available Over the last few years, the adoption of automatic milking systems (AMS has experienced significant increase. However, hardly any studies have been conducted to investigate the distribution of mastitis pathogens in dairy herds with AMS. Because quick mastitis detection in AMS is very important, the primary objective of this study was to determine operational reliability and sensibility of mastitis detection systems from AMS. Additionally, the frequency of pathogen-specific was determined. For this purpose, 228 cows from ten farms in Galicia (NW Spain using this system were investigated. The California Mastitis Test (CMT was considered the gold-standard test for mastitis diagnosis and milk samples were analysed from CMT-positive cows for the bacterial examination. Mean farm prevalence of clinical mastitis was 9% and of 912 milk quarters examined, 23% were positive to the AMS mastitis detection system and 35% were positive to the CMT. The majority of CMT-positive samples had a score of 1 or 2 on a 1 (lowest mastitis severity to 4 (highest mastitis severity scale. The average sensitivity and specificity of the AMS mastitis detection system were 58.2% and 94.0% respectively being similar to other previous studies, what could suggest limitations for getting higher values of reliability and sensibility in the current AMSs. The most frequently isolated pathogens were Streptococcus dysgalactiae (8.8%, followed by Streptococcus uberis (8.3% and Staphylococcus aureus (3.3%. The relatively high prevalence of these pathogens indicates suboptimal cleaning and disinfection of teat dipping cups, brushes and milk liners in dairy farms with AMS in the present study.
Arede, Margarida; Nielsen, Per Kantsø; Ahmed, Syed Sayeem Uddin;
Mycoplasma bovis is an important pathogen causing severe disease outbreaks in cattle farms. Since 2011, there has been an apparent increase in M. bovis outbreaks among Danish dairy cattle herds. The dairy cattle industry performed cross-sectional antibody screening for M. bovis on four occasions,...
Meadows, C; Rajala-Schultz, P J; Frazer, G S
A spreadsheet-based model was developed to estimate the economic effect of varying reproductive performance in dairy herds. Scenarios were created to model an average cow with respect to production, herd lifetime, and reproductive events. Average milk yield per day of life as well as lifetime calf and replacement heifer production were examined. Additional inputs representing milk, feed, semen, calf, and salvage prices were used to calculate net cash flow for each day of herd life for the average cow in a scenario. Economic comparison of different scenarios was accomplished using an equivalent annual cash flow (annuity) methodology.Herd performance measures and prices representative of Ohio dairy herds were used to establish a baseline average cow that had a 160-d calving-to-conception interval [days open (DO)]. Alternative scenarios that differed from baseline in DO, annual culling rate, and feed and milk prices were created to characterize the effects of changes. Under scenario inputs representative of typical Ohio dairy herds, the model indicated that a lower annual culling rate (25%) was preferable to higher annual culling rates (34 or 45%). The model estimated maximum average milk yield per day of life to occur at 110 DO. At 34% annual culling rate, calves and replacement heifers produced per lifetime declined as DO increased; beyond 150 DO, the modeled cow produced less than 1 replacement heifer per lifetime. The model also estimated a loss of $1.37 per cow per year for a 1-d increase in DO beyond 160 d. At 20% higher feed and milk prices, the model estimated a loss of $1.52 per cow per year; at 20% lower feed and milk prices, the model estimated a loss of $1.23 per cow per year. Furthermore, the model suggested that the loss associated with a 1-d increase in DO changed as DO changed. Using baseline inputs, the model calculated losses for a 1-d increase of $0.44 per cow per year at 130 DO and $1.71 per cow per year at 190 DO. The nonuniform nature of the cost
Piepers, S; Zrimšek, P; Passchyn, P; De Vliegher, S
Associations between herd management practices and both bacterial counts (BC) and coliform counts (CC) from 254 and 242 dairy herds in Flanders (Belgium), respectively, were studied. Data were analyzed using multivariable, multilevel linear regression analysis, allowing variance components analyses. Both BC and CC fluctuated throughout the year, although the milk quality parameters followed an opposite pattern. Bacterial count values decreased with each increase of the cleaning frequency of the cubicles (once per week, once per day, twice per day, or more than twice per day) between January and March. Herds with a conventional milking parlor had substantially lower BC than herds where the cows were milked using an automatic milking system. Lower BC were observed when the milking parlor was equipped with an automatic cluster removal system, when premilking teat disinfection was applied, when the dry cows were supplemented with a mix of minerals and vitamins, and when the teats were prepared either first wet and dried or via an automatic milking system. Milking cows with a high-pipeline milking parlor setup or with an automatic milking system was associated with substantially higher CC values. Herds where prepartum heifers were often treated with antimicrobials before calving had a lower CC than farms where heifers were either not or only rarely treated. Most variation in BC and CC resided at the herd level rather than at the observation level, indicating that management is important in the control of both BC and CC. Still, only a small proportion of the total variance was explained by factors capturing information related to the milking, herd health, and dry cow management, which suggests that the bacteriological milk quality and, in particular, CC is primarily driven by other factors than the ones included in this study.
O' Doherty, E; Berry, D P; O' Grady, L; Sayers, R
A survey of management practices in 309 Irish dairy herds was used to identify risk factors for the presence of antibodies to Salmonella, Neospora caninum and Leptospira interrogans serovar hardjo in extensively managed unvaccinated dairy herds. A previous study documented a herd-level seroprevalence in bulk milk of 49%, 19% and 86% for Salmonella, Neospora caninum and leptospira interrogans serovar hardjo, respectively in the unvaccinated proportion of these 309 herds in 2009. Association analyses in the present study were carried out using multiple logistic regression models. Herds where cattle were purchased or introduced had a greater likelihood of being positive to leptospira interrogans serovar hardjo (PNeospora caninum (PNeospora caninum possibly due to limited access of dogs to infected materials including afterbirths. The information from this study will assist in the design of suitable control programmes for the diseases under investigation in pasture-based livestock systems.
Houe, H; Vaarst, M; Enevoldsen, C
This study examined the possibilities of using clinical parameters related to the bovine udder for characterisation of udder health. Five clinicians performed systematic clinical recordings of udder health at 3 visits to 4 dairy herds. Several of the clinical parameters were scored on an ordinal scale. The agreement between clinicians was compared using kappa statistics. Factor analysis was used to identify udder types. The clinical evaluations showed substantial variation among clinicians. Parameters that were not directly related to pathological conditions showed the highest variation e.g. length of the claws, teat shape and hardness of the udder parenchyma. On the other hand, evaluation of pathological parameters such as nodes in the udder, skin lesions and oedema showed good agreement between clinicians. Udder types identified by means of factor analysis were found to be suitable for characterisation of udder health. Especially one factor related to dry quarters and udder asymmetry showed a more consistent relationship to milk yield than traditionally applied udder health parameters such as treatment rate and cell count. It is concluded that there is a considerable need for increased efforts among clinicians in order to standardise clinical recordings. It is further concluded that certain combinations of extended clinical recordings have significant perspectives for future characterisation of udder health.
Full Text Available Helicobacter pylori is responsible for gastritis and gastric adenocarcinoma in humans, but the routes of transmission of this bacterium have not been clearly defined. Few studies led to supposing that H. pylori could be transmitted through raw milk, and no one investigated the presence of other Helicobacteraceae in milk. In the current work, the presence of Helicobacteraceae was investigated in the bulk tank milk of dairy cattle herds located in northern Italy both by direct plating onto H. pylori selective medium and by screening PCR for Helicobacteraceae, followed by specific PCRs for H. pylori, Wolinella spp., and “Candidatus Helicobacter bovis.” Three out of 163 bulk milk samples tested positive for Helicobacteraceae, but not for the subsequent PCRs. H. pylori was not isolated in any case. However, given similar growth conditions, Arcobacter butzleri, A. cryaerophilus, and A. skirrowii were recovered. In conclusion, the prevalence of Helicobacteraceae in raw milk was negligible (1.8%, and H. pylori was not identified in any of the positive samples, suggesting that, at least in the farming conditions of the investigated area, bovine milk does not represent a potential source of infection.
Randall, L V; Green, M J; Chagunda, M G G; Mason, C; Archer, S C; Green, L E; Huxley, J N
Lameness in dairy cows is a multifactorial and progressive disease with complex interactions between risk factors contributing to its occurrence. Detailed records were obtained from one United Kingdom dairy herd over an 8-yr period. Weekly locomotion scores were used to classify cows as not lame (score 1 to 2), mildly lame (score 3) and severely lame (score 4 to 5). These outcomes were used to investigate the hypothesis that low body condition score (BCS) is associated with an increased risk of lameness in dairy cows. Mixed effect multinomial logistic regression models were used to investigate the association between prior BCS and repeat lameness events during the longitudinal period of the study. Discrete time survival models were used to explore the relationship between prior BCS and first lifetime lameness events. In total, 79,565 cow weeks at risk were obtained for 724 cows. The number of lameness events was 17,114, of which 8,799 were categorized as mildly lame and 8,315 as severely lame. The median BCS was 2.25 (range, 0.75 to 4.25) and the mean body weight (BW) and age at first calving were 619.5 kg (range, 355.6 to 956.4 kg) and 25.8 mo (range, 20.5 to 37.8 mo), respectively. Subsets of the data were used in the discrete time survival models: 333 mild and 211 severe first lifetime lameness events in heifers (first lactation cows), and 81 mild and 49 severe first lifetime lameness events in cows second lactation or greater. Low BCS 3 wk before a repeated lameness event was associated with a significantly increased risk of lameness. Cows with BCS<2 were at greatest risk of mild or severe lameness, and an increased BCS above 2 was associated with a reduced risk of mild or severe lameness. Low BCS 16 or 8 wk before a first mild or severe lifetime lameness event, respectively, also had a positive association with risk of lameness in cows second lactation or greater. This provides evidence to support targeting management toward maintaining BCS to minimize the
Kessels, J A; Cha, E; Johnson, S K; Welcome, F L; Kristensen, A R; Gröhn, Y T
This study used an existing dynamic optimization model to compare costs of common treatment protocols and J5 vaccination for clinical mastitis in US dairy herds. Clinical mastitis is an infection of the mammary gland causing major economic losses in dairy herds due to reduced milk production, reduced conception, and increased risk of mortality and culling for infected cows. Treatment protocols were developed to reflect common practices in dairy herds. These included targeted therapy following pathogen identification, and therapy without pathogen identification using a broad-spectrum antimicrobial or treating with the cheapest treatment option. The cost-benefit of J5 vaccination was also estimated. Effects of treatment were accounted for as changes in treatment costs, milk loss due to mastitis, milk discarded due to treatment, and mortality. Following ineffective treatments, secondary decisions included extending the current treatment, alternative treatment, discontinuing treatment, and pathogen identification followed by recommended treatment. Average net returns for treatment protocols and vaccination were generated using an existing dynamic programming model. This model incorporates cow and pathogen characteristics to optimize management decisions to treat, inseminate, or cull cows. Of the treatment protocols where 100% of cows received recommended treatment, pathogen-specific identification followed by recommended therapy yielded the highest average net returns per cow per year. Out of all treatment scenarios, the highest net returns were achieved with selecting the cheapest treatment option and discontinuing treatment, or alternate treatment with a similar spectrum therapy; however, this may not account for the full consequences of giving nonrecommended therapies to cows with clinical mastitis. Vaccination increased average net returns in all scenarios. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Full Text Available Abstract Background The primary aims of this study were to determine the incidence of Giardia infections in dairy herds on farms in the New York City Watershed region and to evaluate risk factors associated with infections. Because co-infections of Giardia and Cryptosporidium spp. are common in this population, we also evaluated the effect of herd infection status on Giardia infections. Methods Farms were grouped into three cohorts based on their prior infection status with Giardia and/or Cryptosporidium spp. The sampling plan included collecting fecal samples from all calves below 30 days of age and proportional sampling of calves, young stock, and adults. A total of 10,672 fecal samples were collected and analyzed for the presence of Giardia cysts using zinc sulfate flotation. Herds enrolled in the study were sampled seasonally for a study period of two years. The probability of shedding cysts past a certain age and the factors that influenced the likelihood of shedding were evaluated using survival analysis. Linear regression was used to evaluate factors that were associated with the intensity of shedding. Results The majority of Giardia infections occurred in calves within their first 180 days of age, with the most number of calves shedding Giardia cysts between 11 and 20 days of age. The incidence of shedding of Giardia cysts ranged from 0.0004 per animal day for cattle in the low risk cohort to 0.0011 per animal day for cattle in the high risk cohort. The likelihood of shedding was influenced by the prior infection status of the herd and the season of collection. Infected animals shed on average 9,658 cysts/gram and the intensity of shedding Giardia cysts varied significantly with the age (p Conclusion Giardia infections are common in dairy herds in the New York City watershed, particularly in calves less than 6 months of age. Seasonality may be an important factor in the perpetuation of infections based on changes in management practices
Ito, K; Chapinal, N; Weary, D M; von Keyserlingk, M A G
Our objective was to investigate the associations between herd-level factors and lying behavior of high-producing dairy cows housed in freestall barns. Lying behavior of approximately 40 focal cows in one high-producing pen was monitored on each of 40 farms in the northeastern United States (NE) and 39 farms in California (CA). All cows within the pen were gait scored using a 1-to-5 scale to calculate the prevalence of clinical lameness (score ≥3) and severe lameness (score ≥4). Facility and management measures, including stall design, bedding, and flooring type within the pen, were collected. Herd-level factors associated with daily lying time, standard deviation (SD) of daily lying time, frequency of lying bouts, and lying bout duration at the univariate level were submitted to multivariable general linear models. In the NE, daily lying time increased with the use of deep bedding (estimate = 0.80±0.31h/d) and as average days in milk (DIM) of the focal cows increased (estimate = 0.08±0.04h/d for a 10-d increase in DIM). The SD of daily lying time decreased as stall stocking density increased (estimate = -0.08±0.03h/d for a 10% increase), and increased with the presence of rubber flooring in the pen (estimate = 0.16±0.08h/d) and percentage of stalls with fecal contamination (estimate = 0.04±0.01h/d for a 10% increase). Frequency of lying bouts decreased (estimate = -1.90±0.63 bouts/d) and average bout duration increased (estimate = 15.44±3.02 min) with the use of deep bedding. In CA, where all farms used deep bedding, daily lying time increased as average DIM of the focal cows increased (estimate = 0.08±0.03h/d for a 10-d increase). The SD of daily lying time decreased when feed was delivered more than once per day (estimate = -0.24±0.08h/d). The percentage of lame cows was correlated with the percentage of stalls with fecal contamination (r=0.45), which in turn was associated with fewer (estimate = -0.25±0.06 bouts/d) and longer lying bouts (estimate
Hoorfar, Jeffrey; Lind, Peter; Bitsch, V.
Levels of antibodies to the O antigens (0:1,9,12) of Salmonella dublin were tested in 1355 serum, 1143 cow milk and 160 bulk milk samples from dairy herds using an enzyme-linked immunosorbent assay (ELISA). In order to define the background reaction, milk samples from all lactating cows and serum......-positive. A significant correlation was found between ELISA reactions in milk and in serum of cows (34% and 32% respectively, r(s) = 0.69, P milk samples to screening and, eventually, regular certification of herds....... of 0.95. While none of the sera in the herds from Bornholm was ELISA positive, 2 herds had a few reactors in the milk ELISA. Using the same cutoff, all but 1 bulk milk sample from 150 herds on Bornholm was ELISA-negative, and all 10 salmonellosis-positive herds from Jutland were ELISA...
Sova, A D; LeBlanc, S J; McBride, B W; DeVries, T J
The challenges associated with group-housed dairy cows include within-herd variability in nutrient consumption and milk production, which may be related to feeding management. The objective of this observational study was to examine the association of herd-level feeding management factors, feed sorting, and milk production. Twenty-two freestall herds with an average lactating herd size of 162±118 cows, feeding total mixed rations, were each studied for 7 consecutive days in summer and winter. In cases of multiple feeding groups within a herd, the highest producing group of cows with an even distribution of days in milk and parity was selected for this study. The average group size studied was 83±31 cows. The average study group consisted of cows 187±47 days in milk, with a parity of 2.3±0.6, consuming 24.3±2.6kg of dry matter, with an average group-level yield of 34.3±6kg of milk/d, 3.7±0.3% milk fat, and 3.2±0.18% milk protein. Milk production parameters, including yield, fat, and protein, were recorded through regular Dairy Herd Improvement milk testing. A survey of feeding management practices and barn characteristics was administered on each farm. The amounts of feed offered and refused were recorded and sampled daily to assess dry matter intake (DMI) and particle size distribution. Feeding twice per day compared with once per day was associated with an average increase of 1.42kg of DMI, 2.0kg of milk yield, and less sorting against long ration particles (>19mm). Every 2% group-level selective refusal (sorting) of long particles was associated with 1kg/d of reduction in milk yield. A 10cm/cow increase in feed bunk space was associated with a 0.06-percentage-point increase in group-average milk fat and a 13% decrease in group-average somatic cell count. These results support that herd-level management practices to promote feed access, such as increased feeding frequency and bunk space, may improve DMI and promote more balanced nutrient intake and greater
Gates, M C; Woolhouse, M E J; Gunn, G J; Humphry, R W
The success of bovine viral diarrhoea virus (BVDV) eradication campaigns can be undermined by spread through local transmission pathways and poor farmer compliance with biosecurity recommendations. This work combines recent survey data with cattle movement data to explore the issues likely to impact on the success of BVDV control in Scotland. In this analysis, data from 249 beef suckler herds and 185 dairy herds in Scotland were studied retrospectively to determine the relative influence of cattle movements, local spread, and biosecurity on BVDV seropositivity. Multivariable logistic regression models revealed that cattle movement risk factors had approximately 3 times greater explanatory power than risk factors for local spread amongst beef suckler herds, but approximately the same explanatory power as risk factors for local spread amongst dairy herds. These findings are most likely related to differences in cattle husbandry practices and suggest that where financial prioritization is required, focusing on reducing movement-based risk is likely to be of greatest benefit when applied to beef suckler herds. The reported use of biosecurity measures such as purchasing cattle from BVDV accredited herds only, performing diagnostic screening at the time of sale, implementing isolation periods for purchased cattle, and installing double fencing on shared field boundaries had minimal impact on the risk of beef or dairy herds being seropositive for BVDV. Only 28% of beef farmers and 24% of dairy farmers with seropositive herds recognized that their cattle were affected by BVDV and those that did perceive a problem were no less likely to sell animals as replacement breeding stock and no more likely to implement biosecurity measures against local spread than farmers with no perceived problems. In relation to the current legislative framework for BVDV control in Scotland, these findings emphasize the importance of requiring infected herds take appropriate biosecurity measures
Wernike, Kerstin; Holsteg, Mark; Sasserath, Michael; Beer, Martin
In late 2011, the novel insect-transmitted orthobunyavirus Schmallenberg virus (SBV) emerged in Central Europe. Since that year, a dairy cattle herd kept in the German region in which the virus was initially detected was continuously monitored. In order to evaluate the development of the within-herd seroprevalence, but also to assess the long-term persistence of antibodies against SBV in individual animals, blood samples of all cows older than 24 months were taken yearly after the respective vector season and serologically analyzed. In December 2011, in 74% of the tested animals SBV-specific antibodies were detectable. Additional scattered seroconversions were observed between the 2011 and 2012 vector seasons, thereafter all seronegative animals remained negative. Until December 2014, the intra-herd seroprevalence decreased to 58%. A total of 122 cows infected presumable in autumn 2011 were sampled every year, 9 of them became seronegative until December 2014. Consequently, though SBV-specific antibodies were detected in about 90% of the monitored animals for more than three years, a lifelong antibody-based immunity is not expected in every animal. The loss of anti-SBV antibodies in individual animals combined with the missing infection of young stock results in a declining herd seroprevalence and increases the risk of a renewed virus circulation to a greater extent within the next years.
Detilleux, J; Theron, L; Beduin, J-M; Hanzen, C
In dairy cattle, many farming practices have been associated with occurrence of mastitis but it is often difficult to disentangle the causal threads. Structural equation models may reduce the complexity of such situations. Here, we applied the method to examine the links between mastitis (subclinical and clinical) and risk factors such as herd demographics, housing conditions, feeding procedures, milking practices, and strategies of mastitis prevention and treatment in 345 dairy herds from the Walloon region of Belgium. During the period January 2006 to October 2007, up to 110 different herd management variables were recorded by two surveyors using a questionnaire for the farm managers and during a farm visit. Monthly somatic cell counts of all lactating cows were collected by the local dairy herd improvement association. Structural equation models were created to obtain a latent measure of mastitis and to reduce the complexity of the relationships between farming practices, between indicators of herd mastitis and between both. Robust maximum likelihood estimates were obtained for the effects of the herd management variables on the latent measure of herd mastitis. Variables associated directly (pteat disinfection; the presence of cows with hyperkeratotic teats, of cubicles for housing and of dirty liners before milking; the treatment of subclinical cases of mastitis; and the age of the herd (latent variable for average age and parity of cows, and percentage of heifers in the herd). Treatment of subclinical mastitis was also an intermediate in the association between herd mastitis and post-milking teat disinfection. The study illustrates how structural equation model provides information regarding the linear relationships between risk factors and a latent measure of mastitis, distinguishes between direct relationships and relationships mediated through intermediate risk factors, allows the construction of latent variables and tests the directional hypotheses
Full Text Available Abstract Background Quarter milk samples from cows with high risk of intramammary infection were examined to determine the prevalence of Staphylococcus aureus (SA and penicillin resistant SA (SAr in conventional and organic dairy herds and herds converting to organic farming in a combined longitudinal and cross-sectional study. Methods 20 conventional herds, 18 organic herds that converted before 1995, and 19 herds converting to organic farming in 1999 or 2000 were included in the study. Herds converting to organic farming were sampled three times one year apart; the other herds were sampled once. Risk of infection was estimated based on somatic cell count, milk production, breed, age and lactation stage. Results The high-risk cows represented about 49 % of the cows in the herds. The overall prevalence of SA and SAr among these cows was 29% (95% confidence interval: 24%–34% and 4% (95% confidence interval: 2%–5% respectively. The prevalence of penicillin resistance among SA infected cows was 12% (95% confidence interval: 6%–19% when calculated from the first herd visits. No statistically significant differences were observed in the prevalence of SAr or the proportion of isolates resistant to penicillin between herd groups. Conclusion The proportion of isolates resistant to penicillin was low compared to studies in other countries except Norway and Sweden. Based on the low prevalence of penicillin resistance of SA, penicillin should still be the first choice of antimicrobial agent for treatment of bovine intramammary infection in Denmark.
Weber, M F; Groenendaal, H
In many epidemiological models for paratuberculosis, it is assumed that infected young stock (stock from adult cattle (≥ 2 years) would largely prevent postnatal infections, provided that uninfected adult cattle are highly resistant to infection. However, this assumption is in contrast with observed faecal shedding of MAP in young stock. Consequently, this assumption may have resulted in an underestimation of the effects of MAP transmission in herds participating in certification-, surveillance-, and control programmes for paratuberculosis. Therefore, the aim of the present study was to evaluate the long-term effects of transmission of MAP amongst young stock on key output parameters of certification-, surveillance-, and control programmes for paratuberculosis in simulated closed dairy herds. Closed Dutch dairy herds participating in a paratuberculosis programme were simulated with a stochastic model, JohneSSim. Various test schemes, preventive management measures, distributions of age at onset of faecal shedding and rates of effective contacts between young stock were simulated. The results indicate that transmission of MAP amongst young stock has no relevant effects on the animal-level prevalence and milk quality of herds that are certified in a paratuberculosis programme. However, transmission of MAP amongst young stock increased the economic losses due to paratuberculosis and costs of participation in a programme. Moreover, it substantially decreased the beneficial effect of the separation of young stock from adult cattle on the probability of being certified. However, even in the presence of transmission of MAP amongst young stock, preventive management measures to separate young stock from adult cattle remain important. Copyright © 2011 Elsevier B.V. All rights reserved.
Nielsen, Liza Rosenbaum; Kudahl, Anne Margrethe Braad; Østergaard, Søren
of the six age-groups; 2) S. Dublin incidence and number of animals in each infection state; and 3) S. Dublin related morbidity and mortality in the acutely infected animals. The effects of introducing one infectious heifer on the risk of spread of S. Dublin within the herd and on the duration of infection...... for the individual animals in each of the six age groups in the herd. The hygiene level was highly influential on the probability that the infection spread within the herd, duration of infection and epidemic size. The herd susceptibility level was also influential, but not likely to provide sufficient prevention...... the probability of extinction. In general, disease and mortality patterns followed epidemic waves in the herds. However, an interesting pattern was seen for acute infections and abortions in adult cattle after the first 2 years of infection in herds with poor hygiene and high susceptibility. Repeated infections...
Juan Zambrano A.; Julián Echeverri Z.; Albeiro López-Herrera
ABSTRACTObjective. To determine the associations of BoLA DRB3.2 alleles present in Holstein and BON x Holstein cattle to production and milk quality traits in a dairy herd of Antioquia, Colombia. Materials and methods. Ninety-one cows, 66 Holstein and 25 BxH, were genotyped for the BoLA DRB3.2 gene, through PCR-RFLP technique. Furthermore, the association of the alleles of the gene BoLA DRB3.2 with milk yield (PL305), fat yield (PG305), protein yield (PP305) fat percentage (PGRA) and protein ...
Juan Zambrano A; Julián Echeverri Z.; Albeiro López-Herrera
ABSTRACTObjective. To determine the associations of BoLA DRB3.2 alleles present in Holstein and BON x Holstein cattle to production and milk quality traits in a dairy herd of Antioquia, Colombia. Materials and methods. Ninety-one cows, 66 Holstein and 25 BxH, were genotyped for the BoLA DRB3.2 gene, through PCR-RFLP technique. Furthermore, the association of the alleles of the gene BoLA DRB3.2 with milk yield (PL305), fat yield (PG305), protein yield (PP305) fat percentage (PGRA) and protein ...
Ivemeyer, S; Smolders, G; Brinkmann, J
Achieving and maintaining high herd health and welfare status and low veterinary medicine inputs are important aims in organic livestock farming. Therefore, an on-farm intervention study (CORE Organic ANIPLAN) was conducted on 128 organic dairy farms in seven European countries aiming at minimising...... generated in Stable Schools (adapted Farmer Field Schools) or using face-to-face advice but following similar principles. Most frequently chosen focus areas were metabolic disorders (66% of farms), udder health (58%), lameness (47%), and fertility (39%). General linear models for repeated measures were used...
Kashongwe, O B; Bebe, B O; Matofari, J W; Huelsebusch, C G
Associations between feeding practices, milk yield, and composition were assessed in smallholder rural and peri-urban dairy cow (n = 97) and pastoral camel (n = 15) herds. A cross-sectional survey supplemented by follow-up collection of feed and milk samples for laboratory analyses was conducted. Data was analyzed using descriptive, correlation, and analysis of variance statistics. Feeding practices in rural smallholder dairy cows' herds were pastured based (87.7%) with napier grass (89.4%) and concentrates (93.9%) as forage and concentrate supplements. In smallholder peri-urban dairy cows' herds, it was napier grass based (68.4%) with concentrates (100%), oat forages (42.9%), and crop residues (28.6%). Pastoral camel herds were shrub browsing (53%), rangeland pasture grazing (20%), or Euphorbia tirucalli feeding (27%). Smallholder rural farmers offered more feeds (16.1 vs 15.3 kg/day) than peri-urban farmers, hence net energy for lactation (1.4 vs 1.3 Mcal/kg), crude protein (CP) (10 vs 12%), and milk yields (12 vs 9 kg/herd/day) was higher. Milk fat was higher in smallholder peri-urban (4.3%) than that of rural (3.9%). In pastoral camels, E. tirucalli feeding had higher daily milk yield/herd, fat, and CP (63 kg, 4.5 and 3.6%) than shrub browsing (35 kg, 4.2 and 3.0%) and grazing (23 kg yield, 2.6 and 2.7%). Five feeding practices out of 14 in smallholder dairy cattle herds resulted in more than 10 kg milk/cow/day because of low forage-to-concentrate ratio (2.5), inclusion of legume crop residue, or processing forages. They present opportunities for improved production in smallholder herds. In pastoral camel, E. tirucalli feeding showed the highest potential.
Elmoslemany, A M; Keefe, G P; Dohoo, I R; Jayarao, B M
The objective of this study was to determine on-farm risk factors for bacteriological quality of bulk tank milk. Bulk tank raw milk quality was evaluated on all Prince Edward Island dairy herds (n = 235) over a 2-yr period (March 2005 to March 2007). Biweekly total bacterial, preliminary incubation, laboratory pasteurization, and coliform counts were conducted using a Petrifilm culture system. For the assessment of risk factors, a case-control study was conducted from January 2006 to May 2007. Case and control herds were defined based on the last 6 analyses of bulk tank bacterial counts before on-farm evaluation. Cases were herds that had multiple elevated counts for any of the parameters measured. A total of 69 herds (39 cases and 30 control herds) were evaluated. Data collection included 1) observation and questionnaire on basic hygiene and farm management practices; 2) complete wash analysis of the milking equipment, monitoring the presence of bacterial films on equipment and evaluation of cooling system function; and 3) environmental and cow hygiene scoring. Data were analyzed using multivariable logistic regression. The results of the final model indicated that high alkalinity in the wash water and poor teat-end cleanliness were associated with high bacterial counts in bulk tank milk (odds ratios = 12 and 5.3, respectively). It was also observed that high water temperature of detergent wash and the use of a water softener were associated with low bacterial counts in bulk tank milk (odds ratios = 0.87 and 0.11, respectively). A significant association between udder hair clipping and teat-end cleanliness was also observed. In conclusion, this study highlights the importance of udder hygiene and milking system washing factors on hygienic quality of bulk tank milk.
Cabrera, V E
The purpose of the study was 2-fold: 1) to propose a novel modeling framework using Markovian linear programming to optimize dairy farmer-defined goals under different decision schemes and 2) to illustrate the model with a practical application testing diets for entire lactations. A dairy herd population was represented by cow state variables defined by parity (1 to 15), month in lactation (1 to 24), and pregnancy status (0 nonpregnant and 1 to 9 mo of pregnancy). A database of 326,000 lactations of Holsteins from AgSource Dairy Herd Improvement service (http://agsource.crinet.com/page249/DHI) was used to parameterize reproduction, mortality, and involuntary culling. The problem was set up as a Markovian linear program model containing 5,580 decision variables and 8,731 constraints. The model optimized the net revenue of the steady state dairy herd population having 2 options in each state: keeping or replacing an animal. Five diets were studied to assess economic, environmental, and herd structural outcomes. Diets varied in proportions of alfalfa silage (38 to 98% of dry matter), high-moisture ear corn (0 to 42% of dry matter), and soybean meal (0 to 18% of dry matter) within and between lactations, which determined dry matter intake, milk production, and N excretion. Diet ingredient compositions ranged from one of high concentrates to alfalfa silage only. Hence, the model identified the maximum net revenue that included the value of nutrient excretion and the cost of manure disposal associated with the optimal policy. Outcomes related to optimal solutions included the herd population structure, the replacement policy, and the amount of N excreted under each diet experiment. The problem was solved using the Excel Risk Solver Platform with the Standard LP/Quadratic Engine. Consistent replacement policies were to (1) keep pregnant cows, (2) keep primiparous cows longer than multiparous cows, and (3) decrease replacement rates when milk and feed prices are favorable
DiGiacomo, R F; Hopkins, S G; Darlington, R L; Evermann, J F
Following the demonstration that bovine leukosis virus was transmitted in calves by gouge dehorning, electrical dehorning at a younger age was implemented in a commercial Holstein herd. Subsequently, annual testing of the herd revealed a decline in the prevalence of bovine leukosis virus antibodies as older cattle dehorned by the former method were replaced by younger cattle dehorned by the latter method.
Elbers, A R; Miltenburg, J D; De Lange, D; Crauwels, A P; Barkema, H W; Schukken, Y H
The incidence of clinical mastitis in dairy cows was estimated in 171 randomly selected dairy herds from the southern part of The Netherlands. A total of 1103 quarter cases was reported. The mean annual incidence rate was 12.7 quarter cases/yr per 100 cows. The modeling incidence rate of clinical mastitis at the herd level indicated that a number of risk factors were associated with a higher rate of clinical mastitis: one or more cows that were leaking milk, one or more cows with trampled teats, no disinfection of the maternity area after calving, consistent use of post-milking teat disinfection, Red and White cattle (Meuse-Rhine-Yssel) as the predominant breed, and an annual bulk milk somatic cell count teats, no disinfection of the maternity area after calving, consistent use of post-milking teat disinfection, use of a thick layer of bedding in the stall, and the stripping of foremilk before cluster attachment. The following risk factors were associated with a higher rate of clinical mastitis caused by Staphylococcus aureus: Red and White cattle (Meuse-Rhine-Yssel) as the predominant breed, cows with trampled teats, the stripping of foremilk before cluster attachment, no regular disinfection of the stall, no regular replacement of stall bedding, and an annual bulk milk somatic cell count < 150,000 cells/ml.
Full Text Available Abstract Johne's disease (JD is caused by infection with the organism Mycobacterium avium spp. paratuberculosis, leading to chronic diarrhoea and ill thrift in adult cattle. JD is considered to adversely affect farm performance and profitability. This retrospective case study was undertaken on a single commercial dairy herd in the south west of Ireland. Animal production records were interrogated to assess the effect of JD on milk yield (total kg per lactation, somatic cell count (the geometric mean over the lactation, reasons for culling, cull price and changes in herd parity structure over time. JD groups were defined using clinical signs and test results. One control animal was matched to each case animal on parity number and year. Specific lactations (clinical, pre-clinical and test-positive only from 1994 to 2004 were compared between JD case and control cows. A significantly lower milk yield (1259.3 kg/lactation was noted from cows with clinical JD in comparison to their matched control group. Clinical animals had an average cull price of €516 less than animals culled without signs of clinical disease. In contrast, little effect was noted for sub-clinical infections. These direct effects of JD infections, in combination with increased culling for infertility and increasing replacement rates, had a negative impact on farm production. Results from this study provide preliminary information regarding the effects of JD status on both herd and animal-level performance in Ireland.
Santman-Berends, I M G A; Mars, M H; van Duijn, L; van Schaik, G
Bovine viral diarrhea virus (BVDV) is an important endemic infection. However, no information was available on whether it would be economically beneficial to implement a national control program in the Netherlands. Therefore, a stochastic simulation model was developed in which control scenarios were added to compare the epidemiological and economic consequences of BVDV control in Dutch dairy herds in the next 10 yr. In the epidemiological part of the model, herds could be classified as susceptible, infectious, recovered, or vaccinated. The outputs of the epidemiological module served as input for the economic module. Net costs that could be attributed to bovine viral diarrhea consisted of production losses, costs for testing, and culling persistently infected cattle in the present voluntary Dutch BVDV control program and costs for vaccination. Four different control scenarios were simulated, involving testing and culling of persistently infected (based on serum or ear-notch testing), and monitoring BVDV statuses and vaccination and were derived from BVDV control programs that are currently executed in Europe. The costs and benefits of BVDV control in the current situation and in each of the simulated control scenarios were evaluated assuming an annual discount rate of 2%. The model estimated a mean BVDV herd prevalence of 18.0% in 2014 and showed a slightly decreasing prevalence over time. The outputs seemed realistic for the present situation in the Netherlands when compared with actual survey data. The average annual net costs associated with bovine viral diarrhea were estimated at €27.8 million for the dairy industry. Two control scenarios were beneficial in controlling BVDV during the study period (between 2015 and 2025). In the scenario where tracing and removing of PI animals and monitoring of the subsequent status was obligatory, the benefit to cost (B/C) ratio was 1.5 (€1.5 benefit for each invested euro). In the scenario in which the BVDV status of
Coignard, M; Guatteo, R; Veissier, I; de Boyer des Roches, A; Mounier, L; Lehébel, A; Bareille, N
Extensive information is available in the literature on the specific risk factors of the main health disorders afflicting dairy cattle herds. However, it remains difficult to manage a herd's overall health because measures to control one risk factor can exacerbate the risk of another disease. To achieve and maintain good overall herd health, livestock systems and management practices need to simultaneously take into account all of the main health disorders. We aimed to identify the characteristics of systems and practices conducive to good herd health using the Welfare Quality(®) assessment protocol for cattle. This protocol allows an assessment of the level of health and welfare at the herd level according to the opinion of a selected group of 13 experts from animal sciences. Our objectives were to (i) describe the distribution of dairy herds' health scores in a representative sample of French dairy cattle herds, and (ii) to investigate systems (housing system, milking system, herd size, breed, farm location) and management practices associated with variations of the overall health score of dairy herds. This protocol was carried out on 130 farms between December 2010 and March 2011. A multivariable analysis of variance (ANOVA) was performed to investigate the factors of variation of the overall health score at the herd level. The overall health scores of the farms in the sample were classified as moderate for the vast majority of farms (95.4%) (mainly due to subclinical mastitis, dystocia and pain induced by disbudding/dehorning) and varied little between farms. Some livestock systems were associated with a higher overall health score: straw yards and milking parlors (P<0.0001), highland vs. lowland locations (P=0.013), Montbeliarde rather than Holstein breeds (P=0.006). Some management practices also were associated with a higher level of health: medium herd average parity (P=0.03), low proportion of dirty cows (P=0.002) and low proportion of cows with abnormal
Salmonella spp. in cattle are contributing to bacterial foodborne disease for humans. Reduction of Salmonella prevalence in herds is important to prevent human Salmonella infections. Typical control measures are culling of infectious animals, vaccination, and improved hygiene management. Vaccines ha...
Full Text Available Abstract Background Although several attempts have been made to control enzootic bovine leukosis (EBL at the local level, a nationwide control program has not been implemented in Japan, except for passive surveillance. Effective control of EBL requires that the transmission routes of bovine leukemia virus (BLV infection should be identified and intercepted based on scientific evidence. In this cross-sectional study, we examined the risk factors associated with within-herd transmission of BLV on infected dairy farms in Japan. Blood samples taken from 30 randomly selected adult cows at each of 139 dairy farms were tested by enzyme-linked immunosorbent assay (ELISA. Information on herd management was collected using a structured questionnaire. Results Infected farms were defined as those with more than one ELISA-positive animal and accounted for 110 (79.1% of the 139 farms in the study. Completed questionnaires obtained from 90 of these 110 farms were used for statistical analysis. Seroprevalence, which was defined as the proportions of animals that tested positive out of all animals tested on the farm, was 17.1%, 48.1%, and 68.5% for the 25th, 50th, and 75th percentiles, respectively. A mixed logistic regression analysis implicated a loose housing system, dehorning, and a large number of horseflies in summer as risk factors (coefficient = 0.71, 1.11, and 0.82; p = 0.03, Conclusion Control of EBL in infected dairy farms in Japan will be improved by focusing particularly on these risk and protective factors.
Dolecheck, K A; Silvia, W J; Heersche, G; Wood, C L; McQuerry, K J; Bewley, J M
The objective of this study was to compare the reproductive performance of cows inseminated based on automated activity monitoring with hormone intervention (AAM) to cows from the same herds inseminated using only an intensive timed artificial insemination (TAI) program. Cows (n=523) from 3 commercial dairy herds participated in this study. To be considered eligible for participation, cows must have been classified with a body condition score of at least 2.50, but no more than 3.50, passed a reproductive tract examination, and experienced no incidences of clinical, recorded metabolic diseases in the current lactation. Within each herd, cows were balanced for parity and predicted milk yield, then randomly assigned to 1 of 2 treatments: TAI or AAM. Cows assigned to the TAI group were subjected to an ovulation synchronization protocol consisting of presynchronization, Ovsynch, and Resynch for up to 3 inseminations. Cows assigned to the AAM treatment were fitted with a leg-mounted accelerometer (AfiAct Pedometer Plus, Afimilk, Kibbutz Afikim, Israel) at least 10 d before the end of the herd voluntary waiting period (VWP). Cows in the AAM treatment were inseminated at times indicated by the automated alert system for up to 90 d after the VWP. If an open cow experienced no AAM alert for a 39±7-d period (beginning at the end of the VWP), hormone intervention in the form of a single injection of either PGF2α or GnRH (no TAI) was permitted as directed by the herd veterinarian. Subsequent to hormone intervention, cows were inseminated when alerted in estrus by the AAM system. Pregnancy was diagnosed by ultrasound 33 to 46 d after insemination. Pregnancy loss was determined via a second ultrasound after 60 d pregnant. Timed artificial insemination cows experienced a median 11.0 d shorter time to first service. Automated activity-monitored cows experienced a median 17.5-d shorter service interval. No treatment difference in probability of pregnancy to first AI, probability
Nielsen, C; Ostergaard, S; Emanuelson, U; Andersson, H; Berglund, B; Strandberg, E
The main aim was to assess the impact of mastitis on technical and economic results of a dairy herd under current Swedish farming conditions. The second aim was to investigate the effects obtained by withdrawing milk with high somatic cell count (SCC). A dynamic and stochastic simulation model, SimHerd, was used to study the effects of mastitis in a herd with 150 cows. Results given the initial incidence of mastitis (32 and 33 clinical and subclinical cases per 100 cow-years, respectively) were studied, together with the consequences of reducing or increasing the incidence of mastitis by 50%, modelling no clinical mastitis (CM) while keeping the incidence of subclinical mastitis (SCM) constant and vice versa. Six different strategies to withdraw milk with high SCC were compared. The decision to withdraw milk was based on herd-level information in three scenarios: withdrawal was initiated when the predicted bulk tank SCC exceeded 220 000, 200 000 or 180 000 cells/ml, and on cow-level information in three scenarios: withdrawal was initiated when the predicted SCC in an individual cow's milk exceeded 1 000 000, 750 000 or 500 000 cells/ml. The accuracy with which SCC was measured and predicted was assumed to affect the profitability of withdrawing milk with high SCC and this was investigated by applying high, low or no uncertainty to true SCC. The yearly avoidable cost of mastitis was estimated at €8235, assuming that the initial incidence of mastitis could be reduced by 50%. This cost corresponded to 5% of the herd net return given the initial incidence of mastitis. Expressed per cow-year, the avoidable cost of mastitis was €55. The costs per case of CM and SCM were estimated at €278 and €60, respectively. Withdrawing milk with high SCC was never profitable because this generated a substantial amount of milk withdrawal that was not offset by a sufficient increase in the average price per delivered kg milk. It had the most negative impact on net return when
Full Text Available To define mean herd size, structural traits, animal sourcing and use, management and aspects related to the milk production, 118 dairy herds, involved in a FAO dairy development project were studied. The mean herd size after allocation to clusters: Small (≤38 heads, Medium (>38, ≤61 heads and Large (>61 heads was 52.8±25.8, ranging from 7 to 134 heads of cattle. The following genotypes: Cross bred (CR 58.8%, Zebu (ZB 23.2% and Taurine cattle (TA 18.0% which were not uniformly distributed neither across nor within herds were identified. Sex ratio was two thirds of females (70.6%, one third of males (28.1% and a low proportion (1.3% of castrated males. No mature TA males compared to 53.3% of the male ZB and 31.4% of the male CR, were indicated as potential sires. Investments in purchase of animals were higher in Small than in Medium and Large herds; of all purchased sires 53.8% were found in Small herds vs. 28.2% and 18.0% in Medium and Large. Herd property was equally distributed between single (56.8% and multi property (43.2%. There was more manpower available per 100 cows in Small, being almost double and triple than in Medium and Large herds. Although milk extracted, was similar in all clusters averaging 2.4±0.5 litres/day/cow, milk off take rate, due to higher proportion of lactating cows, appeared higher in Small herds.
Katholm, Jørgen; Bennedsgaard, T.W.; Koskinen, M.T.;
Results of a commercial real-time PCR analysis for 11 mastitis pathogens from bulk tank milk (BTM) samples from all 4,258 Danish dairy herds in November 2009 to January 2010 were compared with somatic cell count (SCC) and total bacteria count (TBC) estimates in BTM. For Streptococcus agalactiae, ...
Full Text Available A total of 355 cows were sampled (serum, n=315; faeces, n=355; milk, n=209 from dairy farms located in the Punjab state of India. Faeces and serum/milk samples were screened by acid fast staining and “indigenous ELISA,” respectively. IS900 PCR was used to screen faeces and milk samples. Bio-load of MAP in dairy cows was 36.9, 15.6, 16.3, and 14.4%, using microscopy, serum ELISA, milk ELISA and milk PCR, respectively. Estimated kappa values between different test combinations: serum and milk ELISA, faecal microscopy and faecal PCR, milk ELISA and milk PCR, faecal PCR and serum ELISA were 0.325, 0.241, 0.682, and 0.677, respectively. Estimation of the relative sensitivity and specificity of different tests in the present study indicated that “serum ELISA” and “milk ELISA” were good screening tests, add “milk PCR” was “confirmatory test” for MAP infection. Combination of milk ELISA with milk PCR may be adopted as a model strategy for screening and diagnosis of JD in lactating/dairy cattle herds in Indian conditions.
Santman-Berends, I M G A; Swinkels, J M; Lam, T J G M; Keurentjes, J; van Schaik, G
Recently, many changes have been implemented in Dutch dairy herds. Herd sizes have increased and antimicrobial use has been reduced. Certain types of antimicrobials can only be used in specific circumstances, and the preventive use of antimicrobials in dry cows is prohibited. The aim of this study was to quantify clinical mastitis (CM), subclinical mastitis (SCM), and risk factors associated with CM in Dutch dairy herds in 2013, in the context of these changes. For this study, 240 dairy herds were randomly selected from farms that participated in test-day milk recording, used a conventional milking system, and agreed to participate in the study. Eventually, 233 Dutch dairy farmers had complete records of CM in their herds in 2013 and 224 of these farmers completed a questionnaire on management factors potentially associated with CM. All participating farmers gave consent to use their routinely collected herd data such as test-day records and cow identification and registration data. Clinical and subclinical mastitis incidence rate (CMI and SCMI, respectively) per 100 cows per year, subclinical mastitis prevalence, and average bulk tank milk somatic cell count were obtained for 2013. The risk factor analysis was conducted using a generalized linear model with a log link function and a negative binomial distribution on herd level in Stata 13.1. A median CMI of 28.6 per 100 cows at risk per year, SCMI of 70.1 per 100 cows at risk per year, SCM prevalence of 15.8%, and bulk tank milk somatic cell count of 171 × 10(3) cells/mL were observed in 2013. Factors that were significantly associated with a higher CMI were cleaning slatted floors only once per day compared with more than 4 times a day (i.e., mechanical), a higher percentage of Holstein Friesian cows present in the herd, treating less than 50% of the cows with CM with antimicrobials, postmilking teat disinfection, and treatment of cows with elevated somatic cell count with antimicrobials. The results of this
Mele, M; Macciotta, N P P; Cecchinato, A; Conte, G; Schiavon, S; Bittante, G
We investigated the potential of using multivariate factor analysis to extract metabolic information from data on the quantity and quality of milk produced under different management systems. We collected data from individual milk samples taken from 1,158 Brown Swiss cows farmed in 85 traditional or modern herds in Trento Province (Italy). Factor analysis was carried out on 47 individual fatty acids, milk yield, and 5 compositional milk traits (fat, protein, casein, and lactose contents, somatic cell score). According to a previous study on multivariate factor analysis, a variable was considered to be associated with a specific factor if the absolute value of its correlation with the factor was ≥0.60. The extracted factors were representative of the following 12 groups of fatty acids or functions: de novo fatty acids, branched fatty acid-milk yield, biohydrogenation, long-chain fatty acids, desaturation, short-chain fatty acids, milk protein and fat contents, odd fatty acids, conjugated linoleic acids, linoleic acid, udder health, and vaccelenic acid. Only 5 fatty acids showed small correlations with these groups. Factor analysis suggested the existence of differences in the metabolic pathways for de novo short- and medium-chain fatty acids and Δ(9)-desaturase products. An ANOVA of factor scores highlighted significant effects of the dairy farming system (traditional or modern), season, herd/date, parity, and days in milk. Factor behavior across levels of fixed factors was consistent with current knowledge. For example, compared with cows farmed in modern herds, those in traditional herds had higher scores for branched fatty acids, which were inversely associated with milk yield; primiparous cows had lower scores than older cows for de novo fatty acids, probably due to a larger contribution of lipids mobilized from body depots on milk fat yield. The statistical approach allowed us to reduce a large number of variables to a few latent factors with biological
Between 2007 and 2009, the largest human Q fever epidemic ever described occurred in the Netherlands. The source was traced back to dairy goat farms, where abortion storms caused by Coxiella burnetii had been observed. Intervention measures included vaccination of dairy goats, followed by one-time c
Ettema, Jehan Frans; Østergaard, Søren; Sørensen, M K
Herd simulation modelling has been recognized as a relevant method to study reproduction management strategies in a dairy herd (Dijkhuizen et al., 1997; Marsh et al., 1987; Østergaard et al., 2005a). These models estimate the technical and economic effects of certain replacement and breeding...... strategies based on the phenotypical states of the individual animals over a number of years. Typically, the genetic levels of replacement heifers in these models are not different from those of the culling candidates in the herd; continuous genetic improvement in the population is ignored. The importance...... of including genetic progress when evaluating reproductive strategies with simulation models has not been explored. Improved reproductive efficiency does allow a higher selection intensity of which cows to stay in the herd and give birth to own young stock....
Lunardi, Michele; de Camargo Tozato, Claudia; Alfieri, Alice Fernandes; de Alcântara, Brígida Kussumoto; Vilas-Boas, Laurival Antonio; Otonel, Rodrigo Alejandro Arellano; Headley, Selwyn Arlington; Alfieri, Amauri Alcindo
Teat papillomatosis affects dairy cows worldwide. Milking can become difficult due to teat warts, and maintaining affected cows in the herds may diminish economic profit in the dairy industry. Currently, 13 bovine papillomavirus (BPV) types have been fully characterized, and numerous putative BPV types have been identified through partial L1 gene PCR. In order to identify the viral types present in warts on the udders of dairy cows, 40 teat lesions from 24 cows from 13 cattle farms in three States of Brazil were evaluated by PV L1 gene PCR. The warts that were evaluated contained sequences from BPVs 6-10, the putative BPV types BAPV9 and BAPV4, and two unreported putative papillomavirus (PV) types, named BPV/BR-UEL6 and BPV/BR-UEL7. In addition, mixed infections and coinfections were identified, since more than one lesion was observed on the udders of 13 cows. Phylogenetic analysis showed that BPV/BR-UEL6 is closely related to BPVs belonging to the genus Xipapillomavirus, while BPV/BR-UEL7 clustered with the previously reported strains Cervus timorensis and Pudu puda PVs, which represent a putative new PV type, and it was only distantly related to xi-, epsilon-, delta- and dyoxi-PVs. These results provide information that will assist in the understanding of the association of BPVs 6, 7, 8, 9, and 10, as well as putative BPV types BAPV4 and BAPV9, with mammary papillomatosis. This is the first characterization of putative novel PV types BPV/BR-UEL6 and BPV/BR-UEL7 in teat warts of dairy cows, highlighting the high genetic diversity of BPVs associated with teat papillomatosis.
Larsen, H. D.; Sloth, K. H.; Elsberg, C.
skin lesions, milking personnel, and non-farm-related human carriers were included in the study. Certain types predominated in one or several herds during the study period of one-and-a-half to two years, whereas the presence of other types was of a more sporadic nature. Within the individual herds......, there was a close correspondence between ribo- and phage types of S. aureus isolated from bovine intramammmary infections and skin lesions. Isolates from milking personnel, however, were not identical to any of the predominant intramammary strains. Furthermore, several of the isolates from milking personnel showed...
Arango-Sabogal, Juan C; Côté, Geneviève; Paré, Julie; Labrecque, Olivia; Roy, Jean-Philippe; Buczinski, Sébastien; Doré, Elizabeth; Fairbrother, Julie H; Bissonnette, Nathalie; Wellemans, Vincent; Fecteau, Gilles
Mycobacterium avium ssp. paratuberculosis (MAP) is the etiologic agent of Johne's disease, a chronic contagious enteritis of ruminants that causes major economic losses. Several studies, most involving large free-stall herds, have found environmental sampling to be a suitable method for detecting MAP-infected herds. In eastern Canada, where small tie-stall herds are predominant, certain conditions and management practices may influence the survival and transmission of MAP and recovery (isolation). Our objective was to estimate the performance of a standardized environmental and targeted pooled sampling technique for the detection of MAP-infected tie-stall dairy herds. Twenty-four farms (19 MAP-infected and 5 non-infected) were enrolled, but only 20 were visited twice in the same year, to collect 7 environmental samples and 2 pooled samples (sick cows and cows with poor body condition). Concurrent individual sampling of all adult cows in the herds was also carried out. Isolation of MAP was achieved using the MGIT Para TB culture media and the BACTEC 960 detection system. Overall, MAP was isolated in 7% of the environmental cultures. The sensitivity of the environmental culture was 44% [95% confidence interval (CI): 20% to 70%] when combining results from 2 different herd visits and 32% (95% CI: 13% to 57%) when results from only 1 random herd visit were used. The best sampling strategy was to combine samples from the manure pit, gutter, sick cows, and cows with poor body condition. The standardized environmental sampling technique and the targeted pooled samples presented in this study is an alternative sampling strategy to costly individual cultures for detecting MAP-infected tie-stall dairies. Repeated samplings may improve the detection of MAP-infected herds.
Saa, Luis Rodrigo; Perea, Anselmo; Jara, Diego Vinicio; Arenas, Antonio José; Garcia-Bocanegra, Ignacio; Borge, Carmen; Carbonero, Alfonso
A cross-sectional study was carried out to determine the seroprevalence and risk factors associated with bovine respiratory syncytial virus (BRSV) infection in non-vaccinated dairy and dual-purpose cattle herds from Ecuador. A total of 2,367 serum samples from 346 herds were collected from June 2008 to February 2009. A questionnaire, which included variables related to cattle, health, management measures, and the environment, was filled out in each herd. Presence of antibodies against BRSV was analyzed using a commercial indirect ELISA test. A logistic regression model was used to determine risk factors associated with BRSV at herd level. The individual seroprevalence against BRSV in non-vaccinated herds in Ecuador was 80.48% [1,905/2,367; 95% confidence interval (CI) = 78.9-82.1]. The herd prevalence was 91.3% (316/346; 95% CI = 88.3-94.3), and the intra-herd prevalence ranged between 25% and 100% (mean, 90.47%). The logistic regression model showed that the existence of bordering cattle farms, the dual-purpose farms, and the altitude of the farm (more than 2,338 m above sea level) were risk factors associated with BRSV infection. This is the first study about BRSV prevalence in Ecuador. It shows the wide spread of the BRSV infection in the country. The risk factors found will help to design effective control strategies.
Darío Cedeño Q.
Full Text Available Objective. To determine seroprevalence and risk factors associated to Neospora caninum in non-vaccinated dairy cattle against infectious agents of reproductive syndrome in the municipality of Pasto, Colombia. Materials and methods. Farms over 2527 meters over sea level were selected, a total of 238 serum samples of Holstein cows were collected and analyzed using the indirect ELISA test to determine N. caninum seropositivity. An epidemiological survey was realized in each herd which included variables related to health and management measures of cattle. A multivariate analysis of binary logistic regression was used with a confidence interval of 95% (p<0.05 using SPSS19® program. Results. The estimated prevalence of N. caninum was 76.9%. The risk factors associated to neosporosis infection in the analyzed farms are as follows: residues of abortions generally left outdoors and not buried (OR 3.81, 95% CI 1.5 - 9.6; dogs fed with leftovers (OR 15.44 IC 95% 1.94-123.22 and bulls allowed to mate with cows (OR 19.68, 95% CI 2.34 - 165.52. Conclusions. The high prevalence of N. caninum and the low abortion rate in dairy herds of the municipality of Pasto corroborated no existence of the disease in all animals serologically positive, but it did suggest that at some point in their lives they were exposed to N. caninum. From the identified risk factors in this study, recommendations can be provided for an effective control of reproductive diseases like Neosporosis present in this region.
Fanke, Jane; Charlier, Johannes; Steppin, Torsten; von Samson-Himmelstjerna, Georg; Vercruysse, Jozef; Demeler, Janina
The aim of the current study was to estimate economic costs of Ostertagia ostertagi and Fasciola hepatica infections in dairy cattle herds in Germany using the online calculation programme Paracalc(®). Following a questionnaire, survey data were available from 464 farms in 14 federal states. On those farms bulk tank milk (BTM) samples and additionally up to six serum samples collected from first season grazing calves were analysed, using a commercially available ELISA (Boehringer Ingelheim SVANOVA Biotech AB, Uppsala, Sweden), an in-house ELISA (F. hepatica) and an in-house serum pepsinogen test. In total, samples obtained from 344 farms were included in the analysis since those were the only farms with complete questionnaires. Median costs per farm and year were estimated for gastrointestinal (GI) nematode infections (€721.38) and F. hepatica infection (€565.61). Decreases in milk yield in multiparous cows were the major reason for annual production losses due to GI nematodes (€13.33 per cow) and F. hepatica infections (€7.95 per cow), which was followed by annual costs for anthelmintic treatment against GI nematode infections in adult cows (€10.00 per cow) and F. hepatica infection associated annual costs due to repeated artificial insemination (€10.13 per cow) and prolonged calving intervals (€9.40 per cow). The study demonstrated that if all required information is provided, the Paracalc(®) tool can assist to identify productions losses in dairy cattle herds due to helminth infections and to optimise farm economics in Germany. Copyright © 2017 Elsevier B.V. All rights reserved.
Piepers, S; Peeters, K; Opsomer, G; Barkema, H W; Frankena, K; De Vliegher, S
Risk factors for intramammary infections caused by coagulase-negative staphylococci, contagious major pathogens and environmental major pathogens in early lactating heifers were evaluated at the herd, heifer and quarter levels. In total, 764 quarters of 191 dairy heifers in 20 randomly selected farms in Flanders (Belgium) were sampled. Quarter milk samples were collected between 1 and 4 days in milk and between 5 and 8 days in milk for bacteriological culture. Data were analyzed using multivariable, multilevel logistic regression analysis. Higher average herd milk somatic cell count (>200,000 cells/mL), not having an effective fly control strategy, contact with lactating cows prior to calving and moderate to severe udder edema prior to calving increased the odds of intramammary infections caused by contagious major pathogens. Poor heifer hygiene and lack of mineral/vitamin supplementation prior to calving were risk factors for intramammary infection caused by environmental major pathogens. Teat apex colonization with coagulase-negative staphylococci prior to calving seemed to protect quarters against intramammary infections caused by major pathogens. Poor heifer hygiene before calving, a non-clipped udder and not practicing of teat dipping prior to calving increased the odds of intramammary infection with coagulase-negative staphylococci. Although management is important in the prevention and control of intramammary infections in early lactating heifers, most variation in the prevalence of intramammary infections resided at the heifer and quarter levels, indicating that the susceptibility for intramammary infections around calving is mainly determined by heifer and quarter characteristics.
Baumgartner, Martina; Giffinger, Friederike; Hoppe, Jan Christoph; Spergser, Joachim
This study is reporting an outbreak of subclinical mastitis due to beta-hemolytic group L streptococci in an Austrian dairy herd with a history of high somatic cell count. At the first survey 16 of 33 lactating cows (28 quarters of 132) were cultured positive for beta-hemolytic, CAMP and esculin negative cocci that grew on Columbia blood agar with small grey catalase negative colonies. With the commercial API 20 Strep system (bioMerieux, F) isolates were classified as members of streptococci group L. All tested strains (eight of 28) produced acid from ribose, lactose, trehalose, amidon and glycogen; they hydrolysed hippurate and showed beta-glucuronidase, beta-galactosidase, alkaline phosphatase, leucinaminopeptidase and arginindehydrolase activity. Isolates were sensitive to bacitracin but resistant to tetracycline. Using phenotypic characterisation as well as sequence analysis of the 16S-23S intergenic spacer region of a representative strain, recovered isolates were identified as Streptococcus (S.) dysgalactiae ssp. equisimilis. Mastitis was characterized by normal milk secretions and absence of clinical abnormalities but high elevations of somatic cell count. Based on the characteristics of the strains and on the observations during the first herd survey, contagious transmission during milking as a result of poor milking hygiene was assumed. The mastitis was controlled through implementation of a strict hygiene protocol including use of single-use udder towels, post milking teat desinfection and cluster disinfection between milking cows in combination with antibiotic treatment of infected udders.
Otten, Nina; Nielsen, Liza Rosenbaum; Thomsen, Peter T.
AWL) defined as occurrence of at least one of the two most frequently violated measures found at recent inspections in Denmark, namely (a) presence of injured animals not separated from the rest of the group and/or (b) animals in a condition warranting euthanasia still being present in the herd. A total of 25...
Bontje, D.M.; Backer, J.A.; Roest, H.I.J.; Asseldonk, van M.A.P.M.; Bergevoet, R.H.M.; Roermund, van H.J.W.
To analyse the disease dynamics in goat herds and to study the effect of control measures, a Q fever transmission model was developed by CVI. With such a model we can study questions like ‘What strategy can lower the incidence of Q fever in goats or even lead to disease extinction?’ and ‘Is vaccinat
Nielsen, Lennarth Ravn; Warnick, L. D.; Greiner, M.
test positive to negative, whereas the breed and neighbor factors were not found to be important for small herds. Organic production was associated with remaining test positive, but not with becoming test positive. The results emphasize the importance of external and internal biosecurity measures...
Bontje, D.M.; Backer, J.A.; Roest, H.I.J.; Asseldonk, van M.A.P.M.; Bergevoet, R.H.M.; Roermund, van H.J.W.
To analyse the disease dynamics in goat herds and to study the effect of control measures, a Q fever transmission model was developed by CVI. With such a model we can study questions like ‘What strategy can lower the incidence of Q fever in goats or even lead to disease extinction?’ and ‘Is vaccinat
Charlier, J.; Levecke, B.; Devleesschauwer, B.; Vercruysse, J.; Hogeveen, Henk
Current control practices against gastrointestinal nematodes in dairy cows rely strongly on anthelmintic use. To reduce the development of anthelmintic resistance or disposition of drug residues in the environment, novel control approaches are currently proposed that target anthelmintic treatment to
Logue, David N; Mayne, C Sinclair
As European dairy farms become larger and diverge between grass-based and fully housed systems, interest in the welfare of the dairy cow and related environmental issues by consumers and legislators is increasing. These pressures mean that good nutrition and management, which underpin much dairy cow welfare, is critical. Despite considerable research into the management and nutrition of the dairy cow from calf to adulthood there is much on-farm variability in its application. While the incidences of many endemic diseases are reduced most are still significant, for example lameness. In addition, trade and climate change are bringing a more diverse range of pathogens, parasites and pests into Northern Europe. Housing aspects are limited in application by economics and in most cases still do not match grazing for welfare in temperate climates. Genomic technologies offer increased opportunities to breed for 'robustness' but like 'precision animal management systems' have still to be fully exploited.
Charlier, J.; Levecke, B.; Devleesschauwer, B.; Vercruysse, J.; Hogeveen, Henk
Current control practices against gastrointestinal nematodes in dairy cows rely strongly on anthelmintic use. To reduce the development of anthelmintic resistance or disposition of drug residues in the environment, novel control approaches are currently proposed that target anthelmintic treatment to
Duplessis, M; Girard, C L; Santschi, D E; Laforest, J-P; Durocher, J; Pellerin, D
This study was undertaken to determine the effect of a combined folic acid and vitamin B12 supplement given in early lactation on culling rate, metabolic disorders and other diseases, and reproduction in commercial dairy herds. A total of 805 cows (271 primiparous and 534 multiparous cows) in 15 commercial dairy herds were involved. Every 2mo from February to December 2010 and within each herd, cows were assigned according to parity, previous 305-d milk production, and calving interval to 5mL of either (1) saline 0.9% NaCl (control group) or (2) 320mg of folic acid + 10mg of vitamin B12 (vitamin group). Treatments were administered weekly by intramuscular injections starting 3wk before the expected calving date until 8wk after parturition. A total of 221 cows were culled before the next dry period. Culling rate was not affected by treatment and was 27.5%; culling rate was greater for multiparous (32.2%) than for primiparous cows (18.8%). Within the first 60d in milk (DIM), 47 cows were culled, representing 21.3% of total culling, and no treatment effect was noted. Ketosis incidence based on a threshold ≥100µmol/L of β-hydroxybutyrate in milk was 38.3±2.9% for the vitamin group and 41.8±3.0% for the control group and was not affected by treatment. The combined supplement of folic acid and vitamin B12 did not decrease incidence of retained placenta, displaced abomasum, milk fever, metritis, or mastitis. However, the incidence of dystocia decreased by 50% in multiparous cows receiving the vitamin supplement, although no effect was observed in primiparous cows. The first breeding postpartum for multiparous cows occurred 3.8d earlier with the vitamin supplement compared with controls, whereas no treatment effect was seen for primiparous cows. Days open, first- and second-breeding conception rates, number of breedings per conception, and percentage of cows pregnant at 150 DIM were not affected by treatment. The reduced percentage of dystocia combined with the
Full Text Available Caseins are a family of milk proteins that exist in several molecular forms and arethe main proteins present in the bovine milk. Genetic variation of these proteins hasbeen associated with the quality and quantity of cheese derived from milk.This study was focused on possibilities to evaluate the frequency of the K-casein Ballele in dairy herds from the Research and Development Station for Bovine RaisingArad in order to have breeding programs that target an increase in the frequency ofthe B allele in the dairy cattle population.In order to differentiate the favorable genotype for superior composition and highercheese yield, we used simple DNA extraction method from fresh blood andtechniques based on DNA analysis, which include polymerase chain reaction andrestriction fragment length polymorphisms (PCR-RFLP methods. Employing thesetechniques we were able to determine the k-casein genotype of all individuals in agiven population under selection, regardless of sex, age or physiological stage.As a result, it is now possible to include information on milk protein genotypes intomarker assisted selection programs and consequently improve response to selection.
Full Text Available Caseins are a family of milk proteins that exist in several molecular forms and arethe main proteins present in the bovine milk. Genetic variation of these proteins hasbeen associated with the quality and quantity of cheese derived from milk.This study was focused on possibilities to evaluate the frequency of the K-casein Ballele in dairy herds from the Research and Development Station for Bovine RaisingArad in order to have breeding programs that target an increase in the frequency ofthe B allele in the dairy cattle population.In order to differentiate the favorable genotype for superior composition and highercheese yield, we used simple DNA extraction method from fresh blood andtechniques based on DNA analysis, which include polymerase chain reaction andrestriction fragment length polymorphisms (PCR-RFLP methods. Employing thesetechniques we were able to determine the k-casein genotype of all individuals in agiven population under selection, regardless of sex, age or physiological stage.As a result, it is now possible to include information on milk protein genotypes intomarker assisted selection programs and consequently improve response to selection.
Kudahl, Anne Margrethe Braad; Nielsen, S S; Østergaard, Søren
the ranking between the different culling strategies. Increased market price (20%) of replacement heifers made all culling strategies less profitable and made culling based on a milk yield criterion the most profitable culling strategy for a longer period (11 to 13 yr). A 20% reduction in heifer price made...... reproduction management. However, this strategy only stabilized the prevalence and did not reduce it. In the long term (>7 yr from implementation of a strategy), it was most profitable to cull cows immediately or as soon as possible after testing positive the first time. Varying milk prices did not affect...... immediate culling after a positive test the most profitable strategy overall in herds with typical reproduction, and after 9 yr in herd with poor reproduction. To conclude, the ideal culling strategy depends on the aim of intervention, the time horizon, and the reproductive capabilities combined with prices...
Full Text Available A survey of blood selenium (Se concentrations in Norwegian Red heifers and dry period cows was conducted to reveal possible association to management, feeding, health and fertility. Selenium contents were determined in 254 herd blood samples consisting of pooled samples from individual non-lactating animals from herds in 5 counties. The Se concentrations showed a normal distribution with mean 0.09 μg Se/g blood, with a standard deviation (SD of 0.05, and ranged from 0.02 to 0.23 μg/g, with 50 % of the samples being between 0.06 and 0.11 μg/g. The herds with Se concentrations below 0.06 μg/g were smaller (21.4 ± 8.7 cow-years than those with Se levels above 0.11 μg/g (27.5 ± 14.1 cow-years (P pre partum and decreased incidence of mastitis, ovarian cysts and anoestrus/silent oestrus post partum.
Ingrid Bortolin Affonso
Full Text Available Bovine respiratory syncytial virus (BRSV causes important lower respiratory tract illness in calves. According to F and G proteins genetic sequences, three BRSV subgroups have been reported and characterized in several countries, showing differences in its distribution. In Brazil, the virus is widely disseminated throughout the herds and the few characterized isolates revealed the solely occurrence of the subgroup B. This study describes the detection and characterization of an untyped BRSV strain from a twenty-days-old calf from a herd without clinical respiratory disease. Nasal swabs were analyzed by RT-nested PCR for the F and G proteins genes. One sample has amplified the F protein gene. Sequencing and subsequent phylogenetic reconstruction were accomplished, revealing that the strain could not be grouped with any other BRSV subgroups reported. This result may suggest that the BRSV is in constantly evolution, even in Brazil, where the vaccination is not a common practice. More detailed studies about BRSV characterization are necessary to know the virus subgroups distribution among the Brazilian herds to recommend appropriated immunoprophylaxis.
Kalantari, A S; Cabrera, V E
The objective of this study was to determine the effect of reproductive performance on dairy cattle herd value. Herd value was defined as the herd's average retention payoff (RPO). Individual cow RPO is the expected profit from keeping the cow compared with immediate replacement. First, a daily dynamic programming model was developed to calculate the RPO of all cow states in a herd. Second, a daily Markov chain model was applied to estimate the herd demographics. Finally, the herd value was calculated by aggregating the RPO of all cows in the herd. Cow states were described by 5 milk yield classes (76, 88, 100, 112, and 124% with respect to the average), 9 lactations, 750 d in milk, and 282 d in pregnancy. Five different reproductive programs were studied (RP1 to RP5). Reproductive program 1 used 100% timed artificial insemination (TAI; 42% conception rate for first TAI and 30% for second and later services) and the other programs combined TAI with estrus detection. The proportion of cows receiving artificial insemination after estrus detection ranged from 30 to 80%, and conception rate ranged from 25 to 35%. These 5 reproductive programs were categorized according to their 21-d pregnancy rate (21-d PR), which is an indication of the rate that eligible cows become pregnant every 21 d. The 21-d PR was 17% for RP1, 14% for RP2, 16% for RP3, 18% for RP4, and 20% for RP5. Results showed a positive relationship between 21-d PR and herd value. The most extreme herd value difference between 2 reproductive programs was $77/cow per yr for average milk yield (RP5 - RP2), $13/cow per yr for lowest milk yield (RP5 - RP1), and $160/cow per yr for highest milk yield (RP5 - RP2). Reproductive programs were ranked based on their calculated herd value. With the exception of the best reproductive program (RP5), all other programs showed some level of ranking change according to milk yield. The most dramatic ranking change was observed in RP1, which moved from being the worst ranked
Monti, G.E.; Frankena, K.; Jong, de M.C.M.
The purpose of this study was to describe patterns of seroconversion to bovine leukaemia virus and to estimate the main parameters needed for future model building. A longitudinal study was carried out between February 1999 and November 2001 in seven commercial dairy farms in Argentina using 1535
Romero, J.J.; Perez, E.; Dolz, G.; Frankena, K.
Twenty-five specialised Costa Rican dairy farms (located in the Poás area) were used to determine neosporosis seroprevalence and the association of seropositivity with environmental and management factors. The farms involved were selected intentionally and all of them use VAMPP 5.1 (Veterinary Autom
Monti, G.E.; Frankena, K.; Jong, de M.C.M.
The purpose of this study was to describe patterns of seroconversion to bovine leukaemia virus and to estimate the main parameters needed for future model building. A longitudinal study was carried out between February 1999 and November 2001 in seven commercial dairy farms in Argentina using 1535 la
Monge, A.; Elvira, L.; Gonzalez, J.V.; Astiz, S.; Wellenberg, G.J.
In more than 10 Spanish dairy cows, a bovine herpesvirus 4 (BHV4) associated postpartum metritis was confirmed by virus isolation, BHV4-glycoprotein B (gB) PCR and/or serology. In this study, 12 cows with, and, at the time of sampling, 3 cows without clinical signs of acute postpartum metritis from
Kautz, F M; Nickerson, S C; Ely, L O
This investigation evaluated the efficacy of a bacterin in reducing the prevalence of staphylococcal mastitis and somatic cell counts (SCC) in a dairy goat herd. Does were vaccinated or left as controls, and the levels of mastitis and SCC monitored over 18 months. Staphylococcus caprae (42.5%), S. xylosus (15.1%), and S. simulans (10.0%) were the predominant causes of intramammary infections (IMI). The infection rate was 1.64 IMI/doe among vaccinates, which tended to be lower (P mastitis vaccines for use in managing staphylococcal mastitis and SCC in dairy goats. Published by Elsevier Ltd.
Hoorfar, Jeffrey; Wedderkopp, A.
positive (herd specificity, 0.9 and herd sensitivity, 1.0). A sig nificant correlation (P serum and milk samples from cows in the herds with a history of salmonellosis. It was concluded that ELISA testing of individual milk sam ples can be used for surveillance......We investigated the ability of an antibody-specific, O antigen-based ELISA to document Salmonella typhimurium herd infections by screening of milk samples. Three cattle populations, 20 herds with no history of salmonellosis, 8 herds with history of S typhimurium epsiodes within the previous 7...... of herds for S typhimurium infections, but further modifications are needed to test bulk tank milk samples....
N. Patience Manzana
Full Text Available Land redistribution was legislated in 1994; it was designed to resolve historical imbalances inland ownership in South Africa. Between 2002 and 2006, a longitudinal observational studywas conducted with 15 purposively selected small-scale dairy farmers in a land redistributionproject in Central North West Province. Four farmers left the project over the period. For thepurposes of this study, a small-scale dairy farm was defined as a farm that produces less than500 L of milk a day, irrespective of the number of cows or size of the farm. The study wasconducted in three phases. In the first phase, situational analysis using participatory ruralappraisal (PRA and observation was used to outline the extent of the constraints and designappropriate interventions. Feeds that were used were tested and evaluated. In the secondphase, three different feeding systems were designed from the data obtained from PRA. Thesewere: (1 A semi-intensive farm-based ration using available crops, pastures and crop residueswith minimal rations purchased. (2 An intensive, zero-grazing dairy system using a totalmixed ration. (3 A traditional, extensive or dual-purpose system, where the calf drank fromthe cow until weaning and milking was done only once a day. In the third phase, adoptionwas monitored. By July 2006, all remaining farmers had changed to commercially formulatedrations or licks and the body condition score of the cows had improved. It was concluded thatveterinary extension based on PRA and a holistic systems approach was a good option forsuch complex problems. Mentoring by commercial dairy farmers, veterinary and extensionservices appeared to be viable. Further research should be done to optimise the traditionalmodel of dairy farming, as this was relatively profitable, had a lower risk and was less labourintensive.
Manzana, N Patience; McCrindle, Cheryl M E; Sebei, P Julius; Prozesky, Leon
Land redistribution was legislated in 1994; it was designed to resolve historical imbalances inland ownership in South Africa. Between 2002 and 2006, a longitudinal observational studywas conducted with 15 purposively selected small-scale dairy farmers in a land redistributionproject in Central North West Province. Four farmers left the project over the period. For thepurposes of this study, a small-scale dairy farm was defined as a farm that produces less than500 L of milk a day, irrespective of the number of cows or size of the farm. The study wasconducted in three phases. In the first phase, situational analysis using participatory ruralappraisal (PRA) and observation was used to outline the extent of the constraints and designappropriate interventions. Feeds that were used were tested and evaluated. In the secondphase, three different feeding systems were designed from the data obtained from PRA. Thesewere: (1) A semi-intensive farm-based ration using available crops, pastures and crop residueswith minimal rations purchased. (2) An intensive, zero-grazing dairy system using a totalmixed ration. (3) A traditional, extensive or dual-purpose system, where the calf drank fromthe cow until weaning and milking was done only once a day. In the third phase, adoptionwas monitored. By July 2006, all remaining farmers had changed to commercially formulatedrations or licks and the body condition score of the cows had improved. It was concluded thatveterinary extension based on PRA and a holistic systems approach was a good option forsuch complex problems. Mentoring by commercial dairy farmers, veterinary and extensionservices appeared to be viable. Further research should be done to optimise the traditionalmodel of dairy farming, as this was relatively profitable, had a lower risk and was less labourintensive.
Ivemeyer, Silvia; Bell, Nick J.; Brinkmann, Jan
farms. Farmers and facilitators were convinced of the approach and benefits for dairy herds. Farmers’ attitude and attention towards their herds and their ownership of the process appear to be crucial success factors for herd health and welfare situations. In some European countries, this method has......, farmers take responsibility for health and welfare planning by identifying issues, setting goals, and acting to improve the health situation based on farm-specific data, e.g. milk production. This paper reviews the results from intervention studies that used a modified ‘farmer field school’ approach...... for animal health and welfare planning, providing an overview of ongoing activities and their implementation into advisory situations in selected European countries. Studies on stable schools as an intervention tool showed improvements regarding the specific project aim on the majority of the participating...
Nielsen, Bodil; Thomsen, Peter; Sørensen, Jan Tind
ABSTRACT: Digital dermatitis (DD) is a contagious disease of cattle affecting the skin adjacent to the claws. Disease dynamics of DD have been described to some extend, but we still need to quantify the duration of lesions and look into non-treatment factors affecting this. The aim of this study......- and multiparous cows and between different stages in lactation at onset of the lesion. The median duration of lesions were estimated to be 42 days, less than previous published estimates. The relatively aggressive regime of topical treatment in the study herd might have shortened the duration of the lesions...
Full Text Available Fasciolosis caused by Fasciola hepatica is a widespread parasitic disease in cattle farms. The aim of this study was to detect clusters of fasciolosis in dairy cow herds in Munster Province, Ireland and to identify significant climatic and environmental predictors of the exposure risk. In total, 1,292 dairy herds across Munster was sampled in September 2012 providing a single bulk tank milk (BTM sample. The analysis of samples by an in-house antibody-detection enzyme-linked immunosorbent assay (ELISA, showed that 65% of the dairy herds (n = 842 had been exposed to F. hepatica. Using the Getis-Ord Gi* statistic, 16 high-risk and 24 low-risk (P <0.01 clusters of fasciolosis were identified. The spatial distribution of high-risk clusters was more dispersed and mainly located in the northern and western regions of Munster compared to the low-risk clusters that were mostly concentrated in the southern and eastern regions. The most significant classes of variables that could reflect the difference between high-risk and low-risk clusters were the total number of wet-days and rain-days, rainfall, the normalized difference vegetation index (NDVI, temperature and soil type. There was a bigger proportion of well-drained soils among the low-risk clusters, whereas poorly drained soils were more common among the high-risk clusters. These results stress the role of precipitation, grazing, temperature and drainage on the life cycle of F. hepatica in the temperate Irish climate. The findings of this study highlight the importance of cluster analysis for identifying significant differences in climatic and environmental variables between high-risk and low-risk clusters of fasciolosis in Irish dairy herds.
Full Text Available Abstract Background Research has been scarce when it comes to the motivational and behavioral sides of farmers' expectations related to dairy herd health management programs. The objectives of this study were to explore farmers' expectations related to participation in a health management program by: 1 identifying important ambitions, goals and subjective well-being among farmers, 2 submitting those data to a quantitative analysis thereby characterizing perspective(s of value added by health management programs among farmers; and 3 to characterize perceptions of farmers' goals among veterinarians. Methods The subject was initially explored by means of literature, interviews and discussions with farmers, herd health management consultants and researchers to provide an understanding (a concourse of the research entity. The concourse was then broken down into 46 statements. Sixteen Danish dairy farmers and 18 veterinarians associated with one large nationwide veterinary practice were asked to rank the 46 statements that defined the concourse. Next, a principal component analysis was applied to identify correlated statements and thus families of perspectives between respondents. Q-methodology was utilized to represent each of the statements by one row and each respondent by one column in the matrix. A subset of the farmers participated in a series of semi-structured interviews to face validate the concourse and to discuss subjects like animal welfare, veterinarians' competences as experienced by the farmers and time constraints in the farmers' everyday life. Results Farmers' views could be described by four families of perspectives: Teamwork, Animal welfare, Knowledge dissemination, and Production. Veterinarians believed that farmers' primary focus was on production and profit, however, farmers' valued teamwork and animal welfare more. Conclusion The veterinarians in this study appear to focus too much on financial performance and increased
Scott, M. H.
The effects of licensed emissions into air from sour gas processing plants and oilfield batteries on the health and productivity of beef cow-calf and dairy herds was investigated. Four distinct atmospheric dispersion models were used to assess historical exposures at 1,382 dairy and 5,726 beef cow-calf farm sites from 1985 through 1994 to three exposure variables: (1) emissions into air from licensed sour gas processing plants, (2) sulphur dioxide from all larger industrial sources, or (3) solution gas flaring. In the dairy study, none of the emissions were found to have harmful association with herd culling or mortality, milk production, milk somatic cell count, stillbirths or twin births. The beef cow-calf study showed no significant negative association between the sour gas or sulphur dioxide exposure variables and herd culling, the calf-crop delivered, stillbirth, calf mortality, or calf-crop weaned. Some negative association was found to exist between the level of exposure to sulphur dioxide from large industrial sources, which increased the number of twin births and produced an increased calving season profile. However, this finding does not directly implicate the sour gas industry as a cause.
Uttenthal, Åse; Larsen, Lars Erik; Philipsen, J.S.;
Using specific ELISAs, antibody levels of four different isotypes to bovine respiratory syncytial virus (BRSV) were determined in calves, following experimental BRSV infection. Most calves experienced an increase in the specific IgM and IgG1 titres about 6-10 days after infection with BRSV. The Ig......M titre was transient showing positive titres for only 5-10 days, while specific IgG1 was present for a longer time. IgA was detected concomitantly with IgM but at a lower level. Production of IgG2 anti-BRSV antibodies was detected from 3 weeks after infection. In two closed herds, repeated blood...... samplings were performed on young stock to analyse maternal immunity. The passively transferred antibodies were mainly of the IgG1 isotype and the half-life of IgG1 to BRSV was estimated to be 26.6 days. One of the herds had an outbreak of enzootic pneumonia, diagnosed to be caused by BRSV. Furthermore...
Massimo De Marchi
Full Text Available Over the last years, healthy food has gained interest among consumers, especially with regard to the fat content of livestock products which has been associated to the risk of cardiovascular diseases. Individual milk samples (n = 12,624 of 2,977 Holstein-Friesian (HF, Brown Swiss (BS and Simmental (SI cows from 39 multibreed herds were analyzed for fat content, protein content, casein content and somatic cell count using mid-infrared spectroscopy (MIRS. Daily milk yield was also recorded. Groups of fatty acids (FA, expressed as percentage of milk fat, were predicted by MIRS: they were saturated (SFA, unsaturated (UFA, monounsaturated (MUFA and polyunsaturated (PUFA FA. Data were analyzed with a linear mixed model including the fixed effects of month of sampling, parity, days in milk (DIM, herd, breed, and interactions between parity and breed, and DIM and breed. The random effects were cow nested within breed and residual. Milk of HF cows exhibited the lowest percentage of SFA (70.45% and the highest of UFA (31.20%, and milk of SI cows was intermediate between that of HF and BS breeds for all groups of FA. The values of groups of FA across DIM were similar for the different breeds. Results from this study indicate that, under similar environmental and management conditions, milk of HF exhibits better FA profile than milk of BS and SI.
Monti, G.E.; Frankena, K.; Jong, de, F.
The purpose of this study was to describe patterns of seroconversion to bovine leukaemia virus and to estimate the main parameters needed for future model building. A longitudinal study was carried out between February 1999 and November 2001 in seven commercial dairy farms in Argentina using 1535 lactating cows. Time-interval parameters were analysed using a parametric survival model with shared frailty, time until infection was analysed using a Bayesian interval-censoring survival model and ...
More, S J; Clegg, T A; Lynch, P J; O'Grady, L
Somatic cell count (SCC) limits are a key component of national and international regulation for milk quality. As yet, very limited work has been published on SCC regulatory standards, including on the effect of different approaches to SCC data adjustment and interpretation. This study examines the effect of SCC data adjustment and interpretation, as outlined in current European Union (EU) legislation, on herd eligibility to supply raw milk for processing of dairy products for human consumption, using Irish data for illustration. The study used Irish milk-recording data as a proxy for bulk tank SCC (BTSCC) data, to calculate an unadjusted monthly SCC value for each herd during each month of participation. Subsequently, 4 data adjustments were applied, as outlined in EU and national legislation: seasonal adjustment; 3-mo rolling geometric average, without accounting for a break in the supply; 3-mo rolling geometric average, after accounting for a break in the supply; and seasonal adjustment and 3-mo rolling geometric average combined, after accounting for a break in the supply. Analyses were conducted to examine the effect, during the period from 2004 to 2010, of data adjustment on the percentage of herds with herd SCC >400,000 cells/mL. In all, 4 interpretation scenarios, incorporating different data adjustment combinations, were used to estimate herd eligibility (compliant, under warning, or suspended, as defined by legislation) to supply raw milk for processing. The 4 methods of data adjustment each led to a sizable reduction (6.7, 5.0, 5.3, and 11.1 percentage points, respectively, compared with the unadjusted data) in the percentage of herds exceeding a herd SCC of 400,000 cells/mL. Herd eligibility varied by interpretation scenarios, in particular those incorporating seasonal adjustment. The study provides new perspectives on the effect of data adjustment on herd SCC and of interpretation scenarios on herd eligibility. The results provide an illustrative
Tremblay, Marlène; Bennett, Tom; Döpfer, Dörte
Digital dermatitis (DD) is the most important infectious claw disease in the cattle industry causing outbreaks of lameness. The clinical course of disease can be classified using 5 clinical stages. M-stages represent not only different disease severities but also unique clinical characteristics and outcomes. Monitoring the proportions of cows per M-stage is needed to better understand and address DD and factors influencing risks of DD in a herd. Changes in the proportion of cows per M-stage over time or between groups may be attributed to differences in management, environment, or treatment and can have impact on the future claw health of the herd. Yet trends in claw health regarding DD are not intuitively noticed without statistical analysis of detailed records. Our specific aim was to develop a mobile application (app) for persons with less statistical training, experience or supporting programs that would standardize M-stage records, automate data analysis including trends of M-stages over time, the calculation of predictions and assignments of Cow Types (i.e., Cow Types I-III are assigned to cows without active lesions, single and repeated cases of active DD lesions, respectively). The predictions were the stationary distributions of transitions between DD states (i.e., M-stages or signs of chronicity) in a class-structured multi-state Markov chain population model commonly used to model endemic diseases. We hypothesized that the app can be used at different levels of record detail to discover significant trends in the prevalence of M-stages that help to make informed decisions to prevent and control DD on-farm. Four data sets were used to test the flexibility and value of the DD Check App. The app allows easy recording of M-stages in different environments and is flexible in terms of the users' goals and the level of detail used. Results show that this tool discovers trends in M-stage proportions, predicts potential outbreaks of DD, and makes comparisons among
Evink, T L; Endres, M I
Recent trends in dairy farm structure in the United States have included a decreasing number of farms, although farm size has increased, especially the share of milk production from very large herds (>2,500 cows). The objectives of this observational study were to describe common management practices; to characterize labor and operational structure; to measure some aspects of animal health, including lameness, hock lesions, mortality, and mastitis incidence; and to summarize cost of production on farms with more than 2,500 cows in 4 states in the Upper Midwest of the United States. The study included 15 dairy farms in Minnesota, Wisconsin, Iowa, and South Dakota. Farms were visited twice, once each year, and on-farm herd records were collected for those 2 yr. On-farm herd records were used to investigate mortality, culling, pregnancy rate, and clinical mastitis incidence. At least 1 high-producing pen of mature cows and 1 pen of fresh cows were scored for locomotion. Likewise, at least 1 pen of high-producing mature cows was scored for cleanliness and hock lesions. Median herd size was 3,975 cows (range = 2,606-13,266). Milk sold per employee was 1,120,745 kg and the number of cows per employee was 105. Eighty percent of the farms had Holstein cows, 13% had Jersey, and 7% had Jersey-Holstein crosses. All farms used artificial insemination as the sole form of breeding and 100% of the farms used hormonal synchronization or timed artificial insemination programs in their reproductive protocols; 21-d pregnancy rate was 21.7%. Median lameness prevalence was 18.3% and median severe lameness prevalence was 5.1%. Median hock lesion prevalence was 17.4% and median severe hock lesion prevalence was 1.9%; mortality rate was 7.4%. Clinical mastitis incidence was 62.5 cases per 100 cow-years. Feed costs accounted for approximately 53% of the total cost of producing milk, followed by labor at 11%, interest and depreciation expenses at 10%, and replacement costs at 9.5%. Herds in
Mekonnen, S A; Koop, G; Melkie, S T; Getahun, C D; Hogeveen, H; Lam, T J G M
Knowledge of mastitis pathogens and their predominance as well as understanding of risk factors are prerequisites to improve udder health in a herd, region or country. In Ethiopia, such information is scarce, despite the fact that mastitis is an important cattle disease in the country. A cross-sectional study that describes prevalence and causative agents of subclinical mastitis (SCM) as well as risk factors at cow and herd level was conducted on 167 dairy farms in North-West Ethiopia. On average, 33% of the quarters and 62% of the cows were California Mastitis Test (CMT) positive, but the within herd quarter level prevalence ranged between 0 and 100%. A total of 1543 milk samples, being 27 quarters that showed signs of CM, 606 CMT positive quarters and 910 CMT negative quarters were cultured, respectively 40%, 67% and 47% was positive on bacteriological culture. Coagulase negative staphylococci (CNS) (31%) followed by Staphylococcus aureus (9%) were the pathogens most frequently isolated. Based on face-to-face questionnaire data, 35 herd level and 13 cow level factors were evaluated for their association with SCM (based on CMT) and with a positive culture for any bacteria, CNS or S. aureus. Cows with a history of CM, of higher parity, >150days in milk (DIM) and herds with owners that have >10th grade level of education had higher odds of SCM. The odds of being culture positive for any bacteria was higher in cows with ≥25% Holstein Friesian blood level (HBL), >150 DIM, housed on cemented floors, and milked by squeezing rather than stripping. Similarly, the odds of culturing CNS was higher in cows with 25-50% HBL, >150 DIM, and milked by squeezing. Staphylococcus aureus was more often found in cows with a history of CM and in larger herds. Checking the udder for mastitis, feeding cows according to their requirements and allowing calves to suckle the cows were negatively associated with SCM, with culturing any bacteria and with culturing CNS, respectively. Higher
梁琛; 张晓彦; 张建海; 张磊
为了发挥DHI体系在奶牛生产管理中的作用,促进奶牛健康养殖和乳品质量的提高,本研究利用DHI技术对包头某奶牛场6个月的奶牛生产情况进行了分析。结果发现,该奶牛场奶牛的乳脂率较低,体细胞数较高,一些奶牛患有严重的临床性乳房炎或隐性乳房炎。奶牛营养状况差,泌乳高峰期到达时间晚,产奶量少,存在潜在的奶损失。针对上述问题,提出了相应的解决措施。%To determine and analysis the production situation of cows in Baotou cow farm during the time from January to June of 2011, Dairy Herd Improvement （DHI） data report was applied. The results suggested that these cows had lower butter fat rate and higher somatic cell count （SCC）, which displayed they had caught serious mastitis or recessive mastitis. Meanwhile, poor nutritional status and relatively late lactation peak indirectly induced milk losses. Aiming at the above problems, appropriate measures were required immediate action.
Full Text Available There are many factors that can influence reproduction of the dairy cow such as management, physiologic factors, nutrition, genetics, and diseases Reproductive efficiency. Reproductive performance is therefore a major concern in dairy herds to success, and it has to be subject of continuous and accurate evaluation in reproductive herd health programs, in order to detect problems and implement adequate solutions. Controlled breeding programs have allowed dairy producers to optimize service rate with little impact on conception and pregnancy losses in lactating dairy cows.Existen muchos factores que pueden influenciar la reproduccion en ganaderías de leche, tales como el manejo, factores fisiológicos, la nutrición, genéticos, y la presentación de enfermedades, entre otros. Por esta razon la eficiencia reproductiva es de gran importancia en las ganaderías para ser exitosas y debe ser continua y adecuadamente evaluada en los programas reproductivos de salud de hato, con el fin de detectar los problemas y establecer las soluciones adecuadas. Los programas de reproduccion controlados, han permitido a los productores optimizar las tasas de servicios con un muy pequeño impacto en las tasas de concepción y perdida gestacional en ganaderías de leche.
Andrey Pinzón Trujillo; Fausto Camilo Moreno Vásquez; Germán Rodríguez Martínez
The purpose of this work was to carry out a study about the effects of subclinical mastitis in cows of 34 dairy farms in the Upper Chicamocha region (Boyacá department).The farms are registered in the livestock farmers association of Boyacá (FABEGAN). This study was done with the aim to know about the infection status of cows and establish which are the principal etiologic agents associated with the disease and its relation with the milking routine. To this aim, applied comparison even tests ...
Full Text Available An unusual occurrence of actinobacillosis was diagnosed in 4 heifers aged 8-15 months and 2 cattle in a dairy herd with 190 Iranian Holstein breed. Anorexia, dysphagia, drooling of normal or foodtinged saliva and presence of warts-like lesions on the dorsal surface of tongue shaft were observed in a 15-month-old heifer without showing protrusion of tongue or presenting woody tongue and no involvement of either sulcus lingualis or tongue base. In addition to tongue, soft tissues of oral cavity and pharyngeal region including lymph nodes, salivary glands and tonsils were contained multiple whitish nodules. Histopathologically, typical pyogranulomas of actinobacillosis contained radiating eosinophilic clubs surrounded by many neutrophils were diagnosed. Actinobacillus lignieresii was isolated from the lesions in pure culture. Clinical examination of other animals revealed the presence of different degrees of granulomatous abscesses in soft tissues including skin around mandibles in at least 3 heifers aged 8-11 months and 2 cattle. Due to 4 recent droughty years feeding the heifers, dry cows and low milk producing cattle by cheap oat and wheat straw mixed with plant awns could be the cause of this event.
Full Text Available Incidence of health and production problems related to feeding, nutrition and/or metabolism have being growing in dairy herds. Early diagnosis allows their reduction and consequently reduces economic losses. Monitoring nutritional status periodically allows to identify possible causes of nutritional unbalances and/or mistakes in feeding practices and establish corrective measurements.La incidencia de problemas alimenticios, nutricionales y metabólicos es cada vez mayor en hatos lecheros, así como la aparición de problemas sanitarios, productivos y reproductivos asociados a los mismos. La detección oportuna y correcta de éstos permite reducir su incidencia y, por tanto, las pérdidas económicas de los hatos. El monitoreo nutricional periódico hace posible establecer el estado nutricional de una población animal, e identificar las posibles causas de desbalances nutricionales y errores en la alimentación, así como orientar en la toma de decisiones acerca de los correctivos que se deben establecer cuando se detectan problemas. El análisis de las posibles relaciones existentes entre la información aportada por cada uno de los aspectos evaluados en el monitoreo nutricional permite una evaluación más adecuada que su análisis independiente y aislado.
Stevens, M; Piepers, S; Supré, K; Dewulf, J; De Vliegher, S
The main objective of this study was to quantify the (compound-specific) antimicrobial consumption (AMC) in adult cattle in a convenience sample of Flemish dairy herds. Antimicrobial consumption data were obtained between 2012 and 2013 by "garbage can audits" and expressed as antimicrobial treatment incidence (ATI), with the unit of the ATI being the number of defined daily doses animal (DDDA) used per 1,000 cow-days. Herds were stratified by DDDA into low-, medium-, and high-consuming herds to study the AMC per route of administration, and associations with parameters reflecting udder health, milk quality, and production performances were examined. The average ATI in adult dairy cattle for all compounds was 20.78 DDDA (per 1,000 cow-days). Large variation existed between herds (ranging from 8.68 to 41.62 DDDA). Fourth-generation cephalosporins were used most (4.99 DDDA), followed by penicillins (3.70 DDDA) and third-generation cephalosporins (2.95 DDDA). The average ATI of the critically important antimicrobials for human health (i.e., third- and fourth-generation cephalosporins and fluoroquinolones according to the World Organisation for Animal Health classification) was somewhat lower than the average ATI of the other antimicrobials (8.59 and 12.18 DDDA, respectively). The average ATI for intramammary treatment of (sub)clinical mastitis, for dry-cow therapy, and for systemically administered antimicrobials was 6.30, 6.89, and 7.44 DDDA, respectively. In low-consuming herds, most antimicrobials were being used for dry-cow therapy, whereas in high-consuming herds, most antimicrobials were being used as injectable or intramammary mastitis therapy. The incidence rate of treated mastitis was positively associated with ATI. Herds that applied blanket dry-cow therapy tended to have a higher ATI than herds in which cows were selectively dried off with long-acting antimicrobials. The ATI decreased with an increasing prevalence of primiparous cows.
Douhard, F; Tichit, M; Amer, P R; Friggens, N C
Although most of the genetic progress in production efficiency is achieved through selection at a global scale, locally, farm managers can also influence the selection process to better match genotypes and their varying herd environment. This study focused on the influence of a particular management decision--the use of extended lactation (EL) in dairy goat production systems--as it affects the survival and reproduction rates at the herd level, which may then shape different long-term selection responses. The objective was to understand and quantify the influences of EL and variability in achieved intake level on the responses to selection for production, reproduction, and longevity. An animal model of resource allocation between life functions was applied to the dairy goat. It predicts the trajectory of change in the herd genetic composition as affected by the feeding level and the selection pressure applied by the manager. During 40 yr, goats were selected for milk yield, reproduction, and, with a different selection weight for age (WAGE), for longevity. Under varying achieved intake levels, increasing WAGE improved the survival rate but a nonlinear effect was observed for the average milk yield and BCS. When moderately increasing WAGE from 0, resources were reallocated from lactation towards body reserves and survival, which led to a trade-off at the herd level between improving survival and BCS and increasing milk yield. When further increasing WAGE, old females became systematically preferred regardless of their reproductive status and the proportion of EL in the herd increased. Females undergoing EL had reduced energetic costs of reproduction, which improved their probability of survival. Across generations, an increased herd incidence of EL led to a relaxation of the selection pressure on the resource allocation to body reserves, which is normally imposed by the manager's priority to achieve successful reproduction at each mating. As selection for longevity
Full Text Available Staphylococcus aureus is 1 of the most important causes of bovine mastitis and is responsible for significant economic losses to the dairy industry worldwide. One of the principal approaches used in treating intramammary infections is the administration of antimicrobials. Due to the propensity of S. aureus to develop resistance, antimicrobial susceptibility monitoring is necessary to ensure that treatment regimens are effective. As part of this investigation, 90 S. aureus strains isolated from mastitis cases submitted to Allerton Provincial Veterinary Laboratory during 2008 and 2009 were evaluated for their susceptibility to a panel of 10 antimicrobials. Only 8 of the 90 S. aureus isolates tested (8.9 % were found to be susceptible to all of the antimicrobials evaluated. A very high level of resistance to the beta-lactam antibiotics was noted: 47.8 % of the isolates were resistant to penicillin and 65.6 % were resistant to ampicillin. Minimal resistance to oxacillin, cephalothin and trimethoprim-sulfamethoxazole (1.1 % was found. Seventeen (18.9 % of the isolates tested were found to be resistant to 3 or more antimicrobials. The need for vigilant monitoring of bacterial resistance trends in the dairy industry is warranted as the potential public health implications are significant.
Cook, Nigel B; Nordlund, Kenneth V
Free stall housing increases the exposure of dairy cows' claws to concrete walk-ways and to manure between periods of rest, and generally shows the highest rate of lameness compared with other dairy management systems. However, there is great variation within a system, and the rate of new cases of lameness can be reduced to very low levels provided time spent resting per day is maximized through good stall design, access to stalls through stocking density control and comfortable transition cow facilities, limiting the time spent milking, provision of adequate heat abatement, and good leg hygiene. Sand bedded stalls are useful as they also permit lame cows to maintain adequate daily rest. Rubberized alley flooring surfaces benefit the cow by reducing claw wear and trauma compared to concrete, making them ideal for parlor holding areas and long transfer lanes and walk ways. However, caution is required when using rubber floors in pens with uncomfortable stalls due to apparent adverse effects on cow time budgets, which may in turn have a detrimental effect on lameness.
Habing, Greg G; Manning, Shannon; Bolin, Carole; Cui, Yuehua; Rudrik, James; Dietrich, Stephen; Kaneene, John B
Temporal changes in the distribution of Salmonella subtypes in livestock populations may have important impacts on human health. The first objective of this research was to determine the within-farm changes in the population of subtypes of Salmonella on Michigan dairy farms that were sampled longitudinally in 2000-2001 and again in 2009. The second objective was to determine the yearly frequency (2001 through 2012) of reported human illnesses in Michigan associated with the same subtypes. Comparable sampling techniques were used to collect fecal and environmental samples from the same 18 Michigan dairy farms in 2000-2001 and 2009. Serotypes, multilocus sequence types (STs), and pulsed-field gel electrophoresis (PFGE) banding patterns were identified for isolates from 6 farms where >1 Salmonella isolate was recovered in both 2000-2001 and 2009. The distribution of STs was significantly different between time frames (P Salmonella were due to recovery of MDR subtypes of S. enterica serotypes Senftenberg and Typhimurium in 2000-2001 and genetically distinct, pansusceptible subtypes of the same serotypes in 2009. The annual frequency of human illnesses between 2001 and 2012 with a PFGE pattern matching a bovine strain decreased for patterns recovered from dairy farms in 2000-2001 and increased for patterns recovered in 2009. These data suggest important changes in the population of Salmonella on dairy farms and in the frequency of human illnesses associated with cattle-derived subtypes.
Marta Bañolas Jobim
Full Text Available In this work, through microbiological examinations, the etiology of bovine mastitis in 628 milk samples coming from dairy farms from Paraná, Santa Catarina and Rio Grande do Sul along the year of 2007 were evaluated. Out of this total 1,382 microorganisms were isolated. By taking into account the total of isolations, the following microorganisms and their percentage, respectively were found: Staphylococcus spp. (30.53%, Escherichia coli (21.64%, Streptococcus bovis (17.08%, Streptococcus agalactiae (11.07%, Enterobacter spp. (7.53%, Pseudomonas spp. (4.12% and others (8.03%. The microorganisms grouped into the others are: Streptococcus spp., Proteus spp., gram negative rods, Shigella spp., Alcaligenes spp., Klebsiella spp., Edwarsiella spp., Citrobacter spp., Serratia spp., Salmonella spp. e Corynebacterium spp. The environmental pathogens predominated among the isolated microorganisms; 33.13% of the cultures presented more than three pathogens, suggesting contamination of the samples; in the mounts of November and December, there was an increase of the samples sent.
Peeler, E J; Green, M J; Fitzpatrick, J L; Morgan, K L; Green, L E
A cross-sectional survey of dairy farms with low bulk milk somatic cell counts was carried out to assess the level of clinical mastitis and to quantify risk factors associated with the incidence rate of clinical mastitis. Questionnaires were sent to 3009 milk operations with an annual mean bulk milk somatic cell count of less than 100,000 cells/ml during 1997. A response rate was 61%. The mean incidence of clinical mastitis reported was 22.8 cases per 100 cows/yr. Negative binomial regression models were used to assess statistically significant risk factors associated with the incidence of clinical mastitis. The incidence increased when farmers reported that they had straw yard housing for milking cows (compared with cubicle housing), mucked out the calving area less frequently than once per month, kept cows standing in a yard after milking, always practiced postmilking teat disinfection, had greater than 50% replacement rate, had some cows that leaked milk on entry to the parlor, had some cows that leaked milk at other times, and foremilked before cluster attachment. The incidence of clinical mastitis was lower on farms when the gathering yard used before milking was scraped at least twice a day, cows were offered feed after both milkings, rubber gloves were not worn during milking, teat liners were changed after 6000 milkings, and the average dry period was less than 40 d. The study has identified areas of the environment in which efforts to improve hygiene should be focused.
Full Text Available Milk production performance of dairy buffaloes from 9 herds was evaluated. There were a total of 1,858 305D milk production records containing 13,219 milk test records from 1997 to 2006 available for evaluation. Records were analyzed with general linear model to determine the effect of season, parity and age at calving on standard 305D milk yield. Parity, season of calving and age at calving affected milk yield significantly. Average 305D milk production increased significantly from 864 kg in 1997 to 1244 kg in 2006. Genetic evaluation of milk production traits was also done using the same data set. The model for analysis is a multi-trait full animal model. Only the first three lactations are included in the analysis. The first lactation is divided into three stages namely, 100D, 200D, 300D each being considered as three separate traits. The resulting values from the three traits are combined into one to get the first lactation estimated breeding values (EBV. The genetic correlations between traits were all positive ranging from 0.78 to 0.94 between 100D and 303D of the lactation and between the 2nd and third lactation respectively. Estimates of heritabilities used in the analysis were 0.36, 0.39, 0.30, 0.32, and 0.33, for 100D, 200D, 300D, 2nd lactation and 3rd lactation respectively. The average EBVs of cows were plotted against birth year. The trend was positive with 4 kg and 8.4 kg increase per birth year for the 1st and both the 2nd and 3rd lactation respectively. This positive trend is consistent and may be responsible for the increase in milk production performance of cows. Apparently, selection of replacement animals based on milk production performance of dams and use of imported semen from proven bulls was effective before EBV information on sires and dams are available in the Philippines. The use of EBVs in selection would increase the rate of genetic improvement in dairy buffalo population in the Philippines.
Henriksson, M; Cederberg, C; Swensson, C
Feed production is a significant source of greenhouse gas (GHG) emissions from dairy production and demands large arable and pasture acreage. This study analysed how regional conditions influence GHG emissions of dairy feed rations in a life cycle perspective, that is the carbon footprint (CF) and the land area required. Factors assessed included regional climate variations, grass/clover silage nutrient quality, feedstuff availability, crop yield and feed losses. Using the Nordic feed evaluation model NorFor, rations were optimised for different phases of lactation, dry and growing periods for older cows, first calvers and heifers by regional feed advisors and combined to annual herd rations. Feed production data at farm level were based on national statistics and studies. CF estimates followed standards for life cycle assessment and used emissions factors provided by IPCC. The functional unit was 'feed consumption to produce 1 kg energy corrected milk (ECM) from a cow with annual milk yield of 9 900 kg ECM including replacement animals and feed losses'. Feed ration CF varied from 417 to 531 g CO2 e/kg ECM. Grass/clover silage contributed more than 50% of total GHG emissions. Use of higher quality silage increased ration CF by up to 5% as a result of an additional cut and increased rates of synthetic N-fertiliser. Domestically produced horse bean (Vicia faba), by-products from the sugar industry and maize silage were included in the rations with the lowest CF, but horse bean significantly increased ration land requirement. Rations required between 1.4 to 2 m2 cropland and 0.1 to 0.2 m2/kg semi-natural grassland per kg ECM and year. Higher yield levels reduced ration total CF. Inclusion of GHG emissions from land use change associated with Brazilian soya feed significantly increased ration CF. Ration CF and land use depended on ration composition, which was highly influenced by the regional availability and production of feedstuffs. The impact of individual
Julián Reyes Vélez
Full Text Available The objectives of this study are to determine the occurrence of antimicrobial resistance (AMR genes using whole-genome sequence (WGS of Streptococcus uberis (S. uberis and Streptococcus dysgalactiae (S. dysgalactiae isolates, recovered from dairy cows in the Canadian Maritime Provinces. A secondary objective included the exploration of the association between phenotypic AMR and the genomic characteristics (genome size, guanine–cytosine content, and occurrence of unique gene sequences. Initially, 91 isolates were sequenced, and of these isolates, 89 were assembled. Furthermore, 16 isolates were excluded due to larger than expected genomic sizes (>2.3 bp × 1,000 bp. In the final analysis, 73 were used with complete WGS and minimum inhibitory concentration records, which were part of the previous phenotypic AMR study, representing 18 dairy herds from the Maritime region of Canada (1. A total of 23 unique AMR gene sequences were found in the bacterial genomes, with a mean number of 8.1 (minimum: 5; maximum: 13 per genome. Overall, there were 10 AMR genes [ANT(6, TEM-127, TEM-163, TEM-89, TEM-95, Linb, Lnub, Ermb, Ermc, and TetS] present only in S. uberis genomes and 2 genes unique (EF-TU and TEM-71 to the S. dysgalactiae genomes; 11 AMR genes [APH(3′, TEM-1, TEM-136, TEM-157, TEM-47, TetM, bl2b, gyrA, parE, phoP, and rpoB] were found in both bacterial species. Two-way tabulations showed association between the phenotypic susceptibility to lincosamides and the presence of linB (P = 0.002 and lnuB (P < 0.001 genes and the between the presence of tetM (P = 0.015 and tetS (P = 0.064 genes and phenotypic resistance to tetracyclines only for the S. uberis isolates. The logistic model showed that the odds of resistance (to any of the phenotypically tested antimicrobials was 4.35 times higher when there were >11 AMR genes present in the genome, compared with <7 AMR genes (P < 0.001. The odds of resistance was lower for S
López-Gatius, F; Santolaria, P; Yániz, J; Rutllant, J; López-Béjar, M
The present study was designed to establish whether factors such as previous estrus synchronization, corpus luteum and embryo number at the time of pregnancy diagnosis, changes in body condition score, milk production, clinical disease (mastitis or lameness) and the inseminating bull affect pregnancy loss from 38 to 90 days of gestation. We derived data from 601 pregnant lactating dairy cows from a single herd. Pregnancy diagnosis was performed by ultrasonography between Day 38 and 44 following insemination. We also recorded corpus luteum and embryo number at this time. Pregnancy loss was defined as a negative pregnancy diagnosis on the second palpation per rectum undertaken between 90 and 96 days after insemination. Data were analyzed using multiple logistic regression methods. Cows that had an additional corpus luteum were eight times less likely to miscarry. The risk of pregnancy loss was 3.1 times higher in cows bearing twins. A one unit reduction in body condition score from previous partum to 30 days postpartum resulted in a 2.4-fold increase in pregnancy loss. We noted a higher incidence of pregnancy loss in cows inseminated using semen from one of the six bulls used. This particular bull led to a 3.4-fold increase in the rate of pregnancy loss. Logistic regression analysis showed no significant effects of previous estrus synchronization, milk production, clinical disease, body condition at previous partum or at pregnancy diagnosis, or body condition change between previous partum and pregnancy diagnosis. Our findings indicate a positive relationship between the presence of an additional corpus luteum and the maintenance of gestation. Risk factors for pregnancy loss were twin pregnancy, reduced body condition after previous parturition and the inseminating bull.
Wareth, Gamal; Melzer, Falk; Böttcher, Denny; El-Diasty, Mohamed; El-Beskawy, Mohamed; Rasheed, Nesma; Schmoock, Gernot; Roesler, Uwe; Sprague, Lisa D; Neubauer, Heinrich
Bovine brucellosis is endemic in Egypt in spite of application of surveillance and control measures. An increase of abortions was reported in a Holstein dairy cattle herd with 600 animals in Damietta governorate in Egypt after immunisation with Brucella (B.) abortus RB51 vaccine. Twenty one (10.6%) of 197 vaccinated cows aborted after 3 months. All aborted cows had been tested seronegative for brucellosis in the past 3 years. B. abortus was isolated from four foetuses. Conventional biochemical and bacteriological identification and polymerase chain reaction (PCR) confirmed two B. abortus biovar (bv.) 1 smooth and two B. abortus rough strains. None of the B. abortus isolates were identified as RB51. Genotyping analysis by multiple locus of variable number tandem repeats analysis based on 16 markers (MLVA-16) revealed two different profiles with low genetic diversity. B. abortus bv1 was introduced in the herd and caused abortions.
León-Galván, Ma Fabiola; Barboza-Corona, José E; Lechuga-Arana, A Arianna; Valencia-Posadas, Mauricio; Aguayo, Daniel D; Cedillo-Pelaez, Carlos; Martínez-Ortega, Erika A; Gutierrez-Chavez, Abner J
Thirty-two farms (n = 535 cows) located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM) and clinical mastitis (CLM) were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins of Bacillus thuringiensis was tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT) (≥3) and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages for test day milk yield (MY), lactation number (LN), herd size (HS), and number of days in milk (DM) were 20.6 kg, 2.8 lactations, 16.7 animals, and 164.1 days, respectively. MY was dependent on dairy herd (DH), LN, HS, and DM (P antibiotics tested in this study.
Bittante, G; Cipolat-Gotet, C; Malchiodi, F; Sturaro, E; Tagliapietra, F; Schiavon, S; Cecchinato, A
The objectives of this study were to characterize the variation in curd firmness model parameters obtained from coagulating bovine milk samples, and to investigate the effects of the dairy system, season, individual farm, and factors related to individual cows (days in milk and parity). Individual milk samples (n = 1,264) were collected during the evening milking of 85 farms representing different environments and farming systems in the northeastern Italian Alps. The dairy herds were classified into 4 farming system categories: traditional system with tied animals (29 herds), modern dairy systems with traditional feeding based on hay and compound feed (30 herds), modern dairy system with total mixed ration (TMR) that included silage as a large proportion of the diet (9 herds), and modern dairy system with silage-free TMR (17 herds). Milk samples were analyzed for milk composition and coagulation properties, and parameters were modeled using curd firmness measures (CFt) collected every 15 s from a lacto-dynamographic analysis of 90 min. When compared with traditional milk coagulation properties (MCP), the curd firming measures showed greater variability and yielded a more accurate description of the milk coagulation process: the model converged for 93.1% of the milk samples, allowing estimation of 4 CFt parameters and 2 derived traits [maximum CF (CF(max)) and time from rennet addition to CF(max) (t(max))] for each sample. The milk samples whose CFt equations did not converge showed longer rennet coagulation times obtained from the model (RCT(eq)) and higher somatic cell score, and came from less-productive cows. Among the sources of variation tested for the CFt parameters, dairy herd system yielded the greatest differences for the contrast between the traditional farm and the 3 modern farms, with the latter showing earlier coagulation and greater instant syneresis rate constant (k(SR)). The use of TMR yielded a greater tmax because of a higher instant curd
Hospido, Almudena [Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain)]. E-mail: email@example.com; Sonesson, Ulf [Swedish Institute for Food and Biotechnology (SIK), PO Box 5401, SE-402 29 Goeteborg (Sweden)
Mastitis is defined as an inflammatory reaction of udder tissue to bacterial, chemical, thermal or mechanical injury, which causes heavy financial losses and milk wastage throughout the world. Until now, studies have focused on the economic aspects from which perspective mastitis can generally be considered as the most serious disease in dairy cows; however, costs are not the only negative consequence resulting from the infection. The environmental impact is also significant; milk is discarded, which means lower efficiency and hence a greater environmental impact per produced liter of milk. Less milk is produced, which leads to an increased need for calf feed, and meat production is also affected. The main aim of this paper was to quantify the environmental impact of mastitis incidence. A standard scenario (representative of present-day reality in Galicia, Spain) and an improved scenario (in which mastitis incidence rate is reduced by diverse actions) have been defined and compared using Life Cycle Assessment (LCA) methodology. Among the impact categories studied, acidification, eutrophication and global warming were found to be the most significant environmental impacts. In all these categories, it was revealed that a decrease in mastitis incidence has a positive influence as the environmental impact is reduced. Even if the quantitative results cannot show a considerable decrease in the environmental burden, the impact cannot be regarded as negligible when the total consumption or total production of a region is considered. For example, the outcome of the proposed improvement measures for Spain's greenhouse gas emissions can be quantified as 0.06% of total emissions and 0.56% of emissions by the agricultural sector.
Andrey Pinzón Trujillo
Full Text Available The purpose of this work was to carry out a study about the effects of subclinical mastitis in cows of 34 dairy farms in the Upper Chicamocha region (Boyacá department.The farms are registered in the livestock farmers association of Boyacá (FABEGAN. This study was done with the aim to know about the infection status of cows and establish which are the principal etiologic agents associated with the disease and its relation with the milking routine. To this aim, applied comparison even tests for the productive variables to relate with the California Mastitis Test (CMT and the microbiological characterization, a blocks design under factorial 2 x 4 array to analyze the existence of significant differences between the mastitis grades, the sample season and its interaction, and blocks design under factorial 2 x 4 array to analyze the existence of significant differences among the mastitis subclinical grades, the sampling season and its interaction. 6616 quarters were submitted to the California Mastitis Test (CMT in two times and different season. The results did not show any significant differences between the two times of sampling. The positive samples according with CMT (CMT-2 and CMT-3 were submitted to microbiological tests where, in the most of the cases of mastitis, the presence of Streptococcus agalactiae and Staphylococcus aureus was detected. They are the main etiologic agents in the disease. The results indicate the close relation between the milking routine and mastitis. The deficient practices in the milking process are the cause of dissemination and prevalence of mastitis in farms.
Peralta, O A; Pearson, R E; Nebel, R L
The objective of the study was to compare three systems for estrus detection and combinations of these systems on a large commercial dairy (1075 lactating cows) during stress of summer heat. At 37-45 days in milk (DIM), 255 cows were fitted with a HeatWatch device (HW; DDx Inc., Denver, CO), an activity sensor ALPRO (ALPRO; DeLaval Inc., Kansas City, MO), and visually observed (VO) three times daily. Pregnancy status was determined by uterine palpation per rectum 35-49 days following artificial insemination (AI). Effects of DIM, parity, standing events, inseminator, and interval between onset of estrus and AI on conception rates were determined using logistic regression. Efficiencies for detection of estrus, determined by comparing detected periods of estrus with a theoretical total of 570 periods, were 49.3% (VO), 37.2% (ALPRO), 48.0% (HW), and 80.2% for all three systems simultaneously. Conception rates (LSM+/-S.E.) for cows detected by one or more of the three systems were 6.2+/-3.9 for VO, 19.8+/-5.6 for ALPRO, 17.3+/-5.0 for HW, 22.8+/-7.0 for VO+ALPRO, 26.9+/-4.6 for VO+HW, 23.2+/-5.2 for ALPRO+HW, and 18.4+/-4.7 for VO+ALPRO+HW. Inseminations performed during no and mild heat stress (temperature-humidity index; THIheat stress conditions (THI>76; 17.6%). Number of mounts were higher for primiparous versus multiparous cows (PCows over 80 DIM during estrus exhibited fewer (Pdetection.
Slavica Golc Teger
Full Text Available Factors affecting the freezing point of milk in a herd of 200 Black and White cows with the average milk yield of 8 386 kg in the lactation and 8 328 kg in the standard lactation were examinated. Over the period of one year (2002 and based upon 1 773 individual monthly collected milk samples with the average contents of 3.91% fat, 3.26% protein, 4.54% lactose, 33.4 mg/100 ml urea and 331000 somatic cells per ml in milk were determined. The average freezing point of milk (n = 1 680 was estimated to be –0.527 ºC, with a range from -0.562 ºC to -0.423 ºC. In 210 (12.5% samples was higher than -0.515 ºC. The lowest freezing point (-0.532 ºC was found in the samples collected in the first month after calving and highest (-0.522 ºC in the samples of 12th month of lactation. The differences between the freezing point of milk after the first and the second calving (-0.530 ºC; P < 0.05 and those after the fifth calving (-0.523 ºC; P < 0.05 were also significant. The samples collected in month from January to April (-0.538 ºC to -0.532 ºC were significantly lower in comparison to samples collected in May and June (-0.517 ºC and -0.519 ºC. The following statistically significant correlation coefficients between cows' properties, milk composition and the freezing point of milk were found: month of lactation r = 0.233 (P < 0.001; lactation number r = 0.196 (P < 0.001; age of cows (years r = 0.231 (P < 0.001; month of the year r = 0.0253 (P < 0.001; milk yield per milking day r = -0.106 (P < 0.001; fat corrected milk content (FCM per milking day r = -0.234 (P < 0.001; lactose % r = -0.530 (P < 0.001; fat % r = -0.351 (P < 0.001; protein % r = 0.058 (P < 0.05; urea mg/100 mL r = 0.091 (P < 0.001 and somatic cell count r = 0.154 (P < 0.001. The sum of effects (month of the year, lactation lenght and fat, protein and lactose content of milk was found to account for about 70% variability of the total depression of milk freezing point (R2 = 0.698.
Schou, Kirstine Klitgaard; Weiss Nielsen, Martin; Ingerslev, Hans-Christian;
The bacteria associated with the infectious claw disease bovine digital dermatitis (DD) are spirochetes of the genus Treponema; however, their environmental reservoir remains unknown. To our knowledge, the current study is the first report of the discovery and phylogenetic characterization of r......RNA gene sequences from DD-associated treponemes in the dairy herd environment. Although the spread of DD appears to be facilitated by wet floors covered with slurry, no DD-associated treponemes have been isolated from this environment previously. Consequently, there is a lack of knowledge about the spread...
Rugbjerg, Helene; Nielsen, Eva Møller; Andersen, Jens Strodl
A risk-factor study was performed in eight dairy herds found to excrete verocytotoxin-producing Escherichia coli (VTEC) O157 in a former prevalence study. Associations between excretion of VTEC O157 and management factors such as housing and feeding were analysed in a generalised linear mixed model....... The animals were stratified in three age groups and sampled four times during I year. The risk of excreting VTEC O157 was higher among weaned calves than non-weaned calves. Among the calves aged 1-4 months, the risk was reduced if the calf had suckled colostrum from the mother or if the calf had stayed >2...
Simon C Archer
Full Text Available This study predicts the magnitude and between herd variation in changes of methane emissions and production efficiency associated with interventions to improve reproductive efficiency in dairy cows. Data for 10,000 herds of 200 cows were simulated. Probability of conception was predicted daily from the start of the study (parturition for each cow up to day 300 of lactation. Four scenarios of differing first insemination management were simulated for each herd using the same theoretical cows: A baseline scenario based on breeding from observed oestrus only, synchronisation of oestrus for pre-set first insemination using 2 methods, and a regime using prostaglandin treatments followed by first insemination to observed oestrus. Cows that did not conceive to first insemination were re-inseminated following detection of oestrus. For cows that conceived, gestation length was 280 days with cessation of milking 60 days before calving. Those cows not pregnant after 300 days of lactation were culled and replaced by a heifer. Daily milk yield was calculated for 730 days from the start of the study for each cow. Change in mean reproductive and economic outputs were summarised for each herd following the 3 interventions. For each scenario, methane emissions were determined by daily forage dry matter intake, forage quality, and cow replacement risk. Linear regression was used to summarise relationships. In some circumstances improvement in reproductive efficiency using the programmes investigated was associated with reduced cost and methane emissions compared to reliance on detection of oestrus. Efficiency of oestrus detection and the time to commencement of breeding after calving influenced variability in changes in cost and methane emissions. For an average UK herd this was a saving of at least £50 per cow and a 3.6% reduction in methane emissions per L of milk when timing of first insemination was pre-set.
Wüthrich, M; Lechner, I; Aebi, M; Vögtlin, A; Posthaus, H; Schüpbach-Regula, G; Meylan, M
Schmallenberg virus (SBV) was first detected in Switzerland in July 2012 and many Swiss dairy farmers reported acute clinical signs in dairy cattle during the spread of the virus until December 2012. The objectives of the present study were to investigate the effects of an acute infection with SBV on milk yield, fertility and veterinary costs in dairy farms with clinical signs of SBV infection (case farms), and to compare those farms to a matched control group of dairy farms in which cattle did not show clinical signs of SBV infection. Herd size was significantly (pcase farms (33 cows, n=77) than in control farms (25 cows, n=84). Within case herds, 14.8% (median) of the cows showed acute clinical signs. Managers from case farms indicated to have observed a higher abortion rate during the year with SBV (6.5%) than in the previous year (3.7%). Analysis of fertility parameters based on veterinary bills and data from the breeding associations showed no significant differences between case and control farms. The general veterinary costs per cow from July to December 2012 were significantly higher (p=0.02) in case (CHF 19.80; EUR 16.50) than in control farms (CHF 15.90; EUR 13.25). No differences in milk yield were found between groups, but there was a significant decrease in milk production in case farms in the second half year in 2012 compared to the same period in 2011 (pclinical signs (n=461) were treated by a veterinarian. The average calculated loss after SBV infection for a standardized farm was CHF 1606 (EUR 1338), which can be considered as low at the national level, but the losses were subject to great fluctuations between farms, so that individual farms could have very high losses (>CHF 10,000, EUR 8333).
Nylin, Britta; Strøger, Ulla; Rønsholt, Leif
and relative specificity were 82 and 100%, respectively. The herd-level relative sensitivity depended on the within-herd prevalence of seropositive cows and the cut-off value in the assay, but not on the time interval (up to 90 days) between the collection of the bulk-tank milk sample and the individual serum......Bulk-tank milk samples analysed in a Bovine Herpesvirus-1 (BHV-1) blocking ELISA are still in use in the Danish BHV-1 programme as a tool to classify dairy herds as BHV-1 infected or BHV-1 free herds. in this retrospective study, we used data from the Danish BHV-1 eradication campaign to evaluate...... samples. The BHV-1 blocking ELISA on bulk-tank milk could detect seropositive herds (few), with prevalence proportions as low as one seropositive cow out of 70 cows....
Juan Zambrano A.
Full Text Available Objective. To determine the associations of BoLA DRB3.2 alleles present in Holstein and BON x Holstein cattle to production and milk quality traits in a dairy herd of Antioquia, Colombia. Materials and methods. Ninety-one cows, 66 Holstein and 25 BxH, were genotyped for the BoLA DRB3.2 gene, through PCR-RFLP technique. Furthermore, the association of the alleles of the gene BoLA DRB3.2 with milk yield (PL305, fat yield (PG305, protein yield (PP305 fat percentage (PGRA and protein percentage (PPRO were determined, using a general linear model. Results. Twenty-seven BoLA DRB3.2 alleles were identified; the most frequent alleles in Holstein were: BoLA DRB3.2*23, 22, and 24 with frequencies of: 0.159, 0.129, and 0.106, respectively and the most frequent alleles in BxH were: BoLA DRB3.2*23, 24 and 20 with frequencies of: 0.20, 0.140, and 0.120, respectively. Associations of BoLA DRB3.2 alleles with production and milk quality traits were also determined. In Holstein cows the BoLA DRB3.2*36 allele was associated with low PL305 (p≤0.01, high PGRA in multiparous cows (p≤0.05 and high PG305 in primiparous cows (p≤0.01. The BoLA DRB3.2*33 allele was associated with increased in the PPRO in multiparous cows (p≤0.01. In BXH cows only the BoLA DRB3*19 allele was associated with high PGRA (p≤0.05. Conclusions. The gene BoLA DRB3.2 shows high polymorphism in both groups; Holstein and BxH and some of its allelic variants were associated with production and milk quality traits.
Cortimiglia, C; Luini, M; Bianchini, V; Marzagalli, L; Vezzoli, F; Avisani, D; Bertoletti, M; Ianzano, A; Franco, A; Battisti, A
Staphylococcus aureus is the most important causative agent of subclinical mastitis in cattle resulting in reduced milk production and quality. Methicillin-resistant S. aureus (MRSA) strains has a clear zoonotic relevance, especially in the case of occupational exposure. The aim of the study was to evaluate the prevalence of S. aureus and MRSA in bulk tank milk (BTM) from dairy cattle herds in the Lombardy Region (Northern Italy) and to identify the main MRSA circulating genotypes. MRSA strains were characterized by susceptibility testing, multi-locus sequence typing (MLST), spa typing and SCCmec typing. A total 844 BTM samples were analysed and S. aureus and MRSA were detected in 47·2% and 3·8% of dairy herds, respectively. MLST showed that the majority (28/32) of isolates belonged to the typical livestock-associated lineages: ST398, ST97 and ST1. Interestingly, in this study we report for the first time the new ST3211, a single locus variant of ST(CC)22, with the newly described 462 aroE allele. Our study indicates high diffusion of S. aureus mastitis and low, but not negligible, prevalence of MRSA in the considered area, suggesting the need for planning specific control programmes for bovine mastitis caused by S. aureus, especially when MRSA is implicated.
Ranasinghe, R M S B K; Nakao, T; Kobayashi, A
Oestrus detection error and conception rates after AI based only on secondary oestrus signs were evaluated in a high yielding, 24-h tie-stalled dairy herd with low fertility, using milk progesterone profiles. Oestrus detection was based on the secondary oestrus signs such as restlessness, swelling, congestion of vulva and clear mucus discharge. Sixty eight AI conducted after observing the secondary oestrus signs in 44 animals were included in the study. Of the 68 AI, 53 (77.9%) were conducted in the follicular phase, and 13 (19.1%) and 2 (2.9%) were carried out in the luteal phase and during pregnancy, respectively. The overall error in oestrus detection based on milk progesterone profiles was 22.1%. The oestrus detection error did not differ significantly among different secondary oestrus signs. None of the AI conducted in the luteal phase resulted in conception, whereas 20.8% of AI conducted in the follicular phase resulted in conception. No significant difference in the conception rates among the groups of cows with different secondary oestrus signs was shown. The high incidence of oestrus detection error in this study might have been caused by the detection of cows in oestrus based only on secondary oestrus signs due to the confinement of animals. In conclusion, there was a high incidence of heat detection error in the 24-h tie-stalled dairy herd and oestrus detection based only on secondary oestrus signs resulted in low conception rate.
Raspanti, Claudia G; Bonetto, Cesar C; Vissio, Claudina; Pellegrino, Matías S; Reinoso, Elina B; Dieser, Silvana A; Bogni, Cristina I; Larriestra, Alejandro J; Odierno, Liliana M
Coagulase-negative staphylococci (CNS) are a common cause of bovine subclinical mastitis (SCM). The prevalence of CNS species causing SCM identified by genotyping varies among countries. Overall, the antimicrobial resistance in this group of organisms is increasing worldwide; however, little information exists about a CNS species resistant to antibiotics. The aim of the present study was to genotypically characterize CNS at species level and to determine the prevalence and antibiotic resistance profiles of CNS species isolated from bovine SCM in 51 dairy herds located in the central region of the province of Cordoba, Argentina. In this study, we identified 219 CNS isolates at species level by PCR-restriction fragment length polymorphism of the groEL gene. Staphylococcus chromogenes (46.6%) and Staphylococcus haemolyticus (32%) were the most prevalent species. A minimum of three different CNS species were present in 41.2% of the herds. S. chromogenes was isolated from most of the herds (86.3%), whereas S. haemolyticus was isolated from 66.7% of them. The broth microdilution method was used to test in vitro antimicrobial susceptibility. Resistance to a single compound or two related compounds was expressed in 43.8% of the isolates. S. chromogenes and S. haemolyticus showed a very high proportion of isolates resistant to penicillin. Resistance to two or more non-related antimicrobials was found in 30.6% of all CNS. S. haemolyticus exhibited a higher frequency of resistance to two or more non-related antimicrobials than S. chromogenes.
Houe, H.; Baker, J.C.; Maes, R.K.;
for the individual farms on age distribution, housing of animals, herd size, pasturing and purchasing policy was gathered. The prevalence of PI animals was more than 10 times higher in Denmark as compared to Michigan. In herds without PI animals, the annual incidence of seroconversion as calculated from the age...... purchased more than 40 animals within recent 3 1/2-4 years were significantly associated with presence of PI animals in the dairy herds (p = 0.01) when tested by the Mantel-Haenszel chi 2. Using multivariable logistic regression, the occurrence of PI animals was found to be significantly related...... to the study area (Michigan and Denmark) as well as to herd size and purchase intensity....
Van den Brom, R; Santman-Berends, I; Luttikholt, S; Moll, L; Van Engelen, E; Vellema, P
In the period from 2005 to 2009, Coxiella burnetii was a cause of abortion waves at 28 dairy goat farms and 2 dairy sheep farms in the Netherlands. Two years after the first abortion waves, a large human Q fever outbreak started mainly in the same region, and aborting small ruminants were regarded as most probable source. To distinguish between infected and noninfected herds, a surveillance program started in October 2009, based on PCR testing of bulk tank milk (BTM) samples, which had never been described before. The aim of this study was to analyze the effectiveness of this surveillance program and to evaluate both the effect of culling of pregnant dairy goats on positive farms and of vaccination on BTM results. Bulk tank milk samples were tested for C. burnetii DNA using a real-time PCR, and results were analyzed in relation to vaccination, culling, and notifiable (officially reported to government) C. burnetii abortion records. In spring and autumn, BTM samples were also tested for antibodies using an ELISA, and results were evaluated in relation to the compulsory vaccination campaign. Between October 2009 and April 2014, 1,660 (5.6%) out of 29,875 BTM samples from 401 dairy goat farms tested positive for C. burnetii DNA. The percentage of positive samples dropped from 20.5% in 2009 to 0.3% in 2014. In a multivariable model, significantly higher odds of being PCR positive in the BTM surveillance program were found in farms of which all pregnant dairy goats were culled. Additionally, the risk for C. burnetii BTM PCR positivity significantly decreased after multiple vaccinations. Bulk tank milk ELISA results were significantly higher after vaccination than before. The ELISA results were higher after multiple vaccinations compared with a single vaccination, and ELISA results on officially declared infected farms were significantly higher compared with noninfected farms. In conclusion, BTM surveillance is an effective and useful tool to detect C. burnetii shedding
Ståhl, K; Björkman, C; Emanuelson, U; Rivera, H; Zelada, A; Moreno-López, J
We used a prospective seroepidemiological approach to investigate endemic abortion in a dairy herd in Arequipa, Peru, and its association with Neospora caninum and bovine viral-diarrhoea virus (BVDV) infections. Between January 2002 and March 2004, 1094 pregnancies were confirmed in 538 cows. Of these, 137 pregnancies (13%) in 121 cows ended in abortion. The serological status to N. caninum was assessed using a single serological screening, whereas BVDV status was assessed at the herd level through consecutive samplings of young stock. Cox proportional-hazards models were used to estimate the effect of N. caninum and BVDV on the hazard of early (between day 42 and day 100 in gestation), and late (after day 100) abortions, respectively. Serological status to N. caninum was included as a dichotomous variable, and the effect of BVDV estimated at the herd level, as a time-dependent seasonal effect. Because data from repeated pregnancies were included, we considered possible lack of independence between observations and included frailty effects into the models. Our models also considered the possible confounding by parity and animal origin. Only multiparity was associated with the hazard of early abortion (HR=2.8 compared to nulliparous heifers). N. caninum seropositivity significantly affected the hazard of late abortion, but interacted with parity. The HRs for Neospora-positive animals were 6.4, 3.7 and 1.9, respectively, for nulliparous heifers, first-lactation cows and multiparous cows. Evidence of BVDV circulating (or not) among the young stock was not associated with abortions, but few cows in this herd were susceptible to incident infection.
The recent dairy farms in Hokkaido have been increasing the amount of production milk yield by the scale expansion of production facilities and increase in the number of cows. A new machine and a new technology were adopted, and dependence on concentrate feeds became higher in the nourishment of the cow. Furthermore, the production system in dairy farms changed from grazing to housing to maintain stable milk production and stable milk quality. A figure of grazing style in dairy farms disappe...
To estimate time to seroconversion to vesicular stomatitis 1 New Jersey virus (VSNJV) in sentinel cattle in southern Mexico, ninety-two sentinel cattle in four free-ranging dairy herds at high- (=500 mts) and low-elevation (<500 mts) locations in southern Mexico were studied. A prospective cohort s...
Græsbøll, Kaare; Kirkeby, Carsten Thure; Nielsen, Søren Saxmose
The future value of an individual dairy cow depends greatly on its projected milk yield. In developed countries with developed dairy industry infrastructures, facilities exist to record individual cow production and reproduction outcomes consistently and accurately. Accurate prediction of the fut...
Nielsen, C; Østergaard, Søren; Emanuelson, U
no clinical mastitis (CM) while keeping the incidence of subclinical mastitis (SCM) constant and vice versa. Six different strategies to withdraw milk with high SCC were compared. The decision to withdraw milk was based on herd-level information in three scenarios: withdrawal was initiated when the predicted......% of the herd net return given the initial incidence of mastitis. Expressed per cow-year, the avoidable cost of mastitis was €55. The costs per case of CM and SCM were estimated at €278 and €60, respectively. Withdrawing milk with high SCC was never profitable because this generated a substantial amount of milk...... resulted in less negative effect on net return. It was concluded that the current milk-pricing system makes it more profitable for farmers to sell a larger amount of milk with higher SCC than to withdraw milk with high SCC to obtain payment premiums, at least in herds with mastitis incidences within...
Blowey, R W; Collis, K
An iodophor teat disinfectant was applied before milking by dip or spray to 50 cows and 50 cows were left untreated in each of three commercial herds. The mean incidence of clinical mastitis was reduced by 57 per cent, the total bacterial count by 70 per cent and the count of thermoduric organisms by 32 per cent. These results were not statistically significant, except that one herd showed a significant decrease in total bacterial count. There was no effect on somatic cell count, milk production or milk iodine residues. Atmospheric iodine concentrations increased in the two herds which applied the treatment as a spray, but the levels attained were not likely to be detrimental to human health.
Tarazi, Yaser H; Abo-Shehada, Mahmoud N
Salmonellosis is an important disease frequently associated with diarrhea in calves. From January to September 2009, a cross-sectional study involving 91 dairy farms was conducted to determine the prevalence of Salmonella spp. infection in cattle in Al-Dhulail Valley, Jordan. A total of 910 calve and cow fecal samples were collected. Information on farm management practices was obtained through personal interviews using a standardized questionnaire and was tested as risk factors for Salmonella spp. positivity in farms by using logistic regression analysis. Standard conventional methods for Salmonella isolation and serotyping were used, and the disk agar diffusion test was used for antimicrobial testing. The herd-level prevalence of Salmonella spp. in calves, cows, and dairy farms was 12, 12, and 23 %, respectively, and the individual-level prevalence was 4 % for calves, cows, and dairy farms. Forty-six percent of the dairy farms had calf diarrhea, and 4 % had cow diarrhea. Seven (17 %) of the 42 farms with calf diarrhea had Salmonella. However, only 7 % (95 % CI: 4, 10) of the 221 diarrheic and 1 % (95 % CI: 0.2, 4) of the 234 of non-diarrheic calves had Salmonella. A total of 33 Salmonella isolates were obtained from the fecal samples: 12 isolates were Salmonella typhimurium, 6 were Salmonella montevideo, 6 were Salmonella anatum, 2 were Salmonella enteritidis, and 7 isolates were not serotyped. All isolates were susceptible to ciprofloxacin, trimethoprim-sulfamethoxazole, gentamycin, neomycin, colisitin, and amoxicillin at 100, 91, 85, 79, 79, and 70 %, respectively. Out of the 11 variables/categories, the frequency of cleaning every 2 months or more was associated with high odds of infection among calves (OR = 5.6) and farms (OR = 7.0).
Abu Elzein, Eltayb; Alkhalyifa, Mofeed
Little information is published, so far, regarding bovine viral diarrhea (BVD) in Saudi Arabia and the Gulf region. This study is the first of its kind in the country. Its aim was to explore the BVD situation in a large dairy farm, which has been experiencing reproduction problems suggestive of BVD virus infection, albeit the practice of routine vaccination. The study took two pathways; the first involved establishment of a cohort of sentinel calves so as: (a) to note the BVD virus activity in the farm by following the time lapse and pattern for waning of the maternally derived antibodies and detection of any subsequent seroconversion and (b) to look for any clinical signs suggestive of BVD virus infection in these calves. The second pathway was to assess the level of herd immunity in the different age groups of lactating cows and maiden heifers. The obtained results were discussed, and control strategies were outlined.
Vlkova, H; Babak, V; Vrtkova, I; Cervinkova, D; Marosevic, D; Moravkova, M; Jaglic, Z
The aim of the present work was to examine a dairy herd with an anamnesis of recurrent clinical mastitis and decreased milk production. A total of 239 individual cow milk samples originating from asymptomatic cows were collected at four-month intervals and examined mainly for the presence of Staphylococcus aureus and mastitis streptococci using standard cultivation methods. In total, 29.7% and 9.2% samples were positive for S. aureus and mastitis streptococci, respectively. Unlike for mastitis streptococci, the prevalence of animals positive for S. aureus had an increasing trend (pmastitis, reproductive and periparturient disorders and administration of antibiotics. In contrast to S. aureus, the occurrence of mastitis streptococci in milk was linked with previous cases of clinical mastitis and intramammary administration of antibiotics.
Ma. Fabiola León-Galván
Full Text Available Thirty-two farms (n=535 cows located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM and clinical mastitis (CLM were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins of Bacillus thuringiensis was tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT (≥3 and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages for test day milk yield (MY, lactation number (LN, herd size (HS, and number of days in milk (DM were 20.6 kg, 2.8 lactations, 16.7 animals, and 164.1 days, respectively. MY was dependent on dairy herd (DH, LN, HS, and DM P<0.01, and correlations between udder quarters from the CMT were around 0.49 P<0.01. Coagulase-negative staphylococci were mainly identified, as well as Staphylococcus aureus, Streptococcus uberis, Brevibacterium stationis, B. conglomeratum, and Staphylococcus agnetis. Bacterial isolates were resistant to penicillin, clindamycin, ampicillin, and cefotaxime. Bacteriocins synthesized by Bacillus thuringiensis inhibited the growth of multiantibiotic resistance bacteria such as S. agnetis, S. equorum, Streptococcus uberis, Brevibacterium stationis, and Brachybacterium conglomeratum, but they were not active against S. sciuri, a microorganism that showed an 84% resistance to antibiotics tested in this study.
Souto, Luís I M; Minagawa, Clarice Y; Telles, Evelise O; Garbuglio, Márcio A; Amaku, Marcos; Melville, Priscilla A; Dias, Ricardo A; Sakata, Sonia T; Benites, Nilson R
Milk is the normal secretion of the mammary gland, practically free of colostrum and obtained by the complete milking of one or more healthy animals. Mastitis is an inflammatory process of the mammary gland and it may cause alterations in the milk. The present work aimed to verify whether it is possible, by means of the counts of microorganism in the bulk raw milk in four selective culture media, to establish a correlation with the occurrence of mastitis and therefore, to monitor this disease in bovine dairy herds. The following selective culture media were used: KF Streptococcus Agar, Edwards Agar, Baird-Parker Agar, Blood Agar plus potassium tellurite. Spearman's correlation coefficient was calculated in order to compare the occurrence of mastitis (percentage) in each herd with respective selective culture media counts of microorganisms in bulk raw milk. Thirty-six possibilities were analysed (Tamis and CMT-positive rates were compared with the log-transformed count in four selective culture media) and there was a negative correlation between Tamis 3 and the Baird-Parker Agar plate count. The total results of microbiological tests showed that there were three correlations of the counts in selective culture media. Fifty-two possibilities were analysed and there was a negative correlation between no-bacterial-growth mastitis rates and log10 of KF Streptoccocus Agar plate count and there were two positive correlations between coagulase-positive staphylococci and log10 of Baird-Parker Agar plate count and Blood Agar plus potassium tellurite plate count.
Vosough Ahmadi, Bouda; Frankena, Klaas; Turner, Joanne; Velthuis, Annet G J; Hogeveen, Henk; Huirne, Ruud B M
A transmission model developed to investigate the dynamics of Escherichia coli O157:H7 bacteria in a typical Dutch dairy herd was used to assess the effectiveness of vaccination, diet modification, probiotics (colicin) and hygienic measures as to water troughs and bedding, when they are applied single or in combination, in reducing the prevalence of infected animals. The aim was to rank interventions based on their effectiveness in reducing the baseline prevalence of infected animals in the lactating group. The baseline prevalence of the lactating group and the within-herd prevalence were estimated by the model to be 5.02% and 13.96% respectively. The results show that all four interventions, if applied to all four animal groups or only to young stock, are the most effective and will reduce the baseline prevalence by 84% to 99%. In general, combinations of hygiene (applied in all groups) and one other intervention had the highest effectiveness in reducing prevalence in the lactating group. Vaccination and diet modification show a slightly higher effectiveness than colicin and hygiene.
León-Galván, Ma. Fabiola; Barboza-Corona, José E.; Lechuga-Arana, A. Arianna; Valencia-Posadas, Mauricio; Aguayo, Daniel D.; Cedillo-Pelaez, Carlos; Martínez-Ortega, Erika A.; Gutierrez-Chavez, Abner J.
Thirty-two farms (n = 535 cows) located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM) and clinical mastitis (CLM) were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins of Bacillus thuringiensis was tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT) (≥3) and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages for test day milk yield (MY), lactation number (LN), herd size (HS), and number of days in milk (DM) were 20.6 kg, 2.8 lactations, 16.7 animals, and 164.1 days, respectively. MY was dependent on dairy herd (DH), LN, HS, and DM (P < 0.01), and correlations between udder quarters from the CMT were around 0.49 (P < 0.01). Coagulase-negative staphylococci were mainly identified, as well as Staphylococcus aureus, Streptococcus uberis, Brevibacterium stationis, B. conglomeratum, and Staphylococcus agnetis. Bacterial isolates were resistant to penicillin, clindamycin, ampicillin, and cefotaxime. Bacteriocins synthesized by Bacillus thuringiensis inhibited the growth of multiantibiotic resistance bacteria such as S. agnetis, S. equorum, Streptococcus uberis, Brevibacterium stationis, and Brachybacterium conglomeratum, but they were not active against S. sciuri, a microorganism that showed an 84% resistance to antibiotics tested in this study. PMID:25815326
Ruegg, P L; Dohoo, I R
A field trial was conducted to determine the effect of premilking teat disinfection (predipping) on several measures of mastitis in a commercial dairy farm where the predominant organisms isolated from intramammary infections were coagulase negative Staphylococcus spp. Cows were randomly assigned to a treated (predipped with 0.5% iodine germicide plus "good udder preparation") or a control group ("good udder preparation" alone). Sterile composite milk samples were collected at the initiation of the trial and on an approximately bimonthly basis throughout the duration of the trial. There was no difference in the prevalence of isolation of coagulase-negative Staphylococcus spp. from composite milk samples obtained during the 6 herd cultures. The incidence rate for clinical mastitis in the control group was 1.38 cases per 1000 cow days. The incidence rate for clinical mastitis in the treatment group was 1.06 cases per 1000 cow days. The ratio of these 2 was 1.3, suggesting a higher rate in the control group, but the ratio was not statistically significant (P = 0.34). Logistic regression analysis indicated that the effect of treatment group was not significant, although the coefficient suggested that predipping reduced the risk of clinical mastitis. The benefit to cost ratio of 0.37 indicated that the benefit of reduced incidence of clinical cases of mastitis would not have justified the added expense required to predip the herd.
Arendonk, van J.A.M.
Profit equations or functions that reflect the realized profitability of cows have been used in the literature to determine the relative importance of different variables such as milk yield and herd life. In all profit equations, the opportunity cost of postponed replacement, which reflects the prof
Stygar, Anna Helena; Krogh, Mogens Agerbo; Kristensen, Troels
. The objective of this study was to construct a tool to assess the intervention effect on milk production in an evolutionary operations setup. The method used for this purpose was a dynamic linear model (DLM) with Kalman filtering. The DLM consisted of parameters describing milk yield in a herd, individual cows...
DANIELA ILIE; AURELIA SĂLĂJEANU; ANUłA MAGDIN; CLAUDIA STANCA; I. VINTILĂ
The objective of the present study was focused on possibilities to estimate the allele and genotype frequencies of β-lactoglobulin (BLG) gene polymorphisms in dairy cattle belonging to two different genetic groups from the Research and Development Station for Bovine Raising Arad in order to have breeding programs that target an increase in the frequency of the B allele in the dairy cattle population. Genotyping was performed on 20 Romanian Spotted and 18 Brown of Maramures cattle.In order to ...
Lundberg, Å; Nyman, A-K; Aspán, A; Börjesson, S; Unnerstad, H Ericsson; Waller, K Persson
Udder infections with Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis are common causes of bovine mastitis. To study these pathogens in early lactation, a 12-mo longitudinal, observational study was carried out in 13 herds with suboptimal udder health. The aims of the study were to investigate the occurrence of these pathogens and to identify if presence of the 3 pathogens, and of genotypes within the pathogens, differed with respect to herd, season, and parity. Quarter milk samples, collected at calving and 4 d in milk (DIM), were cultured for the 3 pathogens. Genotyping of staphylococcal and streptococcal isolates was performed using spa typing and pulsed-field gel electrophoresis, respectively. For each of the 3 pathogens, cows with an udder infection at calving or 4 DIM were allocated to 1 of 4 infection types: cleared (pathogen present only at calving), persistent (pathogen present in the same quarter at calving and 4 DIM), new (pathogen present only at 4 DIM), or cleared/new (pathogen present in 1 quarter at calving and in another quarter at 4 DIM). Associations between season or parity and overall occurrence of pathogens or infection types were determined using univariable mixed-effect logistic-regression models and the Fisher's exact test, respectively. The most commonly occurring pathogen was Staph. aureus, followed by Strep. dysgalactiae and Strep. uberis. Persistent infections were the most common infection type among Staph. aureus-infected cows, whereas cleared infections were the most common among Strep. dysgalactiae- and Strep. uberis-positive cows. The proportion of cows with persistent Staph. aureus infections and the proportion of cows having a Strep. uberis infection at calving or 4 DIM were higher in the multiparous cows than in primiparous cows. Infections with Strep. dysgalactiae were less common during the early housing season than during the late housing or pasture seasons, whereas persistent Strep. uberis
Brenda Patricia Murphy
Full Text Available A 12-month longitudinal study was undertaken on two dairy herds to ascertain the Shiga-toxin producing Escherichia coli (STEC O157 and O26 shedding status of the animals and its impact (if any on raw milk. Cattle are a recognised reservoir for these organisms with associated public health and environmental implications. Animals shedding E. coli O157 at >10,000 CFU/g of faeces have been deemed super-shedders. There is a gap in the knowledge regarding super-shedding of other STEC serogroups. A cohort of 40 lactating cows from herds previously identified as positive for VTEC in a national surveillance project were sampled every second month between August, 2013 and July, 2014. Metadata on any potential super-shedders was documented including e.g. age of the animal, number of lactations and days in lactation, nutritional condition, somatic cell count and content of protein in milk to assess if any were associated with risk factors for super-shedding. Recto-anal mucosal swabs, raw milk, milk filters and water samples were procured for each herd. The swabs were examined for E. coli O157 and O26 using a quantitative real time PCR method. Counts (CFU swab-1 were obtained from a standard calibration curve that related real-time PCR cycle threshold (Ct values against the initial concentration of O157 or O26 in the samples. Results from Farm A: 305 animals were analysed; 15 E. coli O157 (5% were recovered, 13 were denoted STEC encoding either stx1 and/or stx2 virulence genes and 5 (2% STEC O26 were recovered. One super-shedder was identified shedding STEC O26 (stx1&2. Farm B: 224 animals were analysed; eight E. coli O157 (3.5% were recovered (seven were STEC and 9 (4% STEC O26 were recovered. Three super-shedders were identified, one was shedding STEC O157 (stx2 and two STEC O26 (stx2. Three encoded the adhering and effacement gene (eae and one isolate additionally encoded the haemolysin gene (hlyA. The results of this study show, low numbers of super
Heuvelink, Annet; Hassan, Abdulwahed Ahmed; van Weering, Hilmar; van Engelen, Erik; Bülte, Michael; Akineden, Ömer
Mycobacterium avium subsp. paratuberculosis (MAP) is a vigorous microorganism which causes incurable chronic enteritis, Johne's disease (JD) in cattle. A target of control programmes for JD is to accurately detect MAP-infected cattle early to reduce disease transmission. The present study evaluated the efficacy of two different cultural procedures and a TaqMan real-time PCR assay for detection of subclinical paratuberculosis in dairy herds. Therefore, sixty-one faecal samples were collected from two Dutch dairy herds (n = 40 and n = 21, respectively) which were known to be MAP-ELISA positive. All individual samples were assessed using two different cultural protocols in two different laboratories. The first cultural protocol (first laboratory) included a decontamination step with 0.75% hexadecylpyridinium chloride (HPC) followed by inoculation on Herrold's egg yolk media (HEYM). The second protocol (second laboratory) comprised of a decontamination step using 4% NaOH and malachite green-oxalic acid followed by inoculation on two media, HEYM and in parallel on modified Löwenstein-Jensen media (mLJ). For the TaqMan real-time PCR assay, all faecal samples were tested in two different laboratories using TaqMan® MAP (Johne's) reagents (Life Technologies). The cultural procedures revealed positive reactions in 1.64% of the samples for cultivation protocol 1 and 6.56 and 8.20% of the samples for cultivation protocol 2, respectively. The results of the TaqMan real-time PCR performed in two different laboratories yielded 13.11 and 19.76% positive reaction. The kappa test showed proportional agreement 0.54 between the mLJ media (second laboratory) and TaqMan® real-time PCR method (second laboratory). In conclusion, the TaqMan real-time PCR could be a strongly useful and efficient assay for the detection of subclinical paratuberculosis in dairy cattle leading to an improvement in the efficiency of MAP control strategies.
Smith, J W; Ely, L O; Chapa, A M
Dairy Herd Improvement Holstein herd summary records (n = 11,259) were obtained for the year ending 1998. Reasons cows reportedly left the herd based on termination codes were analyzed for the effect of region, herd size, and herd milk production level. Regions were: North, Midsouth, and South. Herd sizes were: small (25 to 99), low medium (100 to 149), high medium (150 to 299), and large (greater than or equal to 300 cows). Milk production levels were: low (less than 7258 kg), medium (7258 to 9072 kg), and high (greater than 9072 kg). The overall percentage of cows leaving the herd was higher in the Midsouth than the South and increased with herd size. Low producing herds reported a lower percentage of cows left than high producing herds. Herds in the South reported more cows leaving for reproduction, death, and low production and fewer leaving for mastitis. Herds in the North and Midsouth reported more cows leaving for injury/other and disease, respectively. Cows left herds for disease less frequently in the North. Large herds in the South had a higher percentage leaving for low production than any herd size group in the North. Small herds reported more cows leaving for reproduction and mastitis than high medium and low medium size herds. The percentage of cows leaving for feet and leg problems was lowest for small size herds. High producing herds reported more cows leaving for reproduction, mastitis, feet and legs and disease.
Østergaard, Søren; Ettema, Jehan Frans; Kudahl, Anne Braad
SimHerd is a computer model of a dairy herd. In more than a decade the model has been applied and further developed within the research in herd management and animal health economics in dairy herds. Analyses with the SimHerd model have been included in 2 doctoral theses, 9 PhD theses, 4 MSc these....... The following describes experiences with developing a commercial herd health advisory tool based on the history of the research tool - SimHerd.......SimHerd is a computer model of a dairy herd. In more than a decade the model has been applied and further developed within the research in herd management and animal health economics in dairy herds. Analyses with the SimHerd model have been included in 2 doctoral theses, 9 PhD theses, 4 MSc theses...
Erskine, R J; Martinez, R O; Contreras, G A
Recent changes in the US dairy industry include increases in herd size and the proportion of milk that is produced by large herds. These changes have been accompanied by an increased reliance on hired employees and an increasing role of immigrant labor to perform critical tasks such as milking cows. Thus, there is a growing need for training and education programs for dairy employees because many employees lack previous dairy experience and employee turnover rates are problematic on many farms. Although extension programs have played an important role in the education and support of dairy producers and allied professionals in attaining improved milk quality, dairy employees have limited access to educational programs. Additionally, metrics to assess employee learning are not validated and the ability to sustain work-related behavioral change has not been well described. In this article, we propose a model that may further our understanding of communication and cultural barriers between dairy managers and employees, based on a demonstration project in 12 Michigan dairy herds. As part of this demonstration, a pilot survey was tested to assess the management culture on dairy farms. Results from this survey found that only 23% of employees across all herds were able to meet with farm management on a regular basis, 36% of employees did not know somatic cell count goals for the farm for which they worked, and 71% of employees stated they primarily received training on milking protocols by other employees or that they learned on their own. Latino employees were more likely to not know farm goals or receive primary training on milking protocols from other employees or on their own compared with their English-speaking counterparts. The survey information, along with input from focus group discussions with participating dairy producers, veterinarians, and employees, suggests that extension needs to build capacity for on-farm training and education for employees to support
Hagnestam-Nielsen, Christel; Østergaard, Søren
losses was investigated by comparing the results obtained using the potential yield of mastitic cows, had they not developed CM, with those obtained using the yield of non-mastitic cows. The yearly maximum avoidable cost of CM at herd level was estimated at €14 504, corresponding to 6.9% of the net...... and the conventional modelling strategy, with the exception of the cost per case of CM. Similarities between the results obtained using the two methods were particularly evident when the mastitic cows' own yield level, had they not developed CM, was used as the reference for production in healthy cows when yield...
Arfan Ahmad, Masood Rabbani, Muhammad Zubair Shabbir, Khushi Muhammad1, Tahir Yaqub, Muhammad Kashif Saleemi2, Rana Khurram Khalid, Muhammad Abu Bakr Shabbir3 and Shumaila Yousaf Alvi4
Full Text Available Suitability of ear notch biopsy (EN and serum pairs (n= 307 collected from 10 Holstein dairy herds located in Charlottetown, Canada was evaluated for simultaneous detection, nature of bovine viral diarrhea virus (BVDV infection and genotype of the prevailing BVDV through Real time RT-PCR. Depending upon vaccination status and age, the sampled animals were categorized into two groups, A (n=123, ≤ 6 month of age and B (n=184, ≥ 6 months of age originating from 4 vaccinated (n=108 and 3 non-vaccinated (n=76 animal herds. On first round of testing a discrepancy between ear notch biopsies and sera pairs (3.25 and 6.50%; P<0.05 of groups A was observed, however, a complete harmony (50% for EN and sera each, P<0.01 was found on second round of testing that confirmed the presence of 4 persistent infection (PI animals harboring genotype 1 of BVDV. Complete concordance between EN and sera pairs (P<0.01 on first and follow up testing in group B was observed (2.77%, each, depicting 3 PI animals with the same genotype as in group A. In the study, ear notch biopsies did not detect any transient infection (TI but sera samples detected 3.25% transiently infected animals in group A that was 1.30 % among all the test samples (n=307 while no TI animal was found in group B. It may be concluded that both the serum and ear notch biopsy can be used to detect PI animals and that, serum samples are more sensitive than ear notch (P < 0.05 for detection of TI using real time RT-PCR.
Muestreo predial pequeño para predecir una infección activa por virus diarrea viral bovina (VDVB en planteles lecheros de la Xª Región de Chile A small herd sample to predict an active infection with bovine viral diarrhea virus (BVDV in dairy herds of X Region, Chile
Full Text Available La diarrea viral bovina está distribuida mundialmente y la mayoría del ganado es seropositivo, aunque la seroprevalencia varía entre predios y grupos de edad. Los animales con infección persistente son los transmisores más eficientes, pasan desapercibidos y son la fuente más importante para la perpetuación de la infección. Este trabajo entrega los resultados del análisis serológico de una muestra predial de 10 animales entre 6 y 12 meses de edad de 44 predios lecheros de la X Región de Chile. Se constató que en 35 planteles (79.5% existiría infección activa con virus diarrea viral bovina, pues al menos 6 de los 10 sueros estudiados presentaron anticuerpos. De esta manera, mediante una muestra pequeña de animales jóvenes es posible predecir, con certeza, la presencia de infección activa en los plantelesBovine viral diarrhea virus (BVDV has a worldwide distribution and most cattle are seropositive, although the prevalence may vary among herds and among different age groups. Persistently infected (PI animals are the most efficient transmitters of infection often remaining unnoticed in the herds thus, becoming the most important source to perpetuate the infection. In each of the 44 dairy herds studied from X Region, Chile, ten young stock aged 6 _ 12 months were tested for antibodies against BVDV. In 35 dairy herds (79.5% BVDV active infection was predicted because at least 6 over ten sera were antibody carriers. Thus, based on few blood samples, herds with PI animals and herds without PI animals could be distinguished with a high degree of accuracy
Lawrence, K E; Gedye, K; McFadden, A M J; Pulford, D J; Pomroy, W E
Although only recently recognised, Theileria orientalis (Ikeda) is now the most important infectious cause of anaemia in New Zealand cattle. The aim of this study was to test if vertical transmission of T. orientalis (Ikeda) from dam to calf across the placenta occurs in naturally infected New Zealand dairy cattle and to also test whether the infection status of the dam at calving affects the future susceptibility of its offspring to T. orientalis (Ikeda) infection. Dairy cows (n=97) and their calves were sampled at calving; and the calves again at 4 months of age. All samples were measured for haematocrit and screened for T. orientalis genotypes using a multiplex Buffeli, Chitose and Ikeda specific TaqMan assay. Ikeda positive samples were further tested by singleplex PCR in triplicate to calculate the Ikeda infection intensity as genomes/μl of blood from each infected animal. No T. orientalis (Ikeda) infected calves were born to either T. orientalis (Ikeda) infected or uninfected dams. There were 56/97 dams positive for T. orientalis (Ikeda) infection at calving and 79/90 calves positive for T. orientalis (Ikeda) infection at 4 months of age but no effect on calf susceptibility of dam infection status at calving. There was a significant negative effect of infection intensity on haematocrit after controlling for whether the infected animal was a dam or a 4 month old calf. Vertical trans-uterine transmission of T. orientalis (Ikeda) infection is unlikely in chronically infected dairy cows and thus not a factor in the epidemiology of T. orientalis (Ikeda) infection.
Klein, D; Alispahic, M; Sofka, D; Iwersen, M; Drillich, M; Hilbert, F
The objectives of this study were to evaluate the presence of thermophilic Campylobacter in feces of calves with and without diarrhea on dairy farms and to survey farm characteristics and management practices to define risk factors for the presence of Campylobacter. Fifty dairy farms were chosen based on the presence of calf diarrhea, and 50 farms in which calves were free from diarrhea served as a standard of comparison. In total, fecal samples were taken from 382 calves. Farm data and management practices were surveyed using a questionnaire on farm. Campylobacter were isolated from fecal samples and colonies were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis. Campylobacter spp., mainly Campylobacter jejuni (93% of isolated species), were detected on 33% of the farms and in 14.9% of the calves. Detection of Campylobacter did not differ between farms or between calves with and without diarrhea, although we found a tendency for calves suffering from diarrhea to shed Campylobacter more often. Calves may act as a reservoir of Campylobacter and may therefore lead to infections of other animals and humans. To define control strategies to reduce Campylobacter in calves, we identified on-farm risk factors. The presence of poultry on the farm, the time of cow-calf separation following birth, the use of an individual bucket for each calf, the feeding of waste milk, and the duration of individual housing were variables significantly associated with the appearance or absence of Campylobacter. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Nielsen, Torben Dahl; Kudahl, Anne Braad; Østergaard, S.
and dynamic simulation model. The model incorporated six age groups (neonatal, pre-weaned calves, weaned calves, growing heifers, breeding heifers and cows) and five infection stages (susceptible, acutely infected, carrier, super shedder and resistant). The effects of introducing one S. Dublin infectious...... losses. This was more influential in the poorer management scenarios due to increased number of infected cows. The results can be used to inform dairy farmers of the benefits of preventing introduction and controlling spread of S. Dublin. Furthermore, they can be used in cost-benefit analyses of control...
Merialdi, Giuseppe; Bardasi, Lia; Stancampiano, Laura; Taddei, Roberta; Delogu, Mauro; Di Francesco, Antonietta; Guarniero, Ilaria; Grilli, Ester; Fustini, Mattia; Bonfante, Elena; Giacometti, Federica
The objective of this study was to analyse over time the evolution of E. coli O157:H7 faecal shedding in a dairy herd producing raw milk for direct human consumption. The study was performed between October 2012 and September 2013 in an average size Italian dairy farm where animals are housed inside the barn all over the year. The farm housed about 140 animals during the study – 70 cows and 70 calves and heifers. Twenty-six animals were randomly selected from both the cows and young animals group, and faecal sampling was performed rectally six times two months apart in each animal. Eleven animals were culled during the study and a total of 285 faecal samples were collected. At each faecal sampling, three trough water samples and two trough feed samples were also collected for a total of 36 water samples and 24 feed samples. Samples were analysed by real time polymerase chain reaction (RT-PCR) and culture. Overall, 16 (5.6%) faecal samples were positive for E. coli O157 by RT-PCR. Cultural examination found 9 (3.1%) samples positive for E. coli O157; all the isolates were positive for stx1, stx 2 and eae genes. One (4.1%) feed sample was positive for E. coli O157 by RT-PCR; none of the water samples was positive for E. coli O157. The model highlighted a general significant reduction of the number of positive samples observed during the study from the first to the sixth sampling (P=0.000) and a positive relation between the presence of positive samples and average environmental temperature (P=0.003). The results of the study showed that in an Italian dairy farm housing animals all year, faecal shedding of E. coli O157 followed the same temporal trend reported for other types of farming. The enhanced faecal shedding during warmer months may have a significant impact on environmental contamination and the safety of raw milk and its byproducts.
Full Text Available The objective of this study was to analyse over time the evolution of E. coli O157:H7 faecal shedding in a dairy herd producing raw milk for direct human consumption. The study was performed between October 2012 and September 2013 in an average size Italian dairy farm where animals are housed inside the barn all over the year. The farm housed about 140 animals during the study – 70 cows and 70 calves and heifers. Twenty-six animals were randomly selected from both the cows and young animals group, and faecal sampling was performed rectally six times two months apart in each animal. Eleven animals were culled during the study and a total of 285 faecal samples were collected. At each faecal sampling, three trough water samples and two trough feed samples were also collected for a total of 36 water samples and 24 feed samples. Samples were analysed by real time polymerase chain reaction (RT-PCR and culture. Overall, 16 (5.6% faecal samples were positive for E. coli O157 by RT-PCR. Cultural examination found 9 (3.1% samples positive for E. coli O157; all the isolates were positive for stx1, stx 2 and eae genes. One (4.1% feed sample was positive for E. coli O157 by RT-PCR; none of the water samples was positive for E. coli O157. The model highlighted a general significant reduction of the number of positive samples observed during the study from the first to the sixth sampling (P=0.000 and a positive relation between the presence of positive samples and average environmental temperature (P=0.003. The results of the study showed that in an Italian dairy farm housing animals all year, faecal shedding of E. coli O157 followed the same temporal trend reported for other types of farming. The enhanced faecal shedding during warmer months may have a significant impact on environmental contamination and the safety of raw milk and its byproducts.
Full Text Available Twenty-nine dairy farms were selected to determine the incidence of clinical mastitis, prevalence of sub-clinical mastitis and bacterial aetiology in the West Littoral Region of Uruguay. In samples taken by the owner and frozen at -20°C during a week the incidence rate of clinical mastitis was determined as 1.2 cases per 100 cow-months at risk. Staphylococcus aureus was the most common isolated pathogen in 37.5% of 40 milk samples from clinical cases obtained in 1 month. No bacteria grew in the 32.5% of the total samples. A sub-sample including 1077 dairy cows from randomly selected farms was used to determine the prevalence of sub-clinical mastitis. These samples were taken on one visit to each farm. The prevalence was 52.4% on a cow basis and 26.7% on an udder quarter basis. In 55.1% of the quarters of the selected animals with more than 300 000 cells/ml there was no growth. The isolated pathogens from sub-clinical cases and their relative frequencies were: Staphylococcus aureus 62.8%, Streptococcus agalactiae 11.3%, Enterococcus sp. 8%, coagulase-negative staphylococci 7.4%, Streptococus uberis 6.4%, Streptococcus dysgalactiae 1.8%, Escherichia coli 1.5% and Staphylococcus hyicus coagulase-positive 0.6%.
Shitandi, Anakalo; Kihumbu, Gathoni
This study evaluated how predictive the California Mastitis Test (CMT) is for sub-clinical mastitis under tropical smallholder dairy production conditions in Kenya. It intended to establish whether the CMT usage could be contributing to misdiagnosis and consequent mistreatment with animal drugs resulting in residue problems. Milk samples (n = 239) were aseptically collected from lactating cows in the Rift Valley of Kenya and tested using the CMT, somatic cell counts (SCC) and bacterial culture. The samples were also screened for violative drug residues using the commercial delvo test and compared to the milks mastitic status for possible association. There was a numerical but non-significant (p > 0.05) difference evident in the frequencies observed using the three different mastitis indicators. The prevalent bacterial species isolated from mammary glands with subclinical mastitis were Staphylococcus aureus (45.6%), coagulase-negative Staphylococci (13.0%), Streptococci (11.7%) and Escherichia coli 5.9%. There was an overall poor but significant (p CMT and the violative antimicrobial residues in samples from all quarters, infected and non-infected respectively. The results suggest that the CMT use amongst the smallholder dairy sector as a mastitic indicator may not be a risk factor in violative antimicrobial residues problems in milk.
Gianneechini, R; Concha, C; Rivero, R; Delucci, I; López, J Moreno
Twenty-nine dairy farms were selected to determine the incidence of clinical mastitis, prevalence of sub-clinical mastitis and bacterial aetiology in the West Littoral Region of Uruguay. In samples taken by the owner and frozen at -20°C during a week the incidence rate of clinical mastitis was determined as 1.2 cases per 100 cow-months at risk. Staphylococcus aureus was the most common isolated pathogen in 37.5% of 40 milk samples from clinical cases obtained in 1 month. No bacteria grew in the 32.5% of the total samples. A sub-sample including 1077 dairy cows from randomly selected farms was used to determine the prevalence of sub-clinical mastitis. These samples were taken on one visit to each farm. The prevalence was 52.4% on a cow basis and 26.7% on an udder quarter basis. In 55.1% of the quarters of the selected animals with more than 300 000 cells/ml there was no growth. The isolated pathogens from sub-clinical cases and their relative frequencies were: Staphylococcus aureus 62.8%, Streptococcus agalactiae 11.3%, Enterococcus sp. 8%, coagulase-negative staphylococci 7.4%, Streptococus uberis 6.4%, Streptococcus dysgalactiae 1.8%, Escherichia coli 1.5% and Staphylococcus hyicus coagulase-positive 0.6%. PMID:12831175
张佳兰; 茹彩霞; 王建华
[Objective] The research aimed to analyze the incidence of subclinical mastitis in dairy cattle so as to provide scientific basis for the control of subclinical mastitis. [ Method] According to the number of somatic cells in the DHI report of three dairy farms in 2009, the incidence of subclinical mastitis in three dairy farms, at different lactation periods and parities was studied. [ Result] The incidence of subclinical mastitis was different on different dairy farms, the lactating cattle on farm 1 had low incidence of subclinical mastitis than on other two farms (P 0.05). [Conclusion] The incidence of subclinical mastitis was influenced by the lactation periods and parity as well as the breeding and management of the cattle farms. Each farm should take measures to control the incidence of subclinical mastitis according to their own conditions and DHI results.%[目的]分析奶牛隐性乳房炎的发生情况,为隐性乳房炎的控制提供科学依据.[方法]以3个牛场2009年DHI报告的体细胞数大小来分析隐性乳房炎在不同牛场、泌乳阶段和胎次的发生情况.[结果]不同牛场隐性乳房炎发生率存在差异,牛场1泌乳牛隐性乳房炎的发生率显著低于另外2个场(P＜0.05).随着泌乳时间的增加,奶牛隐性乳房炎的发生率呈增加的趋势,牛场3在第6、7、8和第12泌乳月隐性乳房炎的发生率显著高于其他泌乳月.随着胎次的增加,奶牛隐性乳房炎的发生率呈增加趋势,牛场1在4胎以后奶牛隐性乳房炎的发生率显著增加且与其他2个场差异不显著(P＞0.05).[结论]奶牛隐性乳房炎的发生率与泌乳阶段和胎次有关,与牛场自身的饲养管理有关.各个牛场应根据自身条件及DHI结果采取相应的措施控制奶牛隐性乳房炎的发生.
Kleen, Joachim L; Atkinson, Owen; Noordhuizen, Jos Ptm
The importance of communication skills in veterinary medicine is increasingly recognised. Appropriate communication skills towards the client are of utmost importance in both companion animal practice and production animal field and consultancy work. The need for building a relationship with the client, alongside developing a structure for the consultation is widely recognised and applies to both types of veterinary practice. Veterinary advisory practice in production animal medicine is, however, characterised by a more complex communication on different levels. While the person-orientated communication is a permanent process between veterinarian and client with a rather personal perspective and defines the roles of interaction, the problem-orientated communication deals with emerging difficulties; the objective is to solve an acute health problem. The solution - orientated communication is a form of communication in which both veterinarian and client address longstanding situations or problems with the objective to improve herd health and subsequently productivity performance. All three forms of communication overlap. Based on this model, it appears useful for a veterinary practice to offer both a curative and an advisory service, but to keep these two separated when deemed appropriate. In veterinary education, the strategies and techniques necessary for solution orientated communication should be included in the teaching of communication skills.
Galvão, K N; Federico, P; De Vries, A; Schuenemann, G M
The objective of this study was to compare the economic outcome of reproductive programs using estrus detection (ED), timed artificial insemination (TAI), or a combination of both (TAI-ED) using a stochastic dynamic Monte-Carlo simulation model. Programs evaluated were (1) ED only; (2) TAI: Presynch-Ovsynch for first AI, and Ovsynch for resynchronization of open cows at 32 d after AI; (3) TAI-ED: Presynch-Ovsynch for first AI, but cows underwent ED and AI after first AI, and cows diagnosed open 32 d after AI were resynchronized using Ovsynch. Evaluated were the effect of ED rate (40 vs. 60%; ED40 or ED60), accuracy of estrus detection (85 vs. 95%), compliance with the timed AI protocol (85 vs. 95%), and milk price ($0.33 vs. 0.44/kg). Conception rate to first service was set at 33.9% and then decreased by 2.6% for every subsequent service. Abortion was set at 11.3%. Cows were not AI after 366 d in milk, and open cows were culled after 450 d in milk. Culled cows were immediately replaced. Herd size was maintained at 1,000 cows, and the model accounted for all incomes and costs. Simulation was performed until steady state was reached (3,000 d), and then average daily values for the subsequent 2,000 d were used to calculate profit/cow per year. Net daily value was calculated by subtracting the costs (replacement, feeding, breeding, and other costs) from the daily income (milk sales, cow sales, and calf sales). The ED40 models resulted in greater profits than the TAI-85 model but lower profits than the TAI-95 model. Both ED60 models resulted in greater profits than the TAI-95 model. Combining TAI and ED increased profits within each level of accuracy or compliance. Adding TAI to ED would increase overall profit/cow per year by $46.8 to $74.7 with 40% ED, and by $8.9 to $30.5 with 60% ED. Adding ED to TAI would increase profit/cow per year by $64.2 to $99.4 with 85% compliance and by $31.8 to $59.7 with 95% compliance. Although combining TAI and ED increased profits
Fouz, R; Gandoy, F; Sanjuán, M L; Yus, E; Diéguez, F J
This study was designed to analyse the evolution in the use of beef bull semen for dairy cattle insemination and, mainly, to assess calving difficulty, gestation length and proportion of stillbirths after breeding pure Holsteins or crossbreeding. Data were collected during 2004 to 2011 for 552 571 Holstein calvings (457 070 Holstein × Holstein, 43 384 Holstein × Limousine, 32 174 Holstein × Belgian Blue and 19 943 Holstein × Galician Blonde). The highest calving difficulty, compared with pure Holsteins was for crosses with Belgian Blue followed by Limousine and Galician Blonde. The Holstein × Limousine and Holstein × Galician Blonde crossbred calves had significantly longer gestation lengths than Holstein × Holstein and Holstein × Belgian Blue calves. Between the latter two, pure Holstein had the shortest gestation length. Calving difficulty and gestation length decreased as the age of the dam advanced. The most difficult calvings were observed in twin calvings, followed by the calvings of male calves and female calves. The gestations leading to the birth of male calves were longer than those leading to female calves and twin calves. Stillbirths were not related to the breed used for mating. Through examining these parameters, sire breed should be considered when selecting a beef breed for the insemination of milk-producing dams.
Vidanarachchi, Janak K; Li, Shengjie; Lundh, Åse Sternesjö; Johansson, Monika
The objective of this study was to determine the lipolytic activity on milk fat of 2 bovine mastitis pathogens, that is, Staphylococcus aureus and Streptococcus agalactiae. The lipolytic activity was determined by 2 different techniques, that is, thin-layer chromatography and an extraction-titration method, in an experimental model using the most commonly occurring field strains of the 2 mastitic bacteria isolated from Swedish dairy farms. The microorganisms were inoculated into bacteria-free control milk and incubated at 37°C to reflect physiological temperatures in the mammary gland. Levels of free fatty acids (FFA) were analyzed at time of inoculation (t=0) and after 2 and 6h of incubation, showing significant increase in FFA levels. After 2h the FFA content had increased by approximately 40% in milk samples inoculated with Staph. aureus and Strep. agalactiae, and at 6h the pathogens had increased FFA levels by 47% compared with the bacteria-free control milk. Changes in lipid composition compared with the bacteria-free control were investigated at 2 and 6h of incubation. Diacylglycerols, triacylglycerols, and phospholipids increased significantly after 6h incubation with the mastitis bacteria, whereas cholesterol and sterol esters decreased. Our results suggest that during mammary infections with Staph. aureus and Strep. agalactiae, the action of lipases originating from the mastitis pathogens will contribute significantly to milk fat lipolysis and thus to raw milk deterioration.
Guimarães, F F; Manzi, M P; Joaquim, S F; Richini-Pereira, V B; Langoni, H
Cows are probably the main source of contamination of raw milk with Staphylococcus aureus. Mammary glands with subclinical mastitis can shed large numbers of Staph. aureus in milk. Because of the risk of this pathogen to human health as well as animal health, the aim of this paper was to describe an outbreak of mastitis caused by methicillin-resistant Staph. aureus (MRSA), oxacillin-susceptible mecA-positive Staph. aureus (OS-MRSA), and methicillin-susceptible Staph. aureus (MSSA) on a dairy farm. Milk samples were obtained from all quarters, showing an elevated somatic cell count by the California Mastitis Test. The isolates were identified by phenotypic and genotypic methods. Staphylococcus spp. were isolated from 53% (61/115) of the milk samples, with 60 isolates identified as Staph. aureus (98.4%) and 1 isolate identified as Staphylococcus epidermidis (1.6%). The presence of the mecA gene was verified in 48.3% of Staph. aureus isolates. Of the Staph. aureus isolates, 23.3% were MRSA and 25.0% were OS-MRSA. The total of mastitis cases infected with MRSA was 12.2%. The detection of this large percentage of mastitis cases caused by MRSA and OS-MRSA is of great concern for the animals' health, because β-lactams are still the most important antimicrobials used to treat mastitis. In addition, Staph. aureus isolates causing bovine mastitis represent a public health risk.
Kumar, B; Pachauri, S P
Haematological profile-haemoglobin concentration (Hb), total erythrocytes count (TEC), packed cell volume (PCV), erythrocyte indices-mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were studied in crossbred dairy cattle (Holstein Friesian x Sahiwal) under various physiological states: non-pregnant heifers (NPH), pregnant heifers (PH), empty dry cows (EDC), pregnant lactating cows (PLC), medium yield early lactating cows (MYELC) and high yield early lactating cows (HYELC) during summer and winter seasons at 1700 metres altitude from mean sea level in the Central Himalayas. On comparison of annual means, the highest values of Hb and PCV were recorded in PH and of TEC in NPH, whereas the lowest values of these parameters were found in EDC. The Hb and TEC tended to decrease with increasing milk yield. Comparison of annual means of erythrocyte indices revealed the highest MCV and MCH in EDC, which simultaneously showed the lowest MCHC. Significant seasonal variations in haematological profile were recorded. The overall group mean (OGM) of Hb, MCV, MCH and MCHC was found to be significantly higher (P OGM (P < 0.01) during the winter season.
Azevedo, Carla; Pacheco, Diana; Soares, Luísa; Romão, Ricardo; Moitoso, Mónica; Maldonado, Jaime; Guix, Roger; Simões, João
This study aimed to assess the degree of contamination of bulk tank milk (BTM) by Staphylococcus spp. and coliform bacteria and to identify major milking practices that help perpetuate them in dairy cattle herds in São Miguel Island. In July 2014, BTM was sampled and a survey concerning local milking practices was conducted on 100 herds. Semi quantitative multiplex polymerase chain reaction detected coagulase-negative staphylococci, Escherichia coli, Staphylococcus aureus, and other coliform bacteria (Klebsiella oxytoca, Klebsiella pneumoniae, and Serratia marcescens) in 100, 75, 59, and 35 % of BTM, respectively. According to multivariable univariate models, on herds not using hot water for cleaning the milking machine and teat liners, there was at least 3.4 more odds (P < 0.01) to have S. aureus or coliform bacteria contamination in BTM. The likelihood of finding S. aureus in BTM was higher (P < 0.001) on herds without high hygiene during milking, when milking mastitic cows at the end, on abrupt cessation of milking at dry-off, and official milk control implementation. The glove use also favored (odds ratio (OR) 5.8; P < 0.01) the detection of coliform bacteria in BTM. Poor milking practices identified in this study should be avoided in order to decrease S. aureus and coliform bacteria contamination of BTM. Other factors associated with milk quality in São Miguel Island also should be further investigated.
Wernery, Ulrich; El Rasoul, I Hassab; Wong, Emily Y M; Joseph, Marina; Chen, Yixin; Jose, Shanty; Tsang, Alan K L; Patteril, Nissy Annie Georgy; Chen, Honglin; Elizabeth, Shyna K; Yuen, Kwok-Yung; Joseph, Sunitha; Xia, Ningshao; Wernery, Renate; Lau, Susanna K P; Woo, Patrick C Y
Middle East respiratory syndrome coronavirus (MERS-CoV) was detected by monoclonal antibody-based nucleocapsid protein-capture enzyme-linked immunosorbent assay (ELISA), RNA detection, and viral culture from the nasal sample of a 1-month-old dromedary calf in Dubai with sudden death. Whole genome phylogeny showed that this MERS-CoV strain did not cluster with the other MERS-CoV strains from Dubai that we reported recently. Instead, it formed a unique branch more closely related to other MERS-CoV strains from patients in Qatar and Hafr-Al-Batin in Saudi Arabia, as well as the MERS-CoV strains from patients in the recent Korean outbreak, in which the index patient acquired the infection during travel in the eastern part of the Arabian Peninsula. Non-synonymous mutations, resulting in 11 unique amino acid differences, were observed between the MERS-CoV genome from the present study and all the other available MERS-CoV genomes. Among these 11 unique amino acid differences, four were found in ORF1ab, three were found in the S1 domain of the spike protein, and one each was found in the proteins encoded by ORF4b, ORF5, envelope gene, and ORF8. MERS-CoV detection for all other 254 dromedaries in this closed dairy herd was negative by nucleocapsid protein-capture ELISA and RNA detection. MERS-CoV IgG sero-positivity gradually increased in dromedary calves with increasing age, with positivity rates of 75% at zero to three months, 79% at four months, 89% at five to six months, and 90% at seven to twelve months. The development of a rapid antigen detection kit for instantaneous diagnosis is warranted.Emerging Microbes & Infections (2015) 4, e74; doi:10.1038/emi.2015.74; published online 2 December 2015.
Morrison, S J; Wicks, H C F; Fallon, R J; Twigge, J; Dawson, L E R; Wylie, A R G; Carson, A F
It has been suggested that United Kingdom recommendations for feeding the neonatal calf (500 g milk replacer (MR)/day; 200-230 g CP/kg milk powder) are inadequate to sustain optimal growth rates in early life. The current study was undertaken with 153 high genetic merit, male and female Holstein-Friesian calves (PIN2000 = £48) born between September and March, with heifers reared and bred to calve at 24 months of age. Calves were allocated to one of four pre-weaning dietary treatments arranged in a 2 MR feeding level (5 v. 10 l/day) × 2 MR protein content (210 v. 270 g CP/kg dry matter (DM)) factorial design. MR was reconstituted at a rate of 120 g/l of water, throughout, and was offered via computerised automated milk feeders. Calves were introduced to pre-weaning diets at 5 days of age and weaned at day 56. During the first 56 days of life, calves offered 10 l MR/day had significantly higher liveweight gains (P calves fed 5 l MR/day. No significant differences in liveweight gain were found between calves fed 210 g CP/kg DM MR and those fed 270 g CP/kg DM MR from birth to day 56. Differences in live weight and body size due to feeding level disappeared by day 90. Neither MR feeding level nor MR CP content affected age at first service or age at successful service, and with no milk production effects, the results indicate no post-weaning benefits of increased nutrition during the milk-feeding period in dairy heifers.
Nielsen, Liza Rosenbaum; Nielsen, Søren Saxmose
stock and adult cattle in 10 case herds that were followed for more than three years. The five steps in the structured approach were: 1) risk scoring to determine transmission routes within the herd and into the herd; 2) determining a plan of action; 3) performing management changes to close important...... routes of infection; 4) interpretation of repeated testing of individual animals to detect high-risk animals for special hygienic management or culling; and 5) diagnostic testing of different age groups and bulk tank milk to evaluate progress of control over time. Serology, true prevalence estimates...... and changes in herd classification in the Danish surveillance programme for Salmonella Dublin were used to assess the progress in the herds during and after the control period. Effective control of Salmonella Dublin was achieved in all participating herds through management that focused on closing infection...
Bartels, C.J.M.; Hogeveen, H.; Schaik, van G.; Wouda, W.; Dijkstra, Th.
In this study, direct economic losses due to Neospora caninum infection, based on actual data from N. caninum seropositive reference herds and from herds that experienced an N. caninum- associated abortion epidemic, were calculated using a stochastic model with random elements. The results demonstra
Wedderkopp, A.; Strøger, U.; Lind, Peter
Bulk tank milk from 1,429 herds were collected in 3 rounds from 19 different geographic areas. The milk samples were tested by use of indirect LPS-ELISA procedure to detect Salmonella dublin antibodies. From the obtained OD-values herd seroprevalence in the given area was determined and GR...
Full Text Available Bovine coronavirus (BCoV is a known cause of winter dysentery (WD in adult cattle. The morbidity of the disease is high, that results in a significant decrease in milk production and consequently, economic losses. In the present study, we report on a classical outbreak of WD that affected a high-production Holstein dairy herd raised in a tropical country. The lactating batch included 154 cows, and 138 (90% presented diarrhea in a short (nine days period of time. Three (2% cows died. The other batches of animals did not become ill. The evolution of the disease in the herd, including the clinical signs and epidemiological features, strongly suggested a WD case. Semi-nested PCR and RFLP confirmed that BCoV was the cause of the infection. Samples tested negative for all other enteric pathogens. This case report highlights the importance of BCoV in WD even in tropical countries such as Brazil.O coronavirus bovino (BCoV pode causar a diarreia de inverno (WD - Winter Dysentery ao infectar bovinos adultos, particularmente em regiões de clima temperado ou frio. A morbidade da doença é alta, resultando em queda na produção de leite e, consequentemente, perdas econômicas. No presente estudo, é descrito um surto clássico de WD acometendo um rebanho de bovinos leiteiros da raça Holandesa PB, de alta produção, proveniente do estado do Paraná. O lote afetado era composto por 154 vacas em lactação, sendo que 138 (90% apresentaram diarreia em um curto (nove dias período de tempo e 3 (2% vacas morreram em consequência da diarreia, desidratação e desequilíbrio eletrolítico. As outras categorias de animais do rebanho (bezerras, novilhas e vacas secas não apresentaram sinal clínico. A evolução da doença clínica, assim como a epidemiologia da infecção sugeriu um quadro clássico de WD. O diagnóstico foi realizado por meio da identificação do BCoV, pela técnica de semi-nested PCR e confirmação por RFLP, em amostra fecal de uma vaca
Management factors related to seroprevalences to bovine viral-diarrhoea virus, bovine-leukosis virus, Mycobacterium avium subspecies paratuberculosis, and Neospora caninum in dairy herds in the Canadian Maritimes.
Chi, Junwook; VanLeeuwen, John A; Weersink, Alfons; Keefe, Gregory P
Bovine viral-diarrhoea (BVD), enzootic bovine leukosis (EBL), Johne's disease (JD), and neosporosis lower on-farm productivity, reduce export competitiveness, and increase consumer concerns regarding safety. Our purpose was to examine the relationship between 27 control practices and the estimated true seroprevalences for these four diseases for 2604 cattle in 90 dairy herds in the Maritimes provinces of Canada. Overall, 37.8, 20.4, 3.4, and 19.2% of all sampled cattle were truly exposed to the agents of BVD, EBL, JD, and neosporosis, respectively. The median within-herd true prevalences were 0, 9.3, 0, and 12.3%, respectively. Factor analysis reduced the 27 control practices to two highly correlated factors. Tobit-regression analyses determined that vaccination practices were associated with reduced prevalence of exposure for Bovine viral-diarrhoea and EBL. Also, farms that tended to purchase their dairy animals were associated with higher seroprevalence for Johnes' disease. Neither of these two factors was associated with the seroprevalence of Neospora caninum infection. The few routine biosecurity measures that were investigated in this study were generally not related to the seroprevalences of these farms.
Stevens, M; Piepers, S; De Vliegher, S
The main objectives of this study were to evaluate to what extent variations in herd-level antimicrobial consumption (AMC) can be explained by differences in management practices that are consistently effective in the prevention of (sub)clinical mastitis, on the one hand, and by differences in mastitis treatment strategies, on the other hand. Antimicrobial consumption data were obtained during 2012 and 2013 by "garbage can audits" and expressed as antimicrobial treatment incidences (ATI) for all compounds combined (total ATI) and for the critically important antimicrobials for human health separately. Data on mastitis prevention and control practices were obtained via face-to-face interviews performed during herd visits in March 2013. Some management practices and treatment strategies related to udder health were associated with the total AMC. However, the results demonstrated that implementing effective udder health management practices does not necessarily imply a low AMC and vice versa. Herds participating in a veterinary herd health management program and herds selectively drying off cows used fewer antimicrobials compared with herds not participating in such a program or applying blanket dry-cow therapy. Moreover, herds treating (some) (sub)clinical mastitis cases with intramammary homeopathic substances consumed fewer antimicrobials than herds not applying such homeopathic treatments. Besides these factors, no other direct association was found between effective udder health management practices on the one hand and AMC on the other hand. Also, the use of critically important antimicrobials was only associated with the way in which subclinical mastitis cases were treated. The latter indicates that the AMC of critically important antimicrobials is potentially driven by factors other than those included in this study such as those related to the "mindset" of the veterinarians and their farmers. Future research should therefore aim to unravel the reasoning of
Kirkeby, Carsten; Græsbøll, Kaare; Hisham Beshara Halasa, Tariq;
Background: Mycobacterium avium subsp. paratuberculosis (MAP) infections in cattle are generally challenging to detect and cost-effective test strategies are consequently difficult to identify. MAP-specific antibody ELISAs for milk and serum are relatively inexpensive, but their utility...... within and between groups, and in some groups we found a bimodal distribution of MES. Dairy herds generally showed higher MES than non-dairy herds. Dairy herds in a control programme for paratuberculosis showed a MES similar to all other dairy herds from which animals >2.0 years were tested (both groups...
Mekonnen, Sefinew Alemu; Koop, G.; Melkie, S.T.; Getahun, C.D.; Hogeveen, H.; Lam, Theo J.G.M.
Knowledge of mastitis pathogens and their predominance as well as understanding of risk factors are prerequisites to improve udder health in a herd, region or country. In Ethiopia, such information is scarce, despite the fact that mastitis is an important cattle disease in the country. A
Nielsen, Torben Dahl; Vesterbæk, I L; Kudahl, A B;
by solid walls rather than bars and not introducing biosecurity routines between the barn sections (e.g. boot wash, change of clothing) were associated with increased probability of successful control in the logistic analysis. The latter may seem illogical, but may be explained by successful herds already...
Santman-Berends, I M G A; Gonggrijp, M A; Hage, J J; Heuvelink, A E; Velthuis, A; Lam, T J G M; van Schaik, G
Extended-spectrum β-lactamase and AmpC-producing Escherichia coli (ESBL/AmpC) are an emerging problem and are hypothesized to be associated with antimicrobial use (AMU), and more specifically with the use of third- and fourth-generation cephalosporins. Whether ESBL/AmpC also occur in organic dairy h
Nielsen, Liza Rosenbaum; Dohoo, Ian
on the conditional probability of recovery (i.e. the hazard) was time-dependent: early in the study period, long durations of infection were predictive of a low hazard of recovery. Later in the control programme the effect of duration of infection was reduced indicating a desired effect of an intensified control......-positive herds. Participation in a voluntary paratuberculosis control programme reduced the duration of infection, and there were indications that recovery from S. Dublin infection was stimulated by a centrally organised and targeted control campaign. This is the first large-scale study that investigated...
Nielsen, Torben Dahl; Nielsen, Liza Rosenbaum; Toft, Nils
Specialised veal producers that purchase and raise calves from several dairy herds are potentially at high risk of delivering Salmonella-infected animals to slaughter. However, the true prevalence of Salmonella infected veal producing herds and the prevalence of infected calves delivered...... six of 68 herds obtaining posterior probability of being infected less than 10%. Furthermore, this study indicated that serology is sufficiently sensitive and specific to be used for estimating the prevalence of Salmonella-infected specialised veal producing herds....
Hoorfar, Jeffrey; Lind, Peter; Bell, M.M.
The IgG seroreaction of Salmonella-infected cattle herds against a fimbrial antigen (SEF14) was compared with that against lipopolysaccharide (LPS) antigens. Sera from 23 dairy herds (n = 205) from an island with no occurrence of salmonellosis, four herds (n = 303) with recent outbreaks of S...
A field trial was conducted to determine the effect of premilking teat disinfection (predipping) on several measures of mastitis in a commercial dairy farm where the predominant organisms isolated from intramammary infections were coagulase negative Staphylococcus spp. Cows were randomly assigned to a treated (predipped with 0.5% iodine germicide plus "good udder preparation") or a control group ("good udder preparation" alone). Sterile composite milk samples were collected at the initiation ...
ESTRATEGIC MANAGEMENT DURING THE TRANSICION PERIOD TO OPTIMISE PRODUCTIVITY AND REPRODUCTIVE PERFORMANCE IN THE DAIRY HERD MANEJO ESTRATÉGICO DURANTE EL PERIODO DE TRANSICIÓN PARA OPTIMIZAR LA PRODUCCIÓN Y EL COMPORTAMIENTO REPRODUCTIVO GANADO LECHERO
Full Text Available In dairy herds, the interval between calving and pregnancy depend on many factors including preparation of the cow for calving, dietary management before and after calving. Factors such as hypocalcemia and body condition are determinant in the presentation of postpartum pathologies and ovarian activity resumption. Additionally, management of the dairy cattle should include fixed time artificial insemination protocols to increase the number of animals bred close to the voluntary waiting period and pregnancy rates. The following review will address topics related with cattle body condition and puerperal hypocalcemia that affect negatively postpartum reproductive performance and also will, address management alternatives to improve pregnancy rates y to reduce days open.Los días abiertos en el hato lechero dependen de muchos factores, dentro de los cuales se debe considerar, la preparación de la vaca preparto incluyendo el manejo dietario pre y postparto. Factores como la hipocalcemia y la condición corporal son determinantes en la presentación de patologías puerperales y en el inicio de la ciclicidad. Adicional a este manejo, se debe considerar la utilización de protocolos de inseminación a tiempo fijo que incrementa el número de animales servidos cerca del tiempo voluntario de espera y genera un incremento en las tasas de preñez. La presente revisión discutirá temas relacionados con la condición corporal y la presentación de hipocalcemia puerperal que afectan la fertilidad posparto de la vaca, así como alternativas para mejorar las tasa de preñez y reducir los días abiertos.
Vaarst, Mette; Byarugaba, D.K.; Nakavuma, J.
Abstract Within the framework of a research project investigating methods to decrease mastitis incidence, farmer groups for participatory training in a modified Farmer Field School approach were initiated in order to improve animal health and farmer knowledge in mastitis control technologies...... knowledge and experience from training in systematic clinical examination of animals, evaluation of the farm environments, and identification of improvements. Much of the acquired new knowledge was about basic dairy cow management and husbandry practices. In addition, they gave examples of how they were now...
Full Text Available Monitorear la vaca en transición es fundamental para detectar precozmente enfermedades. El objetivo fue evaluar la incidencia y costo de eventos en el período “vaca parida” en un tambo del partido de Tandil y compararla con resultados del grupo Clave. Se monitoreó diariamente por 12-14 días posparto la producción láctea, actitud, temperatura corporal, función ruminal, palpación transrectal, glándula mamaria y score de locomoción a 240 vacas y 102 vaquillonas Holstein, durante 3 meses desde el 01/03/2010. La alimentación preparto, fue silo de maíz, grano de cebada, heno y sal mineral; durante la transición post parto (12-14 días se conformó con silo de maíz, heno de pastura, pastura y concentrado. El estadístico se realizó mediante el cálculo de Chi². Se observan mayores valores en metritis/endometritis y menores valores en patologías podales en tambo, respecto del grupo Clave. En tambo hubo diferencias (pMonitoring the transition cow is fundamental for early detection of diseases. The objective was to evaluate the incidence and cost of events in the period “calved cow” on a dairy farm in Tandil and compare with results of the Clave group. Postpartum milk production, attitude, body temperature, rumen function, trans-rectal palpation, mammary gland and locomotion score were monitored daily for 12-14 days in 240 Holstein cows and 102 heifers during the 3 months from 01/03/2010. The pre partum diet was corn silage, barley grain, hay and commercial mineral salt; during the postpartum transition (12-14 days the diet was corn silage, pasture hay, pasture and concentrate. The statistical analysis was performed by calculating Chi². Higher values were observed in metritis/ endometritis and lower values in podal diseases on dairy farm, compared with the Clave group. On the dairy farm there were differences (p <0.05 in assisted birth and hypocalcemia/ Mg recovered between categories. Loss of production, discarded milk and costs
Full Text Available Abstract Over a period of two years, growth rate and health were measured for dairy calves allowed to suckle their mothers up to 6–8 weeks of age. Thirty-one calves were weighted weekly, and the mean daily growth rate was 1.2 ± 0.03 kg from birth up to 13 weeks of age. Illness in calves and young stock was not observed. In the cows, the mean incidences of ketosis, displaced abomasum, puerperal paresis, mastitis, teat injury and retained placenta were 0, 0, 8, 22, 1 and 1%, respectively, during a 6-year period. The mean daily gain of 56 growing bulls was 1.4 kg when slaughtered at 15 months of age, which is higher than the mean daily gain of 0.95 kg in the population. Probiotics, hormones and vaccines were not used, and antibiotics were only used for treating illness. The present study indicates many advantages and few problems when dairy calves are penned together with the cows and allowed natural feeding up to 6–8 weeks of age. This production system was easy to manage, preferred by the farmer, and may satisfy the public concern regarding the practice of immediate separation of cow and calf in commercial milk production.
In pastoral system dominated milk production in Nigeria, it still supplies considerable ... return of sales of dairy products and constraints encountered by dairy cattle .... to improve herd productivity is to cross local cows to the exotic bulls and/or.
Full Text Available Abstract Background Eradication of bovine tuberculosis (bTB through the application of test-and-cull programs is a declared goal of developed countries in which the disease is still endemic. Here, longitudinal data from more than 1,700 cattle herds tested during a 12 year-period in the eradication program in the region of Madrid, Spain, were analyzed to quantify the within-herd transmission coefficient (β depending on the herd-type (beef/dairy/bullfighting. In addition, the probability to recover the officially bTB free (OTF status in infected herds depending on the type of herd and the diagnostic strategy implemented was assessed using Cox proportional hazard models. Results Overall, dairy herds showed higher β (median 4.7 than beef or bullfighting herds (2.3 and 2.2 respectively. Introduction of interferon-gamma (IFN-γ as an ancillary test produced an apparent increase in the β coefficient regardless of production type, likely due to an increase in diagnostic sensitivity. Time to recover OTF status was also significantly lower in dairy herds, and length of bTB episodes was significantly reduced when the IFN-γ was implemented to manage the outbreak. Conclusions Our results suggest that bTB spreads more rapidly in dairy herds compared to other herd types, a likely cause being management and demographic-related factors. However, outbreaks in dairy herds can be controlled more rapidly than in typically extensive herd types. Finally, IFN-γ proved its usefulness to rapidly eradicate bTB at a herd-level.
Broeders, D.; Chen, D.; Minderhoud, P.; Schudel, W.
This paper uses unique and detailed transaction data to analyse herding behavior among pension funds. We distinguish between weak, semi strong and strong herding behaviour. Weak herding occurs if pension funds have similar rebalancing strategies. Semi strong herding arises when pension funds react s
Schmidt, Tracy; Kock, Marleen M.; Ehlers, Marthie M.
Staphylococcus aureus is one of the most common etiological agents of contagious bovine mastitis worldwide. The purpose of this study was to genetically characterize a collection of S. aureus isolates (bovine = 146, human = 12) recovered from cases of bovine mastitis and nasal swabs of close human contacts in the dairy environment. Isolates were screened for a combination of clinically significant antimicrobial and virulence gene markers whilst the molecular epidemiology of these isolates and possible inter-species host transmission was investigated using a combination of genotyping techniques. None of the isolates under evaluation tested positive for methicillin or vancomycin resistance encoding genes. Twenty seven percent of the bovine S. aureus isolates tested positive for one or more of the pyrogenic toxin superantigen (PTSAg) genes with the sec and sell genes predominating. Comparatively, 83% of the human S. aureus isolates tested positive for one or more PTSAg genes with a greater variety of genes being detected. Genomic DNA macrorestriction followed by pulsed-field gel electrophoresis (PFGE) of the bovine isolates generated 58 electrophoretic patterns which grouped into 10 pulsotypes at an 80% similarity level. The majority of the bovine isolates, 93.2% (136/146), clustered into four major pulsotypes. Seven sequence types (ST) were identified among the representative bovine S. aureus isolates genotyped, including: ST8 (CC8), ST97 (CC97), ST351 (CC705), ST352 (CC97), ST508 (CC45), ST2992 (CC97) and a novel sequence type, ST3538 (CC97). Based on PFGE analysis, greater genetic diversity was observed among the human S. aureus isolates. Bovine and human isolates from three sampling sites clustered together and were genotypically indistinguishable. Two of the isolates, ST97 and ST352 belong to the common bovine lineage CC97, and their isolation from close human contacts suggests zoonotic transfer. In the context of this study, the third isolate, ST8 (CC8), is
Holzhauer, M.; Bartels, C.J.M.; Dopfer, D.; Schaik, van G.
Lactating Holstein-Friesian dairy cows in four separately housed groups in a herd with endemic digital dermatitis (E)D) were monitored weekly for 4 weeks in December 2004 for the presence of and transition between five stages (MO-M4) of DD. Cows were also monitored for the presence of heel horn eros
Genetic improvement of dairy cattle health using producer-recorded data is feasible. Estimates of heritability are low, indicating that genetic progress will be slow. Improvement of health traits may also be possible with the incorporation of environmental and managerial aspects into herd health pro...
Full Text Available Abstract Background Insulin secretion and tissue sensitivity to insulin is considered to be one of the factors controlling lipid metabolism post partum. The objective of this study was to compare glucose-induced blood insulin and metabolite responses in Estonian Holstein (EH, n = 14 and Estonian Red (ER, n = 14 cows. Methods The study was carried out using the glucose tolerance test (GTT performed at 31 ± 1.9 days post partum during negative energy balance. Blood samples were obtained at -15, -5, 5, 10, 20, 30, 40, 50 and 60 min relative to infusion of 0.15 g/kg BW glucose and analysed for glucose, insulin, triglycerides (TG, non-esterified fatty acids (NEFA, cholesterol and β-hydroxybutyrate (BHB. Applying the MIXED Procedure with the SAS System the basal concentration of cholesterol, and basal concentration and concentrations at post-infusion time points for other metabolites, area under the curve (AUC for glucose and insulin, clearance rate (CR for glucose, and maximum increase from basal concentration for glucose and insulin were compared between breeds. Results There was a breed effect on blood NEFA (P P P P P P th min nadir (P th min postinfusion (P Conclusion Our results imply that glucose-induced changes in insulin concentration and metabolite responses to insulin differ between EH and ER dairy cows.
Fabiana Alves Demeu
Full Text Available Objetivou-se com esta pesquisa, analisar e quantificar a influência do descarte involuntário de matrizes no impacto econômico da mastite em rebanhos leiteiros. A pesquisa foi realizada por meio de simulação no sistema computacional CU$TO MASTITE, considerando rebanhos leiteiros com taxas de descarte de 2, 4 e 6%. Foram considerados como prevenção as despesas com monitoramento (cultura e antibiograma, contagem de células somáticas no tanque e contagem de células somáticas individuais, pré e pós dipping, vacinação, tratamento de vacas secas e manutenção de ordenhadeira. Como medidas curativas consideraram-se os tratamentos de casos clínicos, cuja percentagem foi de 7% das vacas em lactação. O impacto da mastite foi estimado como sendo o total de perdas acrescido das despesas com prevenção e tratamento de casos clínicos. O aumento da taxa de descarte influenciou diretamente no impacto econômico da mastite. O elevado impacto econômico evidencia a necessidade de monitoramento da doença, para diminuírem os prejuízos causados pela mesma. As despesas com tratamento preventivo representaram, no máximo, 9,2% do impacto econômico, o que demonstra vantagem em investir nessa prática, pois ela irá contribuir significativamente para diminuição da contagem de células somáticas no tanque e, consequentemente, para reduzir o impacto econômico da mastite.The objectives of this research were to analyze and quantify the influence of the percentage of involuntary culling of matrices on the economic impact of mastitis in dairy herd. The work was conducted by means of a simulation in the CU$TO MASTITE software, taking into account dairy herds with culling rates of 2, 4 and 6%. The expenditures on monitoring were considered as prevention (culture and ambiogram, bulk tank somatic cell count and individual somatic cell count pre- and post-dipping, vaccination, treatment of dry cows and maintenance of milking machine. As curative
Geraldo Márcio da Costa
Full Text Available O objetivo deste trabalho foi estudar a freqüência de infecções intramamárias ocasionadas por leveduras a partir de amostras de leite (n=1710 coletadas em 40 rebanhos leiteiros do Estado de Minas Gerais. Cinqüenta e seis estirpes de leveduras do gênero Candida e uma linhagem de Trichosporon loubieri foram isoladas. Candida albicans foi a espécie dominante (28,1% das cepas, seguida por Candida parapsilosis (19,3%, Candida catenulata (14,0%, Candida glabrata (14,0% e Candida tropicalis (8,8%. Infecções mistas foram detectadas em 29,8% das vacas levedura-positivas. Amostras positivas para leveduras foram predominantemente obtidas (84% de vacas com mastite subclínica. A baixa taxa de isolamento de leveduras sugere que estes microrganismos não são relevantes para mastite bovina na região estudada.The objective of this study was to report the frequency of intramammary infections by yeasts, in Minas Gerais State, from milk samples (n = 1710 collected in 40 dairy herds. Fifty six yeast strains of the genus Candida and one strain of Trichosporon loubieri were isolated. Candida albicans was the dominant species (28.1% of the strains, followed by Candida parapsilosis (19.3%, Candida catenulata (14.0%, Candida glabrata (14.0%, Candida tropicalis (8.8%. Mixed infections were detected in 29.8% of yeast-positive cows. The yeast infection was more frequent (84% in cows with subclinical mastitis. The low rate of isolation of yeasts suggests that these microorganisms are not relevant to bovine mastitis in the studied region.
Rüdiger Daniel Ollhoff
Full Text Available The prevalence of Enzootic Bovine Leukosis virus infection was determined in adult cows of the catholic university of Paraná (Pontifícia Universidade Católica do Paraná dairy herd in 2000, 2003 and 2006 using the agar-gel immunodiffusion. The prevalence of the infection in adult lactating cows was respectively, over the years, 63.33%, 81.08% and 55.56%. Serum samples of all animals were taken in 2006, observing a continuously rise in antibody prevalence over the time up to more than 80% in animals older than 60 months, after vanishing of colostral maternal antibodies. The possible causes of this high prevalence were discussed under the particular circumstances of a teaching and research farm of an university.Determinou-se a soroprevalência do vírus da Leucose Enzoótica Bovina (LEB em vacas adultas de um rebanho leiteiro da Pontifícia Universidade Católica do Paraná nos anos de 2000, 2003 e 2006 através da imunodifusão em ágar-gel. Avaliou-se a evolução da prevalência da infecção neste rebanho, verificando-se respectivamente uma prevalência nos animais em lactação de 63,33%, 81,08% e 55,56%. Em 2006 determinou-se a soroprevalência para a LEB de todas as faixas etárias do rebanho, verificando-se após a queda dos anticorpos colostrais uma prevalência crescente, culminando com mais de 80% de animais soropositivos após os 60 meses de idade. Discutiram-se as possíveis causas destas soroprevalências ao vírus da LEB considerando-se a particularidade deste rebanho visar o ensino e a extensão.
Robinson, A L; Timms, L L; Stalder, K J; Tyler, H D
when used within 30min of birth. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Ahrens, F; Platz, S; Link, C; Mahling, M; Meyer, H H D; Erhard, M H
The objective was to investigate the effect of changing the flooring in the alleys of a barn from slatted concrete to slatted rubber mats on hoof disorders and animal hygiene in 44 loose-housed Brown Swiss dairy cows. Cows were examined for disorders of the hind hooves (hemorrhages, white line fissures, ulcers, heel horn erosion, and digital dermatitis) and for skin lesions. The dirtiness of the animals and of the floor was recorded. Climatic (temperature, humidity) and ammonia gas conditions were measured. Evaluations were carried out when the cows were housed on a concrete slatted floor and after 4 and 10 mo on soft flooring (slatted rubber mats, 29-mm thick). The anatomical portion of claw (medial, lateral), number of lactations (parity), and days in milk were included as covariates in the statistical model. Changing the flooring from slatted concrete to slatted rubber mats increased the score for white line fissures [1.0 ± 0.3 (concrete) vs. 2.5 ± 0.4 (10 mo rubber mats)] and influenced air humidity (i.e., the difference in the absolute humidity between the inside and outside of the barn increased from 1.5 ± 0.1 to 1.7 ± 0.2g/m(3)), whereas the other hoof disorders, skin lesions (score of 8.7 ± 0.3), the dirtiness of the animals (score of 5.9 ± 0.3), and the floor (score of 2.1 ± 0.1), and ammonia gas concentration (2.6 ± 0.3mg/kg) were not affected (overall scores or measures; mean ± SE). Lateral claws were more affected (except for heel horn erosion) than medial claws (estimated effects between 1.3 ± 0.2 and 3.0 ± 0.6). Parity influenced hoof disorders (except for hemorrhages) and skin lesions (estimated effects between -0.6 ± 0.3 and 0.5 ± 0.2). Days in milk influenced hoof disorders, but had no effect on skin lesions and on the dirtiness of the animal. Irrespective of floor type, the slots (2.6 ± 0.1) were dirtier than the slats (1.6 ± 0.1). In conclusion, covering slatted concrete flooring with slatted rubber mats partially impaired hoof
US Fish and Wildlife Service, Department of the Interior — The Mentasta caribou herd is located in southeast mainland Alaska and Western Yukonn Territory. This small herd has declined from a high Of approximately 3,100...
Herd-level prevalence and associated risk factors for Toxoplasma gondii, Neospora caninum, Chlamydia abortus and bovine viral diarrhoea virus in commercial dairy and beef cattle in eastern, northern and northeastern China.
Sun, Wu-Wen; Meng, Qing-Feng; Cong, Wei; Shan, Xiao-Feng; Wang, Chun-Feng; Qian, Ai-Dong
Although the seroprevalence of Toxoplasma gondii, Neospora caninum, Chlamydia abortus and bovine viral diarrhea virus infection in cattle have been reported in some areas in China, most of them were conducted with small number of cattle samples and very limited districts and neglected the assessment of herd management factors associated with herd-level prevalence of these pathogen infections. Thus, from September 2013 to December 2014, a large-scale seroprevalence study was conducted to determine the animal-level and herd-level seroprevalence and identify herd-level risk factors associated with these pathogen infections in 4487 cattle from 134 herds in five provinces (Heilongjiang, Jilin, Liaoning, Shandong, Hebei) and Inner Mongolia Autonomous Region of China. At animal level, the true prevalence of antibodies against T. gondii, N. caninum, C. abortus and bovine viral diarrhoea virus (BVDV) was 10.48, 17.14, 11.92 and 50.10%, respectively. At herd level, the true prevalence of antibodies against T. gondii, N. caninum, C. abortus and BVDV was 27.16, 29.10, 37.31 and 40.30%, respectively. Multivariate analysis of these characteristics showed that source of water and presence of felids were significantly associated with T. gondii infection in the studied cattle herds. Source of water was significantly associated with N. caninum infection in the studied cattle herds. While herd size and management system were significantly associated with BVDV infection in the studied cattle herds, this is the first report of herd-level prevalence and associated risk factors of T. gondii, N. caninum, C. abortus and BVDV infection in cattle in China.
李栋梁; 赵景义; 沈俊乐; 史苍桀; 曹杰
The epidemiology of the infectious bovine rhinotracheitis (IBR) and bovine viral diarrhea (BVD) were assessed in the medium and small dairy herds and the farming community in Beijing.The percent of IBR antibodypositive heifers was 50.52％,and the result was 70.98％ for BVDV.At the herds level,the antibody positive rate reached 50％ (12/24) for IBR and 87.50％ (21/24) for BVD.IBR high-risk herds were 9,BVD high-risk herds were 12,seven herds were combination risk of IBR and BVDV.The serological investigation and analysis showed that IBR prevalence is relatively serious in Beijing,and vaccine should be considered; Most of herds had BVDV history or contact with acute infection,high-risk herds need to start BVDV eradication program.%本研究对北京地区中小奶牛场及养殖小区进行了牛传染性鼻气管炎(IBR)、牛病毒性腹泻病(BVD)的风险评估.结果表明,参试牛场及小区的后备牛IBR血清阳性率达50.52％,BVD血清抗体阳性率达70.98％;从牛场水平看,24个牛场中IBR抗体场间阳性率达到50％ (12/24),BVD抗体场间阳性率达到87.50％(21/24),IBR高风险牛场9个,BVD高风险牛场12个,双高风险牛场7个.此次评估结果表明,北京地区IBR流行情况较为严重,应考虑疫苗免疫;参试的大部分牛场有BVDV的急性感染史或接触史,高风险牛场应启动BVDV清除计划.
Full Text Available An epidemiological study was carried out on 2823 cows from 34 dairy herds from Goiania in the State of Goias-Brazil during 2001 to 2002. The pregnancy rate was 47.8%. In 1473 non-pregnant cows, causes of reproductive failure problems were sought. The most prevalent uterine infection was endometritis (17.0%. Uterine disorders such as partial hypoplasia of the genital system (0.04%, macerate fetus (0.01%, adhesion of ovaries (0.04%, stillbirth (0.04%, retained placenta (0.01%, cervix inflammation (0.6% and abortion (0.88% also were found. Uterine swabs were collected aseptically for microbiological culture. Gram positives cocci (41.3% and Gram negatives rods (52.6% were found, and Staphylococcus aureus and Escherichia coli were the most prevalent pathogens. Susceptibility patterns of microorganisms suggested the use of chloramphenicol, gentamicin and neomycin for antimicrobial therapy.No período de março 2001 a julho 2002 foram estudadas 2823 fêmeas bovinas, em idade de reprodução, mestiças das raças Holandesa e Gir, pertencentes a 34 propriedades da bacia leiteira de Goiânia. A taxa de prenhez foi 47,8%. Entre os animais não gestantes (n= 1473, 17% apresentaram alterações inflamatórias do útero. Outras anormalidades encontradas foram: aplasia parcial do sistema genital (0,04%, feto macerado (0,01%, ovário aderido (0,04%. Casos de natimortalidade (0,04%, retenção placentária (0,01% e cervicite (0,6% e taxas de abortos (0,88% também foram registrados. Cocos Gram positivos (41,3% e bastonetes Gram negativos (52,6% foram os microrganismos mais isolados, sendo Staphylococcus aureus e Escherichia coli os principais patógenos encontrados nas infeccções uterinas. Testes in vitro mostraram que esses microrganismos apresentaram maior susceptibilidade frente ao cloranfenicol, à gentamicina e à neomicina.
Full Text Available Aim: Monitoring was performed in order to determine the Selenium (Se status of cattle herds in different agricultural areas in Wallonia (Belgium. Materials and Methods: The study included 114 heifers and 184 cows (82 dairy and 102 beef cows from 66 cattle farms situated in Wallonia. The Se status was assessed by measuring the glutathion peroxydase in red cells and converting it to the equivalent Se blood content. Results: The average blood concentrations of Se were very low. The Ardennes region was an area where the lowest Se status was recorded. The highest levels of Se in dairy cows and beef cows were recorded respectively in the limoneuse region and Famenne areas. The Se content in beef herds was lower compared with that of dairy herds (35 vs. 56 μg/L, p<0.01. Conclusion: On average over all the regions, 87% of animals were classified as deficient and only 13% of the animals were classified as adequate. The heifers from both dairy and beef herds in Wallonia exhibited a deficiency in Se classified as moderate to severe. The beef herds showed larger deficiencies compared with the dairy herds. Selenium deficiency can be prevented by ensuring adequate supplementation of deficient animals in Se deficient regions. An increased consumption of vitamin-mineral supplements, the use of Se-enriched fertilizers and ingredients containing high levels of Se can help to reduce or correct deficiencies recorded in cattle herds in Wallonia.
Weber, M.F.; Roermund, van H.J.W.; Velthuis, A.G.J.; Koeijer, de A.A.; Jong, de M.C.M.; Nielen, M.W.F.
A bulk milk quality assurance programme for Mycobacterium avium subsp. paratuberculosis (Map) in dairy herds was simulated. Herds were certified as `low-Map bulk milk¿ if, with a certain probability, the concentration of Map in bulk milk did not exceed a maximum acceptable concentration (MAC). The M
Derks, M.; Woudenbergh, van B.; Boender, M.; Kremer, W.; Werven, van T.; Hogeveen, H.
In providing advice on herd health, veterinarians need to be aware of farmers' goals and priorities. To determine the level of awareness, 29 veterinarians from 15 practices completed questionnaires during visits to dairy farms within the scope of veterinary herd health management (VHHM) programmes.
... cross-bred dairy cows in different dairy herds in Khartoum State, Sudan, during the period from March 2003 to ... The disease was studied based on clinical signs and laboratory examinations of serum calcium, phosphorus and magnesium.
Fatores de risco associados à alta contagem de células somáticas do leite do tanque em rebanhos leiteiros da Zona da Mata de Minas Gerais Risk factors associated with high bulk milk somatic cell count in dairy herds from Zona da Mata of Minas Gerais, Brazil
Full Text Available Características do rebanho e práticas de manejo associadas à contagem de células somáticas do leite do tanque (CCSLT foram estudadas em 175 rebanhos envolvidos em programas de acompanhamento entre junho de 2000 e dezembro de 2001. Os dados foram obtidos por meio de aplicação de questionários. Os rebanhos foram classificados em dois grupos de acordo com a média geométrica de seis CCSLT mensais, consecutivas, tendo como referência o valor de 500.000 células/ml. Os métodos estatísticos utilizados foram a análise exploratória dos dados e os modelos logísticos de regressão. Procedimentos relacionados ao controle e à prevenção de mastite foram adotados por pequeno número de rebanhos. O tipo de ordenha (manual, mecânica canalizada e balde-ao-pé, a idade média dos rebanhos, o local de ordenha e a realização de exames dos primeiros jatos de leite não foram associados à alta CCSLT. Os fatores associados à alta CCSLT foram a não adoção de linha de ordenha, a alimentação durante a ordenha e a ausência de anti-sepsia dos tetos após a ordenha.Herd features and management practices associated with high bulk milk somatic cell count (BMSCC were studied in 175 dairy herds enrolled on BMSCC programs. Herds data were obtained from June/2000 to December/2001 by questionnaires application. Herds were classified according to the geometric mean of six consecutive BMSCC records. Exploratory analysis and logistic regression models were the statistical analysis applied. Procedures about mastitis control and prevention were adopted in a few herds. Type of milking (machine or hand milking, herd age, milking place (milking parlour, pen, corral and strip test practice (first streams of milk were not associated with high BMSCC. Factors associated with high BMSCC were the following: do not milk clinical mastitic cows at the end of milking, feeding cows at milking and absence of post milking teat disinfection.
Chagwiza, Clarietta; Muradian, Roldan; Ruben, Ruerd
This study assesses the impact of cooperative membership among dairy producers in Selale, Ethiopia. We selected ten impact indicators: proportion of dairy income to total household income, total dairy income, proportion of crossbreed cows to the total number of cows in the herd (indicator of tech
Chagwiza, C.; Muradian Sarache, R.P.; Ruben, R.
This study assesses the impact of cooperative membership among dairy producers in Selale, Ethiopia. We selected ten impact indicators: proportion of dairy income to total household income, total dairy income, proportion of crossbreed cows to the total number of cows in the herd (indicator of technol
Caraviello, D Z; Weigel, K A; Fricke, P M; Wiltbank, M C; Florent, M J; Cook, N B; Nordlund, K V; Zwald, N R; Rawson, C L
A survey regarding general management, sire selection, reproductive management, inseminator training and technique, heat abatement, body condition scoring, facility design and grouping, nutrition, employee training and management, and animal health and bio-security was carried out from March to September of 2004 in 153 herds in the Alta Genetics (Watertown, WI) Advantage Progeny Testing Program. A total of 103 herds (67.3%) completed the survey. Herd size was 613 +/- 46 cows, with herds located in Wisconsin (26), California (12), New York (11), Minnesota (10), Michigan (7), Washington (6), Pennsylvania (6), Iowa (5), Idaho (5), Texas (4), Ohio (4), and other states (7). These farms sold 34.5 +/- 0.3 kg of milk/d per cow, with an annual culling rate of 34 +/- 1% and a calving interval of 13.8 +/- 0.1 mo. Cows were observed for estrus 2.8 +/- 0.3 times/d, for a duration of 27 +/- 4 min, but 78% of the respondents admitted that detection of estrus was not the employee's sole responsibility at that time. Managers tried to achieve pregnancy until 8.8 +/- 0.9 failed inseminations, 300 +/- 26 d postpartum, or milk yield cows were culled at 326 +/- 36 d postpartum or milk yield cows, respectively. Hormonal synchronization or timed artificial insemination programs were used in 87% of the herds, with 86% synchronizing first services, 77% resynchronizing repeat services, and 59% treating cystic, anestrous, or anovular cows. Finding good employees was identified as the greatest labor challenge, followed by training and supervising employees. Mastitis and hairy heel warts were noted as the greatest animal health concerns, followed by lameness, abortions, and death losses, whereas the greatest reproductive challenges were artificial insemination service rate, conception rate, twinning, and retained placenta or metritis. Results of this study can provide a useful benchmark or reference with regard to commonly used management practices on large commercial US dairy farms at the
tierra o piedras, ausencia de pediluvios vs presencia de pediluviosThe aim of this study was to determine the risk factors related to the prevalence of foot lesions in 50 dairy farms in three provinces (Valdivia, Osorno and Llanquihue of the Xth Region, Chile. Each farm was visited once between April and July, 2004. During each visit, all lactating cows were observed during locomotion. In those cows showing a degree of lameness, all four feet were examined. The degree of lameness was scored in scale of 1 (slightly lame to 4 (very lame. Data were recorded in an individual recording sheet for each cow. All the facilities and paddocks where the cows were kept were inspected during each visit. A questionnaire was handed to the manager or the owner of the farm. All the data recorded and the answers to the questionnaire were introduced in an Excel spread sheet as numerical variables and analyzed using the statistical program SPSS 8.0. Risk factors for the four more prevalent causes of lameness were determined using a logistic regression model. The associated factors for an increase of the prevalence in the dairy herds were determined with a multivariable linear regression model. A total of 7501 dairy cows were observed, with 641 of them being diagnosed with some degree of lameness. Cows with three or more lactations were 3.8 times more likely to develop chronic lesions of the hooves and cows with two lactations were 2 times more likely to develop overgrowth of the sole, compared with other lactations. German Red-pied cows were 1.7 times more likely to have white line lesions and 2 times more wall lesions than other breeds. Three risk factors related to lameness were identified: i changing the diet 25 days prior to calving vs changing the diet nearer to calving date or not changing the diet, ii concrete roads vs gravel and mud roads, iii the absence of a footbath versus the presence of a footbath
This is a review, written for a lay publication whose core audience in dairy producers. Control of BVD in any dairy operation must rely on the implementation of an organized strategy combining biosecurity, surveillance and increased herd resistance. This article discusses the design and implementati...
Ettema, Jehan Frans; Østergaard, Søren; Kristensen, Anders Ringgaard
Cross sectional data on the prevalence of claw and (inter) digital skin diseases on 4854 Holstein Friesian cows in 50 Danish dairy herds was used in a Bayesian network to create herd specific probability distributions for the presence of lameness causing diseases. Parity and lactation stage...... probabilities and random herd effects are used to formulate cow-level probability distributions of disease presence in a specific Danish dairy herd. By step-wise inclusion of information on cow- and herd-level risk factors, lameness prevalence and clinical diagnosis of diseases on cows in the herd, the Bayesian...... network systematically adjusts the probability distributions for disease presence in the specific herd. Information on population-, herd- and cow-level is combined and the uncertainty in inference on disease probability is quantified....
Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne’s Disease (JD), a chronic enteritis that occurs in dairy cattle and other ruminants. A 2007 NAHMS Dairy Study demonstrated that over 68% of dairy herds are infected with JD so the risk of exposure within a herd is high...
Hutber, A M; Kitching, R P; Conway, D A
Foot-and-mouth disease (FMD) is a highly contagious virus infection of sheep, goats, cattle, pigs and other, non-domesticated species of artiodactyls, and causes both clinical and subclinical infection according to the natural or acquired immunity of the host. Within vaccinated dairy herds FMD may appear as an acute, mild or subclinical infection, dependent upon the immune status of the herd, the level of challenge and the efficacy of the vaccine used. In the large dairy herds of Saudi Arabia, sub-clinical FMD was on a number of occasions, found to have spread amongst the cattle before signs of disease were seen. Such undetected transmission resulted in a large incidence on the first day of diagnosis and curtailed the impact of post-outbreak vaccination (PoV). First day incidence (FDI) for these herds was found to correlate with the final cumulative incidence of clinical disease. Since FDI is available at the start of an outbreak it can be used as a predictive tool for the eventual outcome of an FMD outbreak. During the past 11 years 47 % of dairy herds examined in Saudi Arabia have experienced FMD initially as sub-clinical disease. For the remaining 53 %, waning vaccinal protection did not suppress clinical disease in the initially infected animals, and these showed severe rather than mild signs. Hence, in such herds there was a very low initial level of subclinical infection, so PoV was more effective, and the timing of PoV was found to give a good correlation with cumulative herd incidence: an early PoV resulted in low prevalence of clinically infected animals whilst late PoV permitted high prevalence. PoV timing can thereby be used in tandem with FDI as a predictive tool for future outbreaks, estimating the final cumulative incidence (or prevalence) of clinical FMD cases.
Nielsen, Lars Relund
In a recent paper a hierarchical Markov decision processes (MDP) with finite state and action space was formulated for the dairy cow replacement problem with stage lengths of 1 d. Bayesian updating was used to predict the performance of each cow in the herd and economic decisions were based...
Tomaszewski, M.A.; Haan, de M.H.A.; Thompson, J.A.; Jordan, E.R.
The objective of this study was to determine whether measurable differences existed between farms with and without cooling ponds. Data from Dairy Herd Improvement records for 1999 through 2002 were obtained on 42 herds located in North Central Texas. Nineteen herds had installed cooling ponds,
Kim, Tae Hyong; Johnstone, Jennie; Loeb, Mark
Vaccination ideally protects susceptible populations at high risk for complications of the infection. However, vaccines for these subgroups do not always provide sufficient effectiveness. The herd effect or herd immunity is an attractive way to extend vaccine benefits beyond the directly targeted population. It refers to the indirect protection of unvaccinated persons, whereby an increase in the prevalence of immunity by the vaccine prevents circulation of infectious agents in susceptible populations. The herd effect has had a major impact in the eradication of smallpox, has reduced transmission of pertussis, and protects against influenza and pneumococcal disease. A high uptake of vaccines is generally needed for success. In this paper we aim to provide an update review on the herd effect, focusing on the clinical benefit, by reviewing data for specific vaccines.
Hybschmann, G. K.; Ersbøll, A.K.; Vigre, Håkan
quarter per herd. Three potential herd-level risk factors were evaluated: herd size (number of finishers delivered for slaughter); herd health status (herds in the Specific Pathogen Free (SPF) System, conventional herds); and herd type (herds including only finishers, integrated herds). Data were analyzed...... using general linear mixed models with repeated measurements. Smaller herds had a larger AMU per finisher than larger herds. Integrated herds had lower AMU as compared with herds with only finishers. Herds within the SPF System had a larger decrease in AMU with increasing herd size compared...
Roermund, van H.J.W.; Weber, M.F.; Koeijer, de A.A.; Velthuis, A.G.J.; Jong, de M.C.M.
A bulk milk quality assurance programme for Mycobacterium avium subsp. paratuberculosis (Map) in dairy herds was simulated. Herds were certified as 'low-Map bulk milk' if, with a certain probability, the concentration of Map in bulk milk did not exceed a maximum acceptable concentration (MAC). The M
Sensibilidad del cultivo de pool fecal para detectar infección por Mycobacterium avium subsp. paratuberculosis en rebaños bovinos de leche y su relación con la prueba de ELISA Sensitivity of pooled faecal culture for detecting Mycobacterium avium subsp. paratuberculosis infection in dairy herds and its relationship with the ELISA test
Full Text Available El objetivo del presente estudio fue evaluar la sensibilidad y especificidad del cultivo de pool fecal como alternativa diagnóstica de paratuberculosis en rebaños lecheros bovinos comparado con el cultivo fecal individual y la prueba de ELISA con la finalidad de reducir costos asociados al diagnóstico de la enfermedad. En 12 rebaños lecheros con antecedentes de paratuberculosis se recolectó un máximo de 50 muestras fecales individuales por rebaño (n=598 y se cultivaron en medio de Herrold en forma individual y en pools estratégicos de 5 y 10 animales. Simultáneamente, de cada animal se recolectó una muestra de sangre para la prueba de ELISA. Se evaluó la sensibilidad y especificidad de las pruebas usando como referencia los cultivos fecales individuales mediante tablas de dos entradas. En 10 (83,3% rebaños y en 42 (7% animales fue posible aislar Map en tanto que el 15,8% y 22% de los pools de 5 y 10 animales, respectivamente, resultaron positivos al cultivo fecal. La sensibilidad de los pools fecales de 5 y 10 animales fue 43,2% y 46,4%, respectivamente, mientras que la sensibilidad del ELISA fue 42,9%. El costo de los pools fecales de 5 animales fue similar al de la prueba de ELISA, pero cuatro veces menor que el costo del cultivo fecal individual; sin embargo, la sensibilidad y especificidad de los pools de 5 animales fue similar a los cultivos individuales. El cultivo de pools fecales demostró ser una buena y costo-efectiva alternativa para el diagnóstico de paratuberculosis para detectar rebaños infectados con MapThe aim of the present study was to evaluate the sensitivity and specificity of pooled faecal culture as a better alternative for the diagnosis of paratuberculosis in dairy herds compared to the conventional faecal culture and the ELISA test. Individual faecal and blood samples were collected from 50 cows in each one of 12 dairy herds (n = 598 with a history of paratuberculosis. Faecal samples were cultured on Herrold
Concentraciones sanguíneas de ß-hidroxibutirato, NEFA, colesterol y urea en cabras lecheras de tres rebaños con sistemas intensivos de producción y su relación con el balance nutricional Relationship between blood metabolites (ß-hydroxybutirate, NEFA, cholesterol and urea and nutritional balance in three dairy goat herds under confinement
Full Text Available El objetivo de este estudio fue determinar el comportamiento de algunos metabolitos sanguíneos indicadores del balance metabólico nutricional en la cabra lechera, sometida a sistemas intensivos de producción. Para ello se utilizaron tres rebaños de la región metropolitana de Chile, con 21 cabras cada uno. Los animales fueron divididos en grupos de 7 según su etapa de producción, siendo éstos preparto (PP, 3 a 6 semanas de lactancia (T1 y 16 a 20 semanas de lactancia (T2. Las determinaciones sanguíneas efectuadas correspondieron a ß-hidroxibutirato (ßHB, ácidos grasos no esterificados (NEFA, colesterol y urea, todas realizadas mediante métodos colorimétricos. Además se registró producción de leche y condición corporal (CC en forma individual. Para determinar el aporte de proteína total y energía metabolizable de la ración se realizó un análisis químico proximal de los insumos que componían la dieta de cada grupo productivo analizado. En los tres rebaños analizados se encontraron aumentos significativos de NEFA (PThe aim of this study was to assess some blood metabolites as indicators of nutritional balance in dairy goats under intensive conditions. Three dairy herds were selected and 21 goats chosen in each. Goats were separated into three groups of seven animals each according to their productive stage: pre-partum (PP, 3-6 weeks of lactation (T1 and 16-20 weeks of lactation (T2. Blood samples were obtained during the first milking of the day and ß- hydroxybutirate (BHB, non-esterified fatty acids (NEFA, cholesterol, and urea were determined by colorimetric methods. Body condition score (BCS and milk production were also registered. To establish protein (g/day and metabolic energy (Mcal/day content of the ration fed, a proximal chemical analysis was performed. Nutrient requirements of goats were determined by NRC. In the three herds, significant high values of NEFA (P<0.05 were coincident with a non -significant
Perfil da infecção pelo vírus da diarreia viral bovina (BVDV em um rebanho bovino leiteiro de alta produção e com programa de vacinação contra o BVDV Bovine viral diarrhea virus (BVDV infection profile in a high production dairy herd with vaccination program against BVDV
Full Text Available A infecção pelo vírus da diarreia viral bovina (BVDV foi avaliada em um rebanho bovino leiteiro de alta produção com histórico de problemas reprodutivos e de vacinação regular contra o BVDV. A identificação do vírus foi realizada por RT-PCR em soro sanguíneo e o perfil sorológico por vírus-neutralização. Inicialmente, 100% (n=692 dos animais do rebanho foram avaliados com relação à presença de infecção ativa pelo BVDV por meio da RT-PCR. Quatro meses após, todos os animais positivos (n=29 na primeira avaliação foram avaliados novamente pela RT-PCR, assim como todos os animais que nasceram (n=72 e os que apresentaram problemas reprodutivos (n=36 no intervalo entre a primeira e a segunda colheita de sangue. Os resultados finais do estudo possibilitaram identificar 27 animais transitoriamente infectados e três animais persistentemente infectados (PI. A sorologia, realizada apenas nos animais positivos na primeira avaliação pela RT-PCR e nas vacas que apresentaram problemas reprodutivos entre a primeira e a segunda RT-PCR, demonstrou grande flutuação nos títulos de anticorpos neutralizantes, além de soroconversão na maioria dos animais. Foram identificados aumentos nos títulos de anticorpos neutralizantes que variaram entre 3 e 8 log2, indicando infecção ativa no rebanho. A circulação viral no rebanho avaliado foi responsável pela expressão de sinais clínicos da esfera reprodutiva em animais com baixo título de anticorpos e consequente falha na proteção fetal. Os resultados demonstram que o controle da infecção pelo BVDV apenas por meio da vacinação regular em rebanhos com animais PI pode não ser eficaz na profilaxia dessa virose.The profile of bovine viral diarrhea virus (BVDV infection was studies in a high production dairy herd selected based on a history of reproductive failures and regular vaccination against BVDV. Virus identification was performed by RT-PCR and serological profile was
Francisco J. Diéguez
Full Text Available This study was designed to assess the relationship between antibodies against bovine viral diarrhea virus (BVDV determined in the bulk tank milk (BTM and the within-herd seroprevalence. We also assessed the efficiency of measuring antibody levels in BTM samples to monitor BVDV infection status in a herd. In the 81 farms included in the study, BTM samples were obtained and blood samples withdrawn from all cattle older than one year. The infection status was then determined in serum and milk using a commercial blocking ELISA based on the detection of anti-p80 antibodies. Apart from these baseline serum and milk samples, another BTM sample was collected from each herd 9 months later, and a third BTM sample obtained 9 months after this. In these second and third milk samples, anti-BVDV antibodies were determined using the same ELISA kit. Statistical tests revealed good agreement between herd seroprevalences (% seropositive animals in the herd and the antibody levels detected in the BTM samples. During the 18 months of follow-up, the farms with persistently infected cattle at the study outset (14.8% of the herds showed a significant decrease in BTM antibody titers after virus clearance. Conversely, a significant increase in BTM antibody levels was observed in the herds infected with BVDV during the follow-up period. Our findings indicate that monitoring antibody levels in the BTM is a useful method of identifying changes in the BVDV infection status of a herd.Os objetivos do presente estudo foram avaliar a relação entre os níveis de anticorpos frente ao vírus da diarréia viral bovina (BVDV no tanque de leite e a prevalência de animais seropositivos em cada rebanho; e também avaliar a eficiência da medição dos níveis de anticorpos no tanque de leite como método de monitoramento do status de infecção frente ao BVDV. Nos rebanhos estudados, obtiveram-se amostras de soro de todos os animais com idade superior a um ano, assim como uma
Verdugo, Cristobal; Toft, Nils; Nielsen, Søren
included in the analysis, and one annual milk-ELISA test of all lactating cows present in such herds was considered. A Bayesian latent class model was used to obtain HTP and TP posterior distributions for each year. The model adjusts for uncertainty in age-specific test sensitivity and prior prevalence......This study aimed to estimate the between- (HTP) and within- (TP) herd true prevalence distribution of Mycobacterium avium subsp. paratuberculosis (MAP) infection in dairy cattle herds participating in the Danish MAP control programme. All herds enrolled in the programme between 2011 and 2013 were...... estimates. Bayesian posterior probabilities were computed in order to compare prevalence between the years. A total of 665,700 samples were included in the study, from 221,914, 224,040, and 220,466 cows sourced from 1138, 1112, and 1059 herds in years 2011, 2012, and 2013, respectively. In that period, HTP...
Hoorfar, Jeffrey; Bitsch, V.
A total of 2585 serum samples from 62 dairy herds located in four different regions of Denmark were tested in an O-antigen (0:1,4,5,12)-based ELISA for the detection of antibodies against Salmonella typhimurium. Ten closed herds from an island with no reported occurrence of salmonellosis for seve......A total of 2585 serum samples from 62 dairy herds located in four different regions of Denmark were tested in an O-antigen (0:1,4,5,12)-based ELISA for the detection of antibodies against Salmonella typhimurium. Ten closed herds from an island with no reported occurrence of salmonellosis...... the salmonellosis-free island were ELISA-negative, and all but one of the 12 S typhimurium-infected herds were ELISA-positive, which resulted in a herd test sensitivity of 0.92 and herd test specificity of 1.0. Eleven of the 12 S typhimurium-infected herds were negative in a blocking ELISA based on a monoclonal...
The term "herd immunity" for the indirect effect of meningococcal conjugate vaccines is inaccurate. A more appropriate term is "herd protection," because this term correctly describes the public effects imparted by vaccination campaigns against the meningococcus.
Fatores ambientais que afetam a produção e a composição do leite em rebanhos assistidos por cooperativas no Rio Grande do Sul Effects of environmental factors on milk yield and composition of dairy herds assisted by cooperatives in Rio Grande do Sul, Brazil
Full Text Available Neste estudo, avaliaram-se os efeitos de alguns fatores ambientais sobre a produção, a composição química e a contagem de células somáticas do leite em rebanhos vinculados às cooperativas no Rio Grande do Sul. Foram utilizados dados de um programa de controle leiteiro durante cinco anos, totalizando 165.311 observações, para analisar os seguintes efeitos ambientais: ano e mês do controle leiteiro, idade ao parto, tempo em controle leiteiro e estádio da lactação. A produção média de leite foi de 19,36 L/vaca/dia. Foi encontrada maior produção de leite em vacas de 5 a 6 anos de idade ao parto, nos primeiros 60 dias de lactação, nos meses de inverno e em rebanhos com mais tempo em controle leiteiro. Maior número de células somáticas foi relacionado à redução na produção de leite. Houve menor teor de gordura e de proteína no leite nos primeiros 60 dias de lactação e aumento desses componentes com o aumento no número de células somáticas. A concentração de lactose no leite diminuiu significativamente à medida que aumentaram as células somáticas e a idade ao parto. A contagem de células somáticas aumentou com a idade da vaca e à medida que avançou a lactação. Nos meses de inverno, verificaram-se valores mais elevados de proteína, gordura e lactose, possivelmente como conseqüência da alimentação com gramíneas temperadas. Os resultados revelam a importância das variações ambientais no estudo da composição do leite.The effects of some environmental factors on milk yield and milk chemical composition and also on somatic cells count in dairy herds assisted by cooperatives (DHI in Rio Grande do Sul, Brazil were investigated in this trial. Data were obtained from a 5-year period of dairy control program totalizing 165,311 observations and were used to investigate the effects of year and month of dairy control, age at calving, time of farm on dairy control and stage of lactation on milk yield and
Metcalf, C J E; Ferrari, M; Graham, A L; Grenfell, B T
Individual immunity is a powerful force affecting host health and pathogen evolution. Importantly, the effects of individual immunity also scale up to affect pathogen transmission dynamics and the success of vaccination campaigns for entire host populations. Population-scale immunity is often termed 'herd immunity'. Here we outline how individual immunity maps to population outcomes and discuss implications for control of infectious diseases. Particular immunological characteristics may be more or less likely to result in a population level signature of herd immunity; we detail this and also discuss other population-level outcomes that might emerge from individual-level immunity.
Chemical and microbiological water quality of subsurface agricultural drains during a field trial of liquid dairy manure effluent application rate and varying tillage practices, Upper Tiffin Watershed, southeastern Michigan
Haack, Sheridan Kidd; Duris, Joseph W.
A field trial was done in the Upper Tiffin River Watershed, in southeastern Michigan, to determine the influence of liquid dairy manure effluent (LDME) management practices on the quality of agricultural subsurface-drain water. Samples from subsurface drains were analyzed for nutrients, fecal-coliform and Escherichia coli (E. coli) bacteria, antibiotics, chemicals typically detected in wastewater, and the occurrence of genes indicating the presence of shiga-toxin-producing E. coli, or of bovine-specific Bacteroidetes bacteria. Samples were collected from November 2, 2006, to March 20, 2007, from eight subsurface drains under field plots that received no LDME and no tillage (controls) or received 4,000 or 8,000 gallons per acre (gal/acre) of LDME and either no tillage or two different types of tillage. The two types of tillage tested were (1) ground-driven, rotary, subsurface cultivation and (2) rolling-tine aeration. Samples were collected before LDME application and at 4 hours, and 1, 2, 6, 7, and 14 days post-application. Nutrient concentrations were high in subsurface-drain water throughout the field-trial period and could not be attributed to the field-trial LDME application. Of the 59 drain-water samples, including those collected before LDME application and control samples for each date, 56 had concentrations greater than the U.S. Environmental Protection Agency (USEPA), Ecoregion VI recommended surface-water criterion for total phosphorus, and all samples had concentrations greater than the recommended total nitrogen criterion. Nitrate + nitrite nitrogen concentration exceeded 20 milligrams per liter for every sample and contributed most to the total nitrogen concentrations. Substantial increases in drain-water concentrations of organic and ammonia nitrogen and total phosphorus were found for all treatments, including controls, at 14 days post-application after 0.84 inch of rainfall over 2 days. E. coli concentrations exceeded the USEPA recreational
Cornou, C.; Østergaard, S.; Ancker, M. L.
This application note presents a newly developed surveillance module for monitoring reproduction performances in dairy herds. It is called Critical Control Point and is part of a recently developed management tool, Dairy Management System. This management tool is commercialized as software intended...
Levantamento sorológico da infecção pelo vírus da leucose bovina nos rebanhos leiteiros do Estado do Rio Grande do Sul, Brasil Serological survey of the bovine leukosis virus infection in dairy herds of the Rio Grande do Sul State, Brazil
Mauro Pires Moraes
Full Text Available O vírus da Leucose Enzoótica Bovina (VLB causa uma infecção persistente em bovinos, sendo responsável por perdas econômicas significativas para a pecuária bovina. O objetivo deste estudo foi determinar a prevalência da infecção pelo VLB no rebanho leiteiro do Estado do Rio Grande do Sul, Brasil e estudar alguns aspectos epidemiológicos da infecção. Um total de 39.799 amostras de soro. coletadas em 4.200 propriedades de 172 municípios, distribuídos em 9 regiões geográficas, foram testadas pela técnica de imunodifusão em gel de ágar (IDGA, com antígeno glicoprotéico (glicoproteína gp 51. Os exames sorológicos revelaram 3.645 (9,2% amostras positivas. No entanto, a prevalência média do Estado, quando foi considerada aproximadamente 1% da população em cada região, foi de 12,0% (1.295/10.357 e 29,1% (385/1.321 das propriedades apresentaram pelo menos um animal positivo. A prevalência da infecção variou de 2,2% (17,8% das propriedades em Uruguaiana, a 19,6% (57,8% das propriedades em São Gabriel. Foram observadas taxas de 15,5% (41.8% das propriedades na grande Porto Alegre; 9,9% (64,4% em Pelotas: 19,4% (42,9% em Bagé; 9,2% (36,2% na grande Santa Rosa; 12.9% (37,8% em Erexim; 7,1% (26,5% em Passo Fundo e 8,0% (33,8% em Santa Maria. Esses resultados demonstram que a infecção pelo VLB esta amplamente distribuída no rebanho leiteiro do Estado. No entanto, os índices de infecção são relativamente baixos se comparados com índices de outros estados e países e são compatíveis com programas de controle e erradicação.Bovine leukosis vírus (BLV is associated with a persistem infection in cattle that is responsible for serious lasses to the livestock industry. The objective of this study was to determine the prevalence and to analyse some epidemiological aspects of the BLV infection in the dairy herd of the Rio Grande do Sul state. A total of 39.799 blood samples, collected in 4,200 herds from 172 counties
Herpesvírus bovino tipo 1 (HVB 1: inquérito soro-epidemiológico no rebanho leiteiro do estado do Rio Grande do Sul, Brasil Bovine herpesvirus type 1 (BHV 1: an epidemiological survey in the dairy herd of Rio Grande do Sul state, Brazil
Luciane Teresinha Lovato
á samples studied was 18.8%. The results demonstrated a similar antibody prevalence among the dairy regions. However, two regions had significant differences. Region 7 represented by "Passo Fundo" county had a prevalence of 12% and region 9 represented by "Quaraí" with the highest prevalence with 49.5%. The sera samples were divided into four groups according to cattle age: cattle with less than two years of age, 2 to 4, more than 4 to 6, and older than 6 years age. The results showed that the prevalence increases gradually with age. The major difference was between group 1 and 2. The results also demonstrated that the infection is more frequent in cattle older than two years. There was no significant difference among antibody titers between the age groups. The major relevance of the study was the prevalence of 54.5% positive herds, that represents 371 positive from a total of 685 herds tested. Considering this prevalence, it is clear that the BHV 1 is disseminated among the dairy population of the State. Prevention and control methods should be adopted so the spread of the infection can be withhold.
Langley, David J.; Tan, Chee-Wee; Worm, Daniël
the Netherlands, we develop an analytical model to investigate drivers of herd formation, growth, and dissolution. Finally, combining environmental turbulence literature with our empirical findings, we derive a novel typology of online anti-brand herd behaviors, and put forward six propositions to guide theory...... light on the formation, growth, and dissolution of online anti-brand herds. First we expand on the concept of environmental turbulence to advance core properties unique to online herd behavior. Next, based on evidence gathered from 40 online anti-brand herd episodes targeting two prominent firms from...
Nordlund, Kenneth V; Cook, Nigel B
There is no single monitor that can fully characterize the success of a transition cow management program in a herd. Rather we must rely on a group of key monitors. Table 5 outlines the key indices and targets that we use in herd investigations. By using these monitors, effective transition cow programs can be differentiated from problematic ones, and many of the problems can be resolved for the good of the herd owners, dairy laborers, and most of all, the cows. Development of more sophisticated monitors and software with stronger epidemiologic structure will allow for better analysis of programs in the future.
Jordan, David; Nielsen, Liza Rosenbaum; Warnick, Lorin Dean
Modeling the transmission of a pathogen between herds provides useful insight into how prevention and surveillance programs can be organised. We aimed to devise a technique for simulating the transfer of Salmonella (S.) Dublin between Danish dairy herds based on trading patterns and infection rates...... dairy industry using data fields and logic mimicking the ecology, surveillance and control of S. Dublin. Superimposed on this was a system for simulating movement of cattle between herds and between regions accounting for the infection status of both the source and destination herds. Predictions from...
Langley, David J.; Tan, Chee-Wee; Worm, Daniël
light on the formation, growth, and dissolution of online anti-brand herds. First we expand on the concept of environmental turbulence to advance core properties unique to online herd behavior. Next, based on evidence gathered from 40 online anti-brand herd episodes targeting two prominent firms from...... the Netherlands, we develop an analytical model to investigate drivers of herd formation, growth, and dissolution. Finally, combining environmental turbulence literature with our empirical findings, we derive a novel typology of online anti-brand herd behaviors, and put forward six propositions to guide theory......The online environment offers a fertile breeding ground for anti-brand herds of disgruntled consumers. Firms are often caught off guard by the unpredictability of such herds and, as a consequence, are forced into a reactive, defensive stance. We conduct a social media analysis that aims to shed...
Rudoler, Nir; Rasis, Michal; Sharir, Benny; Novikov, Anna; Shapira, Gregory; Giladi, Michael
Bartonella bovis has been described in beef and dairy cattle worldwide, however the reported prevalence rates are inconsistent, with large variability across studies (0-89%). This study describes the first isolation and characterization of B. bovis among cattle herds in the Middle East. Blood samples from two beef cattle herds (each sampled thrice) and one dairy herd (sampled twice) in Israel were collected during a 16-months period. Overall, 71 of 95 blood samples (75%) grew Bartonella sp., with prevalence of 78% and 59% in beef and dairy cattle, respectively. High level bacteremia (≥100,000 colony forming units/mL) was detected in 25 specimens (26%). Such high-level bacteremia has never been reported in cattle. Two dairy cows and one beef cow remained bacteremic when tested 60 or 120 days apart, respectively, suggesting that cattle may have persistent bacteremia. One third of animals were infested with ticks. Sequence analysis of a gltA fragment of 32 bacterial isolates from 32 animals revealed 100% homology to B. bovis. Species identification was confirmed by sequence analysis of the rpoB gene. Phylogenetic analysis based on the concatenated sequences of gltA and rpoB demonstrated that the isolates described herein form a monophyletic group with B. bovis strains originating from cattle worldwide. Taken together, the high prevalence of bacteremia, including high-level bacteremia, in beef and dairy cattle, the potential to develop prolonged bacteremia, the exposure of cattle to arthropod vectors, and proximity of infected animals to humans, make B. bovis a potential zoonotic agent.
Full Text Available The objective of this study was to evaluate associations between average lactation somatic cell counts (SCC and herd management practices in an arid climate. A total of 38,530 average lactation SCC records for 10,216 Holstein cows gathered on 25 dairy farms from January 2009 to October 2012 in Isfahan (Iran were analyzed. Average lactation SCC (cells × 1,000 was 250.79 ranging from 90.31 to 483.23 cells/mL across investigated farms. Herd-level management factors associated with average lactation SCC were determined separately using mixed linear models in the MIXED procedure with average lactation somatic cell score (SCS included as the dependent variable. Some of the management practices associated with low average lactation SCS included sawdust combined with sand bedding, using automatic cup removers, disinfection of the teats by dipping into disinfectant, using washable towels for teat cleaning, free-stall barns, wet disposable tissue for udder washing, wearing gloves during milking and the use of humidifiers and shade. Lower-production herds and larger-size herds had lower average lactation somatic cell counts. Most herd management practices associated with average lactation SCC in dairy herds in the arid region of Isfahan are in agreement with most previous studies. However, different results are found for use of humidifier, bedding materials and herd size.
Weber, M.F.; Nielen, M.; Velthuis, A.G.J.; Roermund, van H.J.W.
bulk milk quality assurance programme for Mycobacterium avium subsp. paratuberculosis (Map) in dairy herds was simulated with a stochastic simulation model (JohneSSim). The aim of this study was to evaluate the epidemiological and economic effects of preventive management measures and various test s
Ramsbottom, G; Cromie, A R; Horan, B; Berry, D P
Because not all animal factors influencing profitability can be included in total merit breeding indices for profitability, the association between animal total merit index and true profitability, taking cognisance of all factors associated with costs and revenues, is generally not known. One method to estimate such associations is at the herd level, associating herd average genetic merit with herd profitability. The objective of this study was to primarily relate herd average genetic merit for a range of traits, including the Irish total merit index, with indicators of performance, including profitability, using correlation and multiple regression analyses. Physical, genetic and financial performance data from 1131 Irish seasonal calving pasture-based dairy farms were available following edits; data on some herds were available for more than 1 year of the 3-year study period (2007 to 2009). Herd average economic breeding index (EBI) was associated with reduced herd average phenotypic milk yield but with greater milk composition, resulting in higher milk prices. Moderate positive correlations (0.26 to 0.61) existed between genetic merit for an individual trait and average herd performance for that trait (e.g. genetic merit for milk yield and average per cow milk yield). Following adjustment for year, stocking rate, herd size and quantity of purchased feed in the multiple regression analysis, average herd EBI was positively and linearly associated with net margin per cow and per litre as well as gross revenue output per cow and per litre. The change in net margin per cow per unit change in the total merit index was €1.94 (s.e. = 0.42), which was not different from the expectation of €2. This study, based on a large data set of commercial herds with accurate information on profitability and genetic merit, confirms that, after accounting for confounding factors, the change in herd profitability per unit change in herd genetic merit for the total merit index is
The US dairy industry has realized tremendous improvements in efficiencies and milk production since the 1940s. During this time, farm and total cow numbers have decreased and average herd size has increased. This intensification, combined with the shift to a largely urban public, has resulted in increased scrutiny of the dairy industry by social and environmental movements and increased concern regarding the dairy industry's sustainability. In response to these concerns, a group of scientist...
Reproductive efficiency in dairy cows is a key factor for milk producers, and numerous studies have identified impaired reproductive performance as a major cause of reduced production efficiency in the dairy industry. The overall aim of this thesis was to gain knowledge of factors affecting the reproductive performance indicators currently used by herd advisory services and to find other, possibly more efficient, ways to measure reproductive performance in dairy cows. The studies include...
Mahmmod, Y S; Klaas, I C; Katholm, J; Lutton, M; Zadoks, R N
Host-adaptation of Streptococcus agalactiae subpopulations has been described whereby strains that are commonly associated with asymptomatic carriage or disease in people differ phenotypically and genotypically from those causing mastitis in dairy cattle. Based on multilocus sequence typing (MLST), the most common strains in dairy herds in Denmark belong to sequence types (ST) that are also frequently found in people. The aim of this study was to describe epidemiological and diagnostic characteristics of such strains in relation to bovine mastitis. Among 1,199 cattle from 6 herds, cow-level prevalence of S. agalactiae was estimated to be 27.4% based on PCR and 7.8% based on bacteriological culture. Quarter-level prevalence was estimated at 2.8% based on bacteriological culture. Per herd, between 2 and 26 isolates were characterized by pulsed-field gel electrophoresis (PFGE) and MLST. Within each herd, a single PFGE type and ST predominated, consistent with a contagious mode of transmission or point source infection within herds. Evidence of within-herd evolution of S. agalactiae was detected with both typing methods, although ST belonged to a single clonal complex (CC) per herd. Detection of CC23 (3 herds) was associated with significantly lower approximate count (colony-forming units) at the quarter level and significantly lower cycle threshold value at the cow level than detection of CC1 (2 herds) or CC19 (1 herd), indicating a lower bacterial load in CC23 infections. Median values for the number of infected quarters and somatic cell count (SCC) were numerically but not significantly lower for cows infected with CC23 than for cows with CC1 or CC19. For all CC, an SCC threshold of 200,000 cells/mL was an unreliable indicator of infection status, and prescreening of animals based on SCC as part of S. agalactiae detection and eradication campaigns should be discouraged.
Afshari Safavi, E.A.
Full Text Available A 1:1 matched case-control study of calves under 1 month of age was carried out by weekly visits to 7 dairy farms in Mashhad from May 2008 to October 2008. Fecal samples were collected from a total of 112 calves with clinical signs of diarrhea and from 112 matched animals without clinical signs of diarrhea as assessed by a scoring system. The samples were investigated for the presence of Rotavirus and Coronavirus by a commercial antigen capture ELISA test. Rotavirus antigen was detected in 29.5% and 17% of diarrheic and non-diarrheic calves, respectively and Coronavirus antigen was detected in 2.7% and 1.8% of diarrheic and non-diarrheic calves, respectively. Among diarrheic calves Rotavirus was the most common in the third week of life and Coronavirus was detected only in some cases of second week of life. The excretion of Rotavirus in the feces of scouring calves was significantly higher than in non-diarrheic calves (P value =0.03, odds ratio = 1.9 (1.05 – 3.76, but there was not any significant association between shedding of Coronavirus in the feces and diarrhea (P value =0.66, odds ratio = 1.4 (0.24 –9.05. These results indicate that in these industrial dairy farms in Mashhad, infections by Rotavirus can be considered as an important cause for newborn calf diarrhea.
Gonggrijp, M A; Santman-Berends, I M G A; Heuvelink, A E; Buter, G J; van Schaik, G; Hage, J J; Lam, T J G M
A cross-sectional study was conducted to evaluate the prevalence of extended-spectrum β-lactamase (ESBL)- and plasmid-mediated AmpC-producing Escherichia coli and associated risk factors in dairy herds. One hundred dairy herds were randomly selected and sampled to study the presence of ESBL- and Amp
White, P; Frankena, K; O'Keeffe, J; More, S J; Martin, S W
Movement of animals between farms represents a potential risk of bovine tuberculosis (BTB) and other disease transmission. The objectives of this study were to identify and quantify risk factors associated with the first between-herd movement of animals (denoted as risk move). A random sample of 1 percent of Irish calf births registered for 2002 (20,182 animals) was selected. Descriptive and survival analysis on movement over the period 2002-2005 was performed. A total of 12,119 (60%) of animals experienced a risk move over the 4-year study period. Among those that moved, 57% did so within the first 12 months of age. For animals in dairy herds, an early peak in risk move events was observed within the first 12 weeks of age; whereas in animals from suckler herds, a later risk move peak was observed between 21 and 36 weeks of age. The survival models identified a number of risk factors: two that appeared most important in predicting a risk move were gender and enterprise type. Males had a hazard ratio of 2.6 times that of females. The hazards for enterprise type, varied over time, thus a time-varying covariate (ent_type×ln(time)) was included in the Cox model. At 7 days of age, females in suckler herds were at 0.14 times the hazard of females in dairy herds for risk move, and over time, the hazards converged, equalised by day 140, and then diverged, so that by 4 years of age, females in suckler herds were at 4.64 times the hazard of females in dairy herds. Herds with a history of selling animals in previous years maintained that record during the study period with increased hazard of risk move. Enterprise type interacted with gender so that relative to females, males from dairy herds were at greater hazard of risk move than males from suckler herds. Hazard of risk move was also a function of ln (herd area), so that each doubling of farm area was accompanied by a 30.6% decrease in the hazards. The main conclusion was that risk of movement related disease transmission
Holtenius, K; Persson Waller, K; Essén-Gustavsson, B; Holtenius, P; Hallén Sandgren, C
The objective of this study was to determine whether there were differences in metabolic parameters and blood leukocyte profiles between cows in herds with high or low yearly mastitis incidence. In this study, 271 cows from 20 high yielding dairy herds were examined. According to the selection criteria, all herds had low somatic cell counts. Ten of the selected herds represented low mastitis treatment incidence (LMI) and ten herds had high mastitis treatment incidence (HMI). The farms were visited once and blood samples were taken from each cow that was in the interval from three weeks before to 15 weeks after parturition. The eosinophil count was significantly lower among cows from the HMI herds in the period from four weeks to 15 weeks after parturition. The plasma concentrations of beta-hydroxybutyrate, glucose, insulin and urea did not differ between groups, but the concentration of nonesterified fatty acids was significantly higher among HMI cows during the period three weeks after parturition. The concentration of the amino acid tryptophan in plasma was significantly lower among the HMI cows prior to parturition. Glutamine was significantly lower in cows from HMI herds during the first three weeks after parturition. Arginine was consistently lower in HMI cows, although the decrease was only significant during the period from four to fifteen weeks after parturition. The results suggest that there were differences in the metabolism and immune status between herds with high or low yearly mastitis treatment incidence indicating an increased metabolic stress in HMI cows.
Carpenter, Tim E.; Chriél, Mariann; Andersen, Mette M.
Abortion in dairy cows in well-managed dairies is not common but differences have been reported probably due to variation in animal health, nutrition and management, as well as difficulties in observing the aborted material. A 38-month study of 507 large Danish dairy herds revealed 3354 late-term...
Balancing the supply of on-farm grown forages with the production targets of the dairy herd is a crucial aspect of the management of a dairy farm. Models which provides a rapid insight of the impact of the ration, feed quality and feeding management on feed intake and performance of dairy cows are
Nusinovici, S; Hoch, T; Brahim, M L; Joly, A; Beaudeau, F
There is a consensus that wind plays a key role in the transmission of Coxiella burnetii, the causative agent of Q fever, between ruminants and from ruminants to humans. However, no observational study so far has focused on the mechanisms associated with this airborne transmission. This study applied a mechanistic epidemiological approach to investigate the processes underlying the wind effect and to assess its influence on the risk for a dairy herd to become C. burnetii infected. Ninety-five dairy cattle herds located in the Finistère department (western France) were subjected to samplings of bulk tank milk and indoor dust every 4 months over a 1-year period to determine their C. burnetii status using PCR tests. A total of 27 incident herd-periods (negative-tested on both PCR tests and becoming positive-tested at least once at the subsequent sampling time) and 71 negative herd-periods were retained for analysis. Using logistic regression, we assessed the effect of (i) the cumulated number of bacteria in herds located under the main wind direction and (ii) the mean wind speed in this area, on a given herd's risk of becoming incident. Compared to herds in areas with low wind speed (≤5.5 m/s), the risk was significantly higher (OR = 3.7) in herds in areas with high wind speed (>5.5 m/s) and high bacterial load (>10), whereas it was not significantly different from unity in other situations. In agreement with our assumptions, C. burnetii transmission to a previously infection-free herd occurs only when (i) the wind transporting from infected sources and (ii) the load in the contaminated particles/aerosols generated are high enough to act jointly. © 2015 Blackwell Verlag GmbH.
Claridge, Jen; Diggle, Peter; McCann, Catherine M; Mulcahy, Grace; Flynn, Rob; McNair, Jim; Strain, Sam; Welsh, Michael; Baylis, Matthew; Williams, Diana J L
.... Here we show in a study involving 3,026 dairy herds in England and Wales that there is a significant negative association between exposure to the common, ubiquitous helminth parasite, Fasciola...
Chika C. Okafor
Full Text Available Despite ongoing eradication efforts, bovine tuberculosis (BTB remains a challenge in Michigan livestock and wildlife. The objectives of this study were to (1 review the epidemiology of BTB in Michigan cattle, privately owned cervids, and wildlife between 1975 and 2010 and (2 identify important lessons learned from the review and eradication strategies. BTB information was accessed from the Michigan BTB Eradication Project agencies. Cattle herds (49, privately owned deer herds (4, and wild white-tailed deer (668 were found infected with BTB during the review period. BTB has occurred primarily in counties located at the northern portion of the state's Lower Peninsula. Currently used BTB eradication strategies have successfully controlled BTB spread. However additional changes in BTB surveillance, prevention, and eradication strategies could improve eradication efforts.
Okafor, Chika C; Grooms, Daniel L; Bruning-Fann, Colleen S; Averill, James J; Kaneene, John B
Despite ongoing eradication efforts, bovine tuberculosis (BTB) remains a challenge in Michigan livestock and wildlife. The objectives of this study were to (1) review the epidemiology of BTB in Michigan cattle, privately owned cervids, and wildlife between 1975 and 2010 and (2) identify important lessons learned from the review and eradication strategies. BTB information was accessed from the Michigan BTB Eradication Project agencies. Cattle herds (49), privately owned deer herds (4), and wild white-tailed deer (668) were found infected with BTB during the review period. BTB has occurred primarily in counties located at the northern portion of the state's Lower Peninsula. Currently used BTB eradication strategies have successfully controlled BTB spread. However additional changes in BTB surveillance, prevention, and eradication strategies could improve eradication efforts.
John, T J; Samuel, R
The term herd immunity has been used by various authors to conform to different definitions. Earlier this situation had been identified but not corrected. We propose that it should have precise meaning for which purpose a new definition is offered: "the proportion of subjects with immunity in a given population". This definition dissociates herd immunity from the indirect protection observed in the unimmunised segment of a population in which a large proportion is immunised, for which the term 'herd effect' is proposed. It is defined as: "the reduction of infection or disease in the unimmunised segment as a result of immunising a proportion of the population". Herd immunity can be measured by testing a sample of the population for the presence of the chosen immune parameter. Herd effect can be measured by quantifying the decline in incidence in the unimmunised segment of a population in which an immunisation programme is instituted. Herd immunity applies to immunisation or infection, human to human transmitted or otherwise. On the other hand, herd effect applies to immunisation or other health interventions which reduce the probability of transmission, confined to infections transmitted human to human, directly or via vector. The induced herd immunity of a given vaccine exhibits geographic variation as it depends upon coverage and efficacy of the vaccine, both of which can vary geographically. Herd effect is determined by herd immunity as well as the force of transmission of the corresponding infection. Clear understanding of these phenomena and their relationships will help improve the design of effective and efficient immunisation programmes aimed at control, elimination or eradication of vaccine preventable infectious diseases.
Sørensen, M K; Norberg, E; Pedersen, J;
The value of crossbreeding in livestock species has been known for a long time; it has been used heavily within beef cattle, pig, and poultry production systems for several decades. This has not been the case for dairy production but lately there has been increased interest in crossbreeding dairy...... breeds. This review focuses on the practical and theoretical background of crossbreeding and describes the gain to be expected using systematic crossbreeding in dairy production. In Denmark, 24% of dairy farmers would consider starting crossbreeding programs within their herd. Evidence for the value...... through crossbred offspring, this prerequisite can be fulfilled. Crossbreeding can increase dairy income substantially, especially in management systems requiring a high level of functional traits...
Tomasek, R; Rezac, P; Havlicek, Z
The objective was to assess the effects of the month of conception, month of calving, sex of the calf, and twins on gestation length (GL) in Holstein cows and heifers in two dairy herds with different milk yields. The study was performed in northeast Czech Republic over a 6-year period on two commercial dairy herds with a mean annual milk production of 11,060 kg per cow in the higher milk-producing herd and 8854 kg per cow in the lower milk-producing herd. Gestation length in cows that conceived in different months of the year was longer in the higher milk-producing herd than that in the lower milk-producing herd throughout the year (P Gestation length in cows that conceived in different months of the year was longer than that in heifers through the whole year in both herds (P Gestation length in cows and heifers that conceived in the first months of the year was longer than in those that conceived in the last months of the year in both herds (P Gestation length in cows and heifers that calved in late fall and throughout winter was longer than in those that calved in spring and summer in both herds (P Gestation length in females carrying male calves was longer than in those carrying female calves (P Gestation length in cows (P < 0.0001) and heifers (P < 0.05) carrying singles was longer than in those carrying twins in both herds. In conclusion, results indicate that GL in Holstein cattle is associated with the month of conception, month of calving, herd, parity, sex of the calf, and twins.
Full Text Available Newly purchased animals that enter a herd with high milk production can be infected with pathogens of the mammary gland and are a potential risk of infection to the cows on the farm. This risk cannot be avoided entirely, but it can be minimized by taking biosecurity measures that should be written as a policy developed for biosecurity oversight of veterinary service: when older cows are purchased, they should be bought with complete lactations and SCC records, and bacterial examination of milk from the udder quarters must be negative for pathogens of the udder; newly purchased cows should come from herds in which the geometric mean somatic cell count is less than 200,000. The herd must have individual cow SCC recorded at least bimonthly for the previous 6 months; the herd must not have had any history of Strep. agalactiae infection in the last 2 years, the herd should be BVDV-free or vaccinated, and the herd owner must be honest and willing to provide all this information. Our country has accepted the standards for milk quality and hygienic properties that comply with EU standards. The proposed biosafety measures presented in this paper enable the determination of the health status of the herd and the biosecurity level of mastitis in commercial farming in intensive dairy production. [Projekat Ministarstva nauke Republike Srbije, br. TR-31034
The diagnostic performance of an antibody enzyme-linked immunosorbent assay using serum and colostrum to determine the disease status of a Jersey dairy herd infected with Mycobacterium avium subspecies paratuberculosis.
Jenvey, Caitlin J; Reichel, Michael P; Cockcroft, Peter D
Colostrum may have the ability to improve the diagnostic accuracy of some tests when compared to serum for important livestock diseases because of the high concentrations of immunoglobulins present within this sample type. The ELISA for Johne's disease is one such test, as it suffers from low sensitivity when testing serum samples collected during the subclinical stage of infection. Blood and colostrum samples were collected from 34 Jersey dairy cows and tested for antibodies against Mycobacterium avium subspecies paratuberculosis (MAP) by ELISA. Fecal samples were also collected and tested by a high-throughput Johne's polymerase chain reaction (HT-J PCR) assay and fecal culture (FC), with the latter being used as the reference test. A receiver operating characteristic (ROC) analysis was performed, and the area under the curve (AUC) was calculated. The HT-J PCR and FC results were also compared. Of the 34 cows in this study, 4 had FC results consistent with MAP infection. The HT-J PCR did not identify any FC-positive cows. Using a 1:20 dilution and sample-to-positive (S/P) ratio cutoff threshold of 0.15, the relative sensitivity values of both serum (AUC 0. 56) and colostrum (AUC 0.63) were 0%. With lower sample dilutions, the relative sensitivity values of serum were 0% (1:2, AUC 0.62; 1:5, AUC 0.55); however, the relative sensitivity value of colostrum was 75% (95% confidence interval [CI]: 19-99%) at a dilution of 1:5, S/P ratio cutoff threshold of 0.15, and AUC of 0.73 (95% CI: 0.55-0.87). The testing of colostrum samples for MAP-specific antibodies by ELISA may provide improved identification of animals in the early stages of infection with MAP when compared with serum samples.
Sørensen, J.T.; Enevoldsen, Carsten
This paper reviews how the dynamics of the health-production complex in livestock herds is mimicked by livestock herd simulation models. Twelve models simulating the dynamics of dairy, beef, sheep and sow herds were examined. All models basically included options to alter input and output...... of reproductive animals in a manner which could be related to health problems. Direct effects of diseases on growth or milk production were, however, addressed in only a few models and were confined to a few basic relations if modelled. The lack of effects on individual animal production in the models may relate...... and their interactions could be studied by applying the same standards of analysis to simulated data as to real herd data. © 1992....
National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Michigan has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...
Downs, S H; Broughan, J M; Goodchild, A V; Upton, P A; Durr, P A
Field surveillance of British cattle using the single intradermal comparative cervical tuberculin (SICCT) test shows a higher incidence rate of bovine tuberculosis (bTB) in dairy compared to beef herds, but a lower probability of post-mortem examination confirmed (PMC) Mycobacterium bovis infection in dairy herds. A cross-sectional study was conducted to compare animal level differences in bTB detection between dairy and non-dairy cattle in Great Britain. During the period from 2002 to 2005, 200 (41% dairy) reactors in the SICCT test (standard interpretation) were randomly selected, and 200 in-contact cattle (43% dairy) were purposively selected from bTB-infected herds. Interferon (IFN)-γ responses in blood to bovine and avian purified protein derivative (PPD), and early secretory antigen target 6 kDa and culture filtrate protein 10 (ESAT-6/CFP10), were measured. The post-mortem examination included gross pathological examination, mycobacterial culture and histopathology. The proportions of cattle positive to ESAT6/CFP10 were 26% (95% confidence interval, CI, 15-39%) in dairy reactors and 62% (95% CI 51-72%) in non-dairy reactors (P dairy reactors and 69% (95% CI 60-78%) in non-dairy reactors (P dairy reactors compared to non-dairy reactors, after controlling for bTB prevalence, herd size and SICCT test response, was 0.27 (95% CI 0.14-0.53; P dairy reactors than for beef reactors aged >2 years (P <0.001).
Verdugo, Cristobal; Toft, Nils; Nielsen, Søren Saxmose
This study aimed to estimate the between- (HTP) and within- (TP) herd true prevalence distribution of Mycobacterium avium subsp. paratuberculosis (MAP) infection in dairy cattle herds participating in the Danish MAP control programme. All herds enrolled in the programme between 2011 and 2013 were included in the analysis, and one annual milk-ELISA test of all lactating cows present in such herds was considered. A Bayesian latent class model was used to obtain HTP and TP posterior distributions for each year. The model adjusts for uncertainty in age-specific test sensitivity and prior prevalence estimates. Bayesian posterior probabilities were computed in order to compare prevalence between the years. A total of 665,700 samples were included in the study, from 221,914, 224,040, and 220,466 cows sourced from 1138, 1112, and 1059 herds in years 2011, 2012, and 2013, respectively. In that period, HTP estimates of 0.92 (95% posterior probability interval (PPI), 0.87-0.96), 0.78 (95% PPI, 0.74-0.83), and 0.75 (95% PPI, 0.71-0.78) were recorded, respectively. Low TP were observed, with population mean estimates of 0.08 (95% PPI, 0.07-0.08), 0.07 (95% PPI, 0.07-0.08), and 0.07 (95% PPI, 0.06-0.07) for the three consecutive years. Statistically-important differences were recorded for HTP and population mean TP estimates between years, indicating a trend for a decreasing level of MAP infection at both herd and animal level. Model results showed that MAP infection was widespread among the Dairy cattle herds participating in the Danish control programme, though in general it was kept at very low levels.
Parámetros Genéticos para Algunas Características Productivas y Reproductivas en un Hato Holstein del Oriente Antioqueño, Colombia Genetic Parameters for Some Productive and Reproductive Traits in a Dairy Herd in Eastern Antioquia, Colombia
Katerinne Quiroz Osorio
first and second lactation and some other features related to the overall performance of cows during her life, which have wide importance in dairy cattle. Were analyzed 928 records of lactations of 184 Holstein cows born among the years 1985 to 2006 in a dairy herd in the department of Antioquia. The variance components were estimated by univariate and bivariate maximum likelihood methodology derivative free restricted and the correlations by direct estimation with phenotype information and estimated breeding values. The SAS 9.0 software was used for data editing and statistical analysis MTDFREML software was used for genetic analysis. The age and weight at first service did not have significant effect (P>0.05 on milk production in first and second lactation, neither with the total life production, However the age and weight at first fertile service had an effect highly significant (P<0.01 on production in first lactation. Heritability estimates for age and weight at first service were 0.29 ± 0.184 and 0.04 ± 0.170, age and weight at service fertile ± 0.41 0.195 ± 0.210 and 0.08 respectively.
Sørensen, J.T.; Enevoldsen, Carsten
Infectious diseases, such as bovine virus diarrhoea (BVD) virus infections in cattle, are often studied by Markov chain models. However, it is difficult to simulate dynamic interactions between production of a reproductive herd and the disease by this type of model. As an alternative, a dynamic...... stochastic model simulating the herd production was suggested. A dynamic stochastic model simulating the effect of BVD virus infection in a dairy cattle herd was used to exemplify how this type of model could be applied in research. The simulation example demonstrated that the effect of a BVD virus infection...
Wolf, Christopher A
The structure of the dairy farm industry has been changing rapidly in recent years. Milk production has increased, with dramatic increases in milk produced per cow and with a steep decline in number of milk cows and fewer farms with larger herds. The change in dairy farm size has not been uniform across regions. The growth in farm size has occurred much more rapidly in the Pacific and South regions than in the traditional dairy-producing regions (Upper Midwest, Northeast, and Corn Belt). Using USDA data to examine costs and returns over time reveals that the incentives to produce milk have been much greater in the Pacific and South regions in recent years. Although the cash costs are similar across regions, accounting for all costs including unpaid factors such as labor and capital replacement yields a clear advantage for the Pacific region. Dairy farm size and cost of production are jointly determined. The incentive to increase farm size is derived from the economies of size that may be achieved by spreading the capital, labor, and managerial costs across more units of milk production. Empiric evidence from previous studies indicates a declining cost of production over a large range of herd sizes. Even in the presence of a flat average cost curve, the incentive to maximize farm income provides incentive to increase production. Adjustment costs may fix dairy production facilities in their current use. Those firms facing higher adjustment costs because of individual or regional characteristics or because of different timing of growth will be smaller or grow more slowly than if they faced smaller adjustment costs. This situation may explain the continued lag of farm size and technology adoption in the traditional dairy producing regions relative to the Pacific and South regions where the more recent population growth coincided with the presence of modern, large-scale production technologies. Finally, dairy marketing policies almost certainly have affected the
The aim of this thesis was to analyze milk yield and fertility in dairy cattle herds ? combined (Czech Pied cattle) and dojného utility type (Holstein cattle ) in the same breeding system. Further culling was evaluated, the cost of feeding a day and milk production. Observations were carried out in the company Podhoran Černíkov, as in the time sequence of zootechnical 2 years (1st 10th 2009 - 30 9th 2011). By tracking a total of 310 cows of which 47 cows of Czech Pied cattle C1 (C 100 %), bre...
Barnouin, J; Chassagne, M; Bazin, S; Boichard, D
French dairy herds (n = 534) were enrolled in the National 'Zero Mastitis Objective' Program to highlight management practices characterizing very low somatic cell score (SCS) herds. The herds studied were stratified into 2 groups. The first group (LOW) included herds within the first 5 percentiles and the second group (MED) herds within the 50 to 55 percentiles of herds on the basis of mean SCS for the 36 mo preceding the program. Potential explanatory variables, collected through questionnaire surveys, were analyzed using multistep logistic regression models. Twenty-six variables were significant factors in the final models, in which 18 were considered as primary factors for very low SCS. The probability for a herd belonging to the LOW group was associated with: (1) regular use of teat spraying; (2) herdsman precise in his techniques; (3) less than 1 person-year used at activities other than dairy herd; (4) teat dipping after mammary infusion at dry off; (5) heifers kept in a calving pen around parturition; (6) cows locked in feed-line lockups after milking; (7) dry cows with prepartum Ca restriction; (8) heifers on a nondamp pasture; (9) cows culled when at least one damaged teat; (10) heifers at pasture not drinking water from a river; and (11) disinfecting teat ends with alcohol before intramammary infusion at dry off. The probability for a herd belonging to the MED group was associated with: (1) milking cows housed in a straw yard; (2) checking heifers for mastitis only beginning at 2-wk prepartum; (3) no mastitis treatment when at least one clot was observed in milk at successive milkings; (4) distance of herdsman's house to cowshed >300 m; (5) only dirty teats washed before milking; (6) free access of cows from pasture to cowshed during bad weather; and (7) more than 18% of spring calvings. The variables associated with very low SCS should be applied as part of a thorough mastitis-control program adapted to each herd.
Vaessen, M A; Veling, J; Frankena, K; Graat, E A; Klunder, T
In a case-control study of risk factors for Salmonella dublin on 126 dairy farms the following variables were significantly associated with infection. Standardized herd size and water surface area showed a positive association. Contact with cows from other herds during exchange was, unexpectedly, preventive for S. dublin infection. Purchase of cows from other herds was a risk factor. More infections occurred when the feed consisted of grass only compared to grass supplemented with maize or silage. S. dublin infection was highly associated with a liver fluke infection.
Nekouei, Omid; Stryhn, Henrik; VanLeeuwen, John; Kelton, David; Hanna, Paul; Keefe, Greg
Enzootic bovine leukosis (EBL) is an economically important infection of dairy cattle caused by bovine leukemia virus (BLV). Estimating the prevalence of BLV within dairy herds is a fundamental step towards pursuing efficient control programs. The objectives of this study were: (1) to determine the prevalence of BLV infection at the herd level using a bulk-tank milk (BTM) antibody ELISA in the Maritime region of Canada (3 provinces); and (2) to develop appropriate statistical models for predicting within-herd prevalence of BLV infection using BTM antibody ELISA titers. During 2013, three monthly BTM samples were collected from all dairy farms in the Maritime region of Canada (n=623) and tested for BLV milk antibodies using a commercial indirect ELISA. Based on the mean of the 3 BTM titers, 15 strata of herds (5 per province) were defined. From each stratum, 6 herds were randomly selected for a total of 90 farms. Within every selected herd, an additional BTM sample was taken (round 4), approximately 2 months after the third round. On the same day of BTM sampling, all cows that contributed milk to the fourth BTM sample were individually tested for BLV milk antibodies (n=6111) to estimate the true within-herd prevalence for the 90 herds. The association between true within-herd prevalence of BLV and means of various combinations of the BTM titers was assessed using linear regression models, adjusting for the stratified random sampling design. Herd level prevalence of BLV in the region was 90.8%. In the individual testing, 30.4% of cows were positive. True within-herd prevalences ranged from 0 to 94%. All linear regression models were able to predict the true within-herd prevalence of BLV reasonably well (R(2)>0.69). Predictions from the models were particularly accurate for low-to-medium spectrums of the BTM titers. In general, as a greater number of the four repeated BTM titers were incorporated in the models, narrower confidence intervals around the prediction lines
This article attempts to present the broad outlines of technological change in Dutch cattle breeding and dairy farming over the last 150 years. After 1850, Dutch dairy farmers and cattle breeders profited from the rapidly increasing opportunities offered by expanding foreign markets. Herd book
Steeneveld, W.; Hogeveen, H.
To improve cow management in large dairy herds, sensors have been developed that can measure physiological, behavioral, and production indicators on individual cows. Recently, the number of dairy farms using sensor systems has increased. It is not known, however, to what extent sensor systems are
Romero, J.J.; Breda, van S.; Vargas, B.; Dolz, G.; Frankena, K.
A cross-sectional study was conducted to assess the effect of neosporosis on productive and reproductive parameters in dairy cows. Cows (n = 2743) from 94 farms located in the most important dairy areas in Costa Rica were used in the study. The size of the herds ranged from 32 to 379 females (mean =
This article attempts to present the broad outlines of technological change in Dutch cattle breeding and dairy farming over the last 150 years. After 1850, Dutch dairy farmers and cattle breeders profited from the rapidly increasing opportunities offered by expanding foreign markets. Herd book organ
Ouweltjes, W.; Werf, van der J.T.N.; Frankena, K.; Leeuwen, van J.L.
Claw health, locomotion, feed intake, milk yield, body weight, activity, and lying and standing behavior of dairy heifers were monitored in a single dairy herd during the first 3 mo after calving. During the first 8 wk after calving, 2 treatments were applied: restricted freestall access by closing
Full Text Available Abstract Background In Denmark, it has recently become mandatory for all dairy farmers with more than 100 cows to sign up for a herd health programme. Three herd health programmes are available. These differ in a number of aspects, including the frequency of veterinary visits and the farmer’s access to prescription drugs. The objective of this study was to investigate whether dairy farmers’ behavioural intentions, i.e. to call a veterinarian or start medical treatment on the day that they detect a cow with mild clinical mastitis (MCM, are different depending on the type of herd health programme. Methods A questionnaire survey based on the Theory of Planned Behaviour (TPB was conducted. TPB proposes that a person’s behavioural intention is strongly correlated with his or her actual behaviour. Three behavioural factors determine the behavioural intention: attitude, subjective norm and perceived behavioural control. Each of these factors is decided by a set of beliefs, each of which in turn is weighted by an evaluation: 1 the expected outcomes of performing the behaviour, 2 what a person believes that others think of the behaviour, and 3 the person’s perceived power to influence the behaviour. A set of statements about the treatment of MCM based on interviews with 38 dairy farmers were identified initially. The statements were rephrased as questions and the resulting questionnaire was distributed to 400 randomly selected Danish dairy farmers who use the two most restrictive herd health programmes, either Core or Module1, and to all 669 farmers with the least restrictive herd health programme, Module2. The association between intention and the herd health programme was modelled using logistic regression. Results The farmers with the Module2 herd health programme had a significantly higher behavioural intention to perform the behaviour, when compared to farmers with a more restrictive herd health programme (OR = 2.1, p Conclusion Danish dairy
Kolstrup, C Lunner; Hultgren, J
The aim of this study was to gain a deeper understanding of work-related physical and psychosocial exposure and health symptoms of farm staff working in indoor loose-housing dairy systems in Sweden, and to examine possible associations between exposure and health symptoms of farm staff and disease incidence in their dairy herds. A sample of 41 farm owners or managers and 20 directly employed farm workers participated, each from a Swedish dairy farm with loose-housed cows. Mailed questionnaires comprising 29 questions were used to create four separate indices representing physical exposure, psychosocial exposure, physical symptoms, and psychosocial symptoms. Cow herd incidence rates of common veterinary-reported clinical diseases were calculated based on official records. Partial Spearman rank correlation was used to analyze associations. The study confirmed that physical and psychosocial exposure and health symptoms are not uncommon among owners/managers and employed workers. The study also found that farm owners/managers experience more physical symptoms in dairy herds with lower cow disease incidence rates, while more frequent or intensive exposure to negative psychosocial work environment factors among employed dairy workers is associated with a high herd disease incidence rate.
Nielsen, Søren Saxmose; Toft, Nils
Detection of bulk tank milk (BTM) antibodies using ELISA (BTM-ELISA) may constitute an inexpensive test for surveillance of Mycobacterium avium subsp. paratuberculosis (MAP) infection in dairy cattle herds provided that the test is accurate and consistent. The objectives of this study were...... to determine: (a) the correlation between repeated BTM reactions; and (b) the association between the BTM antibody ELISA-level and the within-herd prevalence of antibody-positive cows. Eight BTM samples per herd and approximately four milk samples per lactating cow per herd were collected from each of 108...... Danish Holstein herds over a period of one year. All samples were tested using a commercial indirect ELISA for detection of MAP specific antibodies. The individual cow's results were dichotomised and used to estimate the within-herd antibody prevalence at each test-date. These prevalences were...
Bastin, C; Laloux, L; Gillon, A; Miglior, F; Soyeurt, H; Hammami, H; Bertozzi, C; Gengler, N
The aim of this study was to develop an adapted random regression test-day model for milk urea (MU) and to study the possibility of using predictions and solutions given by the model for management purposes. Data included 607,416 MU test-day records of first-lactation cows from 632 dairy herds in the Walloon Region of Belgium. Several advanced features were used. First, to detect the herd influence, the classical herd x test-day effect was split into 3 new effects: a fixed herd x year effect, a fixed herd x month-period effect, and a random herd test-day effect. A fixed time period regression was added in the model to take into account the yearly oscillations of MU on a population scale. Moreover, first autoregressive processes were introduced and allowed us to consider the link between successive test-day records. The variance component estimation indicated that large variance was associated with the random herd x test-day effect (48% of the total variance), suggesting the strong influence of herd management on the MU level. The heritability estimate was 0.13. By comparing observed and predicted MU levels at both the individual and herd levels, target ranges for MU concentrations were defined to take into account features of each cow and each herd. At the cow level, an MU record was considered as deviant if it was 400 mg/L (target range used in the field) and if the prediction error was >50 mg/L (indicating a significant deviation from the expected level). Approximately 7.5% of the MU records collected between June 2007 and May 2008 were beyond these thresholds. This combination allowed for the detection of potentially suspicious cows. At the herd level, the expected MU level was considered as the sum of the solutions for specific herd effects. A herd was considered as deviant from its target range when the prediction error was greater than the standard deviation of MU averaged by herd test day. Results showed that 6.7% of the herd test-day MU levels between June
Cummings, Kevin J; Warnick, Lorin D; Elton, Mara; Gröhn, Yrjo T; McDonough, Patrick L; Siler, Julie D
The objective of this study was to determine if the within-herd prevalence of fecal Salmonella shedding is higher in dairy herds with clinical outbreaks of disease, as compared to herds with subclinical infections only. Data were collected prospectively from dairy herds throughout New York that had at least 150 lactating cows and that received clinical service from participating veterinarians. After enrollment, Salmonella surveillance consisted of both environmental screening and disease monitoring within the herd. Herds positive by either environmental or fecal culture were sampled during three visits to estimate the within-herd prevalence of Salmonella. We characterized isolates by serovar and antimicrobial resistance pattern. Among 57 enrolled herds, 44 (77%) yielded Salmonella-positive samples during the study period; 27 (61%) of the positive herds had Salmonella isolated from environmental samples only, and 17 (39%) had one or more laboratory-confirmed clinical cases. The within-herd prevalence of fecal Salmonella shedding ranged from 0 to 53%. Salmonella Cerro was the predominant serovar, accounting for 56% of all isolates. Antimicrobial resistance ranged from zero to nine drugs, and 14 (32%) of the positive farms generated multidrug-resistant isolates. Herds with laboratory-confirmed clinical cases had a higher prevalence of fecal Salmonella shedding than herds that only generated positive environmental samples, as estimated by a Poisson regression model (prevalence ratio, 2.7; p = 0.01). An association between dairy herd outbreaks of salmonellosis and a higher prevalence of asymptomatic shedding should help guide strategies for reducing the public health threat of Salmonella, as the ability to recognize high-risk herds by clinical laboratory submissions presents an obvious opportunity to maximize food safety at the preharvest level. This is in contrast with other foodborne zoonotic pathogens, such as Campylobacter jejuni and Escherichia coli O157:H7, which
DIAGNOSIS AND MICROBIOLOGICAL DETERMINATION OF THE MASTITIS IN DAIRY CATTLE HERDS FROM “TABULEIROS COSTEIROS” REGION IN SERGIPE STATE, BRAZIL DIAGNÓSTICO E DETERMINAÇÃO MICROBIOLÓGICA DA MASTITE EM REBANHOS BOVINOS LEITEIROS NOS TABULEIROS COSTEIROS DE SERGIPE.
Hymerson Costa Azevedo
Full Text Available Aiming to determine the occurrence of the mastitis and the microbiological relationhip between the lab tests and the auxiliary tests which are done in the field, two cattle herds were studied for 18 months and 893 milk samples were collected. The udders were clinically examined, and the milk was tested using the strip cup test and the California Mastitis Test (CMT. The Staphylococcus aureus was isolated in 196 (21.95% samples, the coagulase-negative Staphylococcus sp. (SCN in 104 (11.65%, the Streptococcus agalactiae in 67 (7.50%, the esculin-positive Streptococcus sp. (ESCPOS in 20 (2.24%, the esculin-negative Streptococcus sp. (ESCNEG in 29 (3.25%, leavenings in one (0.11% and the Corynebacterium sp. in 16 (1.68% samples. In the total, 433 microrganisms were isolated, 350 milk samples were negative and in 110 (12.32% samples the isolation and identification were not possible. Out of all the isolated microrganisms, the contagious were more frequent, when compared to the positive reaction for the CMT. The CMT test showned to be important in the presuntive diagnose, demanding, however, a periodic microbiologic analyses of the herd.
KEY WORDS: Dairy cattle, mastitis, diagnostic, mastitics, Tabuleiros Costeiros.
Com objetivo de determinar a ocorrência da mastite e a relação microbiológica entre os testes laboratoriais e auxiliares realizados de campo, foram acompanhados dois rebanhos bovinos leiteiros por dezoito meses e coletadas 893 amostras de leite. Procedeu-se a exames clínicos dos úberes, ao teste da caneca telada e ao Califórnia Mastitis Test (CMT. Isolaram-se Staphylococcus aureus em 196 (21,95% amostras, Staphylococcus sp. Coagulase Negativa (SCN em 104 (11,65%, Streptococcus agalactiae, em 67 (7,50%, Streptococcus sp. Esculina Positivos (ESCPOS em 20 (2,24%, Streptococcus sp. Esculina Negativos (ESCNEG em 29 (3,25%, leveduras em uma (0,11% e Corynebacterium sp. em dezesseis (1,68% amostras. No total, foram
Anneberg, Inger; Østergaard, Søren; Ettema, Jehan Frans
Veterinarians often express frustrations when farmers do not implement their advice, and farmers sometimes shake their heads when they receive veterinary advice which is practically unfeasible. This is the background for the development of a focused 3 page economic report created in cooperation...... between veterinarians, farmers, advisers and researchers. Based on herd specific key-figures for management, the report presents the short- and long-term economic effects of changes in 15 management areas. Simulations are performed by the dairy herd simulation model “SimHerd”. The aim is to assist...
Aislamiento de Mycobacterium avium subsp. Paratuberculosis de fecas en rebaños lecheros infectados mediante el Método de Cornell modificado Isolation of Mycobacterium avium subsp. Paratuberculosis from bovine feces of infected dairy herds by the Cornell’s Method modified
J. P SOTO
Full Text Available Con la finalidad de aumentar la tasa de aislamiento de Mycobacterium avium subsp. paratuberculosis (Map, a partir de muestras de fecas bovinas, se evaluó un nuevo procedimiento de descontaminación y cultivo de muestras fecales en 250 animales clínicamente sanos, provenientes de 14 rebaños infectados del sur de Chile. Para la descontaminación de las muestras previo al cultivo se utilizó una solución al 0.9% de cloruro de hexadecilpiridinio (HPC y una solución antibiótica con amfotericina B, vancomicina y ácido nalidíxico. Para el aislamiento del agente se utilizó el medio de Herrold con yema de huevo y micobactina J adicionado de una solución antibiótica similar a la empleada para la descontaminación de las muestras. En el 16% (40 de las muestras analizadas fue posible aislar Map con un 7.6% de contaminación con hongos sólo a partir de la octava semana de incubación. La identidad de las cepas aisladas fue confirmada en el 100% de los casos mediante PCR, utilizando partidores específicos para este agente (P90 y P91. La alta tasa de aislamiento, la especificidad del medio de cultivo y la baja tasa de contaminación de los cultivos, durante el prolongado período de incubación, hacen de este procedimiento una buena alternativa de diagnóstico de Paratuberculosis bovinaIn order to improve the isolation rate of Mycobacterium avium subsp. paratuberculosis (Map from bovine feces a new bacteriological procedure for decontamination and cultivation of fecal samples was evaluated in 250 samples collected from asymptomatic animals in 14 infected dairy herds in southern Chile. Before culture all samples were treated with a decontaminant solution containing 0.9% hexadecylpiridinium chloride and an antibiotic solution containing amphotericin B, vancomycin and nalidixic acid. Herrold Egg Yolk Medium (HEYM and mycobactin J supplemented with the same antibiotics mentioned above was used for the isolation of the agent. Map was isolated from 40
Avaliação sorológica e de fatores de risco para a infecção por Mycobacterium avium subsp. paratuberculosis em rebanhos leiteiros da Microrregião de Garanhuns, Pernambuco Serological evaluation and risk factors for Mycobacterium avium subsp. paratuberculosis infection in dairy herds of Microregion Garanhuns, Pernambuco
Luenda de M. e Sá
Full Text Available Objetivou-se com esse trabalho realizar um inquérito epidemiológico da infecção por Mycobacterium avium subsp. paratuberculosis (MAP em bovinos leiteiros da microrregião de Garanhuns, Pernambuco, Brasil. Para este estudo foram coletadas amostras sanguíneas de 408 animais, provenientes de 19 rebanhos localizados em 15 municípios. O exame sorológico foi realizado por Ensaio Imunoenzimático (ELISA indireto para detecção de anticorpos frente ao MAP. Em todas as propriedades, foi aplicado um questionário investigativo para análise dos fatores de risco, e as coordenadas geográficas coletadas por um aparelho de Global Position System (GPS para realização da distribuição espacial. A prevalência da infecção por MAP foi de 2,7% (11/408; I.C. 1,4-4,9. O número de focos foi 47,4% (9/19. Na análise de regressão logística foi identificado como fator de risco a taxa anual de nascimentos superior a 51 bezerros/ano (OR 3,8; I.C. 1,1-13,1. Desta forma, conclui-se que a infecção por MAP encontra-se presente nos rebanhos bovinos leiteiros da microrregião estudada e que medidas de controle baseadas nos fatores de risco identificados devem ser implementadas com o objetivo de reduzir o número de focos da infecção.The present study aimed to conduct an epidemiological investigation of Mycobacterium avium subsp. paratuberculosis (MAP infection in dairy cattle of the Garanhuns microregion, in Pernambuco, Brazil. Blood samples were collected from 408 animals from 19 herds located in 15 cities. Serological tests were performed by indirect immunoenzymatic assay (ELISA for antibodies against MAP. In all farms, a questionnaire to investigate risk factors was used, and Global Position System (GPS receivers were used to collect geographic coordinates to show the spatial distribution of the animals. The prevalence of MAP infected cattle was 2.7% (11/408; I.C. 1.4-4.9. The rate of infection was 47.4% (9/19. An annual birth rate over 51 calves
Puput Tri Komalasari
Full Text Available Conceptually, the stock market is strong form efficient in the long term. However, in practice, there are various forms of market anomalies that undermine the accuracy of the efficient market hypothesis. One factor suspected as the cause of market inefficiency is herding behavior. Investors herd when they imitate the actions of other investors. This behavior occurs when there is a continuous interaction among rational investors that prevents them from seeking information about market fundamentals. This study provides new insights by including information asymmetry as a moderating variable. This research examines the phenomenon of herding behavior in the Indonesia Stock Exchange as well as examines directly the effect of information asymmetry on herding behavior. The period of study is 2008 using time series of daily stocks data that actively traded in the capital market. Results of this study find that investor tends to follow market consensus when price changes at the low level, but when there is large price swing market participant acts independently from other investors. Interestingly, this study finds that information asymmetry is a necessary condition for the existence of herding behavior.
Goenner, James N.
Michigan's former governor, John Engler, was naturally attracted to charter schools. He had seen for too long how school districts treated students as their property and the state as an endless funding source, and he wanted that to change. Engler saw the chartering strategy as a politically viable means for gaining leverage over school districts…
Smith, Alexander H.
Studies have continued on the diversity of the Michigan bolete flora. During the season of 1972 a variety of Boletus affinis Peck having a reticulate stipe was discovered and abundant material of Boletus bicolor var. subreticulatus Smith & Thiers was obtained. Boletus hortonii Smith & Thiers was col
More, S J; Sergeant, E S G; Strain, S; Cashman, W; Kenny, Kevin; Graham, D
value of P(False+) was substantial when tests with imperfect specificity were used. Testing strategies can substantially influence testing costs but with little effect on test performance. This study illustrates an output-based approach to herd classification, with potential for national and field applications. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Dairy goat husbandry amongst the household agriculture: herd and economic indexes from a case study in Rio de Janeiro, Brazil A caprinocultura leiteira na agricultura familiar: índices zootécnicos e econômicos de um estudo de caso no estado do Rio de Janeiro, Brasil
Ricardo Augusto Mendonça Vieira
Full Text Available Two dairy goat systems conducted according to the household model were evaluated in terms of income generation. An enterprise budget analysis was performed using data collected from August, 2004, to July, 2005. Farms named A and B were smallholdings and raised Saanem goats intensively. Herd indexes, incomes, taxes, fuel, energy, concentrates, opportunity costs and interest in capital were computed. Net present value and internal rate of return were estimated to appreciate the business appeal in terms of income generation. Herd indexes were mostly affected by management decisions interfering on the amounts and time-trends related to milk production. Seasonal variation was reduced at unit B due to heat induction, a decision not shared by farmer A. The daily body weight gain of doelings after weaning (89 and 76 g/d for A and B was low if compared to current recommendations. Average records of lactation (441 and 606 L/doe and fertility (86.95% and 85.71% were amongst the literature range. Daily tasks related to unit B consumed 5 hours and 55 minutes for an average milk production of 40.9 L/d, whereas 8 hours and 16 minutes on average were daily spent at unit A in order to produce 32.2 L/d. Unit B presented a total production cost (R$ 0.79548/L lower than unit A (R$ 1.50239/L, but operated profitably. Unit A presented a positive gross margin (R$ 0.284/L, but operated unprofitably. The income generated on B was equivalent to a monthly salary of R$ 732.96 (US$ 278.52, a competitive income compared to the Brazilian minimum wage of R$ 300.00 (US$ 114.00 paid monthly. These results corroborate the hypothesis that the dairy goat husbandry fits adequately to the household production model and generates income competitively.Dois sistemas de produção de caprinos leiteiros praticados de acordo com o modelo familiar foram avaliados quanto à geração de renda. Um teste para verificação de viabilidade econômica do empreendimento foi executado utilizando
Kemmerling, K; Müller, U; Mielenz, M; Sauerwein, H
The prevalence of Chlamydophila spp. was determined in a cross-sectional study carried out in 2007 using 100 randomly selected dairy herds in the western part of Germany. Ten dairy cows per herd were sampled in herds with fewer than 100 cows; in bigger herds, 10% of the cows were sampled. For the detection of Chlamydophila spp., vaginal swabs from early lactating dairy cows were analyzed using an established highly sensitive genus-specific real-time PCR. In consideration of the discontinuous shedding of the pathogen, a herd was classified as positive if at least 1 animal per herd tested positive for Chlamydophila spp. By use of these methods and definitions, 61% of the dairy herds and 13.5% of the cows were detected as PCR-positive for Chlamydophila spp., which is indicative for ongoing infections. To compare herd health and herd performance between herds testing positive or negative and to identify risk factors for the presence of Chlamydophila spp., a questionnaire was designed to evaluate farm characteristics and management practices. In addition, the performance recordings of the state dairy recording organization were used for these purposes. Milk yield, number of lactations, and calving to first-service interval were lower in herds testing positive for Chlamydophila spp. compared with negative herds. For all these variables, there was no interaction between Chlamydophila status and lactation number. Replacement of animals from outside sources, use of breeding bulls, lack of separate calving pens, and low scores for cleanliness of beddings, walkways, and cows were identified as the main risk factors for Chlamydophila spp.
Vigne, Mathieu; Peyraud, Jean-Louis; Lecomte, Philippe; Corson, Michael S; Wilfart, Aurélie
Emergy accounting (EmA) was applied to a range of dairy systems, from low-input smallholder systems in South Mali (SM), to intermediate-input systems in two regions of France, Poitou-Charentes (PC) and Bretagne (BR), to high-input systems on Reunion Island (RI). These systems were studied at three different levels: whole-farm (dairy system and cropping system), dairy-system (dairy herd and forage land), and herd (animals only). Dairy farms in SM used the lowest total emergy at all levels and was the highest user of renewable resources. Despite the low quality of resources consumed (crop residues and natural pasture), efficiency of their use was similar to that of industrialised inputs by intensive systems in RI, PC and BR. In addition, among the systems studied, SM dairy farms lay closest to environmental sustainability, contradicting the usual image of high environmental impact of cattle production in developing countries. EmA also revealed characteristics of the three intensive systems. Systems from RI and PC had lower resource transformation efficiency and higher environmental impacts than those from BR, due mainly to feeding strategies that differed due to differing socio-climatic constraints. Application of EmA at multiple levels revealed the importance of a multi-level analysis. While the whole-farm level assesses the overall contribution of the system to its environment, the dairy-system level is suitable for comparison of multi-product systems. In contrast, the herd level focuses on herd management and bypasses debates about definition of system boundaries by excluding land management. Combining all levels highlights the contribution of livestock to the global agricultural system and identifies inefficiencies and influences of system components on the environment.