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Sample records for repeat breeder heifers

  1. Repeatability and accuracy of reproductive tract scoring to determine pubertal status in beef heifers.

    Science.gov (United States)

    Rosenkrans, Kelly S; Hardin, David K

    2003-03-01

    The objective of this study was to compare the repeatability and accuracy of palpation per rectum to transrectal ultrasonography and serum progesterone concentrations for determining pubertal status in beef heifers. One hundred and seventy-four rectal examinations were performed on 29 predominantly Angus heifers by two veterinarians (A and B) and assigned individual reproductive tract scores (RTS) during monthly examinations over a 3-month period. Heifers were examined in the morning by both veterinarians, randomized, and re-examined in the afternoon. The size and location of ovarian structures of each heifer were determined by ultrasonography. Heifers with follicles >10mm in diameter or corpora lutea were classified as pubertal. Serum progesterone concentrations at the time of the examination and 10 days later were determined by radioimmunoassay and used to classify heifers as prepubertal (or=1 ng/ml). Kappa, which describes degree of agreement beyond chance, was used to determine repeatability of the RTS system. Multicategory Kappa for agreement was 0.64 within veterinarian, 0.46 between veterinarian, and 0.35 between palpation per rectum and transrectal ultrasonography. Sensitivity and specificity of palpation per rectum for diagnosis of pubertal status compared to serum progesterone levels were higher (82 and 69%, respectively) than sensitivity and specificity of ultrasonography (79 and 59%, respectively). This study validates the RTS system as a repeatable and accurate screening test to evaluate pubertal status in groups of heifers prior to the onset of the breeding season.

  2. Comparison of serum leptin, glucose, total cholesterol and total protein levels in fertile and repeat breeder cows

    Directory of Open Access Journals (Sweden)

    Saime Guzel

    2014-12-01

    Full Text Available In the present study we measured serum glucose, leptin, total cholesterol and total protein concentrations in repeat breeder cows and compared them with fertile cows. For this aim, 20 repeat breeder cows and 20 fertile cows were used as material. Repeat breeder cows were found to have lower levels of leptin and glucose as compared with fertile ones. No significant differences in total cholesterol and total protein levels were observed between the two groups. No significant correlation of leptin with glucose, total cholesterol and total protein was observed in fertile and repeat breeder cows. Low concentrations of glucose and leptin can have some effects on reproductive problems as repeat breeder and help to understand potential mechanisms impairing fertility in repeat breeder cows.

  3. The effect of intrauterine cephapirin treatment after insemination on conception rate in repeat breeder dairy cows subjected to the progesterone-based Ovsynch protocol

    OpenAIRE

    GÜMEN, Ahmet; MECİTOĞLU, Gülnaz YILMAZBAŞ; KESKİN, Abdulkadir; KARAKAYA, Ebru; ALKAN, Ali; TAŞDEMİR, Umut; OKUT, Hayrettin

    2012-01-01

    Subclinical endometritis contributes to repeat breeder syndrome in dairy cows. This study evaluated the effect of intrauterine cephapirin benzathine administration after timed artificial insemination (TAI) on the conception rate (CR) in repeat breeder dairy cows. To determine the antibiotic effects, all cows (n = 335) that had more than 3 services with no clinical abnormalities of the reproductive tract received the same combined synchronisation protocol: an ear implant containing progestagen...

  4. Associations of acute stress and overnight heart rate with feed efficiency in beef heifers.

    Science.gov (United States)

    Munro, J C; Schenkel, F S; Physick-Sheard, P W; Fontoura, A B P; Miller, S P; Tennessen, T; Montanholi, Y R

    2017-03-01

    Proxies have the potential to accelerate feed efficiency (residual feed intake (RFI); kg dry matter/day) improvement, assisting with the reduction of beef cattle feed costs and environmental impact. Heart rate (HR) (beats per minute (BPM)) is associated with feed efficiency and influenced by autonomic activity and peripheral metabolism, suggesting HR could be used as a proxy for feed efficiency. Objectives were to assess associations between overnight HR, lying patterns and RFI, and between acute stress HR and RFI. Heifer calves (n=107; 408±28 days of age, 341±42.2 kg) and yearling heifers (n=36; 604±92 days of age, 539±52.2 kg) were exposed to a performance test to determine productive performance. Overnight HR (electrode based) and lying patterns (accelerometer based) were monitored on a subgroup of heifer calves (n=40; 20 lowest RFI; 20 highest RFI). In the 10-min acute stress assessment, all heifers were individually exposed to the opening and closing of an umbrella and HR before (HRBEF), in response to (HRMAX), after (HRAFT) and change (HRCHG; HRAFT-HRBEF) as a result of exposure were determined. Using polynomial regression, rate of HR decrease pre-exposure (β 1) and rates of HR increase (β 2) and decrease (β 3, β 4) post-exposure were determined. Heifer calves in the overnight assessment were classified into equal RFI groups (low RFI; high RFI) and HR means were treated as repeated measures and compared using multiple regression. In the acute stress assessment, heifers were classified within cattle category into equal RFI groups (low RFI; high RFI) and means and polynomial regression parameters were compared using multiple regression. Low-RFI heifer calves had a lower overnight HR (69.2 v. 72.6 BPM), similar HR change from lying to standing intervals (8.9 v. 9.2 BPM) and similar time lying (61.1% v. 64.5%) compared with high-RFI heifer calves. Low-RFI heifer calves had a higher absolute HRMAX (162.9 v. 145.7 BPM) and β 2 (-0.34 v. -0.20) than high

  5. Use of multiple-locus variable-number tandem-repeats analysis (MLVA) typing to characterize Salmonella Typhimurium DT41 broiler breeder infections

    DEFF Research Database (Denmark)

    Litrup, E.; Christensen, H.; Nordentoft, Steen

    2010-01-01

    To characterize isolates of Salmonella Typhimurium DT41 obtained from infected flocks of broiler breeders by multiple-locus variable-number tandem-repeats analysis (MLVA) and compare results with a diverse strain collection from Germany and United Kingdom and isolates from Danish patients. A total...

  6. Whole rice bran for beef heifers raised on alexander grass pasture

    Directory of Open Access Journals (Sweden)

    P. R. Salvador

    2016-09-01

    Full Text Available The objective of this study was to evaluate the development of beef heifers exclusively fed alexander grass (Urochloa plantaginea (Link Hitch or alexander grass and whole rice meal as supplement offered from Monday to Friday. The experimental design was completely randomized, with repeated measures over time, and consisted of two treatments and three replications of area. Heifers receiving whole rice meal exhibited higher average daily gain after day 42 of pasture use and a 21% higher body weight at the end of the grazing period. The stocking rate, weight gain per area, hip height, weight-height ratio, and body condition score were similar for heifers exclusively fed alexander grass and alexander grass plus rice bran. Beef heifers raised exclusively on alexander grass from 15 to 18 months of age reached adequate body development, reproductive tract score (4.22 points and pelvic area (206.3 cm² to be bred at 18-20 months of age.

  7. Effect of transportation during periods of high ambient temperature on physiologic and behavioral indices of beef heifers.

    Science.gov (United States)

    Theurer, Miles E; White, Brad J; Anderson, David E; Miesner, Matt D; Mosier, Derek A; Coetzee, Johann F; Amrine, David E

    2013-03-01

    To determine the effect of transportation during periods of high ambient temperature on physiologic and behavioral indices of beef heifers. 20 heifers (mean body weight, 217.8 kg). Ten heifers were transported 518 km when the maximum ambient temperature was ≥ 32.2°C while the other 10 heifers served as untransported controls. Blood samples were collected from transported heifers at predetermined intervals during the transportation period. For all heifers, body weights, nasal and rectal temperatures, and behavioral indices were measured at predetermined intervals for 3 days after transportation. A week later, the entire process was repeated such that each group was transported twice and served as the control twice. Transported heifers spent more time near the hay feeder on the day of transportation, had lower nasal and rectal temperatures for 24 hours after transportation, and spent more time lying down for 2 days after transportation, compared with those indices for control heifers. Eight hours after transportation, the weight of transported heifers decreased 6%, whereas that of control heifers increased 0.6%. At 48 hours after initiation of transportation, weight, rectal temperature, and time spent at various pen locations did not differ between transported and control heifers. Cortisol concentrations were higher 4 hours after initiation of transportation, compared with those determined just prior to transportation. Results indicated transportation during periods of high ambient temperatures caused transient changes in physiologic and behavioral indices of beef heifers.

  8. Relationship between clinical and postmortem evaluation in repeat breeder beef cows Relação entre características clínicas e post-mortem em vacas de corte repetidoras de serviço

    Directory of Open Access Journals (Sweden)

    Rogério Ferreira

    2008-08-01

    Full Text Available The objective of this study was to investigate the causes of the repeat breeder syndrome comparing clinical signs and postmortem findings in beef cows. The identification of factors affecting the reproductive tract can support decisions as to whether treatment of repeat breeder cows is justifiable than culling. Since all animals were submitted to clinical examination before being slaughtered, this study has a differential approach when compared with others, where genital tracts from abattoir were examined. In this study, 130 crossbred cows and heifers that have failed to conceive after three or more services were identified, submitted to a clinical examination and blood collection for karyotyping and sent to an abattoir. postmortem examinations included macroscopic evaluation of the genital tracts, bacteriology and histopathology of the uterus. Uterine alterations were predominant followed by oviduct and ovarian pathologies. Histopathological examination was more sensitive as a diagnostic tool than clinical examination. Repeat breeder cows had a predominance of uterine abnormalities (95%, such as inflammatory (42.9% and degenerative (59.7% conditions. Oviduct abnormalities were found in 29.8 % of animals. Furthermore, 1 out 10 karyotyped cows showed aneuploidy. Thus, this study stressed the importance of laboratory exams in the diagnosis of the causes of infertility of repeat breeder cows.O objetivo deste estudo foi avaliar as causas de infertilidade em vacas de corte repetidoras de serviço, relacionando sinais clínicos com características laboratoriais post-mortem. A identificação dos fatores que afetam o desempenho reprodutivo pode fornecer uma fundamentação científica para auxiliar na decisão quanto ao destino de vacas repetidoras de serviço; tratamento ou descarte. Este estudo tem abordagem diferencial dos trabalhos que contemplam somente a ocorrência de alterações post-mortem do trato genital. A correlação das altera

  9. Characterization of clinical mastitis in primiparous heifers.

    Science.gov (United States)

    Myllys, V; Rautala, H

    1995-03-01

    Using data from health records for cows in Finland from between 1983 and 1991, we investigated the general trend for frequency of mastitis in heifers, seasonal variation, breed differences, and etiology of the disease. The performance of the heifers was monitored during first lactation. Treatment of heifer mastitis, defined as mastitis treatment 1 wk before and 1 wk after calving, increased from 1.8 to 4.4% between 1983 and 1991. The increase can be partly attributed to increased milk production, subsequent reduced resistance to mastitis, and the general trend toward more efficient treatment of mastitis. Heifer mastitis was a characteristic disease of well-managed, productive herds with low SCC and a high frequency of mastitis treatments administered by a veterinarian. Of the feeding factors studied, only use of homemade concentrates was associated with higher mastitis frequency. Mastitic heifers had higher genetic potential for milk production than control heifers, but actual milk production was 70 to 80 kg lower than expected. Most mastitic heifers recovered well and were not more susceptible than control heifers to further incidence of mastitis or other diseases. However, heifer mastitis caused more heifers than usual to be culled.

  10. Ingestive behavior of heifers in Alexandergrass pasture receiving different amounts of oat grain as supplement

    Directory of Open Access Journals (Sweden)

    Maria José de Oliveira Sichonany

    2015-08-01

    Full Text Available This study was conducted to evaluate the ingestive behavior, displacement patterns and meal dynamics of beef heifers in Alexandergrass pasture (Urochloa plantaginea (Link. Hitch receiving different amounts of oat grain: 0, 0.80 and 1.12% of body weight (BW. The grazing method was continuous with put-and-take stocking. The experimental design was completely randomized following a repeated measure arrangement. The grazing time decreased and the idling time increased when beef heifers were supplemented, independently of supplement amount, while the rumination time was similar across supplement amounts. The number of feeding stations per minute and the number of steps taken between each feeding station were similar regardless of supplementation. When receiving 1.12% of BW of oat grain, heifers remained longer in each feeding station and took fewer steps per minute. The number of meals decreased and the duration of breaks between meals increased when heifers received oat grain. The duration of each meal was similar for heifers receiving supplement than for those that did not. Understanding how animals adjust their grazing behavior and cope with changing environmental dynamics is essential for the development of management strategies designed to optimize animal production.

  11. Fatores que aumentam a condição de vacas repetidoras em um rebanho leiteiro mestiço submetido à protocolos de sincronização reprodutivos

    Directory of Open Access Journals (Sweden)

    Fransergio Souza

    2017-01-01

    Full Text Available The objective of this study was to evaluate the incidence of repeat breeder (RB in crossbred dairy cows submitted to a timed artificial insemination (TAI and estrous synchronization protocols. Data from 371 heifers and 997 lactating crossbred dairy cows were analyzed. Cows with more than 30 DPP with good uterine condition, no lameness or clinical mastitis, and body condition score ≥ 2.5 were used. The cows were divided between two groups, as: group 1: TAI – those cows with no CL at ultrasound exam that were enrolled in a TAI protocol and group 2: estrous synchronization – all those cows that had CL. The incidences of RB and factors relative to it were analyzed by logistic regression in SAS. The incidence of RB condition was higher in lactating cows than non-lactating heifers (P 0.001; however, lactation degree influenced the incidence of RB (P <0.001. Repeat breeder condition was greater in lactating crossbred dairy cows than in heifers. Moreover, the presence of RB cows was higher in those from second parity group when compared to those from first, third and four parity groups; on the other hand, parturition condition did not influence the appearance of RB cows in the herd.

  12. Custom dairy heifer grower industry characteristics and contract terms.

    Science.gov (United States)

    Wolf, C A

    2003-09-01

    This study examines a national survey of professional custom heifer growers. Sixty-five respondents from 23 states provided information on operation size and characteristics, management practices, and contract terms. Responding operation current heifer inventories ranged from 30 to 20,000 heifers and the average operation had more than 1200 heifers on-farm. The regional pattern of operation size was similar to the regional pattern of dairy farm size with heifer grower operations in the West and South regions being larger, on average, than those in the Midwest and Northeast regions. On average, 71% of total income was derived from the heifer-growing enterprise. Operations in the Northeast region derived the highest percentage of income from heifer growing while operations in the South region derived the least income from heifer growing activities. Many operations entered business to utilize excess facilities, labor, or feed. A majority of the operations had two to five dairy farm clients. Sixty-nine percent of respondents used some form of written contract. Just over 50% of the respondents indicated that a set daily charge per heifer per day was the primary type of contract payment. Although the most common charge was dollars 1.50 per heifer per day, average daily charge was dollars 1.52/heifer. Operations that took heifers from prior to weaning through to prefresh charged a weighted average daily charge of dollars 1.60 per heifer. Explaining price charges as a function of characteristics and contract terms revealed that size and number of clients were negatively related to price while specialization in heifer growing was positively related to price charged.

  13. Pathogen group specific risk factors at herd, heifer and quarter levels for intramammary infections in early lactating dairy heifers

    NARCIS (Netherlands)

    Piepers, S.; Peeters, K.; Opsomer, G.; Barkema, H.W.; Frankena, K.; Vliegher, de S.

    2011-01-01

    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

  14. Effect of Heifer Frame Score on Growth, Fertility, and Economics

    Science.gov (United States)

    Şentürklü, S.; Landblom, D. G.; Perry, G. A.; Petry, T.

    2015-01-01

    A non-traditional forage-based protocol was employed to evaluate replacement heifer growth, fertility, and economics between small frame (SF, 3.50; n = 50) and large frame (LF, 5.56; n = 50) heifers using three increasing gain growth phases. Preceding an 85 d growing-breeding period (Phase 3; P3) the heifers were managed as a common group for Phases 1 and 2 (P1 and P2). During P1, heifers grazed common fields of unharvested corn and corn residue (total digestible nutrients [TDN] 56%) with supplemental hay. For P2, heifers grazed early spring crested wheatgrass pasture (CWG; TDN 62%) that was followed by the final P3 drylot growing and breeding period (TDN 68%). Small frame heifers were lighter at the end of P1 in May and at the start of P3 breeding in August (p = 0.0002). Percent of mature body weight (BW) at the end of P1 (209 d) was 48.7% and 46.8%, respectively, for the SF and LF heifers and the percent pubertal was lower for SF than for LF heifers (18.0% vs 40.0%; p = 0.02). At breeding initiation (P3), the percentage of mature BW was 57.8 and 57.2 and the percentage pubertal was 90.0 and 96.0 (p = 0.07) for the SF and LF heifers, respectively; a 5-fold increase for SF heifers. Breeding cycle pregnancy on days 21, 42, and 63, and total percent pregnant did not differ (p>0.10). In drylot, SF heifer dry matter intake (DMI) was 20.1% less (p = 0.001) and feed cost/d was 20.3% lower (p = 0.001), but feed cost/kg of gain did not differ between SF and LF heifers (p = 0.41). Economically important live animal measurements for muscling were measured in May and at the end of the study in October. SF heifers had greater L. dorsi muscle area per unit of BW than LF heifers (p = 0.03). Small frame heifer value was lower at weaning (p = 0.005) and the non-pregnant ending heifer value was lower for SF heifers than for the LF heifers (p = 0.005). However, the total development cost was lower for SF heifers (p = 0.001) and the net cost per pregnant heifer, after accounting for

  15. Effect of Heifer Frame Score on Growth, Fertility, and Economics

    Directory of Open Access Journals (Sweden)

    S. Şentürklü

    2015-01-01

    Full Text Available A non-traditional forage-based protocol was employed to evaluate replacement heifer growth, fertility, and economics between small frame (SF, 3.50; n = 50 and large frame (LF, 5.56; n = 50 heifers using three increasing gain growth phases. Preceding an 85 d growing-breeding period (Phase 3; P3 the heifers were managed as a common group for Phases 1 and 2 (P1 and P2. During P1, heifers grazed common fields of unharvested corn and corn residue (total digestible nutrients [TDN] 56% with supplemental hay. For P2, heifers grazed early spring crested wheatgrass pasture (CWG; TDN 62% that was followed by the final P3 drylot growing and breeding period (TDN 68%. Small frame heifers were lighter at the end of P1 in May and at the start of P3 breeding in August (p = 0.0002. Percent of mature body weight (BW at the end of P1 (209 d was 48.7% and 46.8%, respectively, for the SF and LF heifers and the percent pubertal was lower for SF than for LF heifers (18.0% vs 40.0%; p = 0.02. At breeding initiation (P3, the percentage of mature BW was 57.8 and 57.2 and the percentage pubertal was 90.0 and 96.0 (p = 0.07 for the SF and LF heifers, respectively; a 5-fold increase for SF heifers. Breeding cycle pregnancy on days 21, 42, and 63, and total percent pregnant did not differ (p>0.10. In drylot, SF heifer dry matter intake (DMI was 20.1% less (p = 0.001 and feed cost/d was 20.3% lower (p = 0.001, but feed cost/kg of gain did not differ between SF and LF heifers (p = 0.41. Economically important live animal measurements for muscling were measured in May and at the end of the study in October. SF heifers had greater L. dorsi muscle area per unit of BW than LF heifers (p = 0.03. Small frame heifer value was lower at weaning (p = 0.005 and the non-pregnant ending heifer value was lower for SF heifers than for the LF heifers (p = 0.005. However, the total development cost was lower for SF heifers (p = 0.001 and the net cost per pregnant heifer, after accounting for

  16. Optimum body size of Holstein replacement heifers.

    Science.gov (United States)

    Hoffman, P C

    1997-03-01

    Criteria that define optimum body size of replacement heifers are required by commercial dairy producers to evaluate replacement heifer management programs. Historically recommended body size criteria have been based on live BW measurements. Numerous research studies have observed a positive relationship between BW at first calving and first lactation milk yield, which has served as the impetus for using live BW to define body size of replacement heifers. Live BW is, however, not the only available measurement to define body size. Skeletal measurements such as wither height, length, and pelvic area have been demonstrated to be related to first lactation performance and (or) dystocia. Live BW measurements also do not define differences in body composition. Differences in body composition of replacement heifers at first calving are also related to key performance variables. An updated research data base is available for the modern Holstein genotype to incorporate measures of skeletal growth and body composition with BW when defining body size. These research projects also lend insight into the relative importance of measurements that define body size of replacement heifers. Incorporation of these measurements from current research into present BW recommendations should aid commercial dairy producers to better define replacement heifer growth and management practices. This article proposes enhancements in defining optimum body size and growth characteristics of Holstein replacement heifers.

  17. Subclinical laminitis in dairy heifers.

    Science.gov (United States)

    Bradley, H K; Shannon, D; Neilson, D R

    1989-08-19

    By causing poorer horn quality, subclinical laminitis is considered to be a major predisposing cause of other hoof problems, particularly sole ulcers in newly calved heifers. In this study the hind hooves of 136 female Friesian/Holstein cattle aged between four months and two years were examined to discover at what age the signs of subclinical laminitis appeared. Sole haemorrhages were found in the hoof horn of calves as young as five months. The consistent finding of these lesions in heifers of all ages indicated that subclinical laminitis of varying degree was a common condition during the early growing period of young dairy heifers.

  18. Congenital Absence of a Teat in a Japanese Black Heifer

    Directory of Open Access Journals (Sweden)

    Mohamed Elshabrawy Ghanem

    2011-01-01

    Full Text Available A case of Japanese Black heifer with a congenital absence of teat (athelia was observed at Highashi-Hiroshima Agricultural High School, Hiroshima Prefecture, Japan. The heifer was born after transfer of embryo from Japanese Black cattle. The sire of the heifer was a proven Japanese Black. The birth weight of the heifer was 27 kg. On physical examination of the heifer at 21 months after birth, the teat at fore left was absent and the remaining three teats were normal in shape without any physical abnormalities. Per rectal palpation of the genital organs revealed the normal cervix and uterine horns. It was difficult to palpate the ovaries due to the fat around the organs. Blood samples were taken for cytogenetic and DNA testing. The heifer had normal chromosomal set. The heifer was culled due to its mammary abnormality. This might be the first to report a case of congenital absence of a teat in Japanese Black heifers.

  19. Proteome profiling of exosomes derived from plasma of heifers with divergent genetic merit for fertility.

    Science.gov (United States)

    Koh, Yong Qin; Peiris, Hassendrini N; Vaswani, Kanchan; Almughlliq, Fatema B; Meier, Susanne; Burke, Chris R; Roche, John R; Reed, Charlotte B; Arachchige, Buddhika J; Reed, Sarah; Mitchell, Murray D

    2018-04-25

    The current study evaluated exosomes isolated from plasma of heifers bred to have high or low fertility through developing extreme diversity in fertility breeding values, however, key animal traits (e.g., body weight, milk production, and percentage of North American genetics) remained similar between the 2 groups. The exosomes were isolated by a combined ultracentrifugation and size exclusion chromatography approach and characterized by their size distribution (nanoparticle tracking analysis), morphology (transmission electron microscopy), and presence of exosomal markers (immunoblotting). In addition, a targeted mass spectrometry approach was used to confirm the presence of 2 exosomal markers, tumor susceptibility gene 101 and flotillin 1. The number of exosomes from plasma of high fertility heifers was greater compared with low fertility heifers. Interestingly, the exosomal proteomic profile, evaluated using mass spectrometry, identified 89 and 116 proteins in the high and low fertility heifers respectively, of which 4 and 31 were unique, respectively. These include proteins associated with specific biological processes and molecular functions of fertility. Most notably, the tetratricopeptide repeat protein 41-related, glycodelin, and kelch-like protein 8 were identified in plasma exosomes unique to the low fertility heifers. These proteins are suggested to play a role in reproduction; however, the role of these proteins in dairy cow reproduction remains to be elucidated. Their identification underscores the potential for proteins within exosomes to provide information on the fertility status and physiological condition of the cow. This may potentially lead to the development of prognostic tools and interventions to improving dairy cow fertility. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  20. Creep-feeding to stimulate metabolic imprinting in nursing beef heifers: impacts on heifer growth, reproductive and physiological variables.

    Science.gov (United States)

    Reis, M M; Cooke, R F; Cappellozza, B I; Marques, R S; Guarnieri Filho, T A; Rodrigues, M C; Bradley, J S; Mueller, C J; Keisler, D H; Johnson, S E; Bohnert, D W

    2015-09-01

    This experiment compared growth, physiological, and reproductive responses of beef heifers with (MI) or without (CON) access to a creep-feeder, as a manner to stimulate metabolic imprinting while nursing their dams. On day 0, 60 Angus × Hereford heifers were ranked by BW and age (140 ± 3 kg and 68±3 days), and assigned to pairs so all ranking criteria were similar between heifers within each pair. On day 1, pairs were randomly assigned to MI (n=15) or CON (n=15). From day 1 to 51, MI pairs and their dams were allocated to 15 drylot pens where heifers had ad libitum access to a corn-based supplement through a creep-feeder. The CON pairs and their dams were maintained in an adjacent single drylot pen. From day 52 to 111, treatments were managed as a single group on a semiarid range pasture. On day 111, heifers were weaned and allocated to two pastures (one pasture/treatment), receiving hay and a corn-based concentrate until day 326. Heifer BW was recorded before and at the end of the creep-feeding period (day 1 to 51), and on days 112 and 326. On days 0, 51, 111, 187, 261, and 325, jugular blood was collected and real-time ultrasonography for longissimus muscle depth and backfat thickness assessment was performed. Blood was also collected every 10 days from days 113 to 323 for puberty evaluation via plasma progesterone. Liver and subcutaneous fat biopsies were performed on days 51, 111, 261 and 325. Average daily gain was greater (Pimprinting effect, but did not hasten their puberty attainment.

  1. Alternative breeder reactor technologies

    International Nuclear Information System (INIS)

    Spinrad, B.I.

    1978-01-01

    The significance of employing breeder reactors to stretch the world resources of nuclear fuels is briefly discussed, and the various types of breeder concepts are described. General descriptions, advantages, and disadvantages of the liquid metal cooled fast breeder, gas cooled fast breeder, molten salt breeder, thermal breeders, and spectral-shift control reactors are presented. Aspects of safeguarding fissile material connected with breeder operation are examined. 31 references

  2. Endocrine studies in ivermectin-treated heifers from birth to puberty.

    Science.gov (United States)

    Lacau-Mengido, I M; Mejía, M E; Díaz-Torga, G S; Gonzalez Iglesias, A; Formía, N; Libertun, C; Becú-Villalobos, D

    2000-04-01

    Continuous treatment with ivermectin from birth to puberty advanced sexual maturation by 3.7 wk in Holstein heifers grazing pastures naturally infected with nematodes. Every 14 d jugular blood samples were taken from birth to 45 wk of age from all heifers. No differences in serum FSH, estradiol, or thyroxine levels were observed during the trial between the treated and untreated group. Mean LH levels were diminished in untreated heifers 4 wk before the first estrus and the amplitude of LH pulses was augmented in treated heifers when puberty was reached. Serum IGF-I levels increased from birth to 22 wk of age and then reached a plateau in both groups, but levels were consistently higher in treated heifers from 26 wk of age onward. Body weight gain was retarded in parasitized heifers and IGF-I values were positively correlated with body weight only during the first 20 wk of life. We suggest that enhanced prepubertal IGF-I levels in conjunction with increased prepubertal LH levels and pubertal LH pulse amplitude might be involved in the accelerated somatic maturation and in puberty advancement observed in ivermectin-treated heifers.

  3. Clinch River Breeder Reactor Plant: a building block in nuclear technology

    International Nuclear Information System (INIS)

    McCormack, M.

    1979-01-01

    Interest in breeder reactors dates from the Manhatten Project to the present effort to build the Clinch River Liquid Metal Fast Breeder Reactor (LMFBR) demonstration plant. Seven breeder-type reactors which were built during this time are described and their technological progress assessed. The Clinch River Breeder Reactor Project (CRBRP) has been designed to demonstrate that it can be licensed, can operate on a large power grid, and can provide industry with important experience. As the next logical step in LMFBR development, the project has suffered repeated cancellation efforts with only minor modifications to its schedule. Controversies have developed over the timing of a large-scale demonstration plant, the risks of proliferation, economics, and other problems. Among the innovative developments adopted for the CRBRP is a higher thermal efficiency potential, the type of development which Senator McCormack feels justifies continuing the project. He argues that the nuclear power program can and should be revitalized by continuing the CRBRP

  4. Clinch River Breeder Reactor Plant: a building block in nuclear technology

    Energy Technology Data Exchange (ETDEWEB)

    McCormack, M.

    1979-01-01

    Interest in breeder reactors dates from the Manhatten Project to the present effort to build the Clinch River Liquid Metal Fast Breeder Reactor (LMFBR) demonstration plant. Seven breeder-type reactors which were built during this time are described and their technological progress assessed. The Clinch River Breeder Reactor Project (CRBRP) has been designed to demonstrate that it can be licensed, can operate on a large power grid, and can provide industry with important experience. As the next logical step in LMFBR development, the project has suffered repeated cancellation efforts with only minor modifications to its schedule. Controversies have developed over the timing of a large-scale demonstration plant, the risks of proliferation, economics, and other problems. Among the innovative developments adopted for the CRBRP is a higher thermal efficiency potential, the type of development which Senator McCormack feels justifies continuing the project. He argues that the nuclear power program can and should be revitalized by continuing the CRBRP.

  5. Heifers infected with coagulase-negative staphylococci in early lactation have fewer cases of clinical mastitis and higher milk production in their first lactation than noninfected heifers.

    Science.gov (United States)

    Piepers, S; Opsomer, G; Barkema, H W; de Kruif, A; De Vliegher, S

    2010-05-01

    Intramammary infections (IMI) in recently calved dairy heifers are more common than was formerly believed but their relevance for future performance has been studied only rarely. In the present study, the association between the IMI status of fresh heifers and their subsequent udder health, milk production, and culling in first lactation was explored. Quarter milk samples were collected between 1 and 4 d in milk (DIM) and between 5 and 8 DIM from 191 dairy heifers in 20 dairy herds for bacteriological culturing and somatic cell count (SCC) analysis. Monthly milk recording data including composite milk SCC and test-day milk yield (MY) were obtained for the first 285 DIM or until culling. Farmer-recorded clinical mastitis cases were available. Data were analyzed using mixed models and survival analysis. Approximately 80% of the fresh heifers (79.8%) had at least one culture-positive quarter. Coagulase-negative staphylococci (CNS) were the most frequently isolated pathogens (72%), followed by esculin-positive streptococci (4.6%) and Staphylococcus aureus (3.5%). Overall geometric mean SCC at quarter level decreased between the first and second samplings from 348,000 to 116,000 cells/mL. Heifers infected with CNS had an intermediate average test-day SCC (84,000 cells/mL) during the first 285 DIM compared with noninfected heifers (53,000 cells/mL) and heifers infected with major pathogens (195,000 cells/mL). Heifers infected with major pathogens had a much lower average daily MY (18.3kg) during first lactation compared with noninfected animals (21.3kg). That CNS-infected heifers out-produced their noninfected counterparts could be at least partially explained by their significantly lower incidence of clinical mastitis (incidence risk 3.6 vs. 21.0%) during first lactation compared with noninfected heifers. We conclude that although CNS cause the majority of IMI in heifers around calving, they should not be a reason for serious concern. Copyright 2010 American Dairy

  6. Can rapeseed lower methane emission from heifers?

    DEFF Research Database (Denmark)

    Hellwing, Anne Louise Frydendahl; Sørensen, Martin Tang; Weisbjerg, Martin Riis

    2013-01-01

    Twelve heifers were assigned to either a control diet (CON) with 26 g fat per kg dry matter (DM) or a supplemented diet (FAT) with crushed rapeseed with 53 g fat per kg DM. Methane (CH4) emission was measured by open-circuit indirect calorimetry for four days when the heifers weighed approximately...

  7. Improved grazing activity of dairy heifers in shaded tropical grasslands

    Directory of Open Access Journals (Sweden)

    Andréia Cristina Tavares de Mello

    Full Text Available ABSTRACT: Trees in the production systems can effectively reduce hot weather-induced stress in the Brazilian Midwest. High temperatures cause changes in animals daily routine, and trees into pastures can promote benefits. The aim of this research was to evaluate the behavior of dairy heifers in silvopastoral systems in the state of Mato Grosso, Brazil. A herd of 24 crossbreed heifers (3/4 and 7/8 Holstein/Zebu, 350kg average weight, was evaluated over three seasons. Piatã grass was managed under three shade levels: full-sun, moderate-shade, and intensive-shade provided by 10 to 12m high Eucalyptus trees. Behavior data were collected every 15 minutes from 8:30h to 16h. Shade availability significantly impacted heifer behavior, mainly affecting grazing frequency and time during the hottest hours. Grazing behavior was affected by shade levels during the different seasons. Heifers showed preferred grazing times. Heifers in the intensive-shade system visited shady areas during the hottest hours throughout the seasons. Heifers in the full sun-system avoided grazing during the warmer times, ceasing feeding activities. Our results from the Brazilian Midwest showed that shade availability causes breed heifers to change their daily routine.

  8. Impact of supplemental protein source offered to primiparous heifers during gestation on I. Average daily gain, feed intake, calf birth body weight, and rebreeding in pregnant beef heifers.

    Science.gov (United States)

    Summers, A F; Meyer, T L; Funston, R N

    2015-04-01

    A 3-yr study was conducted to determine the effect of supplemental protein source on ADG, feed intake, calf birth BW, and subsequent pregnancy rate in pregnant beef heifers. Crossbred, Angus-based, AI-pregnant heifers (yr 1, n = 38; yr 2, n = 40; and yr 3, n = 36) were stratified by BW (450 ± 10 kg) and placed in a Calan Broadbent individual feeding system at approximately d 142 of gestation. Following a 25-d adaptation period, an 84-d feeding trial was conducted. Heifers were offered ad libitum grass hay (8 to 11% CP, DM basis) and no supplement (CON), 0.83 kg/d distillers-based supplement (HI), or 0.83 kg/d dried corn gluten-based supplement (LO). Supplements were formulated to be isocaloric, isonitrogenous (28% CP, DM basis), and equal in lipid content but differed in RUP, with HI (59% RUP) having greater levels of RUP than LO (34% RUP). Dry matter intake was also calculated based on feed NE values to account for different energy levels of the supplement compared with the control diet. Control heifers tended (P = 0.09) to consume less total DM than either supplement treatment. However, forage-only DMI was greater (P < 0.01) for CON heifers (9.94 ± 0.12 kg) compared with HI or LO heifers (8.50 and 8.34 ± 0.12 kg, respectively). Net energy DMI was less (P < 0.01) for CON heifers (4.98 ± 0.23 kg) compared with HI or LO heifers (5.43 and 5.35 ± 0.23 kg, respectively). Control heifers gained less (P < 0.01; 0.59 ± 0.14 kg/d) than either HI (0.82 ± 0.14 kg/d) or LO heifers (0.78 ± 0.14 kg/d), resulting in lower (501 ± 9 kg) BW (P < 0.01) than HI (519 ± 9 kg) heifers at the end of the feeding period. Calf birth BW was similar (P = 0.99) among treatments. At prebreeding, CON heifers weighed less (P < 0.03) than LO heifers. Cow BW was similar (P = 0.48) among treatments at pregnancy diagnosis, and final pregnancy rate was also similar (87%; P = 0.22). Protein supplementation increased ADG in pregnant heifers; however, calf birth BW and subsequent pregnancy

  9. Fast breeder reactors

    International Nuclear Information System (INIS)

    Heinzel, V.

    1975-01-01

    The author gives a survey of 'fast breeder reactors'. In detail the process of breeding, the reasons for the development of fast breeders, the possible breeder reactors, the design criteria, fuels, cladding, coolant, and safety aspects are reported on. Design data of some experimental reactors already in operation are summarized in stabular form. 300 MWe Prototype-Reactors SNR-300 and PFR are explained in detail and data of KWU helium-cooled fast breeder reactors are given. (HR) [de

  10. The optimal number of heifer calves to be reared as dairy replacements.

    Science.gov (United States)

    Mohd Nor, N; Steeneveld, W; Mourits, M C M; Hogeveen, H

    2015-02-01

    Dairy farmers often keep almost all their newborn heifer calves despite the high cost of rearing. By rearing all heifer calves, farmers have more security and retain flexibility to cope with the uncertainty in the availability of replacement heifers in time. This uncertainty is due to mortality or infertility during the rearing period and the variation in culling rate of lactating cows. The objective of this study is to provide insight in the economically optimal number of heifer calves to be reared as replacements. A herd-level stochastic simulation model was developed specific for this purpose with a herd of 100 dairy cows; the biological part of the model consisted of a dairy herd unit and rearing unit for replacement heifers. The dairy herd unit included variation in the number of culled dairy cows. The rearing unit incorporated variation in the number of heifers present in the herd by including uncertainty in mortality and variation in fertility. The dairy herd unit and rearing unit were linked by the number of replacement heifers and culled dairy cows. When not enough replacement heifers were available to replace culled dairy cows, the herd size was temporarily reduced, resulting in an additional cost for the empty slots. When the herd size reached 100 dairy cows, the available replacement heifers that were not needed were sold. It was assumed that no purchase of cows and calves occurred. The optimal percentage of 2-wk-old heifer calves to be retained was defined as the percentage of heifer calves that minimized the average net costs of rearing replacement heifers. In the default scenario, the optimal retention was 73% and the total net cost of rearing was estimated at €40,939 per herd per year. This total net cost was 6.5% lower than when all heifer calves were kept. An earlier first-calving age resulted in an optimal retention of 75%, and the net costs of rearing were €581 per herd per year lower than in the default scenario. For herds with a lower or

  11. Ingestive behavior, performance and forage intake by beef heifers on tropical pasture systems

    Directory of Open Access Journals (Sweden)

    Renato Alves de Oliveira Neto

    2013-08-01

    Full Text Available The experiment was carried out to evaluate forage intake, performance and ingestive behavior of beef heifers. Productive, structural and chemical characteristics of the pasture were also evaluated. The experimental design was completely randomized in a 3 × 2 factorial arrangement, with three pasture systems (Alexandergrass [Urochloa plantaginea Link.] with and without supplement to heifers and Coastcross [Cynodon dactylon (L. Pers.] and two phenological stages: vegetative and flowering. The grazing method was put-and-take stocking. Grazing, ruminating and idle activities, feeding stations, displacement patterns, bite mass and bite rate were evaluated. The forage intake was estimated using chromic oxide as an indicator of fecal output. The heifers modified the use of feeding stations and displacement patterns between phenological stages and pasture systems. Heifers consumed more forage in the vegetative stage (2.81% of body weight in dry matter than in the flowering stage (1.92% of body weight in dry matter. Average daily gain, body condition and stocking rate were similar for heifers in the evaluated systems. Beef heifers receiving protein supplement on Alexandergrass pasture consumed more forage than heifers fed Coastcross exclusively. Regardless of the species, no difference was observed when the heifers were exclusively on pasture. Pasture systems on Alexandergrass or Coastcross provide suitable nutrient intake for heifers to be mated at 18 months of age.

  12. Utilization of macrominerals and trace elements in pregnant heifers with distinct feed efficiencies.

    Science.gov (United States)

    Dias, R S; Montanholi, Y R; Lopez, S; Smith, B; Miller, S P; France, J

    2016-07-01

    The objective of the study was to evaluate utilization of dietary minerals and trace elements in pregnant heifers with distinct residual feed intakes (RFI). Feed intake, body weight (BW), and body composition traits were recorded in 36 crossbred heifers over a period of 37 wk, starting shortly after weaning at 8.3 (0.10; standard deviation) mo of age with an average BW of 276 (7.8) kg. Both BW and body composition were monitored regularly throughout the study, whereas individual feed intake was assessed during the last 84 d of the trial. Data recorded were used to calculate RFI for each heifer. Heifers were ranked based on RFI and assigned to high (n=14) or low (n=10) RFI groups. After the RFI study, 24 selected heifers [age 18.2 (0.14) mo; 87.5 (4.74) d in gestation; 497 (8.5) kg of BW] were used in an indirect digestibility trial (lignin as internal marker). Heifers were fed a ration containing corn silage, haylage, and a mineral premix in which Ca, P, K, Na, Mg, S, Cu, Fe, Mn, Mo, Se, Zn, and Co were provided in the diet according to National Research Council requirements of pregnant replacement heifers. The digestibility trial lasted 1 wk, during which samples of feces were gathered twice daily, and blood and liver biopsy samples were collected on the last day. We noted no significant differences between low- and high-RFI heifers in dry matter digestibility. Apparent absorption of Cu, Zn, and Mn was increased in heifers with low RFI, and apparent absorption of Co tended to be greater for these animals. Concentrations of macrominerals and trace elements in serum of pregnant heifers were similar for both groups except for Se, which was increased in the serum of low-RFI heifers. Liver concentrations of Cu, Fe, Mn, Mo, Se, and Zn did not differ between low- and high-RFI heifers. In conclusion, whereas improved absorption of some trace elements (Cu, Zn, Mn, and Co) and increased Se serum concentration appear to be associated with superior feed efficiency in pregnant

  13. The optimal number of heifer calves to be reared as dairy replacements

    NARCIS (Netherlands)

    Mohd Nor, N.; Steeneveld, W.; Mourits, M.C.M.; Hogeveen, H.

    2015-01-01

    Dairy farmers often keep almost all their newborn heifer calves despite the high cost of rearing. By rearing all heifer calves, farmers have more security and retain flexibility to cope with the uncertainty in the availability of replacement heifers in time. This uncertainty is due to mortality or

  14. The optimal number of heifer calves to be reared as dairy replacements

    NARCIS (Netherlands)

    Mohd Nor, N; Steeneveld, W|info:eu-repo/dai/nl/304833169; Mourits, M C M; Hogeveen, H|info:eu-repo/dai/nl/126322864

    Dairy farmers often keep almost all their newborn heifer calves despite the high cost of rearing. By rearing all heifer calves, farmers have more security and retain flexibility to cope with the uncertainty in the availability of replacement heifers in time. This uncertainty is due to mortality or

  15. Identifying efficient dairy heifer producers using production costs and data envelopment analysis.

    Science.gov (United States)

    Heinrichs, A J; Jones, C M; Gray, S M; Heinrichs, P A; Cornelisse, S A; Goodling, R C

    2013-01-01

    During November and December 2011, data were collected from 44 dairy operations in 13 Pennsylvania counties. Researchers visited each farm to collect information regarding management practices and feeding, and costs for labor, health, bedding, and reproduction for replacement heifers from birth until first calving. Costs per heifer were broken up into 4 time periods: birth until weaning, weaning until 6 mo of age, 6 mo of age until breeding age, and heifers from breeding to calving. Milk production records for each herd were obtained from Dairy Herd Improvement. The average number of milking cows on farms in this study was 197.8 ± 280.1, with a range from 38 to 1,708. Total cost averaged $1,808.23 ± $338.62 from birth until freshening. Raising calves from birth to weaning cost $217.49 ± 86.21; raising heifers from weaning age through 6 mo of age cost $247.38 ± 78.89; raising heifers from 6 mo of age until breeding cost $607.02 ± 192.28; and total cost for bred heifers was $736.33 ± 162.86. Feed costs were the largest component of the cost to raise heifers from birth to calving, accounting for nearly 73% of the total. Data envelopment analysis determined that 9 of the 44 farms had no inefficiencies in inputs or outputs. These farms best combined feed and labor investments, spending, on average, $1,137.40 and $140.62/heifer for feed and labor. These heifers calved at 23.7 mo of age and produced 88.42% of the milk produced by older cows. In contrast, the 35 inefficient farms spent $227 more on feed and $78 more on labor per heifer for animals that calved 1.6 mo later and produced only 82% of the milk made by their mature herdmates. Efficiency was attained by herds with the lowest input costs, but herds with higher input costs were also able to be efficient if age at calving was low and milk production was high for heifers compared with the rest of the herd. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. Ultrasonographic evaluation of reproductive tract measures and fat thickness traits in pre-pubertal Nellore heifers

    Directory of Open Access Journals (Sweden)

    Fabio Morato Monteiro

    2012-02-01

    Full Text Available The aim of this study was to evaluate the relationship between reproductive tract and fat thickness measures obtained by ultrasound in prepubertal Nellore heifers. A total of 128 Nellore heifers born in 2006 and 2007 were submitted to ultrasound evaluations (13, 16, 19 and 22 months of age of reproductive tract measures and fat thickness traits. These animals were from a selection experiment (NeC: control line, and NeS: selection line for yearling weight started in 1981. Mean values of ovary area, height of the right uterine horn (HU, maximum follicular diameter (FOL, backfat thickness (BF, rump fat thickness (RF, and body condition score were analyzed. Repeated records were modeled using the PROC MIXED procedure (SAS, fitting a model that included the selection line, year of birth, measurement as fixed effects, and interactions. Body weight differed between the selected (281.48 kg and control (210.51 kg lines. Only the least square means of FOL were lower in the NeC line compared to the NeS line (P < 0.05, although the difference in mean HU between the two lines was of only borderline significance (P = 0.06. The rate of growth for the three reproductive traits was similar in the two lines. Simple and residual correlations between the reproductive and subcutaneous fat traits ranged from low to medium. The highest correlations were observed between HU and RF (Pearson correlation = 0.71 and residual correlation = 0.34. The current results are consistent with the literature, indicating that fat thickness traits are not good predictors of prepubertal reproductive traits in heifers. Further studies are necessary to clarify the relationship between reproduction and body fat in Nellore heifers.

  17. Performance of heifers supplemented with different levels of corn on pasture

    Directory of Open Access Journals (Sweden)

    F. A. L. Gonzalez

    2016-09-01

    Full Text Available In southern Brazil, production systems are typically extensive and rely on grazing that often results in limited forage quantity and quality, decreasing efficiency and compromising reproductive tract development. The aim of this study was to evaluate the productive performance and reproductive tract development of heifers supplemented with different levels of corn on pasture. The following supplemental treatments were evaluated: T0 [40 g trace-mineralized salt per heifer per day (80 g phosphorus/kg product]; T1 [0.5% of body weight (BW cracked corn + 40 g trace-mineralized salt per heifer per day]; T2 [1% of BW cracked corn + 40 g trace-mineralized salt per heifer per day], and T3 [1.5% of BW cracked corn + 40 g trace-mineralized salt per heifer per day]. Thirty-nine phenotypically homogeneous Brangus heifers (average BW = 184±17 kg, average age = 269±27 days raised on winter pasture (Lolium multiflorum Lam. were randomized to 13 paddocks (one hectare each, with three heifers/paddock, to evaluate the effect of feeding different energy levels. Body condition score, average daily gain, frame score, dry matter availability, reproductive tract score, and stocking density were evaluated. The body condition score, average daily gain, reproductive tract score and stocking density increased (P<0.05 with increasing level of corn supplementation. Daily supplementation levels lower than 1.0% on Lolium multiflorum Lam. pasture can compromise the target breeding weight at 13 months of age. Therefore, daily supplementation at 1.0% of BW after weaning is a strategy to improve the economic and biological efficiency of livestock production systems, allowing to increase stocking density and to anticipate the age of heifers at first breeding.

  18. Comparison of early socialization practices used for litters of small-scale registered dog breeders and nonregistered dog breeders.

    Science.gov (United States)

    Korbelik, Juraj; Rand, Jacquie S; Morton, John M

    2011-10-15

    OBJECTIVE-To compare early socialization practices between litters of breeders registered with the Canine Control Council (CCC) and litters of nonregistered breeders advertising puppies for sale in a local newspaper. DESIGN-Retrospective cohort study. Animals-80 litters of purebred and mixed-breed dogs from registered (n = 40) and non-registered (40) breeders. PROCEDURES-Registered breeders were randomly selected from the CCC website, and nonregistered breeders were randomly selected from a weekly advertising newspaper. The litter sold most recently by each breeder was then enrolled in the study. Information pertaining to socialization practices for each litter was obtained through a questionnaire administered over the telephone. RESULTS-Registered breeders generally had more breeding bitches and had more litters than did nonregistered breeders. Litters of registered breeders were more likely to have been socialized with adult dogs, people of different appearances, and various environmental stimuli, compared with litters of nonregistered breeders. Litters from registered breeders were also much less likely to have been the result of an unplanned pregnancy. CONCLUSIONS AND CLINICAL RELEVANCE-Among those breeders represented, litters of registered breeders received more socialization experience, compared with litters of nonregistered breeders. People purchasing puppies from nonregistered breeders should focus on socializing their puppies between the time of purchase and 14 weeks of age. Additional research is required to determine whether puppies from nonregistered breeders are at increased risk of behavioral problems and are therefore more likely to be relinquished to animal shelters or euthanized, relative to puppies from registered breeders.

  19. Coated ceramic breeder materials

    Science.gov (United States)

    Tam, Shiu-Wing; Johnson, Carl E.

    1987-01-01

    A breeder material for use in a breeder blanket of a nuclear reactor is disclosed. The breeder material comprises a core material of lithium containing ceramic particles which has been coated with a neutron multiplier such as Be or BeO, which coating has a higher thermal conductivity than the core material.

  20. Metabolic profile in growing buffalo heifers fed diet with different energy content

    Directory of Open Access Journals (Sweden)

    B. Gasparrini

    2010-02-01

    Full Text Available Aim of this study was to verify the relation among the mediators and indicators of nutritional status like insulin, glucagon, urea, cholesterol, triglycerides and total proteins in growing buffalo heifers, fed diets with different energy density. 12 Murrah heifers were randomly allocated into two dietary treatments (High, Group H; Low, Group L that differed in energetic levels (Group H: 5.8 UFL/d; Group L: 3.6 UFL/d. Every 30 days, for a total of five times, blood samples were collected at 08.00 h, before feeding, from the jugular vein in vacutainer tubes and analysed to determine metabolic profile. Data on haematic constants were analysed by ANOVA for repeated measures with treatment as the main factor. Low energy availability and low NSC reduced the glucose and insulin and increased glucagone and urea blood levels. The increase of NSC in the diet of group H during the experiment may caused a reduction of the fibre digestibility after the period of adaptation of the rumen microflora and, as a paradox effect, suffered for an energetic lack with a subsequent activation of lipolysis and mobilization of their body reserves. Liver and muscular synthesis increase in group with a high energy availability.

  1. Bovine Nutritional Needs: Digestibility of Dry and Ensiled Forages when Feeding Young Dairy Heifers

    Directory of Open Access Journals (Sweden)

    Shirley Nigaglioni

    2012-01-01

    Full Text Available The diets fed to growing animals are very important to ensure that young animals have the proper nutrients available for growth. When feeding dairy heifers, a farmer’s goal is to feed a very digestible diet that will provide nutrients to keep dairy heifers healthy and allow them to grow faster, while spending less money on feed. The objective of this study was to determine whether feeding heifers diets containing dry or ensiled forage (haylage improved digestibility. Our hypothesis was that incorporating hay into the diet of 16-week-old dairy heifers would provide a more digestible source of nutrients. For this study, 12 heifers were randomly assigned to treatments, with 6 heifers fed hay-based diets and the other 6 heifers fed haylage-based diets. The heifers were housed in individual pens and fed individually on a daily basis for 8 days. Fecal samples were collected during the last 3 days of the feeding period. The fecal collection was achieved by collecting fecal samples from individual heifers every 6 hours over a 3-day period. Digestibility of the diets and nutrients were determined using chromic oxide as an external marker. In order to determine the digestibility of haylage or hay diets fed to the heifers, the percent of chromic oxide in feed was compared to the percent of chromic oxide in feces. The neutral detergent fiber (NDF of the feeds and feces was determined using the Ankom Fiber Analysis System. Data were analyzed using the Proc Mixed procedure of the Statistical Analysis System. The dry matter digestibility of the diets were similar between treatments (P = 0.19 and was 68.4% for the hay diet and 66.6% for the haylage diet. The NDF digestibility was also similar between diets (P = 0.21 with an NDF digestibility of 68.4% for hay and 66.1% for haylage diets. In summary, feeding dairy heifers hay-based diets did not significantly improve either the dry matter or NDF digestibility of the diets.

  2. Fusion breeder

    International Nuclear Information System (INIS)

    Moir, R.W.

    1982-01-01

    The fusion breeder is a fusion reactor designed with special blankets to maximize the transmutation by 14 MeV neutrons of uranium-238 to plutonium or thorium to uranium-233 for use as a fuel for fission reactors. Breeding fissile fuels has not been a goal of the US fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the US fusion program and the US nuclear energy program. The purpose of this paper is to suggest this policy change be made and tell why it should be made, and to outline specific research and development goals so that the fusion breeder will be developed in time to meet fissile fuel needs

  3. Ceramic breeder materials

    International Nuclear Information System (INIS)

    Johnson, C.E.

    1990-01-01

    The breeding blanket is a key component of the fusion reactor because it directly involves tritium breeding and energy extraction, both of which are critical to development of fusion power. The lithium ceramics continue to show promise as candidate breeder materials. This promise was recognized by the International Thermonuclear Reactor (ITER) design team in its selection of ceramics as the first option for the ITER breeder material. Blanket design studies have indicated properties in the candidate materials data base that need further investigation. Current studies are focusing on tritium release behavior at high burnup, changes in thermophysical properties with burnup, compatibility between the ceramic breeder and beryllium multiplier, and phase changes with burnup. Laboratory and in-reactor tests, some as part of an international collaboration for development of ceramic breeder materials, are underway. 32 refs., 1 fig., 1 tab

  4. Determining potential pregnancy status differences based on a new method of yearling heifer prebreeding examination.

    Science.gov (United States)

    Monday, Jessica D; Larson, Robert L; Laflin, Shelie; White, Brad J; Theurer, Miles E

    2018-01-01

    The study objective was to evaluate the Ready-Intermediate-Problem (RIP) replacement heifer evaluation matrix's ability to classify heifers into groups with differing reproductive outcomes. Beef heifers (n = 341) from six Kansas herds were classified according to RIP matrix guidelines and then exposed to AI breeding, bull breeding, or a combination of both as per the management plans for each participating herd. Following the breeding season the heifers were evaluated to determine pregnancy status, AI pregnancy status, days bred, and the number of 21 day cycles needed during the breeding season to become pregnant. After the breeding season, 298 (87%) of the heifers were pregnant, 204 (68%) of which became pregnant in the first 21 days of the breeding season. There was a significant interaction (P = 0.01) in RIP classification and pregnancy by 21 day cycle. Ready classified heifers had a significantly greater risk of becoming pregnant after a single AI exposure (P = 0.03) and in the first 21-day cycle (P = 0.02) compared to Problem classified heifers, and significantly less risk of being non-pregnant at the end of the breeding season (P < 0.01) compared to Problem classified heifers. The RIP matrix can be useful for classifying heifers prior to the onset of the breeding season. Further research is needed to evaluate the matrix in other settings and populations of U.S. beef heifers as well as at different intervals between evaluation and the start of breeding season. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Dietary phosphorus concentrations related to breaking load and chemical bone properties in heifers.

    Science.gov (United States)

    Williams, S N; Lawrence, L A; McDowell, L R; Warnick, A C; Wilkinson, N S

    1990-04-01

    Effects of dietary P on breaking load and chemical properties of bone were evaluated in growing beef heifers. Initially, 14 weaned Angus heifers received ad libitum a low P diet (.10% P dry basis) for 270 d. Heifers were subsequently randomly allotted into two groups (7 heifers/group) and received ad libitum either .12 or .20% P (dry basis). The experimental endpoint was 245 d of the treatment phase for nonpregnant and 3 wk postpartum for pregnant heifers. Results indicate that chemical and physical properties of bovine bones are sensitive to dietary P. Mineralization of rib bones was less at .12% P (dry basis). Rib bone density (g/cm3) and mineral content expressed on a per unit volume basis (mg/cm3) were the most sensitive parameters measured. Breaking load results of 12th ribs also indicated a greater amount of mineral present in heifers receiving .20% P (153.8 vs. 114.3 kg). Vertebral bone density and mineral concentrations on a per unit volume basis were also sensitive to dietary P and clearly ranked the two dietary P amounts, whereas percentage of bone ash or mineral concentration expressed on an ash basis did not.

  6. Alternative breeder and near-breeder systems

    International Nuclear Information System (INIS)

    Critoph, E.

    1983-01-01

    Nuclear power reactor systems have been developed over the last three decades to the point where they are economically competitive, safe and reliable sources of electrical energy. However, with our present knowledge of fissile resources, there is no assurance that the commercially proven reactor systems, using their current fuel cycles, could play a major role in supplying the total world energy needs of the next, and subsequent, centuries. There is a wide consensus that such assurance requires development of reactor systems with very significantly improved fuel resource utilization. The best known of these, and the one currently receiving the lion's share of attention and effort, is the fast breeder reactor (FBR). This paper reviews the characteristics, development status and planned programmes for alternative concepts to the FBR that meet the requirement for large improvement in fuel resource utilization, i.e. alternative breeder and near-breeder systems. These include: heavy-water reactors operating on thorium fuel cycles, light-water high-conversion and breeder reactors, high-temperature gas-cooled reactors operating on thorium fuel cycles, molten salt reactors and heavy-water suspension reactors. Any attempt to make a logical choice for exploitation among these various alternatives involves a consideration of the interplay between reactor system characteristics on the one hand and a forecast of political and economic environments on the other. The reactor breeding (or conversion) ratio has received a great deal of emphasis, but an optimum choice depends also on a consideration of several other factors, including out- and in-reactor specific fuel inventories, fuel fabrication and reprocessing costs, reactor capital cost and load factor, fuel resources and demand growth rate of capacity. Possible variations in this optimum choice with time and regional location are discussed

  7. Efficiency and rumen responses in younger and older Holstein heifers limit-fed diets of differing energy density.

    Science.gov (United States)

    Zanton, G I; Heinrichs, A J

    2016-04-01

    The objective of this study was to evaluate the effects of limit feeding diets of different predicted energy density on the efficiency of utilization of feed and nitrogen and rumen responses in younger and older Holstein heifers. Eight rumen-cannulated Holstein heifers (4 heifers beginning at 257 ± 7 d, hereafter "young," and 4 heifers beginning at 610 ± 16 d, hereafter "old") were limit-fed high [HED; 2.64 Mcal/kg of dry matter (DM), 15.31% crude protein (CP)] or low (LED; 2.42 Mcal/kg of DM, 14.15% CP) energy density diets according to a 4-period, split-plot Latin square design with 28-d periods. Diets were limit-fed to provide isonitrogenous and isoenergetic intake on a rumen empty body weight (BW) basis at a level predicted to support approximately 800 g/d of average daily gain. During the last 7d of each period, rumen contents were subsampled over a 24-h period, rumen contents were completely evacuated, and total collection of feces and urine was made over 4d. Intakes of DM and water were greater for heifers fed LED, although, by design, calculated intake of metabolizable energy did not differ between age groups or diets when expressed relative to rumen empty BW. Rumen pH was lower, ammonia (NH3-N) concentration tended to be higher, and volatile fatty acids (VFA) concentration was not different for HED compared with LED and was unaffected by age group. Rumen content mass was greater for heifers fed LED and for old heifers, so when expressing rumen fermentation responses corrected for this difference in pool size, NH3-N pool size was not different between diets and total moles of VFA in the rumen were greater for heifers fed LED, whereas these pool sizes were greater for old heifers. Total-tract digestibility of potentially digestible neutral detergent fiber (NDF) was greater in heifers fed LED and for young heifers, whereas the fractional rate of ruminal passage and digestion of NDF were both greater in heifers fed LED. Digestibility of N was greater for

  8. Effects of Rumen Protozoa of Brahman Heifers and Nitrate on Fermentation and Methane Production

    Directory of Open Access Journals (Sweden)

    S. H. Nguyen

    2016-06-01

    Full Text Available Two experiments were conducted assessing the effects of presence or absence of rumen protozoa and dietary nitrate addition on rumen fermentation characteristics and in vitro methane production in Brahman heifers. The first experiment assessed changes in rumen fermentation pattern and in vitro methane production post-refaunation and the second experiment investigated whether addition of nitrate to the incubation would give rise to methane mitigation additional to that contributed by defaunation. Ten Brahman heifers were progressively adapted to a diet containing 4.5% coconut oil distillate for 18 d and then all heifers were defaunated using sodium 1-(2-sulfonatooxyethoxy dodecane (Empicol. After 15 d, the heifers were given a second dose of Empicol. Fifteen days after the second dosing, all heifers were allocated to defaunated or refaunated groups by stratified randomisation, and the experiment commenced (d 0. On d 0, an oral dose of rumen fluid collected from unrelated faunated cattle was used to inoculate 5 heifers and form a refaunated group so that the effects of re-establishment of protozoa on fermentation characteristics could be investigated. Samples of rumen fluid collected from each animal using oesophageal intubation before feeding on d 0, 7, 14, and 21 were incubated for in vitro methane production. On d 35, 2% nitrate (as NaNO3 was included in in vitro incubations to test for additivity of nitrate and absence of protozoa effects on fermentation and methane production. It was concluded that increasing protozoal numbers were associated with increased methane production in refaunated heifers 7, 14, and 21 d after refaunation. Methane production rate was significantly higher from refaunated heifers than from defaunated heifers 35 d after refaunation. Concentration and proportions of major volatile fatty acids, however, were not affected by protozoal treatments. There is scope for further reducing methane output through combining

  9. Effect of breeding protocols and reproductive tract score on reproductive performance of dairy heifers and economic outcome of breeding programs.

    Science.gov (United States)

    Stevenson, J L; Rodrigues, J A; Braga, F A; Bitente, S; Dalton, J C; Santos, J E P; Chebel, R C

    2008-09-01

    The objectives of this study were to evaluate the effect of reproductive protocols and reproductive tract score on reproductive performance of dairy heifers and economic outcomes of breeding programs. Holstein heifers (n = 534), 13 +/- 1 mo of age, were randomly assigned to 1 of 4 reproductive protocols. On the day of enrollment (d 0), heifers were palpated per rectum and received a score according to the maturity of their reproductive tract (1 = prepubertal; 2 = peripubertal; and 3 = puber-tal). Estrous detection-control heifers (CON, n = 146) received no treatment and were inseminated on detection of estrus for 28 d. Prostaglandin F(2alpha)-treated heifers (PGED, n = 137) received 1 injection of PGF(2alpha) on d 0 and were inseminated on detection of estrus; heifers not in-seminated by d 14 received a second injection of PGF(2alpha) and were observed for estrus and artificial insemination (AI) for an additional 14 d. Heifers enrolled in the estrous detection-timed AI (EDTAI, n = 140) treatment received a controlled internal drug-release (CIDR) insert on d 0, and 7 d later, the CIDR was removed and all heifers received an injection of PGF(2alpha), heifers received AI on detection of estrus, and those not inseminated by 72 h after PGF(2alpha) received an injection of GnRH concurrent with AI. Heifers in the GnRH-timed AI (GTAI, n = 111) treatment received 1 injection of GnRH on d 0, on d 6 heifers received a CIDR insert and injections of GnRH and PGF(2alpha), on d 13 the CIDR was removed and heifers received an injection of PGF(2alpha), and 48 h later all heifers received an injection of GnRH and AI. Pregnancy was diagnosed at 32 +/- 3 and 62 +/- 3 d after AI. Cost of reproductive protocols and their economic outcomes were calculated for a 28 d period beginning at enrollment. Heifers in the PGED treatment were inseminated at a faster rate than CON heifers. A smaller proportion of prepubertal and peripubertal heifers were inseminated within 14 d of enrollment

  10. [Kinetics of heifers and cows walking on an instrumented treadmill].

    Science.gov (United States)

    Nuss, K; Waldern, N M; Weishaupt, M A; Wiestner, T

    2015-01-01

    Kinetic data of stride characteristics and ground reaction forces of cattle become increasingly important as automated lameness detection may be installed in dairy cow housing systems in the future. Therefore, sound heifers and cows were measured on an instrumented treadmill to collect such basic data. Nine heifers and 10 cows were trained to walk on an instrumented treadmill. Vertical ground reaction forces as well as step and stride timing and length variables were measured for all limbs simultaneously. On average, 16 stride cycles in cows and 24 strides in heifers were analysed in each case. The cows walked on the treadmill at an average speed of 1.2 ± 0.05 m/s (mean ± standard deviation), with a stride rate of 43.0 ± 1.9/min and a stride length of 1.68 ± 0.1 m. The heifers had average values of 1.3 ± 0.04 m/s, 53.7 ± 2.2/min and 1.49 ± 0.05 m, respectively. The stance duration relative to stride duration (the duty factor) was for the cows significantly longer in the forelimbs (67%) than in the hind limbs (64%). Force-time-curves of all limbs showed two peaks, one after landing (FP1) and another during push off (FP2). Vertical ground reaction force was highest for FP1 in the hind limbs, but for FP2 in the forelimbs. At all limbs, force minimum between the peaks occurred shortly before midstance. The vertical impulse carried by both forelimbs amounted to 53.7% of the total stride impulse in cows and to 55.0% in heifers. The location of the centre of body mass varied during the stride cycle but was always located more towards the front limbs. Cows and heifers showed a symmetrical walk with minimal intra-individual variations. Relative stride impulse of the front limbs was higher than that of the hind limbs. Peak vertical force in the hind limbs was highest at landing and in the forelimbs at push off. The present study offers kinetic data of sound cows and heifers which might be helpful as guidelines for automated systems for lameness detection in cattle.

  11. Dietary melatonin alters uterine artery hemodynamics in pregnant Holstein heifers.

    Science.gov (United States)

    Brockus, K E; Hart, C G; Gilfeather, C L; Fleming, B O; Lemley, C O

    2016-04-01

    The objective was to examine uterine artery hemodynamics and maternal serum profiles in pregnant heifers supplemented with dietary melatonin (MEL) or no supplementation (CON). In addition, melatonin receptor-mediated responses in steroid metabolism were examined using a bovine endometrial epithelial culture system. Twenty singleton pregnant Holstein heifers were supplemented with 20 mg of melatonin (n = 10) or no melatonin supplementation (control; n = 10) from days 190 to 262 of gestation. Maternal measurements were recorded on days 180 (baseline), 210, 240, and 262 of gestation. Total uterine blood flow was increased by 25% in the MEL-treated heifers compared with the CON. Concentrations of progesterone were decreased in MEL vs CON heifers. Total serum antioxidant capacity was increased by 43% in MEL-treated heifers when compared with CON. Activity of cytochrome P450 1A, 2C, and superoxide dismutase was increased in bovine endometrial epithelial cells treated with melatonin, whereas the melatonin receptor antagonist, luzindole, negated the increase in cytochrome P450 2C activity. Moreover, estradiol or progesterone treatment altered bovine uterine melatonin receptor expression, which could potentiate the melatonin-mediated responses during late gestation. The observed increase in total uterine blood flow during melatonin supplementation could be related to its antioxidant properties. Compromised pregnancies are typically accompanied by increased oxidative stress; therefore, melatonin could serve as a therapeutic supplementation strategy. This could lead to further fetal programming implications in conjunction with offspring growth and development postnatally. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Precision-feeding dairy heifers a high rumen-undegradable protein diet with different proportions of dietary fiber and forage-to-concentrate ratios.

    Science.gov (United States)

    Koch, L E; Gomez, N A; Bowyer, A; Lascano, G J

    2017-12-01

    The addition of dietary fiber can alter nutrient and N utilization in precision-fed dairy heifers and may further benefit from higher inclusion levels of RUP. The objective of this experiment was to determine the effects of feeding a high-RUP diet when dietary fiber content was manipulated within differing forage-to-concentrate ratios (F:C) on nutrient utilization of precision-fed dairy heifers. Six rumen-cannulated Holstein heifers (555.4 ± 31.4 kg BW; 17.4 ± 0.1 mo) were randomly assigned to 2 levels of forage, high forage (HF; 60% forage) or low forage (LF; 45% forage), and to a fiber proportion sequence (low fiber: 100% oat hay and silage [OA], 0% wheat straw [WS]; medium fiber: 83.4% OA, 16.6% WS; and high fiber: 66.7% OA, 33.3% WS) administered according to a split-plot 3 × 3 Latin square design (21-d periods). Similar levels of N intake (1.70 g N/kg BW) and RUP (55% of CP) were provided. Data were analyzed as a split-plot, 3 × 3 Latin square design using a mixed model with fixed effects of period and treatment. A repeated measures model was used with data that had multiple measurements over time. No differences were observed for DM, OM, NDF, or ADF apparent digestibility coefficients (dC) between HF- and LF-fed heifers. Heifers receiving LF diets had greater starch dC compared to HF heifers. Increasing the fiber level through WS addition resulted in a linear reduction of OM dC. There was a linear interaction for DM dC with a concurrent linear interaction in NDF dC. Nitrogen intake, dC, and retention did not differ; however, urine and total N excretion increased linearly with added fiber. Predicted microbial CP flow (MP) linearly decreased with WS inclusion mainly in LF heifers, as indicated by a significant interaction between F:C and WS. Rumen pH linearly increased with WS addition, although no F:C effect was detected. Ruminal ammonia concentration had an opposite linear effect with respect to MP as WS increased. Diets with the higher proportion of

  13. Accelerator breeder concept

    International Nuclear Information System (INIS)

    Bartholomew, G.A.; Fraser, J.S.; Garvey, P.M.

    1978-10-01

    The principal components and functions of an accelerator breeder are described. The role of the accelerator breeder as a possible long-term fissile production support facility for CANDU (Canada Deuterium Uranium) thorium advanced fuel cycles and the Canadian research and development program leading to such a facility are outlined. (author)

  14. Risk factors related to resistance to Rhipicephalus (Boophilus microplus and weight gain of heifers

    Directory of Open Access Journals (Sweden)

    Jenevaldo Barbosa da Silva

    2015-08-01

    Full Text Available The aim of the present study was to evaluate the influence of age and genetics in dairy heifers on resistance to the cattle tick Rhipicephalus (Boophilus microplus and correlate these parameters with weight gain. Twenty-two heifers were evaluated from birth up to two years of age. Resistance to the cattle tick was evaluated by counting the number of engorged female ticks and subjective qualification of the larvae and nymph infestation. The animals were weighted in the first 24 hours after birth and at six, 12, 18 and 24 months of age. The average tick count and weight gain were compared by Tukey’s test at 5% significance. Subsequently, linear regression was performed to verify the strength of the association between the risk factors age and genetics and infestation by R. (B. microplus. Age and genetics were both significant risk factors for R. (B. microplus infestation in heifers. Between the third and sixth months of age, the animals showed a window of susceptibility to R. (B. microplus. Regardless of age, Bos taurus heifers had higher infestations than Bos indicus, crossbred F1 (½ B. taurus x ½ B. indicus and crossbred Gir-Holstein (Girolando (? B. taurus x ? B. indicus heifers. B. taurus heifers were heavier than B. indicus heifers at birth and had significantly greater weight gain (p < 0.01.

  15. Social behavior and kin discrimination in a mixed group of cloned and non cloned heifers (Bos taurus).

    Science.gov (United States)

    Coulon, M; Baudoin, C; Abdi, H; Heyman, Y; Deputte, B L

    2010-12-01

    For more than ten years, reproductive biotechnologies using somatic cell nuclear transfer have made possible the production of cloned animals in various domestic and laboratory species. The influence of the cloning process on offspring characteristics has been studied in various developmental aspects, however, it has not yet been documented in detail for behavioral traits. Behavioral studies of cloned animals have failed to show clear inter-individual differences associated with the cloning process. Preliminary results showed that clones favor each other's company. Preferential social interactions were observed among cloned heifers from the same donor in a mixed herd that also included cloned heifers and control heifers produced by artificial insemination (AI). These results suggest behavioral differences between cloned and non-cloned animals and similarities between clones from the same donor. The aim of the present study was to replicate and to extend these previous results and to study behavioral and cognitive mechanisms of this preferential grouping. We studied a group composed of five cloned heifers derived from the same donor cow, two cloned heifers derived from another donor cow, and AI heifers. Cloned heifers from the same donor were more spatially associated and interacted more between themselves than with heifers derived from another donor or with the AI individuals. This pattern indicates a possible kin discrimination in clones. To study this process, we performed an experiment (using an instrumental conditioning procedure with food reward) of visual discrimination between images of heads of familiar heifers, either related to the subjects or not. The results showed that all subjects (AI and cloned heifers) discriminated between images of familiar cloned heifers produced from the same donor and images of familiar unrelated heifers. Cattle discriminated well between images and used morphological similarities characteristic of cloned related heifers. Our

  16. Artificial infestation of Boophilus microplus in beef cattle heifers of four genetic groups

    Directory of Open Access Journals (Sweden)

    Ana Mary da Silva

    2007-01-01

    Full Text Available Resistance of beef cattle heifers to the cattle tick Boophilus microplus was evaluated by artificial infestation of 66 beef cattle heifers of the following genetic groups: 16 Nelore (NE, 18 Canchim x Nelore (CN, 16 Angus x Nelore (AN and 16 Simmental x Nelore (SN. The animals, with a mean age of 16.5 months, were maintained with no chemical tick control in a Brachiaria decumbens pasture. Four artificial infestations with 20,000 B. microplus larvae were carried out 14 days apart and from day 18 to day 22 of each infestation the number of engorged female ticks (> 4.5 mm was counted on the left side of each heifer. Data were analyzed as the percentage of return (PR = percentage of ticks counted relative to the number infested, transformed to (PR¼, and as log10 (Cij + 1, in which Cij is the number of ticks in each infestation, using the least squares method with a model that included the effects of genetic group (GG, animal within GG (error a, infestation number (I, GG x I and the residual (error b. Results indicated a significant GG x I interaction, because AN and SN heifers had a higher percentage of return than CN and NE heifers, while CN heifers showed a higher percentage of return than the NE heifers only in infestations 3 and 4. Transformed percentages of return were NE = 0.35 ± 0.06, AN = 0.89 ± 0.06, CN = 0.54 ± 0.05 and SN = 0.85 ± 0.06.

  17. Tritium-assisted fusion breeders

    International Nuclear Information System (INIS)

    Greenspan, E.; Miley, G.H.

    1983-08-01

    This report undertakes a preliminary assessment of the prospects of tritium-assisted D-D fuel cycle fusion breeders. Two well documented fusion power reactor designs - the STARFIRE (D-T fuel cycle) and the WILDCAT (Cat-D fuel cycle) tokamaks - are converted into fusion breeders by replacing the fusion electric blankets with 233 U producing fission suppressed blankets; changing the Cat-D fuel cycle mode of operation by one of the several tritium-assisted D-D-based modes of operation considered; adjusting the reactor power level; and modifying the resulting plant cost to account for the design changes. Three sources of tritium are considered for assisting the D-D fuel cycle: tritium produced in the blankets from lithium or from 3 He and tritium produced in the client fission reactors. The D-D-based fusion breeders using tritium assistance are found to be the most promising economically, especially the Tritium Catalyzed Deuterium mode of operation in which the 3 He exhausted from the plasma is converted, by neutron capture in the blanket, into tritium which is in turn fed back to the plasma. The number of fission reactors of equal thermal power supported by Tritium Catalyzed Deuterium fusion breeders is about 50% higher than that of D-T fusion breeders, and the profitability is found to be slightly lower than that of the D-T fusion breeders

  18. Feed delivery method affects the learning of feeding and competitive behavior in dairy heifers.

    Science.gov (United States)

    Greter, A M; Leslie, K E; Mason, G J; McBride, B W; DeVries, T J

    2010-08-01

    The objective of this study was to determine how different feeding methods may affect the learning of feeding, sorting, and competitive behavior of growing dairy heifers. We hypothesized that heifers previously fed a total mixed ration (TMR) would distribute their feeding time more evenly throughout the day, sort the new ration less, compete less for feed, maintain a more solid fecal consistency, and continue to grow rapidly compared with heifers previously fed a top-dressed ration (TDR). Thirty-two Holstein heifers (237.2+/-21.9 d of age) were divided into 8 groups of 4 and exposed to 1 of 2 treatments for 13 wk: 1) TMR or 2) TDR, with each containing 65% grass/alfalfa haylage and 35% textured concentrate on a dry matter (DM) basis. Following this feeding period, all heifers were switched to an unfamiliar TMR containing 56.1% grass/alfalfa haylage, 21.0% corn silage, 21.0% high-moisture corn, and 1.9% mineral supplement (DM basis) for 7 wk. Group DM intakes were recorded daily throughout the experiment. Feeding behavior, recorded using time-lapse video, and sorting behavior were measured for 7 d during wk 1, 4, and 7 after the dietary change. Feeding competition was measured on d 2, 4, and 6 of each recording week. Sorting activity was determined through particle size analysis of the fresh feed and orts. The particle size separator separated feed into 4 fractions (long, medium, short, and fine). Sorting of each fraction was calculated as actual intake expressed as a percentage of predicted intake. Animals were scored for fecal consistency twice weekly, using a scale from 1 (liquid) to 4 (solid). Heifers were weighed every 2 wk. Neither DM intake (9.0 kg/d) nor average daily gain (1.2 kg/d) differed between treatments. Sorting also did not differ between treatments. Heifers tended to spend more time feeding if they had previously been fed a TDR (198.8 vs. 186.8 min/d). As they had done before the dietary change, heifers previously fed the TDR spent more time at the

  19. The cost of feeding bred dairy heifers on native warm-season grasses and harvested feedstuffs.

    Science.gov (United States)

    Lowe, J K; Boyer, C N; Griffith, A P; Waller, J C; Bates, G E; Keyser, P D; Larson, J A; Holcomb, E

    2016-01-01

    Heifer rearing is one of the largest production expenses for dairy cattle operations, which is one reason milking operations outsource heifer rearing to custom developers. The cost of harvested feedstuffs is a major expense in heifer rearing. A possible way to lower feed costs is to graze dairy heifers, but little research exists on this topic in the mid-south United States. The objectives of this research were to determine the cost of feeding bred dairy heifers grazing native warm-season grasses (NWSG), with and without legumes, and compare the cost of grazing with the cost of rearing heifers using 3 traditional rations. The 3 rations were corn silage with soybean meal, corn silage with dry distillers grain, and a wet distillers grain-based ration. Bred Holstein heifers between 15- and 20-mo-old continuously grazed switchgrass (SG), SG with red clover (SG+RC), a big bluestem and Indiangrass mixture (BBIG), and BBIG with red clover (BBIG+RC) in Tennessee during the summer months. Total grazing days were calculated for each NWSG to determine the average cost/animal per grazing day. The average daily gain (ADG) was calculated for each NWSG to develop 3 harvested feed rations that would result in the same ADG over the same number of grazing day as each NWSG treatment. The average cost/animal per grazing day was lowest for SG ($0.48/animal/grazing d) and highest for BBIG+RC ($1.10/animal/grazing d). For both BBIG and SG, legumes increased the average cost/animal per grazing day because grazing days did not increase enough to account for the additional cost of the legumes. No difference was observed in ADG for heifers grazing BBIG (0.85 kg/d) and BBIG+RC (0.94 kg/d), and no difference was observed in ADG for heifers grazing SG (0.71 kg/d) and SG+RC (0.70 kg/d). However, the ADG for heifers grazing SG and SG+RC was lower than the ADG for heifers grazing either BBIG or BBIG+RC. The average cost/animal per grazing day was lower for all NWSG treatments than the average cost

  20. Fast Breeder Reactor studies

    International Nuclear Information System (INIS)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts

  1. Fast Breeder Reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts.

  2. Tactile stimulation of dairy heifers: effects on behavior and milk production after calving

    Directory of Open Access Journals (Sweden)

    N. R. M. Néri

    2016-09-01

    Full Text Available The positive management of primiparous heifers before calving through tactile stimulation may have beneficial effects on behavior during routine milking. The objective of this study was to evaluate the use of tactile stimulation in dairy heifers and its effects on behavior and milk production after calving. Ten primiparous Holstein heifers were used. Half the group received training with tactile stimulation of all body regions, while the other group did not receive stimulation (control group. The training period was divided into three phases: early, days 1 to 6 of training; intermediate: days 7 to 12, and final, days 13 to 23. During training, movement and displacement scores were obtained over a period of 5 minutes. Physiological parameters were also recorded [respiratory rate (FR and minimum eye temperature (ETmin measured with a thermal imaging camera]. After calving, the heifers were submitted to first milking when the evaluations were started for the first 10 days of milking (20 consecutive milkings. The behavior of the animals was evaluated by attributing a reactivity score of 1 (desirable behaviors or 2 (undesirable behaviors: entry into the pen, teat disinfection, milking one or two jets of milk for mastitis testing, attachment of teat cups, and removal of milk, as well as the amount of milk produced. Mean ETmin and FR decreased over the training period. A significant difference was observed for displacement score (P=0.019, with a reduction in displacement from the early to the final period (from 60.0% to 25.7%. During the attachment of teat cups, stimulated heifers were less reactive (P=0.002, characterized by a lower frequency of undesirable behaviors (12.0%, than unstimulated heifers (30.2%. The average milk yield during the first 60 days of lactation was higher for the group of stimulated heifers (Ln y=2.20–0.0102t+0.331lnt, R2=0.76 compared to unstimulated heifers (Ln y=1.54–0.0191x+0.578lnx, R2=0.79, with this difference being

  3. Estrous synchronization strategies to optimize beef heifer reproductive performance after reproductive tract scoring.

    Science.gov (United States)

    Kasimanickam, Ramanathan K; Whittier, William D; Hall, John B; Kastelic, John P

    2016-08-01

    Three experiments comparing four estrous synchronization protocols were conducted to determine estrous expression rate and artificial insemination pregnancy rate (AI-PR) in heifers with a range (1-5) of reproductive tract scores (RTSs). At enrollment (Day 0), 1783 Angus cross beef heifers from six locations were given body condition score and RTS. The four protocols were: (1) HRTS-DPGF group-heifers with RTS 5 received prostaglandin F2α (PGF; Dinoprost 25 mg; im) on Days 0 and 14; (2) HRTS-CIDR-PGF group-heifers with RTS 5 received a CIDR (1.3-g progesterone) insert on Day 7, followed by CIDR removal and PGF on Day 14; (3) LRTS-CIDR-PGF group-heifers with RTS 4 or less received a CIDR insert on Day 7, followed by CIDR removal and PGF on Day 14; and (4) HRTS-Select-Synch group-heifers with RTS 5 received 100 μg of gonadorelin diacetate tetrahydrate (gonadotropin releasing homone; im) on Day 7 and PGF on Day 14. In all groups, heifers observed in estrus were artificially inseminated (within 120 hours after PGF) using the AM-PM rule. In Experiment 1, estrus expression rates were 82.2% (282/343) and 88.5% (184/208) for HRTS-DPGF and LRTS-CIDR-PGF, respectively (P  0.1) and AI-PR were 52.1 (110/211), 60.3 (129/214), and 58.4% (122/209; P > 0.05). In Experiment 3, estrus expression rates were 77.5 (131/169), 85.5 (142/166), and 83.3% (219/263) for HRTS-DPGF, HRTS-Select-Synch and LRTS-CIDR-PGF (P > 0.05) and AI-PR were 53.3 (90/169), 60.2 (100/166), and 58.6% (154/263; P > 0.1). Overall, estrus expression rates for HRTS-DPGF, HRTS-Select-Synch, LRTS-CIDR-PGF, and HRTS-CIDR-PGF groups were 80.4 (581/723), 85.5 (142/166), 85.1 (579/680), and 86.9% (186/214), respectively; higher for heifers in LRTS-CIDR-PGF and HRTS-CIDR-PGF groups compared to heifers in HRTS-DPGF group (P reproductive performance was reduced compared with other protocols used in this study. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Studies on serum macro and micro minerals status in repeat breeder ...

    African Journals Online (AJOL)

    user01

    2014-03-05

    Mar 5, 2014 ... as well as 11.5% to gross domestic product. Repeat breeding is one of ... signs with no clinical detectable reproductive disorders. *Corresponding ... repeat breeding includes abnormal recommencement of postpartum ovarian ...

  5. Metabolizable protein supply while grazing dormant winter forage during heifer development alters pregnancy and subsequent in-herd retention rate.

    Science.gov (United States)

    Mulliniks, J T; Hawkins, D E; Kane, K K; Cox, S H; Torell, L A; Scholljegerdes, E J; Petersen, M K

    2013-03-01

    Two studies were conducted to evaluate the effects of postweaning management of British crossbred heifers on growth and reproduction. In Exp. 1, 239 spring-born, crossbred heifers were stratified by weaning BW (234 ± 1 kg) and allotted randomly to 1 of 2 treatments. Treatments were fed at a rate equivalent to 1.14 kg/d while grazing dormant forage (6.5% CP and 80% NDF, DM basis) and were 1) 36% CP containing 36% RUP (36RUP) or 2) 36% CP containing 50% RUP (50RUP). Supplementation was initiated in February (1995 and 1996) or November (1997 and 1998) and terminated at the onset of breeding season (mid May). Heifers were weighed monthly up to breeding and again at time of palpation. After timed AI, heifers were exposed to breeding bulls for 42 ± 8 d. In Exp. 2, 191 spring-born, crossbred heifers were stratified by weaning BW to treatments. Heifer development treatments were 1) pasture developed and fed 0.9 kg/day of a 36% CP supplement containing 36% RUP (36RUP), 2) pasture developed and fed 0.9 kg/day of a 36% CP supplement containing 50% RUP (50RUP), and 3) corn silage-based growing diet in a drylot (DRYLOT). Heifers receiving 36RUP and 50RUP treatments were developed on dormant forage. Treatments started in February and ended at the onset of a 45-d breeding season in May. Heifer BW and hip height were taken monthly from initiation of supplementation until breeding and at pregnancy diagnosis. In Exp. 1, BW was not different (P ≥ 0.27) for among treatments at all measurement times. However, 50RUP heifers had greater (P = 0.02; 80 and 67%) pregnancy rates than 36RUP heifers. In Exp. 2, DRYLOT heifers had greater (P RUP or 50RUP developed heifers. However, BW at pregnancy diagnosis was not different (P = 0.24) for between treatments. Pregnancy rates tended to be greater (P = 0.10) for 50RUP heifers than 36RUP and DRYLOT. Net return per heifer was US$99.71 and $87.18 greater for 50RUP and 36RUP heifers, respectively, compared with DRYLOT heifers due to differences

  6. Ability of heifers to discriminate between familiar herdmates and members of an unfamiliar group

    DEFF Research Database (Denmark)

    Koba, Yuki; Munksgaard, Lene; Tanida, Hajime

    2009-01-01

    Using a preference test and operant conditioning in a Y-maze, this experiment examined the ability of heifers to discriminate between their own familiar herdmates and member(s) of an unfamiliar group. Sixteen Danish Friesian heifers, eight older animals (360.6 ± 24.2 days of age) and eight younger...... ones (190.1 ± 14.1 days of age) were used. Each age group was further divided into two experimental groups. Members of each of these groups were housed together in small pens before the experiments began. In experiment 1, each of the 16 animals was allowed to approach either a familiar or an unfamiliar...... unfamiliar heifers. Test animals were rewarded when they chose their own group. In experiment 1, heifers did not show a preference between familiar and unfamiliar individuals. Interestingly the younger stimulus heifers but not the test animals showed an ability to discriminate between unfamiliar animals...

  7. Beef heifer growth and reproductive performance following two levels of pasture allowance during the fall grazing period.

    Science.gov (United States)

    Bailey, B L; Griggs, T C; Rayburn, E B; Krause, K M

    2014-08-01

    The objective of this study was to compare heifer growth and reproductive performance following 2 levels of stockpiled fall forage allowance of orchardgrass (30.5%) and tall fescue (14.1%). Spring-born heifers (n = 203 and BW = 246 ± 28.9 kg) of primarily Angus background were allocated to 2 grazing treatments during the fall period (November 12 to December 17 in yr 1, November 7 to January 4 in yr 2, and November 7 to January 14 in yr 3) each replicated 3 times per year for 3 yr. Treatments consisted of daily pasture DM allowance of 3.5% of BW (LO) or daily pasture DM allowance of 7.0% of BW (HI) under strip-grazing management. Throughout the winter feeding period, mixed grass-legume haylage and soybean hulls were fed. Heifers were grazed as 1 group under continuous stocking after the winter period. Heifers in the LO group gained less than heifers in the HI group during the fall grazing period (0.12 vs. 0.40 kg/d; P < 0.0001). For each 1 10 g increase in NDF/kg fall pasture (DM basis), fall ADG decreased 0.14 kg (P = 0.01). During winter feeding, ADG was 0.30 and 0.39 kg/d for LO vs. HI heifers, respectively (P = 0.0008). During the spring grazing period (April 16 to May 24 in yr 1, April 22 to May 26 in yr 2, and April 5 to May 16 in yr 3), LO heifers had numerically greater ADG than HI heifers (1.38 vs. 1.30 kg/d; P = 0.64). Hip height (122.7 vs. 121.4 cm; P = 0.0055), BCS (5.8 vs. 5.6; P = 0.0057), and BW (356 vs. 335 kg; P < 0.0001) at the end of spring grazing was greater for HI than LO heifers. Heifers in the LO group compensated with greater summer ADG than heifers in the HI group (0.74 vs. 0.66 kg/d; P = 0.03). Total ADG from treatment initiation (November) through pregnancy diagnosis (August) was greater for HI than LO heifers (0.61 vs. 0.55 kg/d; P < 0.001) as was BW at pregnancy diagnosis (415 vs. 402 kg; P = 0.0055). Percentage of heifers reaching puberty by the time of AI was 34% for both groups (P = 0.93). Percentage of heifers becoming pregnant to

  8. Endocrine profiles during attainment of puberty may predict reproductive longevity in heifers

    Science.gov (United States)

    We hypothesized that attainment of puberty through initiation and continuation of cyclic activity may be a predictor of reproductive longevity in heifers. Blood plasma was collected from 379 spring born heifers over four years from weaning to prior to breeding (October-June) in 2012-2015. Four pube...

  9. Transcriptome data of peripheral white blood cells from beef heifers collected at the time of artificial insemination

    Directory of Open Access Journals (Sweden)

    Sarah E. Dickinson

    2018-06-01

    Full Text Available The reproductive performance of heifers within their first breeding season influences the success of beef cattle operations. Therefore, a means to identify infertile and late breeding heifers before the start of the breeding season holds great promise for the future of the beef industry. Pubertal beef heifers were subjected to estrous synchronization and fixed time artificial insemination (FTAI. We collected peripheral blood from the heifers at the time of artificial insemination (AI and generated RNA sequencing data to characterize the transcriptome of peripheral white blood cells (PWBC. Following insemination, heifers were exposed to natural service for a defined breeding season, and pregnancy was evaluated to classify heifers into one of three groups: AI-pregnant, natural-bred (NB pregnant, and non-pregnant. The raw transcriptome data of PWBC is available on the NCBI GEO repository (GSE103628 where the reader can also find raw read counts and normalized gene expression data. The normalized data on transcript coverage can be visualized as a genome browser at HeiferFertilityRNAseq.org. Keywords: Biomarkers, Infertility, Pregnancy

  10. Breeder development and breeder strategies worldwide; Brueterentwicklung und Brueterstrategien weltweit

    Energy Technology Data Exchange (ETDEWEB)

    Marth, W. [Stabsabteilung Finanzen/Controlling, Bereich Stillegung Nuklearer Anlagen, Forschungszentrum Karlsruhe GmbH (Germany)

    1997-05-01

    Fast breeders are currently operated in six countries. In addition, a breeder power plant is under construction in China. The largest plant in operation is the 1250 MWe Superphenix in France. After considerable commissioning problems, it has meanwhile attained a good availability. However, its operating license was revoked on legal grounds; one of the main reasons for that decision was the absence of a public inquiry. The operation of several fast breeders in Russia and Kazakhstan has been almost entirely devoid of problems for years. In contrast, the situation in Japan is somewhat confused at the moment, as the Japanese prototype breeder, MONJU, suffered a sodium leakage accident in 1995 and has since been down. The Indian FBTR experimental breeder is troubled by many technical problems in its commissioning phase. The American FFTR fast reactor has been kept in a hot, but non-nuclear, state for years because the politicians cannot agree on its destiny. The fate of the German SNR-300 prototype breeder is well known: For six years, no operating permit was granted to the Kalkar Nuclear Power Station. After the plant had been decommissioned in 1991 for political reasons, it was dismantled in part and has recently been converted into a fun park. (orig.) [Deutsch] In sechs Laendern werden derzeit Schnelle Brueter betrieben; in China ist darueber hinaus ein Brueterkraftwerk im Bau. Die groesste betriebene Anlage ist der 1250-MWe-Superphenix in Frankreich. Nach betraechtlichen Inbetriebsnahmeproblemen hat er inzwischen eine gute Verfuegbarkeit erreicht; aus juristischen Gruenden wurde im jedoch die Betriebsgenehmigung entzogen, wobei das Fehlen einer oeffentlichen Anhoerung die wesentliche Rolle spielt. Ziemlich problemlos ist seit Jahren der Betrieb mehrerer Schneller Brueter in Russland und Kasachstan. Demgegenueber ist die Situation in Japan derzeit etwas verworren: Der dortige Prototyp Monju erlitt 1995 einen Natriumleckagestoerfall und ist seitdem abgeschaltet. Der

  11. Short communication: Feed sorting of dairy heifers is influenced by method of dietary transition.

    Science.gov (United States)

    Miller-Cushon, E K; Vogel, J P; DeVries, T J

    2015-04-01

    This study investigated the effect of exposing heifers to individual feed components on the extent and pattern of feed sorting upon transition to a novel ration. Holstein heifers (394 ± 62 d old, weighing 409.8 ± 37.3 kg; mean ± SD), consuming a familiar mixed silage-based ration [55% corn silage and 45% haylage, dry matter (DM) basis], were transitioned to a novel total mixed ration [TMR; 41.6% haylage, 36.5% corn silage, 14.6% high-moisture corn, and 7.3% protein supplement, DM basis] by 1 of 2 treatments: direct transition to novel TMR (DIR; n = 5) or exposure to novel TMR components individually before receiving novel TMR (COM; n = 6). During the baseline period (d 1 to 4), all heifers were offered the familiar silage-based ration. During transition (d 5 to 12), DIR heifers received the novel TMR, whereas COM heifers received the novel TMR components offered separately, in amounts according to TMR composition (target 15% orts). After transition (d 13 to 20), all heifers received the novel TMR. Feed intake and feeding time were determined daily and fresh feed and individual orts were sampled every 2d for particle size analysis and neutral detergent fiber content. The particle size separator consisted of 3 screens (18, 9, and 1.18 mm) and a bottom pan, resulting in 4 fractions (long, medium, short, and fine). Sorting activity for each fraction was calculated as actual intake expressed as a percentage of predicted intake. We detected no effect of treatment on dry matter intake or feeding time. After transition to the novel TMR, COM heifers sorted to a greater extent than did DIR heifers, sorting against long particles (95.4 vs. 98.9%) and for short particles (101.7 vs. 100.6%). Differences in sorting patterns resulted in COM heifers tending to have lower neutral detergent fiber intake as a percentage of predicted intake (98.9 vs. 100.5%). The results of this study suggest that the degree of feed sorting may be influenced by method of transition to a novel

  12. Milk yield and reproductive performance of dairy heifers and cows supplemented with polyunsaturated fatty acids

    Directory of Open Access Journals (Sweden)

    Félix Gonzalez

    2015-04-01

    Full Text Available The objective of this work was to determine productive and fertility responses of Holstein-Friesian heifers and cows to supplementation with extruded linseed and soybean as sources of polyunsaturated fatty acids (PUFAs. Supplementation had a positive effect on profitability, with significant increases in milk yield in supplemented cows, but not in heifers. Treatments had no effect on milk fat content, but higher milk protein contents were observed with supplementation. A higher conception rate was found for supplemented heifers, but not for cows. Fat sources containing PUFAs are recommended for dairy cattle supplementation, since they improve fertility in heifers and milk yield in cows.

  13. Effect of vaccinating breeder chickens with a killed Salmonella vaccine on Salmonella prevalences and loads in breeder and broiler chicken flocks.

    Science.gov (United States)

    Berghaus, R D; Thayer, S G; Maurer, J J; Hofacre, C L

    2011-05-01

    The objective of this study was to evaluate the effect of vaccination of breeder chickens on Salmonella prevalences and loads in breeder and broiler chicken flocks. Chickens housed on six commercial breeder farms were vaccinated with a killed Salmonella vaccine containing Salmonella Typhimurium, Salmonella Enteritidis, and Salmonella Kentucky. Unvaccinated breeders placed on six additional farms served as controls. Eggs from vaccinated and unvaccinated breeder flocks were kept separately in the hatchery, and the resulting chicks were used to populate 58 commercial broiler flock houses by using a pair-matched design. Vaccinated breeder flocks had significantly higher Salmonella-specific antibody titers than did the unvaccinated breeder flocks, although they did not differ significantly with respect to environmental Salmonella prevalences or loads. Broiler flocks that were the progeny of vaccinated breeders had significantly lower Salmonella prevalences and loads than broiler flocks that were the progeny of unvaccinated breeders. After adjusting for sample type and clustering at the farm level, the odds of detecting Salmonella in samples collected from broiler flocks originating from vaccinated breeders were 62% lower (odds ratio [95% confidence interval] = 0.38 [0.21, 0.68]) than in flocks from unvaccinated breeders. In addition, the mean load of culture-positive samples was lower in broilers from vaccinated breeders by 0.30 log most probable number per sample (95% confidence interval of -0.51, -0.09; P = 0.004), corresponding to a 50% decrease in Salmonella loads. In summary, vaccination of broiler breeder pullets increased humoral immunity in the breeders and reduced Salmonella prevalences and loads in their broiler progeny, but did not significantly decrease Salmonella in the breeder farm environment.

  14. Status and prospects of advanced fissile fuel breeders

    International Nuclear Information System (INIS)

    Kostoff, R.N.

    1979-01-01

    Fusion--fission hybrid systems, fast breeder systems, and accelerator breeder systems were compared on a common basis using a simple economic model. Electricity prices based on system capital costs only were computed, and were plotted as functions of five key breeder system parameters. Nominally, hybrid system electricity costs were about twenty-five percent lower than fast breeder system electricity costs, and fast breeder system electricity costs were about forty percent lower than accelerator breeder system electricity costs. In addition, hybrid system electricity costs were very insensitive to key parameter variations on the average, fast breeder system electricity costs were moderately sensitive to key parameter variations on the average, and accelerator breeder system electricity costs were the most sensitive to key parameter variations on the average

  15. Social dominance in prepubertal dairy heifers allocated in continuous competitive dyads: Effects on body growth, metabolic status, and reproductive development.

    Science.gov (United States)

    Fiol, C; Carriquiry, M; Ungerfeld, R

    2017-03-01

    The objective of this study was to compare the body weight (BW) and size, metabolic status, and reproductive development of dominant and subordinate prepubertal dairy heifers allocated in competitive dyads. Sixteen Holstein and Jersey × Holstein prepubertal heifers (means ± SEM; 250.8 ± 9.8 d; 208.5 ± 13.9 kg of BW) were assigned to 8 homogeneous dyads according to breed, age, and BW. Dyads were housed in pens separated 1 m from each other during 120 d, receiving a total mixed ration on a 5% restriction of their potential dry matter intake, and had access to the same feeder (60 cm) throughout the experiment. Dominant and subordinate heifers were defined based on the winning agonistic interactions in each dyad. Body development was recorded every 20 d in all heifers, and blood samples were collected on the same days to determine endocrine and metabolic status. The maximum follicle diameter, number of follicles >6 mm, and the presence of corpus luteum were observed weekly by ultrasound. Heifer BW (269.3 vs. 265.3 ± 1.5 kg) and average daily gains (0.858 vs. 0.770 ± 0.02 kg/d) were greater in dominant than subordinate heifers. On d 30, 37, and 53, dominant heifers had more follicles than subordinate heifers, and maximum follicle diameter was greater in dominant than in subordinate heifers (10.0 vs. 9.0 ± 0.3 mm). Dominant heifers achieved puberty earlier than subordinate heifers (313.9 ± 4.9 vs. 329.6 ± 5.7 d) with similar BW (279.4 ± 2.6 vs. 277.4 ± 5.8 kg). Glucose concentrations were greater in dominant than subordinate heifers (89.2 vs. 86.8 ± 1.2 mg/dL), but cholesterol concentrations were greater in subordinate than dominant heifers (86.1 vs. 90.2 ± 2.6 mg/dL). We concluded that, under continuous competitive situations, dominant heifers were more precocious than subordinate ones, achieving an earlier puberty. Dominant heifers had greater body growth and glucose concentrations than subordinate heifers, which may be responsible, at least in part, for

  16. A Novel Protocol to Assess Acclimation Rate in Bos taurus Heifers during Yard Weaning

    Directory of Open Access Journals (Sweden)

    Jessica E. Monk

    2018-04-01

    Full Text Available The speed with which animals acclimate to a new environment could be an important measure of ability to cope with management induced stress. This study developed a measure of acclimation rate in a group of 50 Bos taurus heifers during yard weaning over nine days. We recorded the time and order in which heifers moved through a novel funnel structure into a feeding yard daily. We hypothesised that addition of an obstacle at the entrance would increase the time it took heifers to move through the funnel, but that they would acclimate to the obstacle over a three-day period. The change in latency to move through could then be used as a measure of acclimation rate. We hypothesised that individuals which acclimated to obstacles at a faster rate might display favourable temperament as assessed by flight time. All heifers took longer to move through the funnel after a novel object was introduced, then latency decreased over the following two days while the object was present. This indicates the protocol could be useful for measuring acclimation rate at a group level. Individual acclimation rate variables, measured as change in times and orders of heifers between test days, did not appear to have any consistent relationships with flight time or weight change during or post-weaning (p > 0.05. We concluded that the protocol was inappropriate for assessing acclimation rate at an individual level, due to social effects while testing heifers as a group. Heifers which were consistently one of the first 20 to move through the funnel had a significantly greater average weight 5 and 10 months post-weaning (345 ± 9 kg and 518 ± 10 kg respectively than heifers which were consistently one of the last 20 through the funnel (311 ± 8 kg and 484 ± 8 kg respectively; p < 0.001. This may indicate order of movement through the funnel was related to feeding motivation or another aspect of temperament not reflected by flight time.

  17. Residual feed intake, body composition, and fertility in yearling beef heifers.

    Science.gov (United States)

    Shaffer, K S; Turk, P; Wagner, W R; Felton, E E D

    2011-04-01

    One hundred thirty-seven spring-born yearling beef heifers of British breed types were used to determine the relationships between residual feed intake (RFI) and growth rate, body composition, mature size, and fertility. Heifers were housed in a dry lot facility during the experimental period, and data were collected over a 2-yr period (yr 1, n = 67; yr 2, n = 70). Individual feed intake, BW, BCS, hip height, and ultrasonic measurements [subcutaneous rib fat (UBF), rump fat (URF), LM area (LMA), and intramuscular fat (IMF)] of body composition were recorded. Individual feed intakes (kg of TDN consumed/d) were used to calculate RFI combining both years of data. Heifers averaged 387.0 ± 19.4 d of age and 337.1 ± 29.9 kg of BW at initiation of the experiment. Mean ADG was 1.14 ± 0.21 kg/d during the trial. Based on RFI, with year of test and farm of origin included in the model as covariates, heifers were classified into groups: positive (POS; 0.74 kg of TDN/d) or negative (NEG; -0.73 kg TDN/d) for first analysis and high (HI), medium (MED), or low (LO; mean RFI = 1.06, -0.01, and -1.13 kg of TDN/d, respectively) subsequently. An initial phenotypic relationship (P r = 0.19 and 0.17, respectively) was sustained (P r = 0.27) and URF (r = 0.24) to trial conclusion. No other correlations with RFI were significant. Heifers classified as POS reached puberty earlier than those classified as NEG (414 ± 3.83 vs. 427 ± 4.67 d of age, P = 0.03), and possessed greater LMA per 100 kg of BW (LMACWT) at conclusion of the trial (P 0.10) from MED heifers at either the beginning or the end of test. Additionally, a negative linear relationship was observed between RFI and age at puberty (P 0.10). Differences in body fat and rate of metabolism associated with RFI could delay reproductive maturity.

  18. Effects of growth-promoting agents and season on yearling feedlot heifer performance.

    Science.gov (United States)

    Kreikemeier, W M; Mader, T L

    2004-08-01

    Angus x crossbred heifers (270 per trial) were used in an experiment conducted over one 105-d summer and one 104-d winter feeding period. Treatments were identical for each trial and included: 1) control, 2) estrogenic implant (E), 3) trenbolone acetate implant (TBA), 4) E + TBA (ET), 5) melengestrol acetate (MGA) in the feed, and 6) ET + MGA (ETM). Each treatment was replicated in five pens, with nine heifers per pen in each season. Initial weights (mean = 384 kg, SE = 57) were the same for each season. There were no treatment x season interactions for final BW, ADG, G:F, water intake, or carcass characteristics. Heifers receiving a growth-promoting agent were 11.6 kg (SE = 4.08) heavier and gained 0.108 kg/d (SE = 0.04) more (P coldest and hottest portions of the year. Heifers fed MGA and implanted with ET tended (P = 0.07) to have greater DMI in the summer but lesser DMI in the winter. In general, differences among growth-promotant programs were relatively similar over the entire summer and in winter.

  19. BREEDER: a microcomputer program for financial analysis of a large-scale prototype breeder reactor

    International Nuclear Information System (INIS)

    Giese, R.F.

    1984-04-01

    This report describes a microcomputer-based, single-project financial analysis program: BREEDER. BREEDER is a user-friendly model designed to facilitate frequent and rapid analyses of the financial implications associated with alternative design and financing strategies for electric generating plants and large-scale prototype breeder (LSPB) reactors in particular. The model has proved to be a useful tool in establishing cost goals for LSPB reactors. The program is available on floppy disks for use on an IBM personal computer (or IBM look-a-like) running under PC-DOS or a Kaypro II transportable computer running under CP/M (and many other CP/M machines). The report documents version 1.5 of BREEDER and contains a user's guide. The report also includes a general overview of BREEDER, a summary of hardware requirements, a definition of all required program inputs, a description of all algorithms used in performing the construction-period and operation-period analyses, and a summary of all available reports. The appendixes contain a complete source-code listing, a cross-reference table, a sample interactive session, several sample runs, and additional documentation of the net-equity program option

  20. Reprocessing in breeder fuel cycles

    International Nuclear Information System (INIS)

    Burch, W.D.; Groenier, W.S.

    1982-01-01

    Over the past decade, the United States has developed plans and carried out programs directed toward the demonstration of breeder fuel reprocessing in connection with the first breeder demonstration reactor. A renewed commitment to moving forward with the construction of the Clinch River Breeder Reactor (CRBR) has been made, with startup anticipated near the end of this decade. While plans for the CRBR and its associated fuel cycle are still being firmed up, the basic research and development programs required to carry out the demonstrations have continued. This paper updates the status of the reprocessing plans and programs. Policies call for breeder recycle to begin in the early to mid-1990's. Contents of this paper are: (1) evolving plans for breeder reprocessing (demonstration reprocessing plant, reprocessing head-end colocated at an existing facility); (2) relationship to LWR reprocessing; (3) integrated equipment test (IET) facility and related hardware development activities (mechanical considerations in shearing and dissolving, remote operations and maintenance demonstration phase of IET, integrated process demonstration phase of IET, separate component development activities); and (4) supporting process R and D

  1. Fall-grown oat to extend the fall grazing season for replacement dairy heifers.

    Science.gov (United States)

    Coblentz, W K; Brink, G E; Hoffman, P C; Esser, N M; Bertram, M G

    2014-03-01

    Our objective was to assess the pasture productivity and forage characteristics of 2 fall-grown oat (Avena sativa L.) cultivars, specifically for extending the grazing season and reducing reliance on harvested forages by replacement dairy heifers. A total of 160 gravid Holstein heifers (80 heifers/yr) were stratified by weight, and assigned to 1 of 10 identical research pens (8 heifers/pen). Initial body weights were 480 ± 43.5 kg in 2011 and 509 ± 39.4 kg in 2012. During both years of the trial, four 1.0-ha pasture replicates were seeded in August with Ogle oat (Schumitsch Seed Inc., Antigo, WI), and 4 separate, but similarly configured, pasture replicates were seeded with Forage Plus oat (Kratz Farms, Slinger, WI). Heifer groups were maintained as units, assigned to specific pastures, and then allowed to graze fall-oat pastures for 6h daily before returning to the barn, where they were offered a forage-based basal total mixed ration. Two heifer groups were retained in confinement (without grazing) as controls and offered the identical total mixed ration as pasture groups. During 2011, available forage mass increased with strong linear and quadratic effects for both cultivars, peaking at almost 9 Mg/ha on October 31. In contrast, forage mass was not affected by evaluation date in 2012, remaining ≤ 2,639 kg/ha across all dates because of droughty climatic conditions. During 2012, Ogle exhibited greater forage mass than Forage Plus across all sampling dates (2,678 vs. 1,856 kg/ha), largely because of its more rapid maturation rate and greater canopy height. Estimates of energy density for oat forage ranged from 59.6 to 69.1% during 2011, and ranged narrowly from 68.4 to 70.4% during 2012. For 2011, responses for both cultivars had strong quadratic character, in which the most energy-dense forages occurred in mid November, largely due to accumulation of water-soluble carbohydrates that reached maximum concentrations of 18.2 and 15.1% for Forage Plus and Ogle

  2. Concentrations of isoflavones and their metabolites in the blood of pregnant and non-pregnant heifers fed soy bean.

    Science.gov (United States)

    Woclawek-Potocka, Izabela; Piskula, Mariusz Krzysztof; Bah, Mamadou; Siemieniuch, Marta Jolanta; Korzekwa, Anna; Brzezicka, Edyta; Skarzynski, Dariusz Jan

    2008-10-01

    The present study compared the changes in isoflavones (daidzein and genistein) and their metabolite (equol and para-ethyl-phenol) concentrations in the blood plasma of cyclic and pregnant heifers after feeding with soy bean. Twelve healthy heifers were divided into three groups: cyclic heifers (days 8-12 of the estrous cycle; control group; n=4), an early pregnancy group (2 months pregnant; n=4) and a late pregnancy group (8 months pregnant; n=4). All heifers were fed a single dose of 2.5 kg of soy bean and then blood samples were taken from the jugular vein for 8 h at predetermined intervals. The concentrations of soy bean-derived isoflavones and their active metabolites were measured in the blood plasma on an HPLC system. In the blood plasma of the early- and late-pregnant heifers, we found lower concentrations and time-dependent decreases in daidzein and genistein in comparison to cyclic heifers (P0.05). In conclusion, physiological status (cyclicity or pregnancy) of the females influenced the concentrations of isoflavone metabolites in the blood plasma of the heifers. The stage of pregnancy affects isoflavone absorption, biotransformation and metabolism differently and results in higher concentrations of active metabolites of isoflavones during early pregnancy in comparison to their lower concentrations during late pregnancy. Therefore, we surmise that cows are more sensitive to active isoflavone metabolite actions during early pregnancy than cyclic heifers and heifers in late pregnancy.

  3. Effects of two different blends of naturally mycotoxin-contaminated maize meal on growth and metabolic profile in replacement heifers.

    Science.gov (United States)

    Abeni, F; Migliorati, L; Terzano, G M; Capelletti, M; Gallo, A; Masoero, F; Pirlo, G

    2014-10-01

    The aim of this trial was to assess the effects of the administration of different combinations of mycotoxins in naturally contaminated maize grains on dairy heifer growth, blood measurements and puberty onset. A total of 35 Friesian female heifers were randomly allotted to three experimental groups from 18-21 to 42-45 weeks of age. During the 24-week experimental period (EP), heifers were fed the same diet, but with maize meal derived from three differently contaminated lots: very low contamination, as control (C); medium-low aflatoxin-contaminated (A); and mixed aflatoxin-fumonisin contaminated (A-F). At the end of the EP, they returned to a common diet without contaminated maize, and they were monitored for an additional period of 12 weeks (post-experimental period, PEP). BW, wither height, hip height, body length and heart girth were measured every 4 weeks from the beginning of EP to the end of PEP. At the same time, body condition score was evaluated and blood samples were taken from the jugular vein to be analysed for haematological, serum protein and metabolic profiles. Age at puberty was assessed by measuring weekly plasma progesterone levels from 40 to 52 weeks of age. Body growth measurements were processed both by ANOVA of average daily gain of EP and PEP separately, and by the analysis of growth curve parameters. Haematological, serum protein and metabolic profile were evaluated using a mixed model, taking into account the repeated measurements in time on each animal. Heifers' growth was delayed both in A and A-F groups during EP, as evidenced by the different linear coefficients of the BW growth curve in the three groups. Differently contaminated diets did not affect the haematological profile, so that it can be concluded that these levels of mycotoxin contamination do not determine any specific effect on haematopoiesis and immunity in growing heifers. The main blood marker of mycotoxin chronic toxicity was the γ-glutamyl transferase activity level in

  4. A comparison of fusion breeder/fission client and fission breeder/fission client systems for electrical energy production

    International Nuclear Information System (INIS)

    Land, R.J.; Parish, T.A.

    1983-01-01

    A parametric study that evaluated the economic performance of breeder/client systems is described. The linkage of the breeders to the clients was modelled using the stockpile approach to determine the system doubling time. Since the actual capital costs of the breeders are uncertain, a precise prediction of the cost of a breeder was not attempted. Instead, the breakeven capital cost of a breeder relative to the capital cost of a client reactor was established by equating the cost of electricity from the breeder/client system to the cost of a system consisting of clients alone. Specific results are presented for two breeder/client systems. The first consisted of an LMFBR with LWR clients. The second consisted of a DT fusion reactor (with a 238 U fission suppressed blanket) with LWR clients. The economics of each system was studied as a function of the cost of fissile fuel from a conventional source. Generally, the LMFBR/LWR system achieved relatively small breakeven capital cost ratios; the maximum ratio computed was 2.2 (achieved at approximately triple current conventional fissile material cost). The DTFR/LWR system attained a maximum breakeven capital cost ratio of 4.5 (achieved at the highest plasma quality (ignited device) and triple conventional fissile cost)

  5. Characteristics of beef from intensively fed western Baggara bulls and heifers: quality attributes and chemical composition

    Directory of Open Access Journals (Sweden)

    I.M.A. Sharaf Eldin

    2013-06-01

    Full Text Available Fourteen samples of L. dorsi muscles were taken from western Baggara cattle, one sample from each of seven bulls and seven heifers randomly selected for slaughter at the end of an experimental feedlot feeding which lasted for 16 weeks at Kuku Research Station, Khartoum North, Sudan, to study sex effects on meat chemical composition and quality attributes. Moisture content of beef was higher in bulls meat than in heifers meat. Protein and ash content were significantly (P<0.001 higher in bulls meat, whereas fat content was significantly (P<0.001 higher in heifers meat than in bulls meat. Cooking loss of bulls meat was significantly (P<0.001 lower and water-holding capacity was also significantly (P<0.01 lower in the bulls meat than in heifers meat. Bull’s meat colour had low lightness (L and high redness (a and yellowness (b, as determined by Hunter Lab. Tristimulus colorimeter, as compared with heifers meat. Sensory panelist scores were higher for colour darkness and flavour intensity and lower for tenderness, juiciness and overall acceptability of bulls meat as compared with heifers meat.

  6. U.S. and foreign breeder reactors

    International Nuclear Information System (INIS)

    Hill, E.H.

    1977-01-01

    The running battle between Congress and the Administration over the Clinch River Breeder Reactor Plant (CRBRP) Project has provoked an increased interest in domestic and foreign breeder reactor programs. Perhaps an understanding of the history of breeders here and abroad will serve to place the CRBRP in perspective and allow some analysis of how the U.S. appears on the global canvas. Breeder reactor technology has, for the most part, settled down to concentration on the liquid metal fast breeder reactor (LMFBR). This is the result of 32 years of experience with reactors employing a fast neutron flux and even longer experience with liquid metal coolants. However, a number of U.S. utilities are sponsoring a gas cooled fast reactor program as an alternative technology to the LMFBR. This development program is supported by the U.S. Department of Energy

  7. Milk and serum progesterone assay for evaluation of reproductive performance of dairy herds in Thailand

    International Nuclear Information System (INIS)

    Intraraksa, Y.

    1990-01-01

    Cross-bred dairy cows (n=202) were used to study the milk progesterone profiles 0, 5, 7, 12, 20, 28, 35 and 45 days after artificial insemination. It was found that 57% (115/202) of the cows had a normal oestrous cycle and conceived, but in 13% (15/115) of cows that conceived the embryos died between 28 and 35 days of gestation. A total of 43% (87/202) of the cows did not become pregnant and these could be classified into four groups: 15% (31/202) had normal oestrous cycles; 7% (15/202) were inseminated during the luteal phase, i.e. when progesterone concentrations were elevated; 14% (29/202) had irregular cycles; and 6% (12/202) were acyclic. In another study milk samples were collected every 3 days from 90 cross-bred dairy cows, commencing 15 days after parturition and continuing until each animal had been inseminated. The milk progesterone profiles of each cow were collated with the records of oestrus and insemination. The average post-partum anoestrous periods of primiparous and multiparous cows were 35.0 ± 16.4 and 34.9 ± 14.5 days, respectively. In 68% of the primiparous cows and 65% of the multiparous cows oestrus occurred between days 20 and 40 of the post-partum period. Sequential serum samples from 42 repeat breeder cows and 8 infertile heifers were analysed for progesterone, and their ovaries were examined weekly by rectal palpation. They were treated with either human chorionic gonadotrophin (HCG), pregnant mare serum gonadotrophin (PMSG) or prostaglandin F 2α . As a result, 23 cows and 5 heifers re-established oestrous cycles and became pregnant after AI. Progesterone profiles and rectal palpation revealed various causes of infertility, including ovarian cysts, irregular oestrous cycles, inactive ovaries and abnormal oviducts. Fifty-six per cent of repeat breeder cows and infertile heifers responded to hormone treatment in terms of resumed ovarian function. (author). 14 refs, 6 figs, 3 tabs

  8. Effects of cultivar and grazing initiation date on fall-grown oat for replacement dairy heifers.

    Science.gov (United States)

    Coblentz, W K; Brink, G E; Esser, N M; Cavadini, J S

    2015-09-01

    Fall-grown oat has shown promise for extending the grazing season in Wisconsin, but the optimum date for initiating grazing has not been evaluated. Our objectives for this project were (1) to assess the pasture productivity and nutritive value of 2 oat cultivars [Ogle and ForagePlus (OG and FP, respectively)] with late-September (EG) or mid-October (LG) grazing initiation dates; and (2) to evaluate growth performance by heifers grazing these oat forages compared with heifers reared in confinement (CON). A total of 160 gravid Holstein heifers (80 heifers/yr) were assigned to 10 research groups (8 heifers/group). Mean initial body weight was 509±40.5 kg in 2013 and 517±30.2 kg in 2014. Heifer groups were assigned to specific pastures arranged as a 2×2 factorial of oat cultivars and grazing initiation dates. Grazing heifer groups were allowed to strip-graze oat pastures for 6 h daily before returning to the barn, where they were offered a forage-based basal total mixed ration. Main effects of oat cultivar and sampling date interacted for forage characteristics in 2013, but not in 2014. During 2013, oat forage mass increased until early November before declining in response to freezing weather conditions, thereby exhibiting linear and quadratic effects of sampling date, regardless of oat cultivar. Similar trends over time were observed in 2014. For 2013, the maximum forage mass was 5,329 and 5,046 kg/ha for FP and OG, respectively, whereas the mean maximum forage mass for 2014 was 4,806 kg/ha. ForagePlus did not reach the boot stage of growth during either year of the trial; OG matured more rapidly, reaching the late-heading stage during 2013, but exhibited only minor maturity differences from FP in 2014. For 2013, average daily gain for CON did not differ from grazing heifer groups (overall mean=0.63 kg/d); however, average daily gain from FP was greater than OG (0.68 vs. 0.57 kg/d), and greater from EG compared with LG (0.82 vs. 0.43 kg/d). For 2013, advantages in

  9. Progesterone inserts may help to improve breeding readiness in beef heifers

    OpenAIRE

    Favetto, Pedro H; Hoar, Bruce R; Myers, Dan M; Tindall, Justin

    2010-01-01

    The accurate determination of pubertal status in yearling beef heifers, possibly combined with the use of exogenous progesterone, allows females to produce the maximum number of calves over their lifetimes. This study aimed to determine the reliability of a reproductive tract scoring (RTS) system that combines manual palpation with ultrasound as a measure of pubertal status, and whether the treatment of heifers with progesterone-containing vaginal inserts — followed by breeding on the second ...

  10. Economic analysis of fusion breeders

    International Nuclear Information System (INIS)

    Delene, J.G.

    1985-01-01

    This paper presents a study of the economic performance of Fission/Fusion Hybrid devices. This work takes fusion breeder cost estimates and applies methodology and cost factors used in the fission reactor programs to compare fusion breeders with Liquid Metal Fast Breeder Reactors (LMFBR). The results of the analysis indicate that the Hybrid will be in the same competitive range as proposed LMFBRs and have the potential to provide economically competitive power in a future of rising uranium prices. The sensitivity of the results to variations in key parameters is included

  11. Alternative reproductive tactics in female striped mice: Solitary breeders have lower corticosterone levels than communal breeders.

    Science.gov (United States)

    Hill, Davina L; Pillay, Neville; Schradin, Carsten

    2015-05-01

    Alternative reproductive tactics (ARTs), where members of the same sex and population show distinct reproductive phenotypes governed by decision-rules, have been well-documented in males of many species, but are less well understood in females. The relative plasticity hypothesis (RPH) predicts that switches between plastic ARTs are mediated by changes in steroid hormones. This has received much support in males, but little is known about the endocrine control of female ARTs. Here, using a free-living population of African striped mice (Rhabdomys pumilio) over five breeding seasons, we tested whether females following different tactics differed in corticosterone and testosterone levels, as reported for male striped mice using ARTs, and in progesterone and oestrogen, which are important in female reproduction. Female striped mice employ three ARTs: communal breeders give birth in a shared nest and provide alloparental care, returners leave the group temporarily to give birth, and solitary breeders leave to give birth and do not return. We expected communal breeders and returners to have higher corticosterone, owing to the social stress of group-living, and lower testosterone than solitary breeders, which must defend territories alone. Solitary breeders had lower corticosterone than returners and communal breeders, as predicted, but testosterone and progesterone did not differ between ARTs. Oestrogen levels were higher in returners (measured before leaving the group) than in communal and solitary breeders, consistent with a modulatory role. Our study demonstrates hormonal differences between females following (or about to follow) different tactics, and provides the first support for the RPH in females. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Methane emissions, body composition, and rumen fermentation traits of beef heifers differing in residual feed intake.

    Science.gov (United States)

    Fitzsimons, C; Kenny, D A; Deighton, M H; Fahey, A G; McGee, M

    2013-12-01

    This study examined the relationship of residual feed intake (RFI) and performance with methane emissions, rumen fermentation, and digestion in beef heifers. Individual DMI and growth performance were measured for 22 Simmental heifers (mean initial BW 449 kg, SD = 46.2 kg) offered grass silage ad libitum for 120 d. Ultrasonically scanned muscle and fat depth, BCS, muscularity score, skeletal measurements, blood variables, rumen fermentation (via stomach tube), and total tract digestibility (indigestible marker) were measured. Methane production was estimated using the sulfur hexafluoride tracer gas technique over two 5-d periods beginning on d 20 and 75 of the RFI measurement period. Phenotypic RFI was calculated as actual DMI minus expected DMI. The residuals of the regression of DMI on ADG and midtest metabolic body weight, using all heifers, were used to compute individual RFI coefficients. Heifers were ranked by RFI and assigned to low (efficient), medium, or high (inefficient) groupings. Overall ADG and DMI were 0.58 kg (SD = 0.18) and 7.40 kg (SD = 0.72), respectively. High-RFI heifers consumed 9 and 15% more (P composition traits did not differ (P > 0.05) between low- and high-RFI groups. High-RFI heifers had higher concentrations of plasma glucose (6%) and urea (13%) and lower concentrations of plasma creatinine (9%) than low-RFI heifers (P 0.05) between RFI groups, although acetate:propionate ratio was lowest (P = 0.07) for low-RFI (3.5) and highest for high-RFI (4.6) heifers. Methane production expressed as grams per day or grams per kilogram metabolic body weight was greater (P methane emissions. Results suggest that improved RFI will reduce methane emissions without affecting productivity of growing beef cattle.

  13. Swiss breeder research programme

    International Nuclear Information System (INIS)

    1992-01-01

    A new initiative for a Swiss Fast Breeder Research Program has been started during 1991. This was partly the consequence of a vote in Fall 1990, when the Swiss public voted for maintaining nuclear reactors in operation, but also for a moratorium of 10 years, within which period no new reactor project should be proposed. On the other hand the Swiss government decided to keep the option 'atomic reactors' open and therefore it was essential to have programmes which guaranteed that the knowledge of reactor technology could be maintained in the industry and the relevant research organisations. There is also motivation to support a Swiss Breeder Research Program on the part of the utilities, the licensing authorities and the Paul Scherrer Institute (PSI). The utilities recognise the breeder reactor as an advanced reactor system which has to be developed further and might be a candidate, somewhere in the future, for electricity production. In so far they have great interest that a know-how base is maintained in our country, with easy access for technical questions and close attention to the development of this reactor type. The licensing authorities have a legitimate interest that an adequate knowledge of the breeder reactor type and its functions is kept at their disposal. PSI and the former EIR have had for many years a very successful basic research programme concerning breeder reactors, and were in close cooperation with EFR. The activities within this programme had to be terminated owing to limitations in personnel and financial resources. The new PSI research programme is based upon two main areas, reactor physics and reactor thermal hydraulics. In both areas relatively small but valuable basic research tasks, the results of which are of interest to the breeder community, will be carried out. The lack of support of the former Breeder Programme led to capacity problems and finally to a total termination. Therefore one of the problems which had to be solved first was

  14. Identification of an ionotropic glutamate receptor AMPA1/GRIA1 polymorphism in crossbred beef cows differing in fertility.

    Science.gov (United States)

    Cushman, R A; Miles, J R; Rempel, L A; McDaneld, T G; Kuehn, L A; Chitko-McKown, C G; Nonneman, D; Echternkamp, S E

    2013-06-01

    A proposed functional polymorphism in the ionotropic glutamate receptor AMPA1 (GRIA1) has been reported to influence antral follicle numbers and fertility in cows. Repeat breeder cows that fail to produce a calf in multiple seasons have been reported to have reduced numbers of small (1 to 3 mm) antral follicles in their ovaries. Therefore, we tested the hypothesis that this GRIA1 polymorphism was affecting antral follicle numbers in repeat breeder cows. Repeat breeder cows (n = 64) and control cows (n = 72) that had always produced a calf were housed in a dry lot and observed twice daily for behavioral estrus. Blood samples were collected, and cows were genotyped for this GRIA1 polymorphism and for a polymorphism in the GnRH receptor (GnRHR) that was proposed to influence age at puberty. On d 3 to 8 after estrus cows were slaughtered, and reproductive organs were collected to determine antral follicle count, ovary size, and uterine horn diameter. Repeat breeder cows were older at first calving than control cows (P = 0.006). The length (P = 0.03) and height (P = 0.02) of the ovary contralateral to the corpus luteum (CL) were greater in control cows than repeat breeder cows. The endometrial diameter in the horn ipsilateral to the CL was greater in the control cows than the repeat breeder cows. Repeat breeder cows had fewer small (1 to 5 mm) antral follicles than control cows (P = 0.003); however, there was no association between GRIA1 genotype and antral follicle number. The GnRHR polymorphism was associated with age at first calving because cows that were homozygous for the C allele had a greater age at first calving than heterozygous cows or cows that were homozygous for the T allele (P = 0.01). In the granulosa cells from small (1 to 5 mm) antral follicles, mRNA abundances of 2 markers of oocyte quality, anti-Müllerian hormone and pentraxin 3, did not differ between fertility groups (P ≥ 0.12). We conclude that this GRIA1 polymorphism exists in beef cows but

  15. Antral follicles population in heifers and cows of Nelore and Girolando breeds

    Directory of Open Access Journals (Sweden)

    Jair Sábio de Oliveira Junior

    2015-12-01

    Full Text Available The aim of this study was to evaluate ovarian antral follicle populations (OAFP of Nelore and Girolando breed heifers (12–18 months old and cows (24–60 months old. Animals were assigned to four groups: (1 Nelore cows (n = 18, (2 Girolando cows (n = 20, (3 Nelore heifers (n = 7, and (4 Girolando heifers (n = 7. Cows were treated to synchronize follicular wave emergence by implantation of an intravaginal device containing 1.9 g of progesterone, as well as intramuscular administration of 2 mg of estradiol benzoate and 25 mg of dinoprost. This synchronization treatment was administered at a random day of the estrous cycle of each cow, designated D0. Intravaginal devices were removed on D7, and on D11, OAFP counts were performed by transvaginal ovarian ultrasound. For each cow, all follicles ?3 mm in diameter were counted in both ovaries and counts were performed three times at 35-day intervals. Counts were also obtained from heifers, but these animals were not treated for synchronization of follicular wave emergence. Analysis of variance (ANOVA with Tukey’s test and Pearson’s correlation test were used to compare mean OAFPs between counts as well as mean OAFPs between breed and age groups. No differences were observed in mean OAFPs between Nelore and Girolando cows (30.9 vs. 26.7, respectively; P > 0.05 or heifers (16.2 vs. 18.1, respectively; P > 0.05. However, within each breed, there were differences in mean OAFPs between heifers and cows (for Nelore cattle: 16.2 and 30.9, respectively; for Girolando cattle: 18.1 and 26.7, respectively; both P < 0.05. In conclusion, OAFPs were similar between Nelore and Girolando breeds and were influenced by age. Furthermore, we observed a high correlation for individual animals between the mean numbers of follicles counted in both ovaries and total number of follicles counted in either the right or left ovary, indicating that the evaluation of a single ovary is sufficient to estimate the OAFP of an

  16. Breeders. Les surregenerateurs

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    The interest lying in the nuclear energy as a source of electric power is recalled with a view to the consumption of primary energy and electric power; the position of France is particularly discussed. The fast breeder reactor is presented and the state of development of this type of reactor in France is discussed with the planning of the Creys-Malville power plant. The problems successively examined are concerned with: fuel cycle, radioactivity and effluents, breeder safety, licensing procedures, sodium coolant, plutonium, fuel reprocessing, environmental impact and waste management.

  17. Optimal management of replacement heifers in a beef herd: a model for simultaneous optimization of rearing and breeding decisions.

    Science.gov (United States)

    Stygar, A H; Kristensen, A R; Makulska, J

    2014-08-01

    The aim of this study was to provide farmers an efficient tool for supporting optimal decisions in the beef heifer rearing process. The complexity of beef heifer management prompted the development of a model including decisions on the feeding level during prepuberty (age optimal rearing strategy was found by maximizing the total discounted net revenues from the predicted future productivity of the Polish Limousine heifers defined as the cumulative BW of calves born from a cow calved until the age of 5 yr, standardized on the 210th day of age. According to the modeled optimal policy, heifers fed during the whole rearing period at the ADG of 810 g/d and generally weaned after the maximum suckling period of 9 mo should already be bred at the age of 13.2 mo and BW constituting 55.6% of the average mature BW. Based on the optimal strategy, 52% of all heifers conceived from May to July and calved from February to April. This optimal rearing pattern resulted in an average net return of EUR 311.6 per pregnant heifer. It was found that the economic efficiency of beef operations can be improved by applying different herd management practices to those currently used in Poland. Breeding at 55.6% of the average mature BW, after a shorter and less expensive rearing period, resulted in an increase in the average net return per heifer by almost 18% compared to the conventional system, in which heifers were bred after attaining 65% of the mature BW. Extension of the rearing period by 2.5 mo (breeding at the age 15.7 mo), due to a prepubertal growth rate lowered by 200 g, reduced the average net return per heifer by 6.2% compared to the results obtained under the basic model assumptions. In the future, the model may also be extended to investigate additional aspects of the beef heifer development, such as the environmental impacts of various heifer management decisions.

  18. Fast breeder reactors--lecture 4

    International Nuclear Information System (INIS)

    Marshall, W.; Davies, L.M.

    1986-01-01

    This paper discusses the economics of fast breeder reactors. An algebraic background is presented which represents the various views expressed by different nations regarding the cost of fast breeder reactors and their associated fuel cycle services, the timescale by which they might be available, and the simultaneous variations in the price of uranium. Actual presentations made by individual countries in recent discussions serve to verify the general nature of this present discussion. It is assumed that if nuclear power is to make a long term contribution to the needs of the world, the introduction of fast breeder reactors is both essential and necessary

  19. International strategies for breeder development

    International Nuclear Information System (INIS)

    Zaleski, C.P.; Zebroski, E.L.

    1992-01-01

    This paper studies the perspectives of breeder reactors development. The near term context has led some experts to the conclusion that breeder reactor technology is too far ahead of its time. Some have compared breeders to the supersonic airplane, Concorde: good technical performance but failure in its economic dimensions. In this paper, the author points out the major shortcomings of such an assessment which may be valid in the short time. However, with a short-term market-dominated perspective that uses an 8% discount rate, one can neglect every thing that is going to happen in 50 years. 6 refs., 11 figs

  20. Breeder--now or never

    International Nuclear Information System (INIS)

    Murphy, P.M.

    1978-01-01

    The timing of the commercial introduction of the LMFBR (Liquid Metal Fast Breeder Reactor) will be an important factor in its ability to supply a significant fraction of the nation's future electrical needs. The number of breeders we can build initially will be limited by the size of our low-cost urnium resources and by the rate at which LWR's (Light Water Reactors) are placed in service. Since this uranium resource is fixed in size while electrical demand will grow geometrically, it is clear that the sooner the breeder is introduced commercially the larger will be the fraction of electrical demand that it can supply. An early commercial introduction on an adequate scale requires full-scale resumption of LWR construction and redirection of LMFBR development programs toward a near-term commercial prototype

  1. Breeder: now or never

    International Nuclear Information System (INIS)

    Murphy, P.M.

    1978-01-01

    The timing of the commercial introduction of the liquid metal fast breeder reactor (LMFBR) will be an important factor in its ability to supply a significant fraction of the nation's future electrical needs. The number of breeders we can build initially will be limited by the size of our low-cost uranium resources and by the rate at which light water reactors (LWRs) are placed in service. Since this uranium resource is fixed in size while electrical demand will grow geometrically, it is clear that the sooner the breeder is introduced commercially the larger will be the fraction of electrical demand it can supply. An early commercial introduction on an adequate scale requires full-scale resumption of LWR construction and redirection of LMFBR development programs toward a near-term commercial prototype

  2. The fast breeder reactor

    International Nuclear Information System (INIS)

    Patterson, W.

    1990-01-01

    The author criticises the United Kingdom Atomic Energy Authority's fast breeder reactor programme in his evidence to the House of Commons Select Committee on Energy in January 1990. He argues for power generation by renewable means and greater efficiency in the use rather than in the generation of electricity. He refutes the arguments for nuclear power on the basis of reduced global warming as he claims support technology produces significant amounts of carbon dioxide in any case. Serious doubts are raised about the costs of a fast breeder reactor programme compared to, say, generation by pressurised water reactors. The idea of a uranium scarcity in several decades is also refuted. The reliability of fast breeder reactor technology is called into question. He argues against reprocessing plutonium for economic, health and safety reasons. (UK)

  3. A manufacturer's view of the US breeder program

    International Nuclear Information System (INIS)

    Arnold, W.H.

    1982-01-01

    A liquid metal fast breeder reactor (LMFBR) was selected for development in a program to develop breeder reactors in general. The LMFBR is a sodium-cooled fast reactor which operates at a high conversion ratio of fertile-to-fissile material while generating electricity at a high thermal efficiency. The breeder has the added capacity to operate on the plutonium in Light Water Reactor spent fuel, and on U-238. A governmental/industrial infrastructure must be developed. Criteria for breeder deployment are listed. Construction of the Clinch River Breeder reactor is a necessary step in the progression to a mature breeder. Then the large prototype LMFBR should be built. Foreign collaboration is considered. Finally, a capital cost analysis indicates LMFBR cost-effectiveness

  4. Influence of green grass-based diets on growth and reproductive performance in dairy heifers

    DEFF Research Database (Denmark)

    Habib, M. R.; Rashid, M. H.; Islam, M. A.

    2018-01-01

    The objective of this study was to monitor the changes in growth, dry matter intake, and blood profiles (nutrition and reproductive hormones) of dairy heifers in response to green grass-based diets. Twelve crossbred heifers were equally divided into group 1: rice straw and concentrate; group 2: r...

  5. Effects of rumen-undegradable protein on intake, performance, and mammary gland development in prepubertal and pubertal dairy heifers.

    Science.gov (United States)

    Silva, A L; Detmann, E; Dijkstra, J; Pedroso, A M; Silva, L H P; Machado, A F; Sousa, F C; Dos Santos, G B; Marcondes, M I

    2018-04-04

    The objective of this study was to evaluate the influence of different amounts of rumen-undegradable protein (RUP) on intake, N balance, performance, mammary gland development, carcass traits, and hormonal status of Holstein heifers at different physiological stages (PS). Sixteen prepubertal (PRE) heifers (initial BW = 106 ± 7.6 kg; age = 4.3 ± 0.46 mo) and 16 pubertal (PUB) heifers (initial BW = 224 ± 7.9 kg; age = 12.6 ± 0.45 mo) were used in an experiment over a period of 84 d. Four diets with increasing RUP contents (38, 44, 51, and 57% of dietary crude protein) and heifers at 2 PS (PRE or PUB) were used in a 4 × 2 factorial arrangement of treatments in a completely randomized design. Throughout the experiment, 2 digestibility trials were performed over 5 consecutive days (starting at d 36 and 78) involving feed and ort sampling and spot collections of feces and urine. At d 0 and 83, body ultrasound images were obtained for real-time carcass trait evaluation. The mammary gland was ultrasonically scanned at d 0 and every 3 wk during the experiment. Blood samples were taken at d 0 and 84 to determine serum concentrations of progesterone, estrogen, insulin-like growth factor I (IGF-I), and insulin. No interaction between PS and the level of RUP was found for any trait. Apparent digestibility of dry matter, organic matter, and neutral detergent fiber corrected for ash and protein was not affected by RUP level but was lower for PRE compared with PUB heifers. Sorting against neutral detergent fiber corrected for ash and protein (tendency only) and for crude protein was greater for PUB than PRE heifers. Pubertal heifers had greater average daily gain (905 vs. 505 g/d) and N retention (25.9 vs. 12.5 g/d) than PRE heifers. In addition, average daily gain and N retention were greatest at 51% RUP of dietary protein. Mammary ultrasonography indicated no effects of RUP amounts on mammary gland composition, whereas PRE heifers had greater pixel values than PUB

  6. Effect of extended photoperiod during winter on growth and onset of puberty in Murrah buffalo heifers

    Directory of Open Access Journals (Sweden)

    Ashwani Kumar Roy

    2016-02-01

    Full Text Available Aim: To investigate the effect of extended photoperiod on growth rate, hormonal levels, and puberty in Murrah heifers. Materials and Methods: About 14 Murrah buffalo heifers were divided into normal day photoperiod (NDP; n=7 and extended NDP (ENDP; n=7 groups. The ENDP group was exposed to 4 h of extended photoperiod with artificial light (160 lux after sunset for 3 months during winter. Results: Group, age and group-by-age interaction effects on plasma glucose concentrations were non-significant (p>0.05. A significant effect of age on non-esterified fatty acids (p0.05 while significant (p0.05. Average daily gain and dry matter intake of heifers were nonsignificant between the NDP and ENDP groups but were comparatively higher in ENDP group. By the end of the experiment, 6 out of 7 heifers attained puberty in ENDP group in comparison to 4 out of 7 in NDP group. Conclusion: Extending the photoperiod by artificial light for 4 h during winter season resulted in better growth rate and early onset of puberty in Murrah buffalo heifers.

  7. Status and prospects of thermal breeders

    International Nuclear Information System (INIS)

    1978-08-01

    The main objective of this cooperative study and of this report is to evaluate the extent to which thermal breeders might complement or serve as an alternative to fast breeders in solving the long-term nuclear fuel supply problem. A secondary objective is to consider in a general way issues such as proliferation, safety, environmental impacts, economics, power plant availability, and fuel cycle versatility to determine whether thermal breeder reactors offer advantages or disadvantages with respect to such issues

  8. Incorporating reproductive management of beef heifers into a veterinary practice.

    Science.gov (United States)

    Poock, Scott E; Payne, Craig A

    2013-11-01

    Veterinarians play an important role in reproductive management of dairy herds across the United States; however, in many cases, their involvement in reproductive management of beef herds has been limited. The reasons for this vary; however, there are ways for veterinarians to become more actively involved in reproductive management of US beef herds. Veterinarians can have an impact on producers' profits by implementing their skills and knowledge to beef heifer development programs. This article provides an overview of the services veterinarians can provide to beef cattle producers that pertain to reproductive management of replacement beef heifers. Published by Elsevier Inc.

  9. Gastrointestinal parasite control during prepuberty improves mammary parenchyma development in Holstein heifers.

    Science.gov (United States)

    Perri, Adrián F; Mejía, Miguel E; Licoff, Nicolás; Diab, Santiago S; Formía, Néstor; Ornstein, Ana; Becú-Villalobos, Damasia; Lacau-Mengido, Isabel M

    2013-12-06

    Parasitism during development impairs normal growth and delays the onset of puberty through altered hormone profiles, including insulin-like growth factor one (IGF-1). As mammary gland development during prepuberty is strongly dependent on IGF-1, we determined if antiparasitic treatment during this stage of growth improved mammary gland development. One group of Holstein heifers was treated monthly, rotationally with antiparasitic drugs from birth to 70 weeks of age, a second group was untreated. Treated heifer calves had between 56% and 65% less EPG counts than untreated ones. Presence of Ostertagia, Cooperia, Haemonchus and Trichostrongylus was demonstrated. Treatment effectively advanced the onset of puberty and increased IGF-1 levels. At 20, 30, 40 and 70 weeks of age biopsies from the mammary gland were taken and histological sections were prepared and stained with hematoxylin-eosin. Pictures were analyzed to compare parenchyma area in relation to total mammary tissue between groups. Mammary samples from treated heifers had higher ratios of parenchyma/total area than untreated ones. As mammary development during prepuberty is crucial for mammary performance during lactation, these results add new evidence to the importance of gastrointestinal parasite control in heifers. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Short communication: Limit feeding dairy heifers: effect of feed bunk space and provision of a low-nutritive feedstuff.

    Science.gov (United States)

    Greter, A M; Kitts, B L; Devries, T J

    2011-06-01

    The objectives of this study were to examine the behavioral effects of providing limit-fed dairy heifers an increased amount of feed bunk space compared with recommended feed bunk allowance, and to determine if the effects of provision of extra bunk space would be comparable to those seen when limit-fed heifers are provided a low-nutritive feedstuff. Twelve Holstein dairy heifers (381.1 ± 44.8 d of age, 417.3 ± 47.9 kg), divided into groups of 4, were exposed to each of 3 treatments using a 3 × 3 Latin square design with 7-d periods. The treatments were (1) 0.68 m of feed bunk space/heifer (TMR-0.68), (2) 0.34 m of feed bunk space/heifer (TMR-0.34), and (3) 0.34 m of feed bunk space/heifer with an additional 0.34 m of feed bunk space available for free-choice straw (TMR-S). The total mixed ration was fed once daily at a restricted level (1.83% of body weight) and contained (dry matter basis) 19.9% alfalfa/grass haylage, 20.1% corn silage, 49.6% high-moisture corn, and 10.4% protein supplement. Group dry matter intake (DMI) was recorded daily. Behavior at the feed bunk was recorded for the last 4 d of each treatment period. Due to the provision of straw, DMI was highest on the TMR-S treatment compared with the other treatments (9.4 vs. 7.8 kg/d). Heifers spent the most time feeding when on the TMR-S treatment (147.7 min/d), with no difference in feeding time between the limit-fed TMR treatments (64.5 min/d). Within the TMR-S treatment, feeding time on the straw was 76.9 min/d; thus, the rate of consumption of only the TMR was similar across all treatments. Unrewarded time at the feed bunk (when no feed was present) did not differ between treatments. Heifers did not differ in competitive behavior when on the limit-fed TMR treatments (13.1 displacements/heifer per day). However, while on the TMR-S treatment, heifers displaced each other more frequently (23.8 displacements/heifer per day) than while on the other 2 treatments. Overall, results suggest that neither

  11. The fast breeder reactor

    International Nuclear Information System (INIS)

    Keck, O.

    1984-01-01

    Nowadays the fast-breeder reactor is a negative symbol of advanced technology which is getting out of control and, due to its complexity, is incomprehensible for politicians and therefore by-passes the established order. The author lists the most important decisions over state aid to the fast-breeder-reactors up until the mid-seventies and uses documents from the appropriate advisory bodies as reference. He was also aided by interviews with those directly involved with the project. The empirical facts forces us to discard our traditional view of the relationship between state and industry with regard to advanced technology. The author explains that it is impossible to find any economic value in the fast-breeder reactor. The insight gained through this project allows him to draw conclusions which apply to all aspects of state aid to advanced technology. (orig.) [de

  12. International cooperation on breeder reactors

    International Nuclear Information System (INIS)

    Gray, J.E.; Kratzer, M.B.; Leslie, K.E.; Paige, H.W.; Shantzis, S.B.

    1978-01-01

    In March 1977, as the result of discussions which began in the fall of 1976, the Rockefeller Foundation requested International Energy Associates Limited (IEAL) to undertake a study of the role of international cooperation in the development and application of the breeder reactor. While there had been considerable international exchange in the development of breeder technology, the existence of at least seven major national breeder development programs raised a prima facie issue of the adequacy of international cooperation. The final product of the study was to be the identification of options for international cooperation which merited further consideration and which might become the subject of subsequent, more detailed analysis. During the course of the study, modifications in U.S. breeder policy led to an expansion of the analysis to embrace the pros and cons of the major breeder-related policy issues, as well as the respective views of national governments on those issues. The resulting examination of views and patterns of international collaboration emphasizes what was implicit from the outset: Options for international cooperation cannot be fashioned independently of national objectives, policies and programs. Moreover, while similarity of views can stimulate cooperation, this cannot of itself provide compelling justification for cooperative undertakings. Such undertakings are influenced by an array of other national factors, including technological development, industrial infrastructure, economic strength, existing international ties, and historic experience

  13. A new application of pelvis area data as culling tool to aid in the management of dystocia in heifers.

    Science.gov (United States)

    Holm, D E; Webb, E C; Thompson, P N

    2014-05-01

    Although fetomaternal disproportion is the major cause of dystocia in heifers, pelvis area (PA) is not recommended as a culling tool due to its relatively low importance and genetic correlation with calf birth weight (BWT), the most important factor associated with dystocia. The objective of this observational study of 484 limited bred yearling beef heifers was to compare the effects of different methods of adjustment of PA data for culling to select against dystocia. Multivariable analyses were used to determine predictors of PA, calf BWT, and dystocia. Hypothetical culling rates of 10 and 20% were then applied after ranking heifers by each of the following: unadjusted PA, PA adjusted to 365 d of age by subtracting 0.27 cm(2) per day of age difference between each heifer's age and 365 d (APA), PA:prebreeding BW ratio (PA:BW), PA adjusted to the median BW of the group using the regression coefficient of PA on BW within age group (BWPA), and PA similarly adjusted to the median lean BW (LBWPA). Dam parity, sire, prebreeding age, prebreeding BW, and prebreeding BCS were associated with PA whereas dam parity, sire, own BWT, PA, AI bull, and calf gender were associated with calf BWT (P dystocia (P dystocia. After hypothetical culling by PA, retained heifers were heavier and had a higher calving rate and calves tended to be heavier at birth compared to culled heifers, but dystocia rates were not different. Culling by APA resulted in similar effects, except that dystocia rate tended to be lower in retained heifers. Culling by PA:BW resulted in lower dystocia rate in retained than in culled heifers, but retained heifers had lower prebreeding BW than culls. Culling by BWPA and LBWPA resulted in lower proportions with dystocia and a tendency towards higher calving rates in the retained heifers, without affecting the prebreeding BW or calf BWT. It is concluded that pelvimetry is a useful culling tool to aid in the management of dystocia in yearling heifers and that adjustment

  14. Subclinical and clinical mastitis in heifers following the use of a teat sealant precalving.

    Science.gov (United States)

    Parker, K I; Compton, C; Anniss, F M; Weir, A; Heuer, C; McDougall, S

    2007-01-01

    This study investigated the effect in heifers of infusion of a bismuth subnitrate teat-canal sealant and bacterial intramammary infection (IMI) precalving on prevalence of postcalving IMI and incidence of clinical mastitis in the first 2 wk postcalving. Glands (n = 1,020) from heifers (n = 255) in 5 seasonally calving, pasture-fed dairy herds were randomly assigned within heifer to 1 of 4 treatment groups (no treatment; mammary gland secretion collection; infusion of a teat sealant; or sample collection with infusion of teat sealant). Heifers within a herd were enrolled on one calendar day, 31 d on average before the planned start of the seasonal calving period. Duplicate milk samples were collected from each gland within 4 d after calving for bacterial culture. Herd owners collected duplicate milk samples, before treatment, for bacterial culture from glands they defined as having clinical mastitis. The gland prevalence of IMI precalving was 15.5% and did not differ between herds. Bacteria isolated precalving included coagulase-negative staphylococci (76.9% of all bacteriologically positive samples), Streptococcus uberis (14.1%), Staphylococcus aureus (5.1%), Corynebacterium spp. (3.8%), and others (0.1%). The presence of an IMI precalving increased the risk of an IMI postcalving 3.6-fold and the risk of clinical mastitis 4-fold, relative to no IMI precalving. Infusion of the teat sealant reduced the risk of postcalving IMI due to Strep. uberis by 84%, and of clinical mastitis by 68%. Sampling the glands precalving had no effect on postcalving IMI or on clinical mastitis incidence. Use of an internal teat canal sealant in heifers precalving may be a useful tool for reducing the risk of subclinical and clinical mastitis in heifers.

  15. A possible association between dietary intake of copper, zinc and phosphate and delayed puberty in heifers in Sudan.

    Science.gov (United States)

    Ahmed, M M M; Fadlalla, I M T; Barri, M E S

    2002-02-01

    Zinc and copper deficiencies have been reported in heifers of various breeds at four different locations in Sudan. These were Kuku (5 km north of Khartoum), Seleit (20 km northwest of Khartoum), Medani (180 km south of Khartoum) and El Obeid (600 km west of Khartoum). Phosphorus deficiency was only observed in the serum of heifers at El Obeid. The heifers at all locations showed delayed puberty, stunted growth and infertility. The heifers of the local breeds at El Obeid only attained puberty by 1530 days of age compared with 840 days for the pure Friesian heifers at Seleit. The crossbred animals at Kuku and Medani attained puberty at 1440 and 1020 days of age, respectively. The marginal or low zinc and copper contents in pasture, soil or animal feed may have been predisposing factors for the observed deficiencies and might have been responsible for the delayed age of puberty.

  16. EFFECT OF GnRH AND PHOSPHORUS IN DELAYED PUBERTAL SURTI BUFFALO HEIFERS

    Directory of Open Access Journals (Sweden)

    H.B. Dhamsaniya

    2016-06-01

    Full Text Available The study was conducted on eighteen delayed pubertal Surti buffalo heifers, divided into three equal groups (6 in each to evaluate the efficacy of GnRH alone and in combination of phosphorus. The buffalo heifers in Group-I and Group-II were treated with Buserelin acetate (5 ml, IM. Buffalo heifers in Group-II also received additional injection of Toldimphos sodium (10 ml, IM at 3 day interval for 4 times, while buffalo heifers in Group-III served as control. The percentage of induced estrus was highest (83.33% in each treated groups as compared to control group (50%. The mean estrus induction intervals were significantly (P<0.05 shorter in Group-I (20.20 ± 2.18 days and Group-II (18.80 ± 2.32 days as compared to control group (30.24 ± 0.81 days. The conception rate at induced estrus was highest in Group-II (50% followed by Group-I (33.33%. The plasma progesterone levels being significantly lowest on the day of estrus (less than 0.5 ng/ml as compared to pre-treatment days in all groups. The mean total protein and triglycerides levels were differed significantly between the groups on the day of estrus and being significantly higher in Group-II as compared to Group-I and III on that day. A significantly higher level of cholesterol in both treatment groups as compared to the control group during different intervals and also being higher on the day of estrus as compared to pre-treatment days. The mean plasma glucose levels were differed nonsignificantly between and within the treatment and control groups. It is concluded that estrus can be successfully induced in delayed pubertal heifers with the use of GnRH alone and in combination with phosphorus.

  17. Fast breeder reactors

    International Nuclear Information System (INIS)

    Waltar, A.E.; Reynolds, A.B.

    1981-01-01

    This book describes the major design features of fast breeder reactors and the methods used for their design and analysis. The foremost objective of this book is to fulfill the need for a textbook on Fast Breeder Reactor (FBR) technology at the graduate level or the advanced undergraduate level. It is assumed that the reader has an introductory understanding of reactor theory, heat transfer, and fluid mechanics. The book is expected to be used most widely for a one-semester general course on fast breeder reactors, with the extent of material covered to vary according to the interest of the instructor. The book could also be used effectively for a two-quarter or a two-semester course. In addition, the book could serve as a text for a course on fast reactor safety since many topics other than those appearing in the safety chapters relate to FBR safety. Methodology in fast reactor design and analysis, together with physical descriptions of systems, is emphasized in this text more than numerical results. Analytical and design results continue to change with the ongoing evolution of FBR design whereas many design methods have remained fundamentally unchanged for a considerable time

  18. Effect of Aegle marmelos and Murraya koenigii in treatment of delayed pubertal buffaloes heifers

    Directory of Open Access Journals (Sweden)

    Mohan M. Baitule

    2016-12-01

    Full Text Available Aim: This study aims to study the estrus induction, ovulation, and conception rate of delayed puberty in buffaloes heifers by feeding a herbal plants Aegle marmelos (bael/bili/bhel leaf and Murraya koenigii (Curry leaf. Materials and Methods: Totally, 24 buffalo heifers with delayed puberty were selected for the present study and divided randomly in four equal groups (n=6. Before experiment, all animals were dewormed with albendazole at 10 mg/kg body weight to prevent them from the stress of parasitism. In the present experiment, four group taken and Group I (n=6 treated with A. marmelos, Group II (n=6 treated with M. koenigii, Group III (n=6 treated with mixture of A. marmelos and M. koenigii and fed for 9 days. Group IV (n=6 considered as control and fed with concentrate only. The blood samples were collected from all the animals on day 0 (before treatment, 4, 9 (during treatment, on the day of estrus and day 8 after the onset of estrus. The 10 ml blood was collected from the jugular vein of all the experimental animals for estimation of serum calcium, inorganic phosphorus, and progesterone (P4. The estrus response, ovulation, conception rate along with serum calcium, inorganic phosphorus, and progesterone level were determined by the standard protocol. Results: From Group III 4 heifers, from Group II 3 heifers, and from Group I and IV (Control 2 heifers each, exhibited the estrus. The estrus response was recorded as 33.33%, 50.00%, 75.00%, and 33.33% in Group I, Group II, Group III, and Group IV, respectively. In treatment Group III, serum calcium found significantly more (p<0.05 on day 8 post-estrus as compared to other groups at a similar interval. Inorganic phosphorus and progesterone show no significant difference between groups. The ovulation and conception rates are comparatively better in Group III (75% buffalo heifers than other groups. Conclusion: Herbal supplementation of A. marmelos and M. koenigii in combination, as well as M

  19. On the economics of fusion breeders

    International Nuclear Information System (INIS)

    Greenspan, E.

    1984-01-01

    The potential for improving the economics of tandem mirror fusion breeders by assisting them with tritium produced in the control of the client light water reactors and/or by operating them with polarized plasma is assessed. Also assessed is the promise of a Starfire tokamak and a compact reversed field pinch fusion driver for fusion breeder applications. All three approaches are found to promise a significant reduction in the cost of fusion breeder produced fissile fuel, potentially making the FB-LWR system economically competitive with conventional nuclear energy systems. (orig.) [de

  20. Analysis of Non-Genetic Factors Influencing Reproductive Traits of Japanese Black Heifer

    Science.gov (United States)

    Setiaji, A.; Oikawa, T.

    2018-02-01

    This study aimed was to identify non-genetic factors strongly associated with reproductive traits on Japanese Black heifer. Artificial insemination and calving records were analyzed to investigate non-genetic effect on reproductive performances. A total of 2220 records of heifer raised between 2005 and 2016 were utilized in this study. Studied traits were first service non return rate to 56 days (NRR), first service pregnancy rate (FPR), days from first to successful insemination (FSI), number of services per conception (NSC), age at first calving (AFC), and gestation length (GL). Test of significance for effects in the statistical model was performed using GLM procedure of SAS 9.3. The yearling trend was plotted on the adjusted mean of parameters, by the least square mean procedure. Means of NRR, FPR, FSI, NSC, AFC and GL were 72%, 53%, 52.71 days, 1.76, 760.71 days and 288.26 days, respectively. The effect of farm was significant (Page of heifer at first insemination was significant (P<0.001) for AFC. Month of insemination and sex of calf were significant (P<0.001) for GL. Compared with average value of reproductive traits, NSC and GL were generally within standard values for Japanese Black cattle, while AFC was slightly earlier. The result indicated that different management of farms strongly influenced reproductive traits of Japanese Black heifer.

  1. Influence of puberty and antral follicle count on calving day in crossbred beef heifers.

    Science.gov (United States)

    McNeel, Anthony K; Cushman, Robert A

    2015-10-15

    Lifetime productivity and longevity are greater in beef cows that give birth early in their first calving season. The ability of heifers to conceive early in the breeding season is traditionally thought to be a function of pubertal status; however, recent evidence suggests that antral follicle count is positively associated with calving day in pubertal beef heifers. Additionally, there is evidence to suggest that the total number of ovarian follicles may alter response to hormonal synchronization protocols. The objectives of this study were to confirm the beneficial influence of antral follicle count on calving day in beef heifers and to determine whether response to PGF2α is associated with differences in antral follicle counts. A 2 × 2 factorial experiment was designed to investigate the interaction between calving period (early vs. late) and PGF2α (control vs. PGF) on calving day and antral follicle count in yearling beef heifers (n = 95). As intended, calving day was less in the early calving period compared to the late calving period (P 0.05). There was a significant interaction between calving period and PGF2α on age at first calving (P reproductive tract scoring for commercial production because of its association with calving day. As a prebreeding ovarian phenotype, antral follicle counts may hold additional applicability for organic beef producers looking to reduce the length of their calving season without increasing the total number of replacement heifers retained. Published by Elsevier Inc.

  2. Fast breeder project (PSB)

    International Nuclear Information System (INIS)

    1976-07-01

    Activities performed during the 1st quarter of 1976 at or on behalf of the Gesellschaft fuer Kernforschung mbH, Karlsruhe, within the framework of the Fast Breeder Project are given a survey. The following project subdivisions are dealt with: Fuel rod development; materials testing and developments; corrosion studies and coolant analyses; physical experiments; reactor theory; safety of fast breeders; instrumentation and signal processing for core monitoring; effects on the environment; sodium technology tests; thermodynamic and fluid flow tests in gas. (HR) [de

  3. Conception rates to fixed-time artificial insemination of two oestrus synchronisation programmes in dairy heifers.

    Science.gov (United States)

    Sahu, S K; Parkinson, T J; Laven, R A

    2015-05-01

    To evaluate the conception rate to fixed-time artificial insemination (FTAI) of two oestrus synchronisation programmes in dairy heifers on eight farms over 2 years. The study was conducted in 2008 and 2010 on eight farms near Palmerston North, New Zealand. Nulliparous Friesian and Friesian×Jersey heifers (13-15 months of age) were randomly allocated to one of two oestrus synchronisation programmes. Group 1 (GPG+P4; n=330), received gonadotrophin-releasing hormone (GnRH) I/M on Day 0, a progesterone (P4)-releasing intravaginal device from Days 0-7, prostaglandin F2α (PGF) I/M on Day 7 and a second dose of GnRH at the time of FTAI on Day 9. The second group (P4+PGF; n=343) received a P4-releasing intravaginal device from Days 0-7, PGF on Day 6 and FTAI on Day 9. Pregnancy was diagnosed from Days 42-52 by transrectal ultrasonography. The overall conception rate was 52.4% and 54.8% for the GPG+P4 and P4+PGF groups, respectively. The odds of conception for the two treatments were not different (OR=0.90; 95% CI=0.67-1.23), nor was there any difference between groups in different years (p=0.58). Farm affected conception rate (p=0.002), but there was no interaction with treatment (p=0.92) . This study has shown that an alternative synchronisation programme can produce similar results in terms of conception rate to the GPG+P4 treatment, currently commonly used in heifers. More research is required to establish whether other modifications to the GPG+P4 programme can produce similar results at lower costs, and to identify and quantify farm factors which affect the economic benefit of heifer synchronisation. This study indicated that synchronising heifers with P4 and PGF resulted in conception rates equivalent to those resulting from a GPG+P4 treatment, but with reduced drug costs. However, because heifers in the GPG+P4 group received the second GnRH injection at the time of AI, they needed only three yardings as opposed to the four required for the heifers treated with P4

  4. Liquid metal cooled fast breeder nuclear reactors

    International Nuclear Information System (INIS)

    Gatley, J.A.

    1979-01-01

    Breeder fuel sub-assemblies with electromagnetic brakes and fluidic valves for liquid metal cooled fast breeder reactors are described. The electromagnetic brakes are of relatively small proportions and the valves are of the controlled vortex type. The outlet coolant temperature of at least some of the breeder sub-assemblies are maintained by these means substantially constant throughout the life of the fuel assembly without severely pressurising the sub-assembly. (UK)

  5. Effect of feeding rumen-protected rice bran on mineral status of non-lactating dairy heifers

    NARCIS (Netherlands)

    Martin-Tereso Lopez, J.; Distefano, C.; Laar, van H.; Mulder, K.; Hartog, den L.A.; Verstegen, M.W.A.

    2011-01-01

    Adapting Ca homeostasis of dairy cows before calving can prevent milk fever. Rice bran, treated with formaldehyde to prevent ruminal degradation of phytic acid, was fed to heifers to study its effect on Ca homeostasis. For 3 weeks 18 heifers were supplemented 3 kg of two feeds: placebo (PF) and rice

  6. Candidate gene expression in Bos indicus ovarian tissues: pre-pubertal and post-pubertal heifers in diestrus

    Directory of Open Access Journals (Sweden)

    Mayara Morena Del Cambre Amaral Weller

    2016-10-01

    Full Text Available Growth factors such as bone morphogenetic proteins 6, 7, 15 and two isoforms of transforming growth factor-beta (BMP6, BMP7, BMP15, TGFB1 and TGFB2 and insulin-like growth factor system act as local regulators of ovarian follicular development. To elucidate if these factors as well as others candidate genes such as estrogen receptor 1 (ESR1, growth differentiation factor 9 (GDF9, follicle stimulating hormone receptor (FSHR, luteinizing hormone receptor (LHR, bone morphogenetic protein receptor, type 2 (BMPR2, type 1 insulin-like growth factor receptor (IGFR1, and key steroidogenic enzymes cytochrome P450 aromatase and 3-β-hydroxysteroid dehydrogenase (CYP19A1 and HSD3B1 could modulate or influence diestrus on the onset of puberty in Brahman heifers, their ovarian mRNA expression was measured before and after puberty (luteal phase. Six post-pubertal (POST heifers were euthanized on the luteal phase of their second cycle, confirmed by corpus luteum observation, and six pre-pubertal (PRE heifers were euthanized in the same day. Quantitative real-time PCR analysis showed that the expression of FSHR, BMP7, CYP19A1, IGF1 and IGFR1 mRNA was greater in PRE heifers, when contrasted to POST heifers. The expression of LHR and HSD3B1 was lower in PRE heifers. Differential expression of ovarian genes could be associated with changes in follicular dynamics and different cell populations that have emerged as consequence of puberty and the luteal phase. The emerging hypothesis is that BMP7 and IGF1 are co-expressed and may modulate the expression of FSHR, LHR and IGFR1 and CYP19A1. BMP7 could influence the down-regulation of LHR and up-regulation of FSHR and CYP19A1, which mediates the follicular dynamics in heifer ovaries. Up-regulation of IGF1 expression pre-puberty, compared to post-puberty diestrus, correlates with increased levels FSHR and CYP19A1. Thus, BMP7 and IGF1 may play synergic roles and were predicted to interact, from the expression data (P = 0

  7. Clinch River breeder project gets boost

    International Nuclear Information System (INIS)

    Hill, W.H.

    1982-01-01

    Progress on the Clinch River Breeder Reactor Plant project, the United States' next step in developing liquid metal fast breeder technology is examined including consideration of Plant design, component fabrication and testing, construction schedule, funding, fuel cycle development and licensing. (U.K.)

  8. Expression of androgen-producing enzyme genes and testosterone concentration in Angus and Nellore heifers with high and low ovarian follicle count.

    Science.gov (United States)

    Loureiro, Bárbara; Ereno, Ronaldo L; Favoreto, Mauricio G; Barros, Ciro M

    2016-07-15

    Follicle population is important when animals are used in assisted reproductive programs. Bos indicus animals have more follicles per follicular wave than Bos taurus animals. On the other hand, B taurus animals present better fertility when compared with B indicus animals. Androgens are positively related with the number of antral follicles; moreover, they increase growth factor expression in granulose cells and oocytes. Experimentation was designed to compare testosterone concentration in plasma, and follicular fluid and androgen enzymes mRNA expression (CYP11A1, CYP17A1, 3BHSD, and 17BHSD) in follicles from Angus and Nellore heifers. Heifers were assigned into two groups according to the number of follicles: low and high follicle count groups. Increased testosterone concentration was measured in both plasma and follicular fluid of Angus heifers. However, there was no difference within groups. Expression of CYP11A1 gene was higher in follicles from Angus heifers; however, there was no difference within groups. Expression of CYP17A1, 3BHSD, and 17BHSD genes was higher in follicles from Nellore heifers, and expression of CYP17A1 and 3BHSD genes was also higher in HFC groups from both breeds. It was found that Nellore heifers have more antral follicles than Angus heifers. Testosterone concentration was higher in Angus heifers; this increase could be associated with the increased mRNA expression of CYP11A1. Increased expression of androgen-producing enzyme genes (CYP17A1, 3BHSD, and 17BHSD) was detected in Nellore heifers. It can be suggested that testosterone is acting through different mechanisms to increase follicle development in Nellore and improve fertility in Angus heifers. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Prepartum teat apex colonization with Staphylococcus chromogenes in dairy heifers is associated with low somatic cell count in early lactation.

    Science.gov (United States)

    De Vliegher, S; Laevens, H; Devriese, L A; Opsomer, G; Leroy, J L M; Barkema, H W; de Kruif, A

    2003-04-02

    A high number of dairy heifers freshen with udder health problems. The prevalence of teat apex colonization (TAC) with Staphylococcus chromogenes, one of the most widespread coagulase-negative staphylococci (CNS) in milk samples from freshly calved dairy heifers, was measured cross-sectionally in non-lactating heifers on eight commercial dairy farms in Belgium. The influence of age on this prevalence, and the association between teat apex colonization with S. chromogenes prepartum and quarter milk somatic cell count (SCC) in early lactation were studied. In total, 492 teat apices were sampled from 123 heifers. The age of the heifers varied from 8 to 34 months. Overall, 20% of the heifers had at least one teat apex colonized with S. chromogenes. Of all teats sampled, 10% were colonized with S. chromogenes. The chance of having at least one teat apex colonized with S. chromogenes increased with age of the heifer. The presence of prepartum teat apex colonization with S. chromogenes was not associated with intramammary infection (IMI) early postpartum with the same bacterium. On the contrary, teat apex colonization with S. chromogenes prepartum appeared to protect quarters in the first few days of lactation from having somatic cell count >or=200000cells/ml milk, commonly accepted as the threshold for intramammary infection.

  10. Competitive breeder power plants

    International Nuclear Information System (INIS)

    Winkleblack, R.K.

    1984-01-01

    To utilize the fissile material that is accumulating in the utilities' spent fuel pools, breeder plants must be less expensive than current LWR costs (or utilities will not buy nuclear plants in the near future) and also be highly reliable. The fundamental differences between LWRs and LMFBRs are discussed and recommendations are made for making the most of these differences to design a superior breeder plant that can sell in the future, opening the way to U.S. utilities becoming self-sufficient for fuel supply for centuries

  11. Astrid (fast breeder nuclear reactor)

    International Nuclear Information System (INIS)

    2014-01-01

    This document presents ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration), a French project of sodium-cooled fast breeder reactor, fourth generation reactor which should be fuelled by uranium 238 rather than uranium 235, and should therefore need less extracted natural uranium to produce electricity. The operation principle of fast breeder reactors is described. They notably directly consume plutonium, allow an easier radioactive waste management as they transform long life radioactive elements into shorter life elements by transmutation. The regeneration process is briefly described, and the various operation modes are evoked (iso-generator, sub-generator, and breeder). Some peculiarities of sodium-cooled reactors are outlined. The Astrid operation principle is described, its main design innovations outlined. Various challenges are discussed regarding safety of supply and waste processing, and the safety of future reactors. Major actors are indicated: CEA, Areva, EDF, SEIV Alcen, Toshiba, Rolls Royce, and Comex. Some key data are indicated: expected lifetime, expected availability rate, cost. The projected site is Marcoule and fast breeder reactors operated or under construction in the world are indicated. The document also proposes an overview of the background and evolution of reactors of 4. generation

  12. On fusion and fission breeder reactors

    International Nuclear Information System (INIS)

    Brandt, B.; Schuurman, W.; Klippel, H.Th.

    1981-02-01

    Fast breeder reactors and fusion reactors are suitable candidates for centralized, long-term energy production, their fuel reserves being practically unlimited. The technology of a durable and economical fusion reactor is still to be developed. Such a development parallel with the fast breeder is valuable by reasons of safety, proliferation, new fuel reserves, and by the very broad potential of the development of the fusion reactor. In order to facilitate a discussion of these aspects, the fusion reactor and the fast breeder reactor were compared in the IIASA-report. Aspects of both reactor systems are compared

  13. Trainability of eliminative behaviour in dairy heifers using a secondary reinforcer

    DEFF Research Database (Denmark)

    Whistance, Lindsay Kay; Sinclair, Liam A.; Arney, David Richard

    2009-01-01

    Soiled bedding influences cleanliness and disease levels in dairy cows and there is no evidence of an inherent latrine behaviour in cattle. If cows were trained to use a concrete area of the housing system as a latrine, a cleaner bed could be maintained. Thirteen group-housed, 14-16-month......-old Holstein-Friesian heifers, were clicker trained with heifer-rearing concentrate pellets as a reward. Training was carried out in four phases. (Phase 1) Association of feed reward with clicker, criterion: 34/40 correct responses. (Phase 2) Simple task (nose-butting a disc) to reinforce phase 1 association...

  14. Thermal conductivity of fusion solid breeder materials

    International Nuclear Information System (INIS)

    Liu, Y.Y.; Tam, S.W.

    1986-06-01

    Several simple and useful formulae for estimating the thermal conductivity of lithium-containing ceramic tritium breeder materials for fusion reactor blankets are given. These formulae account for the effects of irradiation, as well as solid breeder configuration, i.e., monolith or a packed bed. In the latter case, a coated-sphere concept is found more attractive in incorporating beryllia (a neutron multiplier) into the blanket than a random mixture of solid breeder and beryllia spheres

  15. Development and reproductive performance of Hereford heifers of different frame sizes up to mating at 14-15 months of age

    Directory of Open Access Journals (Sweden)

    Maurício Dallmann da Silva

    2018-02-01

    Full Text Available ABSTRACT Body development and reproductive performance of a hundred forty-two 14 to 15-month-old heifers, classified at weaning according to frame size as small, medium, and large, were evaluated. The parameters evaluated were: body weight, hip height, body condition score, weight gain, ovarian activity, and pregnancy rate. At weaning, body weight and hip height were significantly different among frame scores, (small – 133.0 kg, 92.2 cm; medium – 158.5 kg, 96.6 cm; and large – 185.2 kg; 100.2 cm. After weaning, heifers grazed together on natural pastures during the autumn and on ryegrass (Lolium multiflorum La. during the winter and spring. Frame score differences remained until the beginning of the breeding season (BS, starting on average at 14 months of age. Weight gain between weaning and the beginning of BS was not different among frame scores (0.740 kg/day, on average. Body weights at the beginning of the BS were significantly different, of 255.7 kg (53.3% of the mature weight for small heifers, 285.0 kg (59.4% for medium heifers, and 307.6 kg (64.1% for large heifers. Ovarian activity at the beginning of the BS was not different among the three groups. The average weight gain values during the BS of 0.492, 0.472, and 0.421 kg/day for small, medium, and large heifers, respectively, were significantly different. Pregnancy rates were not different among groups (small, 71.4%; medium, 76.4%; and large, 76.5%. Frame score did not influence the reproductive performance of heifers, but the small and medium heifers conceived 29 and 20 days earlier, respectively, than the large heifers.

  16. Pathogen-group specific association between CXCR1 polymorphisms and subclinical mastitis in dairy heifers.

    Science.gov (United States)

    Verbeke, Joren; Piepers, Sofie; Peelman, Luc; Van Poucke, Mario; De Vliegher, Sarne

    2012-08-01

    The chemokine (C-X-C motif) receptor 1 (CXCR1) gene encodes the homonymous receptor for interleukin 8 (IL8) on polymorphonuclear neutrophilic leucocytes (PMNL). Binding causes migration from blood to milk, activation and prolonged survival of PMNL, a crucial process in the innate immune defence of the bovine mammary gland against invading mastitis-causing pathogens. The main objective of this study was to screen the entire coding region of the CXCR1 gene for polymorphisms and to analyse their association with udder health of dairy heifers. One-hundred-and-forty Belgian Holstein heifers originating from 20 commercial dairy farms were genotyped by DNA sequencing. Detailed phenotypic data on udder health was available including quarter bacteriological culture results and somatic cell count (SCC) in early lactation and composite milk SCC during first lactation. In total, 16 polymorphisms (including 8 missense mutations) were detected. Polymorphism c.980A>G was associated with pathogen-group specific IMI: heifers with genotype AG were less likely to have an IMI due to major mastitis pathogens compared with heifers with genotype GG but did not have less IMI by coagulase-negative staphylococci, so-called minor pathogens. CXCR1 genotype was neither associated with quarter SCC in early lactation nor with composite SCC during lactation. Although mastitis susceptibility is influenced by many factors, some genetic polymorphisms potentially have major effects on udder health of heifers, as was shown here. These results trigger us to further study the relationship between CXCR1 polymorphisms and mastitis susceptibility in both observational and experimental trials.

  17. A review of fusion breeder blanket technology, part 1

    International Nuclear Information System (INIS)

    Jackson, D.P.; Selander, W.N.; Townes, B.M.

    1985-01-01

    This report presents the results of a study of fusion breeder blanket technology. It reviews the role of the breeder blanket, the current understanding of the scientific and engineering bases of liquid metal and solid breeder blankets and the programs now underway internationally to resolve the uncertainities in current knowledge. In view of existing national expertise and experience, a solid breeder R and D program for Canada is recommended

  18. Radionuclides in milk of dairy heifers raised on forages harvested from phosphatic clay soils on reclaimed mined land

    International Nuclear Information System (INIS)

    Staples, C.R.; Umana, R.; Hayen, M.J.

    1994-01-01

    Alfalfa (AR; Medicago sativa L.) and corn (CSR; Zea mays L.) were grown in phosphatic clay soils on phosphate-mined reclaimed land in central Florida. Corn (CSC) also was grown on unmined land and served as a control forage. Upon harvesting, plants were chopped and ensiled. Concentrations of 226 Ra averaged 2.44, 0.26 and 0.15; 210 Pb averaged 1.04, 0.63, and 0.52; and 210 Po averaged 1.59, 0.59, and 1.26 Bq kg -1 DM for AR, CSR, and CSC, respectively. These forages were fed separately to Holstein dairy replacement heifers (Bos taurus) (n=15 per forage) from approximately 9 to 25 mo of age. Heifers gave birth to calves at approximately 24 mo of age. Samples of milk were collected on d 1, 15, and 30 of lactation and analyzed for radionuclides. Averaged across sampling days, heifers fed AR had greater milk concentrations of 226 Ra compared with those fed CSR (0.27 vs. 0.22 Bq kg -1 DM; P -1 DM; P 210 Po compared with heifers fed CSR (0.58 vs. 0.30 Bq kg -1 DM; P -1 DM). Lead-210 was greater in milk from heifers fed CSR compared with those fed AR or CSC (1.38 vs. 0.94 and 0.92 Bq kg -1 DM; P < 0.13), respectively. Plasma S and Cu concentrations suggested subclinical molybdenosis in heifers fed AR. However, all heifers grew at an acceptable rate, conceived normally, had normal gestation periods, gave high quality colostrum at calving, and produced similar amounts of milk. 17 refs., 9 tabs

  19. Evaluation of two progestogen-based estrous synchronization protocols in yearling heifers of Bos indicus × Bos taurus breeding.

    Science.gov (United States)

    McKinniss, E N; Esterman, R D; Woodall, S A; Austin, B R; Hersom, M J; Thatcher, W W; Yelich, J V

    2011-06-01

    Yearling Bos indicus × Bos taurus heifers (n = 410) from three locations, were synchronized with either the Select Synch/CIDR+timed-AI (SSC+TAI) or 7-11+timed-AI (7-11+TAI) treatments. On Day 0 of the experiment, within each location, heifers were equally distributed to treatments by reproductive tract score (RTS; Scale 1-5: 1 = immature, 5 = estrous cycling) and body condition score. The 7-11+TAI treatment consisted of melengestrol acetate (0.5 mg/head/d) from Days 0 to 7, with PGF(2α) (25 mg im) on Day 7, GnRH (100 μg im) on Day 11, and PGF(2α) (25 mg im) on Day 18. The SSC+TAI heifers received the same carrier supplement (without MGA) from Days 0 to 7, and on Day 11 they were given 100 μg GnRH and an intravaginal CIDR (containing 1.38 g progesterone). The CIDR were removed on Day 18, concurrent with 25 mg PGF(2α) im For both treatments, estrus was visually detected for 1 h twice daily (0700 and 1600 h) for 72 h after PGF(2α), with AI done 6 to 12 h after a detected estrus. Non-responders were timed-AI and received GnRH (100 μg im) 72 to 76 h post PGF(2α). The 7-11+TAI heifers had a greater (P conception rate (47.0 vs 31.3%), and synchronized pregnancy rate (33.5 vs 24.8%) compared to SSC+TAI heifers, respectively. Heifers exhibiting estrus at 60 h (61.7%) had a greater (P conception rate compared to heifers that exhibited estrus at ≤ 36 (35.3%), 48 (31.6%), and 72 h (36.2%), which were similar (P > 0.05) to each other. As RTS increased from ≤ 2 to ≥ 3, estrous response, conception rate, synchronized pregnancy rate, and 30 d pregnancy rate all increased (P rates compared to SSC+TAI treatment in yearling Bos indicus × Bos taurus heifers. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Effects of co-grazing dairy heifers with goats on animal performance, dry matter yield, and pasture forage composition.

    Science.gov (United States)

    Dennis, T S; Unruh-Snyder, L J; Neary, M K; Nennich, T D

    2012-12-01

    Mixed livestock grazing can offer an alternative management system for rearing dairy replacement heifers (Bos taurus). A 2-yr study was conducted during 2009 (yr 1) and 2010 (yr 2) to determine the effects of co-grazing Holstein heifers under rotational stocking with Boer × Kiko goats on animal performance, pasture DM yield, and botanical composition. Each year, 24 heifers (134 ± 6 d of age and 147.4 ± 31.2 kg BW in yr 1; 166 ± 11 d of age and 168.0 ± 27.6 kg BW in yr 2) and 6 goats (2 yr old and 39.7 ± 16.2 kg BW in yr 1; 1 yr old and 33.7 ± 7.4 kg BW in yr 2) were divided into 6 paddocks with 4 heifers and 2 goats, where applicable, per group. Low endophyte-infected tall fescue (Festuca arundinacea Schreb.) and white clover (Trifolium repens L.) pastures were used to evaluate 2 grazing strategies (heifers grazed alone [HO] or heifers co-grazed with goats [HG]). In addition, 6 goats were assigned to 2 paddocks and grazed alone (GO) each year to estimate goat pasture forage intake and compare Haemonchus contortus infection to co-grazed goats. Forage samples were taken monthly to assess DM yield and botanical composition. Samples collected for botanical composition were manually sorted into grass, legume, and weed species. Forage DMI was estimated using a rising plate meter before and after grazing. Heifer BW at the conclusion of yr 1 and yr 2 did not differ between HO and HG (P = 0.40 and P = 0.12, respectively). Likewise, overall ADG did not differ between HO and HG, averaging 0.65 kg/d and 0.63 kg/d over both grazing seasons (P = 0.70). Grazing strategy did not affect forage or total DMI in yr 1; however, HO consumed 2.3 kg/d more forage DM than HG (P pastures (P dairy heifers can be co-grazed with goats without negative effects on ADG or feed efficiency.

  1. Prospects of ceramic tritium breeder materials

    International Nuclear Information System (INIS)

    Roth, E.; Roux, N.; Conservatoire National des Arts et Metiers; CEA Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette

    1989-01-01

    In this paper the authors examine the prospects of the main ceramics proposed as breeder materials for fusion reactors, i.e. Li-2O, Li-2ZrO-3, LiAlO-2, Li-4SiO-4. To do so they review terms of reference of contemplated blankets for NET, ITER and DEMO, and the proposed blanket concepts and materials. Issues respective to the use of each breeder material are examined, and from this review it is concluded that ceramics are the most favorable breeder materials whose use can be contemplated as well for a driver blanket for NET or ITER and for a DEMO blanket. Ceramics are then compared between themselves and it is seen that, subject to the confirmation of recent experimental results, lithium zirconate could be used with advantage in any of the present blanket concepts, except in those employing lithium at its natural isotopic abundance, in which case only Li-2O can be used. However in specific cases, or in parts of a blanket, other ceramics may be profitably employed. As a general conclusion suggestions are made to further improve ceramic breeder performances, and it is recommended to intensify also work on problems that have to be solved in order to operate ceramic breeder blankets e.g. tritium extraction and recovery systems and conditions of beryllium use. (author). 37 refs.; 12 tabs

  2. The accelerator breeder

    International Nuclear Information System (INIS)

    Johansson, E.

    1986-01-01

    Interactions of high-energy particles with atomic nuclei, in particular heavy ones, leads to a strong emission of neutrons. Preferably these high-energy particles are protons or deuterons obtained from a linear accelerator. The neutrons emitted are utilized in the conversion of U238 to Pu239 or of Th232 to U233. The above is the basis of the accelerator breeder, a concept studied abroad in many variants. No such breeder has, however, so far been built, but there exists vast practical experience on the neutron production and on the linear accelerator. Some of the variants mentioned are described in the report, after a presentation of general characteristics for the particle-nucleus interaction and for the linear accelerator. (author)

  3. Effect of space allowance and floor type on performance, welfare and physiological measurements of finishing beef heifers.

    Science.gov (United States)

    Keane, M P; McGee, M; O'Riordan, E G; Kelly, A K; Earley, B

    2017-12-01

    Accommodating cattle indoors during the winter is widely practiced throughout Europe. There is currently no legislation surrounding the space allowance and floor type that should be provided to cattle during this time, however, concerns have been raised regarding the type of housing systems currently in use. The objective of the study was to investigate the effect of space allowance and floor type on performance and welfare of finishing beef heifers. Continental crossbred heifers (n=240: mean initial live; weight, 504 (SD 35.8) kg) were blocked by breed, weight and age and randomly assigned to one of four treatments; (i) 3.0 m2, (ii) 4.5 m2 and (iii) 6.0 m2 space allowance per animal on a fully slatted concrete floor and (iv) 6.0 m2 space allowance per animal on a straw-bedded floor, for 105 days. Heifers were offered a total mixed ration ad libitum. Dry matter intake was recorded on a pen basis and refusals were weighed back twice weekly. Heifers were weighed, dirt scored and blood sampled every 3 weeks. Whole blood was analysed for complete cell counts and serum samples were assayed for metabolite concentrations. Behaviour was recorded continuously using IR cameras from days 70 to 87. Heifers' hooves were inspected for lesions at the start of the study and again after slaughter. Post-slaughter, carcass weight, conformation and fat scores and hide weight were recorded. Heifers housed at 4.5 m2 had a greater average daily live weight gain (ADG) than those on both of the other concrete slat treatments; however, space allowance had no effect on carcass weight. Heifers accommodated on straw had a greater ADG (0.15 kg) (PSpace allowance and floor type had no effect on the number of hoof lesions gained or on any of the haematological or metabolic variables measured. It was concluded that increasing space allowance above 3.0 m2/animal on concrete slats was of no benefit to animal performance but it did improve animal cleanliness. Housing heifers on straw instead of

  4. Effect of reproductive tract scoring on reproductive efficiency in beef heifers bred by timed insemination and natural service versus only natural service.

    Science.gov (United States)

    Gutierrez, K; Kasimanickam, R; Tibary, A; Gay, J M; Kastelic, J P; Hall, J B; Whittier, W D

    2014-04-15

    The objective was to determine the effects of reproductive tract score (RTS) on reproductive performance in beef heifers bred by timed artificial insemination followed by natural service (AI-NS) or by natural service only (NSO). Angus cross beef heifers (n = 2660) in the AI-NS group were artificially inseminated at a fixed time (5- or 7-day CO-Synch + controlled internal drug release protocol) once, then exposed to bulls 2 weeks later (bull-to-heifer ratio = 1:40-1:50) for the reminder of the 85-day breeding season. Angus cross beef heifers (n = 1381) in NSO group were submitted to bulls (bull-to-heifer ratio = 1:20-1:25) for the entire 85-day breeding season. Heifers were reproductive tract scored from 1 (prepubertal) to 5 (cyclic) 4 weeks before, and were body condition scored (BCS) from 1 (emaciated) to 9 (obese) at the beginning of breeding season. Pregnancy diagnosis was performed 70 days after AI for AI-NS group and 2 months after the end of breeding season for both groups. Heifers in both groups were well managed and of similar age (14.9 ± 0.4 [AI-NS] and 14.7 ± 0.8 [NSO] months). Pregnancy rates (PRs) and number of days to become pregnant were calculated using PROC GLIMMIX and PROC LIFETEST procedures of SAS. Adjusting for BCS (P = 0.07), expressed estrus (P < 0.05), year (P < 0.05), and BCS by year interaction (P < 0.05), the AI-PR was greater for heifers in AI-NS group with higher RTS (P < 0.0001; 40.7%, 48.3%, 57.6%, and 64.6% for RTS of 2 or less, 3, 4, and 5, respectively). Controlling for BCS (P < 0.05), year (P < 0.05) and the breeding season pregnancy rates (BS-PRs) were greater for heifers in the AI-NS group with higher RTS (P < 0.01; 81.2%, 86.5%, 90.4%, and 95.2% for RTS of 2 or less, 3, 4, and 5, respectively). Similarly, adjusting for BCS, year (P < 0.05), the BS-PR was greater for heifers in NSO group with higher RTS (P < 0.01; 79.7%, 84.3%, 88.4%, and 90.2% for RTS of 2 or less, 3, 4, and 5, respectively). Heifers with higher RTS

  5. Growth performance and sorting characteristics of corn silage-alfalfa haylage diets with or without forage dilution offered to replacement Holstein dairy heifers.

    Science.gov (United States)

    Coblentz, W K; Esser, N M; Hoffman, P C; Akins, M S

    2015-11-01

    Gravid heifers consuming high-quality forage diets are susceptible to excessive weight gains and overconditioning. One approach for controlling this problem is to dilute diets with low-energy forages, such as straw, that reduce the caloric density and dry matter intake (DMI) of that diet by heifers. These diluting agents are often sortable by dairy heifers, but previous visual evidence has suggested that eastern gamagrass haylage may be a nonsortable alternative. Our objectives were (1) to compare the growth performance of dairy heifers offered a high-quality forage diet (control) with diets containing 1 of 3 diluting agents [eastern gamagrass haylage (EGH), chopped wheat straw (WS), or chopped corn fodder (CF)]; and (2) evaluate sorting behaviors of heifers offered these forage diets. Holstein heifers (n=128) were stratified (32 heifers/block) on the basis of initial body weight (heavy, 560 ± 27.7 kg; medium-heavy, 481 ± 17.7 kg; medium-light, 441 ± 22.0 kg; and light, 399 ± 14.4 kg), and then assigned to 1 of 16 identical research pens (4 pens/block; 8 heifers/pen), where each of the 4 research diets were assigned to 1 pen within each block. Diets were offered in a 118-d feeding trial with heifers crowded to 133% of capacity at the feed bunk. Inclusion of low-energy forages was effective in reducing both diet energy density and DMI. Concentrations of physically effective fiber (pef) particles did not change during the 24-h period following feeding for either the control or EGH diets; however, this response for pef particles masked the competing (and cancelling) responses for individual large and medium particles, which heifers sorted with discrimination and preference, respectively. Sorting against pef particles was detected for WS, and much more severely for the CF diet. Sorting of forage particles by heifers could not be related to heifer performance. Compared with control (1.16 kg/d), average daily gains (ADG) were reduced by dilution in all cases, but

  6. Study on tritium recovery from breeder materials

    International Nuclear Information System (INIS)

    Moriyama, H.; Moritani, K.

    1997-01-01

    For the development of fusion reactor blanket systems, some of the key issues on the tritium recovery performance of solid and liquid breeder materials were studied. In the case of solid breeder materials, a special attention was focussed on the effects of irradiation on the tritium recovery performance, and tritium release experiments, luminescence measurements of irradiation defects and modeling studies were systematically performed. For liquid breeder materials, tritium recovery experiments from molten salt and liquid lithium were performed, and the technical feasibility of tritium recovery methods was discussed. (author)

  7. Canadian accelerator breeder system development

    International Nuclear Information System (INIS)

    Schriber, S.O.

    1982-11-01

    A shortage of fissile material at a reasonable price is expected to occur in the early part of the twenty-first century. Converting fertile material to fissile material by electronuclar methods is an option that can extend th world's resources of fissionable material, supplying fuel for nuclear power stations. This paper presents the rationale for electronuclear breeders and describes the Canadian development program for an accelerator breeder facility that could produce 1 Mg of fissile material per year

  8. Effect of type of forage offered and breed on performance of crossbred suckler heifers and their calves

    Directory of Open Access Journals (Sweden)

    M. MANNINEN

    2008-12-01

    Full Text Available Thirty Hereford-Ayrshire (HfAy and 29 Limousine-Ayrshire (LiAy spring-calving heifers in calf to a Aberdeen Angus (Ab bull were used to study the effects of cow breed and winter diet on performance. The diets were either primarily based on hay (H, of dry matter (DM intake, silage or silage (S, of DM intake, hay . In addition, animals were offered 1.0 kg milled barley per head daily for two months prior to calving and 1.5 kg/day from calving until grazing commenced. Animals also had free access to barley straw. During the indoor feeding period from 15 December to 1 June HfAy-heifers consumed slightly but not significantly more feed DM, metabolizable energy and AAT (amino acids absorbed from the small intestine than LiAy-heifers on both diets. At the start of the experiment LiAy- and HfAy-heifers were 572 and 596 (P

  9. Hair coat characteristics in Friesian heifers in the Netherlands and Kenya : experimental data and a review of literature

    NARCIS (Netherlands)

    Udo, H.M.J.

    1978-01-01

    The export of about 2600 Friesian heifers to Kenya between 1971-1973 provided an opportunity of studying the adaptation problems experienced by these heifers. Within the framework of the NUFFIC (Netherlands Universities Foundation for International Cooperation) a research project entitled

  10. A note on the early calving of beef heifers

    African Journals Online (AJOL)

    and weaning mass (156,3 versus 174,4) of the progeny produced by the two groups ... production in the early calving group due to reduced udder development. ..... adipose tissue is different to that of a lean heifer and that this storage adipose ...

  11. Effect of age and carcass weight on quality traits of m. rectus abdominis from Charolais heifers.

    Science.gov (United States)

    Ellies-Oury, M P; Dumont, R; Perrier, G; Roux, M; Micol, D; Picard, B

    2017-04-01

    In practice cattle may be slaughtered at different combinations of age and weight. As each of these factors could affect meat quality traits, the present work aimed to identify which combination can be expected to increase overall meat quality of m. rectus abdominis of Charolais heifers. Totally, 40 heifers were slaughtered either at 26±1 or at 36±1 months of age. Young heifers were sampled at two different carcass weights (349±12 and 394±8 kg). Old heifers were also sampled at two different carcass weights (397±6 and 451±9 kg). The m. rectus abdominis was excised 24 h postmortem to determine metabolic enzyme activities, myosin heavy-chain isoform proportions, lipid contents, collagen content and collagen solubility. Shear force measurements were evaluated on raw and broiled meat after 14 days of ageing. Meat quality traits scored between 0 and 10 by sensory analysis. Increasing slaughter age from 26 to 36 months had no impact on either raw/broiled shear force (0.31⩽P⩽0.47) and/or meat quality traits (0.62⩽P⩽0.91) or on physicochemical properties of heifer's meat samples. Increasing carcass weight for a similar slaughter age of 26 months had also impact neither on meat quality traits (0.52⩽P⩽0.91) nor on muscular properties. On the contrary, increasing carcass weight for a similar slaughter age of 36 months had induced a decrease of muscular shear force (raw muscle; P=0.009) and a concomitant decrease of total collagen content (P=0.03). Nevertheless, no significant impact on meat quality traits was revealed by the sensorial panel (0.13⩽P⩽0.49). Metabolic enzyme activities (0.13⩽P⩽0.86) and myosin heavy-chain proportions (0.13⩽P⩽0.96) were not significantly impacted by slaughter age and carcass weight. Thus, the impact of increasing carcass weight and/or slaughter age in young Charolais heifers has a limited impact on meat quality traits and associated muscular characteristics. Modulating heifer's cycles (age and/or carcass weight in

  12. Expected net present value of pure and mixed sexed semen artificial insemination strategies in dairy heifers.

    Science.gov (United States)

    Olynk, N J; Wolf, C A

    2007-05-01

    Sexed semen has been a long-anticipated tool for dairy farmers to obtain more heifer calves, but challenges exist for integrating sexed semen into commercial dairy farm reproduction programs. The decreased conception rates (CR) experienced with sexed semen make virgin heifers better suited for insemination with sexed semen than lactating dairy cows. This research sought to identify when various sexed semen breeding strategies provided higher expected net present value (NPV) than conventional artificial insemination (AI) breeding schemes, indicating which breeding scheme is advisable under various scenarios. Budgets were developed to calculate the expected NPV of various AI breeding strategies incorporating conventional (non-sexed) and sexed semen. In the base budgets, heifer and bull calf values were held constant at $500 and $110, respectively. The percentage of heifers expected to be born after breeding with conventional and sexed semen used was 49.2 and 90%, respectively. Breeding costs per AI were held constant at $15.00 per AI for conventional semen and $45.00 per AI for sexed semen of approximately the same genetic value. Conventional semen CR of 58 and 65% were used, and an AI submission rate was set at 100%. Breeding strategies with sexed semen were assessed for breakeven heifer calf values and sexed semen costs to obtain a NPV equal to that achieved with conventional semen. Breakeven heifer calf values for pure sexed semen strategies with a constant 58 and 65% base CR in which sexed semen achieved 53% of the base CR are $732.11 and $664.26, respectively. Breakeven sexed semen costs per AI of $17.16 and $22.39, compared with $45.00 per AI, were obtained to obtain a NPV equal to that obtained with pure conventional semen for base CR of 58 and 65%, respectively. The strategy employing purely sexed semen, with base CR of both 58 and 65%, yielded a lower NPV than purely conventional semen in all but the best-case scenario in which sexed semen provides 90% of

  13. Zinc source and concentration altered physiological responses of beef heifers during a combined viral-bacterial respiratory challenge

    Science.gov (United States)

    Three treatments were evaluated in feedlot heifers to determine the effects of zinc supplementation on the immune response to a combined viral-bacterial respiratory disease challenge. Thirty-two beef heifers (255+/-15 kg) were subjected to a 30d period of Zn depletion, then randomly assigned to one ...

  14. Molecular characterization of non-aureus Staphylococcus spp. from heifer intramammary infections and body sites.

    Science.gov (United States)

    Adkins, P R F; Dufour, S; Spain, J N; Calcutt, M J; Reilly, T J; Stewart, G C; Middleton, J R

    2018-03-07

    The purpose of this study was to investigate non-aureus Staphylococcus spp. intramammary infections (IMI) in periparturient heifers and determine the relationship of precalving body site isolation with precalving IMI and postcalving IMI using molecular speciation and strain-typing methods. Primiparous heifers were enrolled at approximately 14 d before expected calving date. Precalving mammary quarter secretions and body site swabbing samples (teat skin, inguinal skin, muzzle, and perineum) were collected. Postcalving, mammary quarter milk samples were collected for culture and somatic cell counting. Precalving body site samples were cultured, and up to 10 staphylococcal colonies were saved for characterization. Staphylococcal isolates were speciated using matrix-assisted laser/desorption ionization time-of-flight mass spectrometry or sequencing of rpoB or tuf. Pulsed-field gel electrophoresis was used to strain type a subset of isolates. Overall, Staphylococcus chromogenes, Staphylococcus agnetis, and Staphylococcus simulans were the most common species identified in precalving mammary secretions, whereas S. chromogenes, Staphylococcus xylosus, and S. agnetis were the most common species found in postcalving milk samples. The most common species identified from body site samples were S. chromogenes, S. xylosus, and Staphylococcus haemolyticus. Mammary quarters that had a precalving mammary secretion that was culture positive for S. agnetis, S. chromogenes, or Staphylococcus devriesei had increased odds of having an IMI with the same species postcalving. A S. chromogenes IMI postcalving was associated with higher somatic cell count when compared with postcalving culture-negative quarters. Among heifers identified with a non-aureus Staphylococcus spp. IMI either precalving or postcalving, heifers that had S. agnetis or S. chromogenes isolated from their teat skin had increased odds of having the same species found in their precalving mammary secretions, and heifers

  15. European DEMO BOT solid breeder blanket

    International Nuclear Information System (INIS)

    Dalle Donne, M.

    1994-11-01

    The BOT (Breeder Outside Tube) Solid Breeder Blanket for a fusion DEMO reactor is presented. This is one of the four blanket concepts under development in the frame of the European fusion technology program with the aim to select in 1995 the two most promising ones for further development. In the paper the reference blanket design and external loops are described as well as the results of the theoretical and experimental work in the fields of neutronics, thermohydraulics, mechanical stresses, tritium control and extraction, development and irradiation of the ceramic breeder material, beryllium development, ferromagnetic forces caused by disruptions, safety and reliability. An outlook is given on the remaining open questions and on the required R and D program. (orig.) [de

  16. Effects of by-product feed-based silage on feeding, rumination, and excretion in growing Hanwoo heifers.

    Science.gov (United States)

    Kim, Young-Il; Lee, Sang Moo; Lee, Youn Hee; Lee, Myeon; Choi, Do Young; Kwak, Wan Sup

    2015-01-01

    This study investigated the effects of feeding by-product feed (BF)-based silage on the behavior of growing Hanwoo heifers. Twelve Hanwoo heifers (13.2 months-old, 315 kg body weight; four heifers per pen) were assigned to three diets: a rice straw (RS) diet (concentrate mix and free access to RS), a RS and BF-based silage (RSBFS) diet (concentrate mix and free access to RS and BF-based silage), and a BF-based silage (BFS) diet (concentrate mix and free access to BF-based silage). Behavior was recorded for 5 days using camcorders. Compared to the RS group, the BFS group showed 21.7% higher dry matter intake, shorter feeding, rumination, and chewing times, as well as longer resting time (p < 0.05). Although all groups exhibited similar drinking, urination, and defecation frequencies, the BFS group exhibited higher feeding rates, rumination efficiency, and chewing efficiency than the RS group (p < 0.05). Compared to the BFS group, the RSBFS group showed higher peNDF8.0 intake (15.2% vs. 25.0% dry matter intake), longer feeding and sitting times, lower defecation frequency (p < 0.05), and similar rumination efficiency. In conclusion, complete replacement of conventional RS with BF-based silage reduced rumination and chewing activity in growing Hanwoo heifers, and BF-based silage feeding with large-particle straw is an effective approach in improving heifer behavior.

  17. Vascular perfusion of reproductive organs in pony mares and heifers during sedation with detomidine or xylazine.

    Science.gov (United States)

    Araujo, Reno R; Ginther, O J

    2009-01-01

    To assess the vascular effects of detomidine and xylazine in pony mares and heifers, respectively, as determined in a major artery and by extent of vascular perfusion of reproductive organs. 10 pony mares and 10 Holstein heifers. Pony mares were assigned to receive physiologic saline (0.9% NaCl) solution (n = 5) or detomidine (3.0 mg/mare, IV; 5). Heifers were assigned to receive saline solution (5) or xylazine (14 mg/heifer, IM; 5). Color Doppler ultrasonographic examinations were performed immediately before and 10 minutes after administration of saline solution or sedative. In spectral Doppler mode, a spectral graph of blood flow velocities during a cardiac cycle was obtained at the internal iliac artery and at the ovarian pedicle. In color-flow mode, color signals of blood flow in vessels of the corpus luteum and endometrium were assessed. Systemic effects of sedation in the 2 species were evident as a decrease in heart rate; increase in duration of systole, diastole, or both; decrease in volume of blood flow; and decrease in velocity of blood flow within the internal iliac artery. However, an effect of sedatives on local vascular perfusion in the ovaries and endometrium was not detected. Sedation with detomidine in pony mares and xylazine in heifers did not affect vascular perfusion in reproductive organs. These sedatives can be used in experimental and clinical color Doppler evaluations of vascular perfusion of the corpus luteum and endometrium.

  18. The breeder reactor and Europe

    International Nuclear Information System (INIS)

    Daglish, J.

    1979-01-01

    A report is given of a conference on the breeder reactor and Europe held in Lucerne, Switzerland from 14 - 17 October 1979 sponsored by the Swiss Association for Atomic Energy and the Association of European Atomic Forums. The underlying theme of the conference was the question that if nuclear power is to play a major role in meeting world energy needs in the long term, thermal reactors must in time be complemented with more advanced reactor systems that conserve uranium resources which are huge but not unlimited. This is not questioned; disagreement begins with discussion of the desirability of the breeder, and how fast and how far the introduction of such reactors should go. Aspects considered at the conference which are especially dealt with in this review are; why breed, commercial aspects, alternatives to the LMFBR, how to build a fast reactor, the breeder programmes in Europe, Britain, the Soviet Union, Japan and the United States. (U.K.)

  19. Symbiotic molten-salt systems coupled with accelerator molten-salt breeder (AMSB) or inertial-confined fusion hybrid molten-salt breeder (IHMSB) and their comparison

    International Nuclear Information System (INIS)

    Furukawa, K.

    1984-01-01

    Two types of breeder systems are proposed. One is the combined system of Accelerator Molten-Salt Breeder (AMSB) and Molten-Salt Converter Reactor (MSCR), and the other is the combined system of Inertial-confined Fusion Hybrid Molten-Salt Breeder (IHMSB) and modified MSCR. Both apply the molten-fluorides and have technically deep relations. AMSB would be much simpler and have already high technical feasibility. This will become economical the Th breeder system having a doubling time shorter than ten years and distributing any size of power stations MSCR. (orig.) [de

  20. Effect of feeding urea-molasses blocks with incorporated fenbendazole on grazing dairy heifers naturally infected with gastrointestinal nematodes

    Directory of Open Access Journals (Sweden)

    R.M. Waruiru

    2003-06-01

    Full Text Available Between June 1999 and August 2000, the effects of feeding medicated urea-molasses supplement blocks on the growth of dairy heifers in a marginal area of central Kenya were assessed by comparing the live-weight gain of supplemented and unsupplemented heifers grazing the same pasture. Thirty-nine heifers with an average age of 9.6 months were initially treated orally with albendazole (10 mg / kg body weight and assigned to 3 groups : group I was fed urea-molasses blocks with incorporated fenbendazole (MUMB, group II was fed urea-molasses blocks (UMB and group III heifers (control received no block supplementation (NBS. Body weights of the heifers and faecal egg counts (FECs were measured monthly and larval cultures were made of positive faecal samples of each group. The mean cumulative live-weight responses of the MUMB and UMB groups were significantly greater than the NBS group (P 0.05. The FECs were moderate to low in all groups and decreased progressively with increasing age of the animals; FECs for the urea-molasses-supplemented groups remained significantly lower than those of the NBS group throughout the experimental period (P <0.05. Haemonchus and Trichostrongylus were the predominant nematode genera found in the heifers, but Cooperia, Bunostomum and Oesophagostomum were also present. These results indicate that feeding of urea-molasses blocks substantially reduced production losses attributable to nematode infection of young grazing cattle, and confirms previous observations that well-fed animals are better able to overcome the effects of helminth infections.

  1. Laminitis and dermatitis in heifers associated with excessive carbohydrate intake : skin lesions and biochemical findings : case report

    Directory of Open Access Journals (Sweden)

    I. Yeruham

    1999-07-01

    Full Text Available The effects of a sudden addition of a large quantity of readily fermentable carbohydrate to the feed ration of pregnant heifers are described. Clinical and pathological changes caused by the resulting disease were confined to the digits and skin. The 4 acutely affected heifers were reluctant to get up or move (group II. They tended to lie down or stand with feet bunched together and the back arched, often shifting weight from limb to limb. They walked stiffly with great tenderness and pain in the digits. Extreme pain was noticed when the digits were examined. In 4 of 8 heifers, separation of the sole at the heel, with leakage of exudate, and under-running of the sole were observed. Necrotic dermatitis of the legs, alopecia and hyperkeratosis of the tail were noticed in all 8 heifers. Skin lesions appeared simultaneously. Four of the heifers (group I recovered, and the other 4 (group II were sent to slaughter. No post mortem examination was performed. The biochemical findings revealed a significantly higher concentration of total serum globulins and sodium, and increased activity, in CK, LDH and AST. A significantly decreasing pattern was noted in blood urea concentration, cholesterol, triglycerides, albumin and calcium. No significant differences among the various groups were found in the activities of amylase, GGT, and concentration of creatinine, total bilirubin, inorganic phosphorus, magnesium and potassium.

  2. in meat production III. Feeder - breeder dimorphism

    African Journals Online (AJOL)

    Feeder- breeder dimorphism is advantageous when large offspring for slaughter is obtained from small breeding animals. The effect of feeder- breeder dimorphism on herd efficiency is evaluated for terminal crossbreeding and growth modification by biotechnological or dietary means. Selection criteria for breeds or lines in ...

  3. The cost-benefit of genomic testing of heifers and using sexed semen in pasture-based dairy herds.

    Science.gov (United States)

    Newton, J E; Hayes, B J; Pryce, J E

    2018-04-25

    Recent improvements in dairy cow fertility and female reproductive technologies offer an opportunity to apply greater selection pressure to females. This means there may be greater incentive to obtain genomic breeding values for females. We modeled the impact of changes to key parameters on the net benefit from genomic testing of heifer calves with and without usage of sexed semen. This paper builds on earlier cost-benefit studies but uses parameters relevant to pasture-based systems. A deterministic model was used to evaluate the effect on net benefit due to changes in (1) reproduction rate, (2) genomic test costs, (3) availability of parent-derived breeding values (EBV PA ), and (4) replacement rate. When the use of sexed semen was included, we also considered (1) the proportion of heifers and cows mated to sexed semen, (2) decreases in conception rate in inseminations with sexed semen, and (3) the marginal return for surplus heifers. Scenarios with lower replacement rates and no availability of EBV PA had the largest net benefits. Under current Australian parameters, the net benefit of genomic testing realized over the lifetime of genotyped heifers is expected to range from A$204 to A$1,124 per 100 cows for a herd with median reproductive performance. The cost of a genomic test, a perceived barrier to many farmers, had only a small effect on net benefit. Genomic testing alone was always more profitable than using sexed semen and genomic testing together if the only benefit considered was increased genetic gain in heifer replacements. When other benefits (i.e., the higher sale price of a surplus heifer compared with a male calf) were considered, there were combinations of parameters where net benefit from using sexed semen and genomic testing was higher than the equivalent scenario with genomic testing only. Using sexed semen alongside genomic testing is most likely to be profitable when (1) used in heifers, (2) the marginal return for selling surplus heifers

  4. Alternative nuclear fuel cycles and gas-cooled breeders

    International Nuclear Information System (INIS)

    Pellaud, B.; Dahlberg, R.C.

    1979-01-01

    The authors assert that it is prudent to concurrently develop more than one breeder system and to develop advanced converter reactors along with breeders. They provide arguments to support these assertions. (Auth.)

  5. Risk Factors Influencing Conception Rate in Holstein Heifers before Artificial Insemination or Embryo Transfer

    OpenAIRE

    M. Yusuf; T. Nakao; S. T. Long; S. Fujita

    2016-01-01

    The objective of this study was to show the risk factors affecting the conception rate in Holstein heifers after synchronization of estrus. A total of 275 Holstein heifers housed in a free barn were used for the experiment. The herd was visited regularly at four week intervals for synchronization of estrus using Heatsynch and CIDR-Heatsynch protocols. A group of four to 14 animals, depending on the availability, were referred to the experiment at each visit. Estrus induction rates in the two ...

  6. Safety of the novel influenza viral vector Brucella abortus vaccine in pregnant heifers

    Directory of Open Access Journals (Sweden)

    Kaissar Tabynov

    2016-01-01

    Full Text Available ABSTRACT: The present study provides the first information about the safety of a new influenza viral vector vaccine expressing the Brucella ribosomal protein L7/L12 or Omp16 containing the adjuvant Montanide Gel01 in pregnant heifers. Immunization of pregnant heifers was conducted via the conjunctival (n=10 or subcutaneous (n=10 route using cross prime and booster vaccination schedules at an interval of 28 days. The vector vaccine was evaluated in comparison with positive control groups vaccinated with B. abortus S19 (n=10 or B. abortus RB51 (n=10 and a negative (PBS+Montanide Gel01; n=10 control group. Clinical studies, thermometry, assessment of local reactogenicity and observation of abortion showed that the vector vaccine via the conjunctival or subcutaneous route was completely safe for pregnant heifers compared to the commercial vaccines B. abortus S19 or B. abortus RB51. The only single adverse event was the formation of infiltration at the site of subcutaneous injection; this reaction was not observed for the conjunctival route.

  7. Effects of continuous ivermectin treatment from birth to puberty on growth and reproduction in dairy heifers.

    Science.gov (United States)

    Mejía, M; Gonzalez-Iglesias, A; Díaz-Torga, G S; Villafañe, P; Formía, N; Libertun, C; Becú-Villalobos, D; Lacau-Mengido, I M

    1999-06-01

    The effect of continuous ivermectin treatment from birth to puberty on growth and reproductive performance was studied in Holstein heifer calves grown on pastures in comparison to naturally nematode-infected, untreated animals. Ivermectin effectively abated the presence of nematode eggs in feces. Eggs per gram (EPG) in parasitized animals increased rapidly from wk 12 to 18 of age and then decreased. Animals treated with ivermectin grew faster than untreated ones, and differences in body weight became significant at 6 wk of life, even before eggs appeared in the feces of either treatment group. Ivermectin-treated heifers reached puberty 3 wk earlier than infected ones as assessed with serum progesterone concentrations (ivermectin, 30.4 +/- .8 vs untreated, 33.7 +/- 1.3 wk of age). This delay was not directly related to body weight. In addition, pelvic area at 39 wk and at 15 mo of age was increased in treated heifers (8 and 11%, respectively) compared with parasitized animals. No differences in the wither heights were observed. We conclude that ivermectin treatment in dairy heifers may increase growth rate during development, advance the onset of ovarian function, and positively affect yearling pelvic area.

  8. Breeder reactor fuel reprocessing

    International Nuclear Information System (INIS)

    Trauger, D.B.

    1983-01-01

    The time cycle for breeder reactor development and deployment is longer than the planning horizons for most private industry and governments. The potential advantage and possible desperate need for widely deployed breeder reactors in the future seems to dictate that suitable long-term development and deployment programs be established to provide an adequate base of technology and in time to meet the need. The problems of failing to do so and being confronted with a major requirement for nuclear energy could result in very serious economic and social disruption. The cost of maintaining the needed program, although substantial, is certainly modest compared with the potential problems which could ensue should we fail to proceed

  9. Start of puberty on heifers of Ecuadorian highlands by determination of progesterone hormone by radio-immuno analysis (RIA)

    International Nuclear Information System (INIS)

    Villalba, Patricio; Alarcon, Mariana; Utreras, Gina; Vazconez, L.

    1994-01-01

    The objective of this research was to determine the beginning of the puberty in Heifers of two Ecuadorian highland farms, observing the weight, age and height in which appeared levels of progesterone hormone that were significant, the samples were analyzed throughout the radioimmunoassay technique (RIA). The experiment was performed with twenty-eight Heifers Holstein Friesan half-breed of 6 to 9 months old, fourteen each farm. The blood samples were collected each eight days, additional data as weight and height were compiled each fifteen days and fecal samples were taken each thirty days. The Heifers were separate the trial when showed levels of progesterone equal or superior 0,5 ng/ml blood serum as an indicative that the ovarian physiology has begun. The age was highly significant in the groups, showing the puberty the Heifers of the farm ''A'' 5.47 months before that the farm B, for the parameters weight and height that was not significant

  10. Fusion Breeder Program interim report

    International Nuclear Information System (INIS)

    Moir, R.; Lee, J.D.; Neef, W.

    1982-01-01

    This interim report for the FY82 Fusion Breeder Program covers work performed during the scoping phase of the study, December, 1981-February 1982. The goals for the FY82 study are the identification and development of a reference blanket concept using the fission suppression concept and the definition of a development plan to further the fusion breeder application. The context of the study is the tandem mirror reactor, but emphasis is placed upon blanket engineering. A tokamak driver and blanket concept will be selected and studied in more detail during FY83

  11. Social relationships enhance the time spent eating and intake of a novel diet in pregnant Hanwoo (Bos taurus coreanae) heifers.

    Science.gov (United States)

    Shin, Dong-Han; Kang, Hyun-Min; Seo, Seongwon

    2017-01-01

    The objective of this study was to evaluate the effects of social relationships on the feed intake, eating behavior, and growth, upon exposure to a novel diet, in Hanwoo ( Bos taurus coreanae ) heifers during pregnancy. Twenty-four pregnant Hanwoo heifers, averaging 438 ± 27.8 kg in weight, 21 months in age, and 194 ± 8.5 days in pregnancy, were involved in a two-month (eight weeks) experiment. The heifers were randomly assigned to either the single housing group (SG; one individual per pen, n = 12), or the paired housing group (PG; two individuals per pen, n = 12). All pens were of the same size (5 × 5 m) and provided with one feed bin, which automatically recorded the individual feed intake and eating behavior. As the experiment began, the diet of the heifers was switched from a total mixed ration (TMR; 250 g/kg ryegrass straw and 750 g/kg concentrate mix) to a forage-only diet (mixed hay cubes composed of 500 g/kg alfalfa, 250 g/kg timothy, and 250 g/kg blue grass hay). The heifers were fed ad libitum twice a day. The individual feed intake and eating behavior were recorded daily throughout the experiment, and body weights (BWs) were measured every four weeks before the morning feeding. PG animals visited the feed bin 22% less often than SG. PG, however, stayed 39% longer in the feed bin and consumed 40% more feed per visit, compared with SG. Consequently, PG heifers spent 23% more time in eating and had 16% more daily dry matter intake than SG during the experiment. Average daily gain during the experimental period tended to be greater in PG than in SG. When pregnant Hanwoo heifers encountered a novel diet, social relationships (i.e., presence of a pen-mate) enhanced their time spent eating and feed intake. Social interactions, even with an unfamiliar individual, may be helpful for pregnant Hanwoo heifers cope with a diet challenge compared to solitary situation.

  12. Ultrasound monitoring of blood flow and echotexture of the corpus luteum and uterus during early pregnancy of beef heifers.

    Science.gov (United States)

    Scully, S; Evans, A C O; Carter, F; Duffy, P; Lonergan, P; Crowe, M A

    2015-02-01

    The aim was to characterize changes in the ultrasound characteristics of the CL and uterus in pregnant, inseminated nonpregnant, and cyclic beef heifers and to correlate findings with systemic progesterone (P4) concentrations with the intention of identifying possible markers for early identification of pregnancy. Heifers were randomly selected for artificial insemination after estrus synchronization. Ultrasound examinations of the CL and uterus were carried out by transrectal ultrasonography using a high-resolution ultrasound scanner equipped with a 12 MHz linear array probe on Days 7, 11, 14, 16, and 18 after artificial insemination (Day 0; i.e., estrus). Cross-sectional B-mode images of the CL were captured for calculation of CL tissue area and echotexture. Images of the CL and associated blood flow were captured and stored for analysis of luteal blood flow area and ratio. Longitudinal B-mode images of the uterine horns were captured just beyond the bifurcation of the uterine horns and stored for analysis of contrast and homogeneity (MaZda v4.6; Technical University of Lodz, Institute of Electronics, Poland). A total of three images were captured for each structure of interest. Serum concentrations of P4 were determined from blood samples collected at each ultrasound examination. After pregnancy diagnosis by ultrasound, heifers were retrospectively allocated as being pregnant (embryonic heartbeat on Day 28; n = 14) or nonpregnant (interestrous interval 18-21 days; n = 8) and their data were compared with noninseminated cyclic heifers (n = 10). Corpus luteum tissue area did not appear to change between pregnant, nonpregnant, or cyclic control groups between Days 7 and 18 (P > 0.05). No significant differences in CL echotexture characteristics were found between groups at any time point. There were no significant differences between pregnant, nonpregnant, and cyclic control groups for CL blood flow area (P > 0.05). However, CL blood flow ratio

  13. Effects of grazing system on production and parasitism of dairy breed heifers and steers grazing wet marginal grasslands

    DEFF Research Database (Denmark)

    Kristensen, Troels; Thamsborg, S.M.; Andersen, Refsgaard

    2006-01-01

    Production and endoparasitism of first grazing season Holstein heifers and steers were investigated over two grazing seasons. Studies were conducted on low-lying peaty soil. In year 2000, 40 animals were included in a 2x2 factorial, replicated experiment with two sexes (steers v. heifers) and two...

  14. Effect of early calving of Simmentaler heifers under an extensive ...

    African Journals Online (AJOL)

    is concluded that improved productivity is unlikely in an early mating system without additional inputs. ... heifers are managed to calve for the first time at three years of age. ..... It should therefore not be considered as a standard management.

  15. Nutritional Programming of Accelerated Puberty in Heifers: Involvement of Pro-Opiomelanocortin Neurones in the Arcuate Nucleus.

    Science.gov (United States)

    Cardoso, R C; Alves, B R C; Sharpton, S M; Williams, G L; Amstalden, M

    2015-08-01

    The timing of puberty and subsequent fertility in female mammals are dependent on the integration of metabolic signals by the hypothalamus. Pro-opiomelanocortin (POMC) neurones in the arcuate nucleus (ARC) comprise a critical metabolic-sensing pathway controlling the reproductive neuroendocrine axis. α-Melanocyte-stimulating hormone (αMSH), a product of the POMC gene, has excitatory effects on gonadotrophin-releasing hormone (GnRH) neurones and fibres containing αMSH project to GnRH and kisspeptin neurones. Because kisspeptin is a potent stimulator of GnRH release, αMSH may also stimulate GnRH secretion indirectly via kisspeptin neurones. In the present work, we report studies conducted in young female cattle (heifers) aiming to determine whether increased nutrient intake during the juvenile period (4-8 months of age), a strategy previously shown to advance puberty, alters POMC and KISS1 mRNA expression, as well as αMSH close contacts on GnRH and kisspeptin neurones. In Experiment 1, POMC mRNA expression, detected by in situ hybridisation, was greater (P high-gain, HG; n = 6) compared to heifers that gained 0.5 kg/day (low-gain, LG; n = 5). The number of KISS1-expressing cells in the middle ARC was reduced (P < 0.05) in HG compared to LG heifers. In Experiment 2, double-immunofluorescence showed limited αMSH-positive close contacts on GnRH neurones, and the magnitude of these inputs was not influenced by nutritional status. Conversely, a large number of kisspeptin-immunoreactive cells in the ARC were observed in close proximity to αMSH-containing varicosities. Furthermore, HG heifers (n = 5) exhibited a greater (P < 0.05) percentage of kisspeptin neurones in direct apposition to αMSH fibres and an increased (P < 0.05) number of αMSH close contacts per kisspeptin cell compared to LG heifers (n = 6). These results indicate that the POMC-kisspeptin pathway may be important in mediating the nutritional acceleration of puberty in heifers.

  16. Supplementary winter feeding and reproduction of beef heifers on ...

    African Journals Online (AJOL)

    Supplementary winter feeding and reproduction of beef heifers on Dohne sourveld. JA Erasmus, HH Barnard. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for ...

  17. Heifer fertility and carry over consequences for life time production in dairy and beef cattle.

    Science.gov (United States)

    Wathes, D C; Pollott, G E; Johnson, K F; Richardson, H; Cooke, J S

    2014-05-01

    The rearing period has a key influence on the later performance of cattle, affecting future fertility and longevity. Producers usually aim to breed replacement heifers by 15 months to calve at 24 months. An age at first calving (AFC) close to 2 years (23 to 25 months) is optimum for economic performance as it minimises the non-productive period and maintains a seasonal calving pattern. This is rarely achieved in either dairy or beef herds, with average AFC for dairy herds usually between 26 and 30 months. Maintaining a low AFC requires good heifer management with adequate growth to ensure an appropriate BW and frame size at calving. Puberty should occur at least 6 weeks before the target breeding age to enable animals to undergo oestrous cycles before mating. Cattle reach puberty at a fairly consistent, but breed-dependent, proportion of mature BW. Heifer fertility is a critical component of AFC. In US Holsteins the conception rate peaked at 57% at 15 to 16 months, declining in older heifers. Wide variations in growth rates on the same farm often lead to some animals having delayed first breeding and/or conception. Oestrous synchronisation regimes and sexed semen can both be used but unless heifers have been previously well-managed the success rates may be unacceptably low. Altering the nutritional input above or below those needed for maintenance at any stage from birth to first calving clearly alters the average daily gain (ADG) in weight. In general an ADG of around 0.75 kg/day seems optimal for dairy heifers, with lower rates delaying puberty and AFC. There is some scope to vary ADG at different ages providing animals reach an adequate size by calving. Major periods of nutritional deficiency and/or severe calfhood disease will, however, compromise development with long-term adverse consequences. Infectious disease can also cause pregnancy loss/abortion. First lactation milk yield may be slightly lower in younger calving cows but lifetime production is higher as

  18. Dietary melatonin alters uterine artery hemodynamics in pregnant holstein heifers

    Science.gov (United States)

    The objective was to examine uterine artery hemodynamics and maternal serum profiles in pregnant heifers supplemented with dietary melatonin (MEL) or no supplementation (CON). In addition, melatonin receptor–mediated responses in steroid metabolism were examined using a bovine endometrial epithelial...

  19. Environmental Enrichment for Broiler Breeders: An Undeveloped Field

    Directory of Open Access Journals (Sweden)

    Anja B. Riber

    2017-06-01

    Full Text Available Welfare problems, such as hunger, frustration, aggression, and abnormal sexual behavior, are commonly found in broiler breeder production. To prevent or reduce these welfare problems, it has been suggested to provide stimulating enriched environments. We review the effect of the different types of environmental enrichment for broiler breeders, which have been described in the scientific literature, on behavior and welfare. Environmental enrichment is defined as an improvement of the environment of captive animals, which increases the behavioral opportunities of the animal and leads to improvements in biological function. This definition has been broadened to include practical and economic aspects as any enrichment strategy that adversely affects the health of animals (e.g., environmental hygiene, or that has too many economic or practical constraints will never be implemented on commercial farms and thus never benefit animals. Environmental enrichment for broiler breeders often has the purpose of satisfying the behavioral motivations for feeding and foraging, resting, and/or encouraging normal sexual behavior. Potentially successful enrichments for broiler breeders are elevated resting places, cover panels, and substrate (for broiler breeders housed in cage systems. However, most of the ideas for environmental enrichment for broiler breeders need to be further developed and studied with respect to the use, the effect on behavior and welfare, and the interaction with genotype and production system. In addition, information on practical use and the economics of the production system is often lacking although it is important for application in practice.

  20. Proceedings of the fifteenth international workshop on ceramic breeder blanket interactions

    International Nuclear Information System (INIS)

    Tanigawa, Hisashi; Enoeda, Mikio

    2010-03-01

    This report is the Proceedings of 'the Fifteenth International Workshop on Ceramic Breeder Blanket Interactions' which was held as a workshop on ceramic breeders Under the IEA Implementing Agreement on the Nuclear Technology of Fusion Reactors. This workshop was held in Sapporo, Japan on 3-4, Sept. 2009. Twenty six participants from EU, Japan, India, Russia and USA attended the workshop. The scope of the workshop included 1) evolutions in ceramic breeder blanket design, 2) progress in ceramic breeder material development, 3) irradiation testing, 4) breeder material properties, 5) out-of-pile pebble bed experiment, 6) modeling of the thermal, mechanical and tritium transfer behavior of pebble beds and 7) interfacing issues of solid breeder blanket development. By this workshop, advance of key technologies for solid breeder blanket development was shared among the participants. Also, desired direction of further investigation and development was recognized. The 20 of the presented papers are indexed individually. (J.P.N.)

  1. Proceedings of the fifteenth international workshop on ceramic breeder blanket interactions

    Energy Technology Data Exchange (ETDEWEB)

    Tanigawa, Hisashi; Enoeda, Mikio [Japan Atomic Energy Agency, Fusion Research and Development Directorate, Naka, Ibaraki (Japan)

    2010-03-15

    This report is the Proceedings of 'the Fifteenth International Workshop on Ceramic Breeder Blanket Interactions' which was held as a workshop on ceramic breeders Under the IEA Implementing Agreement on the Nuclear Technology of Fusion Reactors. This workshop was held in Sapporo, Japan on 3-4, Sept. 2009. Twenty six participants from EU, Japan, India, Russia and USA attended the workshop. The scope of the workshop included 1) evolutions in ceramic breeder blanket design, 2) progress in ceramic breeder material development, 3) irradiation testing, 4) breeder material properties, 5) out-of-pile pebble bed experiment, 6) modeling of the thermal, mechanical and tritium transfer behavior of pebble beds and 7) interfacing issues of solid breeder blanket development. By this workshop, advance of key technologies for solid breeder blanket development was shared among the participants. Also, desired direction of further investigation and development was recognized. The 20 of the presented papers are indexed individually. (J.P.N.)

  2. A review of prospects for an accelerator breeder

    International Nuclear Information System (INIS)

    Fraser, J.S.; Hoffman, C.R.; Schriber, S.O.; Garvey, P.M.; Townes, B.M.

    1981-12-01

    The scientific feasibility, engineering practicability and economic prospects for an Accelerator Breeder are reviewed. The scientific feasibiliity of high power accelerator components rests on a firm basis as a result of technical advances made in recent years but there is a need to combine all components in a demonstration model working under realistic conditions. The engineering practicability of Accelerator Breeder components should be tested in a staged development culminating in a full-scale demonstration plant. The economic assessment depends on calculations of allowed and estimated capital costs of an Accelerator Breeder for a CANDU system operating on the Th-U fuel cycle. The results indicate that the ratio of estimated to allowed capital cost is approximately 3.5 for a breeder with a 2% enriched uranium metal blanket and for separated U235 valued at 48 $/g

  3. Staphylococcus agnetis, a potential pathogen in broiler breeders

    DEFF Research Database (Denmark)

    Poulsen, Louise Ladefoged; Thøfner, Ida; Bisgaard, Magne

    2017-01-01

    In this study, four broiler parent flocks have been followed from the onset of the production period (week 20) until slaughter (week 60). Every week, approximately ten dead broiler breeders, randomly selected among birds dead on their own, were collected and subjected to a full post mortem analysis...... including bacteriological examination. In total 997 breeders were investigated and for the first time Staphylococcus agnetis was isolated in pure culture from cases of endocarditis and septicemia from 16 broiler breeders. In addition, the cloacal flora from newly hatched chickens originating from the same...... from both broiler breeders and broilers. Three isolates were whole genome sequenced to obtain knowledge on virulence genes. The isolates harbored a number of genes encoding different fibrinogen binding proteins and toxins which might be important for virulence. The present findings demonstrate that S...

  4. Risk Factors Influencing Conception Rate in Holstein Heifers before Artificial Insemination or Embryo Transfer

    Directory of Open Access Journals (Sweden)

    M. Yusuf

    2016-12-01

    Full Text Available The objective of this study was to show the risk factors affecting the conception rate in Holstein heifers after synchronization of estrus. A total of 275 Holstein heifers housed in a free barn were used for the experiment. The herd was visited regularly at four week intervals for synchronization of estrus using Heatsynch and CIDR-Heatsynch protocols. A group of four to 14 animals, depending on the availability, were referred to the experiment at each visit. Estrus induction rates in the two protocols were 93.9% and 94.9%, respectively. There was no difference in the conception rate between the two protocols. Conception rate after artificial insemination (AI or embryo transfer (ET were 46.3% and 51.4%, respectively. The risk factors affecting conception rate in heifers were daily weight gain (odds ratio [OR]= 4.673; P= 0.036 and body condition score (BCS (OR= 3.642; P= 0.018. Furthermore, estrus synchronization protocol (OR= 1.774; P= 0.083 and the absence of corpus luteum (CL at the initiation of treatment (OR= 0.512; P= 0.061 had a tendency to affect the conception rate, while age (OR= 0.715; P= 0.008 was a protective factor to conception rate.  In conclusion, positive daily weight gain before AI or ET, higher BCS, younger age, and the presence of CL at the initiation of estrus synchronization in dairy heifers increased the likelihood to conceive.

  5. Relationships between milking frequency, lactation persistency and milk yield in Sweish Red heifers and cows milked in a voluntary attendance automatic milking system

    DEFF Research Database (Denmark)

    Pettersson, Gunnar; Svvenersten-Sjaunja, Kerstin; Knight, Christopher Harold

    2011-01-01

    A large dataset comprising output from an automatic milking (AM) system between 1999 and 2006 was examined and a total of 172 cow lactation curves and 68 heifer lactation curves were identified for further analysis. Relationships between milking frequency at different stages of lactation...... and lactation persistency and total lactation yield were determined. Cows had higher peak and total milk yields than heifers, but heifers had higher persistency (defined as the rate of decline in milk yield between days 100 and 300 post calving). Milking frequency did not differ significantly between cows...... and heifers in early lactation, but thereafter decreased significantly more in cows than in heifers. The effect of milking frequency on yield characteristics was analysed by comparing the highest and lowest quartiles for milking frequency. High milking frequency in early lactation was consistently associated...

  6. Liquid metal cooled fast breeder nuclear reactors

    International Nuclear Information System (INIS)

    Duncombe, E.; Thatcher, G.

    1979-01-01

    The invention described relates to a liquid metal cooled fast breeder nuclear reactor in which the fuel assembly has an inner zone comprised mainly of fissile material and a surrounding outer zone comprised mainly of breeder material. According to the invention the sub-assemblies in the outer zone include electro-magnetic braking devices (magnets, pole pieces and armature) for regulating the flow of coolant through the sub-assemblies. The magnetic fields of the electro-magnetic breaking devices are temperature sensitive so that as the power output of the breeder sub-assemblies increases the electro-magnetic resistance to coolant flow is reduced thereby maintaining the temperature of the coolant outlets from the sub-assemblies substantially constant. (UK)

  7. Fertility after implementation of long- and short-term progesterone-based ovulation synchronization protocols for fixed-time artificial insemination in beef heifers.

    Science.gov (United States)

    Kasimanickam, R; Schroeder, S; Hall, J B; Whittier, W D

    2015-04-15

    Two experiments were conducted to evaluate the effect of long-term (LT; a 14-day controlled internal drug release insert [CIDR]-PGF2α [PGF]-GnRH) and short-term (ST; 5-day CO-Synch + CIDR) progesterone-based protocols on pregnancy rate to fixed-time artificial insemination (FTAI) in beef heifers. In experiment 1, Angus cross beef heifers (N = 1887) at nine locations received a body condition score and a reproductive tract score (RTS). Within the herd, heifers were randomly assigned to LT-72 and ST-56 protocol groups. Heifers in the LT-72 group received a CIDR from Days 0 to 14, followed by 25 mg of PGF 16 days later (Day 30). Heifers in the ST-56 group received a CIDR and 100 μg of gonadorelin hydrochloride (GnRH) on Day 25 followed by 25 mg of PGF at CIDR removal on Day 30 and a second dose of PGF 6 hours later (Day 30). Artificial insemination was performed at 56 hours (Day 32) after CIDR removal for the ST-56 group and at 72 hours (Day 33) after CIDR removal for the LT-72 group, and all heifers were given GnRH (100 μg, intramuscular) at the time of AI. In experiment 2, Angus cross beef heifers (N = 718) at four locations received a body condition score and an RTS. Within the herd, heifers were randomly assigned to LT-72 and ST-72 protocol groups. The protocol was similar to experiment 1 except that AI was performed at 72 hours after CIDR removal for both LT-72 and ST-72 groups. In experiment 1, no difference in AI pregnancy rates between the LT-72 and ST-56 groups was observed (54.5% [489 of 897] and 55.5% [549 of 990], respectively; P = 0.92) after accounting for the RTS. The AI pregnancy rates for heifers with RTS 3 or less, 4, and 5 were 52.6%, 53.6%, and 59.9%, respectively (P < 0.05). In experiment 2, controlling for the RTS, no difference in AI pregnancy rates was observed between the LT-72 and ST-72 groups, 56.9% (198 of 347) and 57.8% (214 of 371), respectively (P = 0.87). The AI pregnancy rates for heifers with RTS 3 or less, 4, and 5 were 49.3%, 58

  8. U.S. reference paper on national decisions on breeder development and deployment

    International Nuclear Information System (INIS)

    1978-10-01

    Factors involved in making national decisions on the deployment of breeder reactor systems are identified in terms of a nation's potential for electrification, capital resources, the available industrial and manpower infrastructure and importance attached to energy independence and the degree to which a breeder program can help realize this objective in the time scale of interest. The specific factors analysed are: the high capital cost of the breeder and the one-time transition costs to bring the breeder to maturity the high breeder research, development and demonstration costs, the impact of discount rate, and the fuel cycle costs, e.g. indigeneous facilities or purchase of services. A principal conclusion of this paper is that nations may find it more economical to continue to deploy LWRs for a number of years rather than to consider the breeder option because of the initial high breeder capital cost and high breeder R and D costs

  9. Breeder reactor fuel fabrication system development

    International Nuclear Information System (INIS)

    Bennett, D.W.; Fritz, R.L.; McLemore, D.R.; Yatabe, J.M.

    1981-01-01

    Significant progress has been made in the design and development of remotely operated breeder reactor fuel fabrication and support systems (e.g., analytical chemistry). These activities are focused by the Secure Automated Fabrication (SAF) Program sponsored by the Department of Energy to provide: a reliable supply of fuel pins to support US liquid metal cooled breeder reactors and at the same time demonstrate the fabrication of mixed uranium/plutonium fuel by remotely operated and automated methods

  10. Differential gene expression profiling of endometrium during the mid-luteal phase of the estrous cycle between a repeat breeder (RB) and non-RB cows.

    Science.gov (United States)

    Hayashi, Ken-Go; Hosoe, Misa; Kizaki, Keiichiro; Fujii, Shiori; Kanahara, Hiroko; Takahashi, Toru; Sakumoto, Ryosuke

    2017-03-23

    Repeat breeding directly affects reproductive efficiency in cattle due to an increase in services per conception and calving interval. This study aimed to investigate whether changes in endometrial gene expression profile are involved in repeat breeding in cows. Differential gene expression profiles of the endometrium were investigated during the mid-luteal phase of the estrous cycle between repeat breeder (RB) and non-RB cows using microarray analysis. The caruncular (CAR) and intercaruncular (ICAR) endometrium of both ipsilateral and contralateral uterine horns to the corpus luteum were collected from RB (inseminated at least three times but not pregnant) and non-RB cows on Day 15 of the estrous cycle (4 cows/group). Global gene expression profiles of these endometrial samples were analyzed with a 15 K custom-made oligo-microarray for cattle. Immunohistochemistry was performed to investigate the cellular localization of proteins of three identified transcripts in the endometrium. Microarray analysis revealed that 405 and 397 genes were differentially expressed in the CAR and ICAR of the ipsilateral uterine horn of RB, respectively when compared with non-RB cows. In the contralateral uterine horn, 443 and 257 differentially expressed genes were identified in the CAR and ICAR of RB, respectively when compared with non-RB cows. Gene ontology analysis revealed that genes involved in development and morphogenesis were mainly up-regulated in the CAR of RB cows. In the ICAR of both the ipsilateral and contralateral uterine horns, genes related to the metabolic process were predominantly enriched in the RB cows when compared with non-RB cows. In the analysis of the whole uterus (combining the data above four endometrial compartments), RB cows showed up-regulation of 37 genes including PRSS2, GSTA3 and PIPOX and down-regulation of 39 genes including CHGA, KRT35 and THBS4 when compared with non-RB cows. Immunohistochemistry revealed that CHGA, GSTA3 and PRSS2 proteins

  11. An Unusual Occurrence of Actinobacillosis in Heifers and Cows in A Dairy Herd in Tehran suburb-Iran

    Directory of Open Access Journals (Sweden)

    Atyabi, N.,

    2010-07-01

    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.

  12. The GBR reactor an economically competitive Breeder

    International Nuclear Information System (INIS)

    Chermanne, J.

    1974-01-01

    In this article the design is described of a 1200 MWe fast breeder, gas-cooled reactor (GBR-4), prepared by a group of experts of the Gas Breeder Reactor Association and used as a reference system for economical and safety evaluations, as well as for defining the research and development program focussed on such concept and the specifications of the prospective demonstrative plant

  13. In vitro growth inhibition of major mastitis pathogens by Staphylococcus chromogenes originating from teat apices of dairy heifers.

    Science.gov (United States)

    De Vliegher, S; Opsomer, G; Vanrolleghem, A; Devriese, L A; Sampimon, O C; Sol, J; Barkema, H W; Haesebrouck, F; de Kruif, A

    2004-07-14

    Earlier field observations suggest that teat apex colonization by Staphylococcus chromogenes pre-partum in dairy heifers protects udder quarters against elevated somatic cell counts early post-partum. To explain these findings, the in vitro inhibitory capability of S. chromogenes from teat apices of heifers towards some major mastitis pathogens was tested using a modified cross-streaking method. Two out of 10 S. chromogenes isolates, both originating from two different teats from the same heifer, consistently inhibited growth of all Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis strains, but none of the Escherichia coli strains. The present study, therefore, supports the protective effect of teat apex colonization by S. chromogenes by in vitro production of inhibitory substances.

  14. Carter's breeder policy has failed, claims Westinghouse manager

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Nuclear nations developing liquid metal fast breeder reactor (LMFBR) technology have not been dissuaded by President Carter's efforts to stop the breeder program as a way to control the proliferation of nuclear weapons. There is no evidence that Carter's policy of moral persuasion has had any impact on their efforts. A review of the eight leading countries cites their extensive progress in the areas of breeder technology and fuel reprocessing, while the US has made only slight gains. The Fast Flux Test Facility at Hanford is near completion, but the Clinch River project has been slowed to a minimum

  15. Environmental impact of heifer management decisions on Dutch dairy farms

    NARCIS (Netherlands)

    Mourits, M.C.M.; Berentsen, P.B.M.; Huirne, R.B.M.; Dijkhuizen, A.A.

    2000-01-01

    Dairy farming contributes substantially to Dutch environmental problems. A dynamic heifer rearing model was used to determine the extent to which the rearing activity influences nutrient flows on a dairy farm. Based on current rearing conditions, the economic optimal rearing policy resulted in an

  16. Optimal reactor strategy for commercializing fast breeder reactors

    International Nuclear Information System (INIS)

    Yamaji, Kenji; Nagano, Koji

    1988-01-01

    In this paper, a fuel cycle optimization model developed for analyzing the condition of selecting fast breeder reactors in the optimal reactor strategy is described. By dividing the period of planning, 1966-2055, into nine ten-year periods, the model was formulated as a compact linear programming model. With the model, the best mix of reactor types as well as the optimal timing of reprocessing spent fuel from LWRs to minimize the total cost were found. The results of the analysis are summarized as follows. Fast breeder reactors could be introduced in the optimal strategy when they can economically compete with LWRs with 30 year storage of spent fuel. In order that fast breeder reactors monopolize the new reactor market after the achievement of their technical availability, their capital cost should be less than 0.9 times as much as that of LWRs. When a certain amount of reprocessing commitment is assumed, the condition of employing fast breeder reactors in the optimal strategy is mitigated. In the optimal strategy, reprocessing is done just to meet plutonium demand, and the storage of spent fuel is selected to adjust the mismatch of plutonium production and utilization. The price hike of uranium ore facilitates the commercial adoption of fast breeder reactors. (Kako, I.)

  17. Feeding behavior, microbial efficiency, and nitrogen balance of Nellore heifers supplemented with crude glycerin

    Directory of Open Access Journals (Sweden)

    Gonçalo Mesquita da Silva

    2016-09-01

    Full Text Available This study aimed to evaluate the inclusion of crude glycerin in diets for Nellore heifers grazing on a Brachiaria brizantha pasture, during the dry season, on urine and plasma urea concentrations, feeding behavior, and microbial protein synthesis. Sixty Nellore heifers with an average initial weight of 285.89 ± 18.74 kg, at approximately 19 ± 2 months of age, were distributed, in a completely randomized design, into the following five treatments with twelve replicates: 0.00, 4.00, 8.00, 12.00, and 16.00% inclusion of crude glycerin in the diet they were fed. Grazing time decreased linearly (P 0.05, averaging 113.73g CP per kg TDN ingested. Plasma nitrogen concentration did not show any effects (P > 0.05, averaging 13.11 mg dL?1. Supplementing heifers during the dry season, at 0.7% BW, using up to 16% crude glycerin in the diet composition, did not elicit positive responses from feeding behavior and had little influence on microbial synthesis.

  18. Impact of an AI heifer calf rearing scheme on dairy stock development in the Western province of Sri Lanka.

    NARCIS (Netherlands)

    Nettisinghe, A.M.P.; Udo, H.M.J.; Steenstra, F.A.

    2004-01-01

    This study evaluated the impact of an AI heifer calf rearing scheme on dairy stock development, in a coconut grazing and a peri-urban smallholder dairy production system in the Western Province of Sri Lanka. The heifer rearing scheme included free advice on calf rearing, drugs, acaricides, minerals

  19. Somatic cell count and milk neutrophil viability of dairy heifers with specific CXCR1 genotypes following experimental intramammary infection with Staphylococcus chromogenes originating from milk.

    Science.gov (United States)

    Verbeke, Joren; Piccart, Kristine; Piepers, Sofie; Van Poucke, Mario; Peelman, Luc; De Visscher, Anneleen; De Vliegher, Sarne

    2015-06-01

    Previous observational studies suggest an association between polymorphism c.980A>G in the CXCR1 gene, encoding the chemokine (C-X-C motif) receptor 1, and the innate immunity and infection status of the mammary gland. Mammary glands of eight Holstein heifers were experimentally infected with a Staphylococcus chromogenes isolate originating from a chronic intramammary infection (IMI) to study differences between CXCR1 genotypes c.980AG and c.980GG. Quarters from heifers with genotypes c.980AG and c.980GG developed subclinical mastitis but showed differences in the early response at 6-18 h post challenge. Bacterial count at 18 h post challenge tended to be higher in quarters from c.980AG heifers compared to c.980GG heifers. Somatic cell count (SCC) was higher at 6 h post challenge and tended to be higher at 9 h post challenge in c.980AG heifers compared to c.980GG heifers. Milk production decreased similarly. Milk neutrophils of c.980AG heifers showed more apoptosis at 9 h post challenge and tended to show more necrosis at 6, 9 and 12 h post challenge than c.980GG heifers. Differences were less pronounced in the later stage (>18 h) of infection. The results demonstrate that CXCR1 polymorphism can influence SCC and milk neutrophil viability following experimental IMI. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Impact of supplemental protein source offered to primiparous heifers during gestation on II. Progeny performance and carcass characteristics.

    Science.gov (United States)

    Summers, A F; Blair, A D; Funston, R N

    2015-04-01

    A 3-yr study using primiparous crossbred beef heifers (n = 114) was conducted to determine the effects of protein supplement during late gestation on progeny performance and carcass characteristics. Pregnant heifers were stratified by heifer development system, initial BW, and AI service sire and placed in an individual feeding system. Heifers were offered meadow hay (8 to 11% CP) from early November to mid-February and provided no supplement (CON; n = 37), 0.83 kg/d (DM basis) of a dried distillers grains with solubles-based supplement (HI; n = 39), or 0.83 kg/d (DM basis) of a dried corn gluten feed-based supplement (LO; n = 38). Supplements were designed to be isonitrogenous (28% CP) and isocaloric but to differ in RUP with HI (59% RUP) having greater levels of RUP than LO (34% RUP). After the individual feeding period, heifers were placed in a drylot for calving. All heifers were bred using a fixed-timed AI protocol and pairs were moved to a commercial ranch in the Nebraska Sandhills for summer grazing. Calf weaning BW did not differ (P = 0.14) based on maternal diet. However, feedlot entry BW was greater (P = 0.03) for HI compared with CON calves. Average daily gain during the initial feedlot phase tended (P = 0.10) to be greatest for calves born to CON dams and lowest for calves born to LO dams. However, overall ADG was similar (P = 0.50) for the entire feedlot period. Residual feed intake during the reimplant and total feeding period was improved in calves born to supplemented dams in yr 2 and 3 compared with calves born to CON dams. There was no difference in final BW among treatments (P = 0.71). Hot carcass weight was similar (P = 0.72) among treatments; however, steers had greater (P RUP supplements, similar to those used in this study, to primiparous heifers in late gestation consuming ad libitum grass hay resulted in increased initial feedlot BW for HI compared to CON calves, improved feed efficiency, and altered carcass characteristics in calves born

  1. A fenbendazole oral drench in addition to an ivermectin pour-on reduces parasite burden and improves feedlot and carcass performance of finishing heifers compared with endectocides alone.

    Science.gov (United States)

    Reinhardt, C D; Hutcheson, J P; Nichols, W T

    2006-08-01

    Two studies utilizing 1,862 yearling heifers were conducted to determine the effects of a fenbendazole oral drench in addition to an ivermectin pour-on (SG+IVPO), compared with an ivermectin pour-on (IVPO) or a doramectin injectable (DMX) alone, on parasite burden, feedlot performance, and carcass merit of feedlot cattle. In the first study, heifers receiving the SG+IVPO had fewer (P = 0.02) cattle retreated for disease and 73% fewer (P = 0.06) worm eggs per fecal sample 98 d after treatment than heifers treated with IVPO. Heifers treated with SG+IVPO consumed more DM, had greater ADG, were heavier at slaughter, and had heavier carcasses than IVPO-treated heifers (P fenbendazole oral drench and an ivermectin pour-on reduced parasite burden and increased feed intake, ADG, and carcass weight in feedlot heifers compared with treatment with an endectocide alone.

  2. Feeding management strategy for male broiler breeders and its effects on body weight, hatchability and fertility

    Directory of Open Access Journals (Sweden)

    MM Silveira

    2014-12-01

    Full Text Available The objective of the present study was to evaluate the supply of a specific-male diet on rooster body weight, hatchability, and fertility. Two diets were supplied during the egg production period: treatment 1, diet formulated for females and containing, in average, 2,830 kcal ME/kg and 15% CP; and treatment 2, diet specifically formulated for male broiler breeders, containing 2,750 kcal ME/kg and 13.5% CP. In the experiment, 26 flocks, with approximately 7,000 females and 840 males each, belonging to the same broiler breeder commercial strain, were distributed into 26 houses (1200m² on the same farm, and submitted to the same management practices. Body weight was evaluated in 13 flocks per treatment and for five weeks (45, 50, 55, 60, 65, and hatchability and fertility in four incubation lots per treatment and for the same weeks. Data were evaluated by the analysis of mixed models for repeated measurements, using the PROC MIXED of SAS 9.3 (SAS Institute Inc., Cary, NC, USA, and means were compared by the test of Tukey-Kramer at 5% significance level. The specific-male diet allowed body weight control during all analyzed weeks and promoted high hatchability and egg fertility. The increase in the number of chicks hatched demonstrates the economic viability of feeding a specific diet for male broiler breeders.

  3. Development of a new cellular solid breeder for enhanced tritium production

    International Nuclear Information System (INIS)

    Sharafat, Shahram; Williams, Brian; Ghoniem, Nasr; Ghoniem, Adam; Shimada, Masashi; Ying, Alice

    2016-01-01

    Highlights: • A new cellular solid breeder is presented with 2 to 3× the thermal conductivity and substantially higher density (∼90%) compared with pebble beds. • The cellular solid breeder contains an internal network of interconnected open micro-channels (∼50 –100 μm diam.) for efficient tritium release. • Cellular breeders are made by melt-infiltrating Li-based ceramic materials into an open-cell carbon foam followed by removal of the foam. • High temperature (750 °C and 40 °C/mm) cyclic compression tests demonstrated good structural integrity (no cracking) and low Young’s modulus of of <5 GPa. • Deuterium absorption–desorption release rates were comparable with those from pebble beds with similar characteristic T-diffusion lengths. - Abstract: A new high-performance cellular solid breeder is presented that has several times the thermal conductivity and is substantially denser compared with sphere-packed breeder beds. The cellular breeder is fabricated using a patented process of melt-infiltrating ceramic breeder material into an open-cell carbon foam. Following solidification the carbon foam is removed by oxidation. This process results in a near 90% dense robust freestanding breeder in a block configuration with an internal network of open interconnected micro-channels for tritium release. The network of interconnected micro-channels was investigated using X-ray tomography. Aside from increased density and thermal conductivity relative to pebble beds, high temperature sintering is eliminated and thermal durability is increased. Cellular breeder morphology, thermal conductivity, specific heat, porosity levels, high temperature mechanical properties, and deuterium charging-desorption rates are presented.

  4. Development of a new cellular solid breeder for enhanced tritium production

    Energy Technology Data Exchange (ETDEWEB)

    Sharafat, Shahram, E-mail: sharams@gmail.com [University of California Los Angeles, 420 Westwood Pl., Los Angeles, CA 90095-1587 (United States); Williams, Brian [Ultramet, Pacoima, CA 91331-2210 (United States); Ghoniem, Nasr [University of California Los Angeles, 420 Westwood Pl., Los Angeles, CA 90095-1587 (United States); Ghoniem, Adam [Digital Materials Solutions, Inc., Westwood, CA 90024 (United States); Shimada, Masashi [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Ying, Alice [University of California Los Angeles, 420 Westwood Pl., Los Angeles, CA 90095-1587 (United States)

    2016-11-01

    Highlights: • A new cellular solid breeder is presented with 2 to 3× the thermal conductivity and substantially higher density (∼90%) compared with pebble beds. • The cellular solid breeder contains an internal network of interconnected open micro-channels (∼50 –100 μm diam.) for efficient tritium release. • Cellular breeders are made by melt-infiltrating Li-based ceramic materials into an open-cell carbon foam followed by removal of the foam. • High temperature (750 °C and 40 °C/mm) cyclic compression tests demonstrated good structural integrity (no cracking) and low Young’s modulus of of <5 GPa. • Deuterium absorption–desorption release rates were comparable with those from pebble beds with similar characteristic T-diffusion lengths. - Abstract: A new high-performance cellular solid breeder is presented that has several times the thermal conductivity and is substantially denser compared with sphere-packed breeder beds. The cellular breeder is fabricated using a patented process of melt-infiltrating ceramic breeder material into an open-cell carbon foam. Following solidification the carbon foam is removed by oxidation. This process results in a near 90% dense robust freestanding breeder in a block configuration with an internal network of open interconnected micro-channels for tritium release. The network of interconnected micro-channels was investigated using X-ray tomography. Aside from increased density and thermal conductivity relative to pebble beds, high temperature sintering is eliminated and thermal durability is increased. Cellular breeder morphology, thermal conductivity, specific heat, porosity levels, high temperature mechanical properties, and deuterium charging-desorption rates are presented.

  5. Universal Fast Breeder Reactor Subassembly Counter manual

    International Nuclear Information System (INIS)

    Menlove, H.O.; Eccleston, G.W.; Swansen, J.E.; Goris, P.; Abedin-Zadeh, R.; Ramalho, A.

    1984-08-01

    A neutron coincidence counter has been designed for the measurement of fast breeder reactor fuel assemblies. This assay system can accommodate the full range of geometries and masses found in fast breeder subassemblies under IAEA safeguards. The system's high-performance capability accommodates high plutonium loadings of up to 16 kg. This manual describes the system and its operation and gives performance and calibration parameters for typical applications

  6. Cross-infection between tropical goats and heifers with Haemonchus contortus.

    Science.gov (United States)

    d'Alexis, S; Mahieu, M; Jackson, F; Boval, M

    2012-03-23

    Developing effective biological control without the systematic use of anthelmintics is necessary to reduce the impact of gastrointestinal nematodes on small ruminants. Therefore, grazing management systems that use different host species to dilute nematodes in pasture appear to be promising for worm control. A trial was carried out to investigate the specificity of Haemonchus contortus for goats and cattle and to evaluate cross-infection between ruminant species. The effect of an experimental infection of 12 heifers by the free-living stages of H. contortus collected from goats (500 larvae per kg liveweight) was evaluated and compared to uninfected controls. After 28 and 35 days, egg excretion was measured. The experimental infection of heifers by H. contortus was not significant, with no egg excretion. These results, i.e., the lack of cross-infection of GIN between goats and cattle, suggest that integrated grazing using such animals could be employed for pasture dilution and decontamination. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Genetic analysis of calf and heifer losses in Danish Holstein

    DEFF Research Database (Denmark)

    Fuerst-Walti, B; Sørensen, Morten Kargo

    2010-01-01

    Mortality in dairy cattle is not only relevant with regard to economic losses but also to animal health and welfare. Thus, the aim of this investigation was to explore the genetic background of postnatal mortality in calves and replacement heifers in different age groups until first calving...... periods, whereas their records were kept for preceding periods. After further data editing, more than 840,000 calves and heifers born in the years 1998 to 2007 were investigated. Mortality rates were 3.23, 2.66, 0.97, 1.92, and 9.36% for the defined periods P1 to P5, respectively. For the estimation...... of genetic parameters, linear and threshold sire models were applied. Effects accounted for were the random effects herd × year × season and sire as well as the fixed effects year × month, number of dam's parity (parities >5 were set to 5), calf size, and calving ease. In total, the pedigree consisted of 4...

  8. Status of fast breeder reactor development in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, S

    1979-07-01

    This document was prepared by the Office of the Program Director for Nuclear Energy, U.S. Department of Energy (USDOE). It sets forth the status and current activities for the development of fast breeder technology in the United States. In April 1977 the United States announced a change in its nuclear energy policy. Concern about the potential for the proliferation of nuclear weapons capability emerged as a major issue in considering whether to proceed with the development, demonstration and eventual deployment of breeder reactor energy systems. Plutonium recycle and the commercialization of the fast breeder were deferred indefinitely. This led to a reorientation of the nuclear fuel cycle program which was previously directed toward the commercialization of fuel reprocessing and plutonium recycle to the investigation of a full range of alternative fuel cycle technologies. Two major system evaluation programs, the Nonproliferation Alternative Systems Assessment Program (NASAP), which is domestic, and the International Nuclear Fuel Cycle Evaluation (INFCE), which is international, are assessing the nonproliferation advantages and other characteristics of advanced reactor concepts and fuel cycles. These evaluations will allow a decision in 1981 on the future direction of the breeder program. In the interim, the technologies of two fast breeder reactor concepts are being developed: the Liquid Metal Fast Breeder Reactor (LMFBR) and the Gas Cooled Fast Reactor (CFR). The principal goals of the fast breeder program are: LMFBR - through a strong R and D program, consistent with US nonproliferation objectives and anticipated national electric energy requirements, maintain the capability to commit to a breeder option; investigate alternative fuels and fuel cycles that might offer nonproliferation advantages; GCFR - provide a viable alternative to the LMFBR that will be consistent with the developing U.S. nonproliferation policy; provide GCFR technology and other needed

  9. Method for cooling a breeder reactor and breeder reactor for applying the method

    International Nuclear Information System (INIS)

    Gast, K.

    1977-01-01

    The fuel assemblies of the fission zone and the breeder subassemblies in the radial breeding blanket are supported on a double bottom. The coolant gets into the interspace of the double bottom below the blanket. This part of the space is separated from the interspace of the double bottom below the fission zone. Each breeder subassembly consists of a twin tube. The coolant enters the inner tube, flows through it upwards in axial direction, is then deflected on the upper end, and afterwards, in the annulus of the twin tube, flows down again in axial direction into the inlet region, below the double bottom. From there on it flows upwards through the fuel assemblies of the fission zone from below. Thereby a uniformly high coolant outlet temperature is obtained. (DG) [de

  10. Pre-breeding blood urea nitrogen concentration and reproductive performance of Bonsmara heifers within different management systems.

    Science.gov (United States)

    Tshuma, Takula; Holm, Dietmar Erik; Fosgate, Geoffrey Theodore; Lourens, Dirk Cornelius

    2014-08-01

    This study investigated the association between pre-breeding blood urea nitrogen (BUN) concentration and reproductive performance of beef heifers within different management systems in South Africa. Bonsmara heifers (n = 369) from five herds with different estimated levels of nitrogen intake during the month prior to the commencement of the breeding season were sampled in November and December 2010 to determine BUN concentrations. Body mass, age, body condition score (BCS) and reproductive tract score (RTS) were recorded at study enrolment. Trans-rectal ultrasound and/or palpation was performed 4-8 weeks after a 3-month breeding season to estimate the stage of pregnancy. Days to pregnancy (DTP) was defined as the number of days from the start of the breeding season until the estimated conception date. Logistic regression and Cox proportional hazards survival analysis were performed to estimate the association of pre-breeding BUN concentration with subsequent pregnancy and DTP, respectively. After stratifying for herd and adjusting for age, heifers with relatively higher pre-breeding BUN concentration took longer to become pregnant when compared to those with relatively lower BUN concentration (P = 0.011). In the herd with the highest estimated nitrogen intake (n = 143), heifers with relatively higher BUN were less likely to become pregnant (P = 0.013) and if they did, it was only later during the breeding season (P = 0.017), after adjusting for body mass. These associations were not present in the herd (n = 106) with the lowest estimated nitrogen intake (P > 0.500). It is concluded that Bonsmara heifers with relatively higher pre-breeding BUN concentration, might be at a disadvantage because of this negative impact on reproductive performance, particularly when the production system includes high levels of nitrogen intake.

  11. Effect of progesterone supplementation in the first week post conception on embryo survival in beef heifers.

    Science.gov (United States)

    Beltman, M E; Lonergan, P; Diskin, M G; Roche, J F; Crowe, M A

    2009-04-15

    Progesterone is essential for establishment and maintenance of pregnancy in mammals. The objective of this study was to examine the effect of elevating progesterone during the different physiological stages of early embryo development on embryo survival. Estrus was synchronized in cross-bred beef heifers (n=197, approximately 2-years old) and they were inseminated 12-18h after estrus onset (=Day 0). Inseminated heifers were randomly assigned to 1 of 3 treatments: (1) Control, n=69; (2) progesterone supplementation using a Controlled Internal Drug Release Device (CIDR) from Day 3 to 6.5, n=64; or (3) progesterone supplementation using a CIDR from Day 4.5 to 8, n=64. Body condition (BCS) and locomotion scores (scale of 1-5) were recorded for all animals. Animals with a locomotion score >/=4 (very lame) were excluded. Embryo survival rate was determined at slaughter on Day 25. Conceptus length and weight were recorded and the corpus luteum (CL) of all pregnant animals was dissected and weighed. Supplementation with exogenous progesterone increased (Prate compared with controls. Mean CL weight, conceptus length and conceptus weight were not different between treatments. There was a positive relationship (Prate in treated heifers and a similar trend existed between the increase from Days 4.5 to 8 (Prate in treated heifers. A direct correlation was seen between locomotion score and embryo survival rate, with higher (Prates in heifers with a lower locomotion score. In conclusion, supplementation with progesterone at different stages of early embryo development increased peripheral progesterone concentration and resulted in a positive association between changes in progesterone concentration during the early luteal phase and embryo survival rate. Supplementation with progesterone had no effect on either CL weight or conceptus size in pregnant animals. Lameness had a significant negative effect on early embryo survival.

  12. R + D work on gas-cooled breeder development

    International Nuclear Information System (INIS)

    Dalle Donne, M.; Dorner, S.; Jacobs, G.; Meyer, L.; Rehme, K.; Schumacher, G.; Wilhelm, D.

    1978-01-01

    The development work for the gas-cooled breeder in the Karlsruhe Nuclear Research Center may be assigned to two different groups: a) Investigations on fuel elements. b) Studies concerning the safety of gas-cooled fast breeder reactors. To the first group there belongs the work related to the: - heat transfer between fuel elements and coolant gas, - influence of increased content of water vapor in helium or the fuel rods. The second group concerns: - establishing a computer code for transient calculations in the primary and secondary circuit of a gas-cooled fast breeder reactor, - steam reactivity coefficients, - the core destruction phase of hypothetical accidents, - the core-catcher using borax. (orig./RW) [de

  13. Genome-wide association for heifer reproduction and calf performance traits in beef cattle.

    Science.gov (United States)

    Akanno, Everestus C; Plastow, Graham; Fitzsimmons, Carolyn; Miller, Stephen P; Baron, Vern; Ominski, Kimberly; Basarab, John A

    2015-12-01

    The aim of this study was to identify SNP markers that associate with variation in beef heifer reproduction and performance of their calves. A genome-wide association study was performed by means of the generalized quasi-likelihood score (GQLS) method using heifer genotypes from the BovineSNP50 BeadChip and estimated breeding values for pre-breeding body weight (PBW), pregnancy rate (PR), calving difficulty (CD), age at first calving (AFC), calf birth weight (BWT), calf weaning weight (WWT), and calf pre-weaning average daily gain (ADG). Data consisted of 785 replacement heifers from three Canadian research herds, namely Brandon Research Centre, Brandon, Manitoba, University of Alberta Roy Berg Kinsella Ranch, Kinsella, Alberta, and Lacombe Research Centre, Lacombe, Alberta. After applying a false discovery rate correction at a 5% significance level, a total of 4, 3, 3, 9, 6, 2, and 1 SNPs were significantly associated with PBW, PR, CD, AFC, BWT, WWT, and ADG, respectively. These SNPs were located on chromosomes 1, 5-7, 9, 13-16, 19-21, 24, 25, and 27-29. Chromosomes 1, 5, and 24 had SNPs with pleiotropic effects. New significant SNPs that impact functional traits were detected, many of which have not been previously reported. The results of this study support quantitative genetic studies related to the inheritance of these traits, and provides new knowledge regarding beef cattle quantitative trait loci effects. The identification of these SNPs provides a starting point to identify genes affecting heifer reproduction traits and performance of their calves (BWT, WWT, and ADG). They also contribute to a better understanding of the biology underlying these traits and will be potentially useful in marker- and genome-assisted selection and management.

  14. International breeder reactor development

    International Nuclear Information System (INIS)

    Traube, K.

    1976-01-01

    For more than a decade, sodium cooled breeder reactors have now been in the focus of advanced nuclear power development in the major industrialized countries. In the sixties, a total of seven small experimental nuclear power stations were commissioned. Two of these have been shut down in the meantime, the others continue to work satisfactorily, their main purpose being the development of fuel elements. The years 1972-1974 saw the commissioning of the prototype power stations in the 300 MWe power category in France, the United Kingdom and the Soviet Union. Presently, other experimental reactors are under construction in the Federal Republic of Germany, Italy, Japan, the United States, plus another Soviet 600 MWe prototype reactor and the SNR 300 DeBeNeLux prototype at Kalkar. A comparison of the technological features either implemented or planned in the prototype and experimental power plants and of their fuel elements reveals a remarkable similarity in the basic concepts pursued in different countries. The two types of breeder reactors, viz. the loop and the pool types, show a closer resemblance to each other than do pressurized and boilling water reactors. The growing awareness of administrative problems emerging in the approaching phase of the introduction of large breeder power stations in a number of European countries has recently led to a streamlining effort in the structure of industries and to tentative steps towards international cooperation on a broad basis. (orig.) [de

  15. Liquid metal cooled fast breeder nuclear reactors

    International Nuclear Information System (INIS)

    Thatcher, G.; Mitchell, A.J.

    1981-01-01

    Fuel sub-assemblies for liquid metal-cooled fast breeder reactors are described which each incorporate a fluid flow control valve for regulating the rate of flow through the sub-assembly. These small electro-magnetic valves seek to maintain the outlet coolant temperature of at least some of the breeder sub-assemblies substantially constant throughout the life of the fuel assembly without severely pressurising the sub-assembly. (U.K.)

  16. Universal Fast Breeder Reactor Subassembly Counter manual

    Energy Technology Data Exchange (ETDEWEB)

    Menlove, H.O.; Eccleston, G.W.; Swansen, J.E.; Goris, P.; Abedin-Zadeh, R.; Ramalho, A.

    1984-08-01

    A neutron coincidence counter has been designed for the measurement of fast breeder reactor fuel assemblies. This assay system can accommodate the full range of geometries and masses found in fast breeder subassemblies under IAEA safeguards. The system's high-performance capability accommodates high plutonium loadings of up to 16 kg. This manual describes the system and its operation and gives performance and calibration parameters for typical applications.

  17. 04 - Sodium cooled fast breeder fourth-generation reactors - The experimental reactor ALLEGRO, the other ways for fast breeder fourth-generation reactors

    International Nuclear Information System (INIS)

    2012-12-01

    The authors first present the technology of gas-cooled fast breeder reactors (basic principles, specific innovations, feasibility studies, fuel element, safety) and notably the ALLEGRO project (design options and expected performances, preliminary safety demonstration). Then, they present the lead-cooled fast-breeder reactor technology: interests and obstacles, return on experience, the issue of lead density, neutron assessment, transmutation potential, dosimetry, safety chemical properties and compatibility with the fuel, water, air and steels. The next part addresses the technology of molten-salt fast-breeder reactors: choice of the liquid fuel and geometry, reactor concept (difficulties, lack of past R and D), demonstration and demonstrators, international context

  18. Fast breeder reactors an engineering introduction

    CERN Document Server

    Judd, A M

    1981-01-01

    Fast Breeder Reactors: An Engineering Introduction is an introductory text to fast breeder reactors and covers topics ranging from reactor physics and design to engineering and safety considerations. Reactor fuels, coolant circuits, steam plants, and control systems are also discussed. This book is comprised of five chapters and opens with a brief summary of the history of fast reactors, with emphasis on international and the prospect of making accessible enormous reserves of energy. The next chapter deals with the physics of fast reactors and considers calculation methods, flux distribution,

  19. Transcriptome analyses identify five transcription factors differentially expressed in the hypothalamus of post- versus prepubertal Brahman heifers.

    Science.gov (United States)

    Fortes, M R S; Nguyen, L T; Weller, M M D C A; Cánovas, A; Islas-Trejo, A; Porto-Neto, L R; Reverter, A; Lehnert, S A; Boe-Hansen, G B; Thomas, M G; Medrano, J F; Moore, S S

    2016-09-01

    Puberty onset is a developmental process influenced by genetic determinants, environment, and nutrition. Mutations and regulatory gene networks constitute the molecular basis for the genetic determinants of puberty onset. The emerging knowledge of these genetic determinants presents opportunities for innovation in the breeding of early pubertal cattle. This paper presents new data on hypothalamic gene expression related to puberty in (Brahman) in age- and weight-matched heifers. Six postpubertal heifers were compared with 6 prepubertal heifers using whole-genome RNA sequencing methodology for quantification of global gene expression in the hypothalamus. Five transcription factors (TF) with potential regulatory roles in the hypothalamus were identified in this experiment: , , , , and . These TF genes were significantly differentially expressed in the hypothalamus of postpubertal versus prepubertal heifers and were also identified as significant according to the applied regulatory impact factor metric ( cancer and developmental processes. Mutations in were associated with puberty in humans. Mutations in these TF, together with other genetic determinants previously discovered, could be used in genomic selection to predict the genetic merit of cattle (i.e., the likelihood of the offspring presenting earlier than average puberty for Brahman). Knowledge of key mutations involved in genetic traits is an advantage for genomic prediction because it can increase its accuracy.

  20. Optimization of binary breeder reactor V - Binary breeder reactors with two and four zones and a conventional LMFBR - (Pu/U) of two zones

    International Nuclear Information System (INIS)

    Dias, A.F.; Ishiguro, Y.

    1986-04-01

    Comparative analyses of a commercial-size Pu/U-fueled liquid metal fast breeder reactor and two binary breeder reactors with different numbers of enrichment zones have been done. Principal parameters of comparison are safety and breeding characteristics and reactivity losses during an operational cycle. The comparison shows that in a binary breeder reactor, good breeding characteristics in both cycles, Pu/U and U/Th, in addition to a possibility of an efficient utilization of thorium, and superior inherent safety than current LMFBRs can be achieved. (Author) [pt

  1. Simulation and design of an electron beam ion source charge breeder for the californium rare isotope breeder upgrade

    Directory of Open Access Journals (Sweden)

    Clayton Dickerson

    2013-02-01

    Full Text Available An electron beam ion source (EBIS will be constructed and used to charge breed ions from the californium rare isotope breeder upgrade (CARIBU for postacceleration into the Argonne tandem linear accelerator system (ATLAS. Simulations of the EBIS charge breeder performance and the related ion transport systems are reported. Propagation of the electron beam through the EBIS was verified, and the anticipated incident power density within the electron collector was identified. The full normalized acceptance of the charge breeder with a 2 A electron beam, 0.024π  mm mrad for nominal operating parameters, was determined by simulating ion injection into the EBIS. The optics of the ion transport lines were carefully optimized to achieve well-matched ion injection, to minimize emittance growth of the injected and extracted ion beams, and to enable adequate testing of the charge bred ions prior to installation in ATLAS.

  2. Correlation between intake and ingestive behavior of pasture-grazed heifers

    Directory of Open Access Journals (Sweden)

    Hermógenes Almeida Santana Junior

    2013-12-01

    Full Text Available The objective of this study was to evaluate the correlation between intake and ingestive behavior of crossbred heifers in grazing tropical. The experiment was conducted on the Princesa do Mateiro Farm, in the city of Ribeirão do Largo, Bahia. A total of 20 heifers with genetic makeup 5/8 dairy Guzerá and 3/8 Holstein, average age of 18 months and body weight of 187 ± 13.1 kg have been used. The experiment lasted 224 days and involved animals raised in a rotational grazing system with Brachiaria brizantha cv. Marandú. Grazing time was not correlated with any of the variables associated with intake. Rumination time showed positive correlations with the intake of forage dry matter (DMIF and neutral detergent fiber (NDFI. Variables associated with the time spent on feeding at the trough, overall feeding and total chewing were not correlated with intake (P>0.05. There have been positive correlations between the number of grazing periods (NGP and rumination periods (NRP and total DM intake (TDMI, organic matter (OMI, forage (DMIF, neutral detergent fiber (NDFI, total carbohydrates (TCHI and ether extract (EEI. Crude protein intake (CPI was positively correlated with NGP and NRP. The mouthful rate was positively correlated with TDMI, OMI, DMIF, NDFI, TCHI, EEI and CPI. Average time per swallow was negatively correlated with TDMI, OMI, NDFI, TCHI and EEI. Positive correlations have been observed between the number of mouthfuls per day and TDMI, OMI, DMIF, NDFI, TCHI, EEI. The number of chews per bolus showed negative correlations with DMIS and CPI. The time per cake ruminated has correlated negatively with the intake of crude protein. The number of chews per bolus showed positive correlations with the intakes of dry matter and neutral detergent fiber. The number of boli per day showed positive correlations with DMIF and TCHI. The time spent on chewing showed no significant correlation with intake. In conflict with the national and international

  3. An empirical analysis of the cost of rearing dairy heifers from birth to first calving and the time taken to repay these costs.

    Science.gov (United States)

    Boulton, A C; Rushton, J; Wathes, D C

    2017-08-01

    Rearing quality dairy heifers is essential to maintain herds by replacing culled cows. Information on the key factors influencing the cost of rearing under different management systems is, however, limited and many farmers are unaware of their true costs. This study determined the cost of rearing heifers from birth to first calving in Great Britain including the cost of mortality, investigated the main factors influencing these costs across differing farming systems and estimated how long it took heifers to repay the cost of rearing on individual farms. Primary data on heifer management from birth to calving was collected through a survey of 101 dairy farms during 2013. Univariate followed by multivariable linear regression was used to analyse the influence of farm factors and key rearing events on costs. An Excel spreadsheet model was developed to determine the time it took for heifers to repay the rearing cost. The mean±SD ages at weaning, conception and calving were 62±13, 509±60 and 784±60 days. The mean total cost of rearing was £1819±387/heifer with a mean daily cost of £2.31±0.41. This included the opportunity cost of the heifer and the mean cost of mortality, which ranged from £103.49 to £146.19/surviving heifer. The multivariable model predicted an increase in mean cost of rearing of £2.87 for each extra day of age at first calving and a decrease in mean cost of £6.06 for each percentile increase in time spent at grass. The model also predicted a decrease in the mean cost of rearing in autumn and spring calving herds of £273.20 and £288.56, respectively, compared with that in all-year-round calving herds. Farms with herd sizes⩾100 had lower mean costs of between £301.75 and £407.83 compared with farms with economic analysis suggest that management decisions on key reproduction events and grazing policy significantly influence the cost of rearing and the time it takes for heifers to start making a profit for the farm.

  4. Status and prospects of thermal breeders and their effect on fuel utilization

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    The report evaluates the extent to which thermal breeders and near-breeders might complement fast breeders or serve as an alternative in solving the long-term nuclear fuel supply problem. It considers in a general way issues such as proliferation, safety, environmental impacts, economics, power plant availability and fuel cycle versatility in order to determine whether thermal breeder reactors offer advantages or disadvantages with respect to such issues.

  5. Status and prospects of thermal breeders and their effect on fuel utilization

    International Nuclear Information System (INIS)

    1979-01-01

    The report evaluates the extent to which thermal breeders and near-breeders might complement fast breeders or serve as an alternative in solving the long-term nuclear fuel supply problem. It considers in a general way issues such as proliferation, safety, environmental impacts, economics, power plant availability and fuel cycle versatility in order to determine whether thermal breeder reactors offer advantages or disadvantages with respect to such issues

  6. Enteric methane emissions from low- and high-residual feed intake beef heifers measured using GreenFeed and respiration chamber techniques.

    Science.gov (United States)

    Alemu, A W; Vyas, D; Manafiazar, G; Basarab, J A; Beauchemin, K A

    2017-08-01

    The objectives of this study were to evaluate the relationship between residual feed intake (RFI; g/d) and enteric methane (CH) production (g/kg DM) and to compare CH and carbon dioxide (CO) emissions measured using respiration chambers (RC) and the GreenFeed emission monitoring (GEM) system (C-Lock Inc., Rapid City, SD). A total of 98 crossbred replacement heifers were group housed in 2 pens and fed barley silage ad libitum and their individual feed intakes were recorded by 16 automated feeding bunks (GrowSafe, Airdrie, AB, Canada) for a period of 72 d to determine their phenotypic RFI. Heifers were ranked on the basis of phenotypic RFI, and 16 heifers (8 with low RFI and 8 with high RFI) were randomly selected for enteric CH and CO emissions measurement. Enteric CH and CO emissions of individual animals were measured over two 25-d periods using RC (2 d/period) and GEM systems (all days when not in chambers). During gas measurements metabolic BW tended to be greater ( ≤ 0.09) for high-RFI heifers but ADG tended ( = 0.09) to be greater for low-RFI heifers. As expected, high-RFI heifers consumed 6.9% more feed ( = 0.03) compared to their more efficient counterparts (7.1 vs. 6.6 kg DM/d). Average CH emissions were 202 and 222 g/d ( = 0.02) with the GEM system and 156 and 164 g/d ( = 0.40) with RC for the low- and high-RFI heifers, respectively. When adjusted for feed intake, CH yield (g/kg DMI) was similar for high- and low-RFI heifers (GEM: 27.7 and 28.5, = 0.25; RC: 26.5 and 26.5, = 0.99). However, CH yield differed between the 2 measurement techniques only for the high-RFI group ( = 0.01). Estimates of CO yield (g/kg DMI) also differed between the 2 techniques ( ≤ 0.03). Our study found that high- and low-efficiency cattle produce similar CH yield but different daily CH emissions. The 2 measurement techniques differ in estimating CH and CO emissions, partially because of differences in conditions (lower feed intakes of cattle while in chambers, fewer days

  7. Fast breeder fuel element development

    International Nuclear Information System (INIS)

    Marth, W.; Muehling, G.

    1983-08-01

    This report is a compilation of the papers which have been presented during a seminar ''Fast Breeder Fuel Element Development'' held on November 15/16, 1982 at KfK. The papers give a survey of the status, of the obtained results and of the necessary work, which still has to be done in the frame of various development programmes for fast breeder fuel elements. In detail the following items were covered by the presentations: - the requirements and boundary conditions for the design of fuel pins and elements both for the reference concept of the SNR 300 core and for the large, commercial breeder type of the future (presentation 1,2 and 6); - the fabrication, properties and characterization of various mixed oxide fuel types (presentations 3,4 and 5); - the operational fuel pin behaviour, limits of different design concepts and possible mechanism for fuel pin failures (presentations (7 and 8); - the situation of cladding- and wrapper materials development especially with respect to the high burn-up values of commercial reactors (presentations 9 and 10); - the results of the irradiation experiments performed under steady-state and non-stationary operational conditions and with failed fuel pins (presentations 11, 12, 13 and 14). (orig./RW) [de

  8. The nuclear question at the start of the '80s: the breeder reactor

    International Nuclear Information System (INIS)

    Owen, R.; Svensson, B.

    1980-01-01

    The four newspaper articles and the letter cover the following matters: general introduction about breeder reactors and the situation in Swedish politics; visit to Dounreay to discuss breeder reactors (breeding, safety, plutonium production, radiation protection); PuO 2 -UO 2 mixed fuel; description of breeder reactors; efficiency in use of U-235; DFR and PFR; breeder reactors in Swedish politics (arguments for and against nuclear power in general, breeder reactors in particular); discussion of the future of nuclear power in Sweden. (U.K.)

  9. Supplement to Final Environmental Statement related to construction and operation of Clinch River Breeder Reactor Plant, Docket No. 50-537

    International Nuclear Information System (INIS)

    1982-10-01

    In February 1977, the Office of Nuclear Reactor Regulation issued a Final Environmental Statement (FES) (NUREG-0139) related to the construction and operation of the proposed Clinch River Breeder Reactor Plant (CRBRP). Since the FES was issued, additional data relative to the site and its environs have been collected, several modifications have been made to the CRBRP design, and its fuel cycle, and the timing of the plant construction and operation has been affected in accordance with deferments under the DOE Liquid Metal Fast Breeder Reactor (LMFBR) program. These changes are summarized and their environmental significance is assessed in this document. The reader should note that this document generally does not repeat the substantial amount of information in the FES which is still current; hence, the FES should be consulted for a comprehensive understanding of the staff's environmental review of the CRBRP project

  10. Genetic covariance functioners for live weight, condition score, and dry-matter intake measured at different lactations stages of Holstein-Friesian heifers

    NARCIS (Netherlands)

    Koenen, E.P.C.; Veerkamp, R.F.

    1998-01-01

    Genetic parameters for live weight, body condition score and dry-matter intake of dairy heifers were estimated using covariance function methodology. Data were from 469 heifers of the Langhill Dairy Cattle Research Centre and included observations during the first 25 weeks in lactation. Genetic

  11. Neutronic optimization of solid breeder blankets for STARFIRE design

    International Nuclear Information System (INIS)

    Gohar, Y.; Abdou, M.A.

    1980-01-01

    Extensive neutronic tradeoff studies were carried out to define and optimize the neutronic performance of the different solid breeder options for the STARFIRE blanket design. A set of criteria were employed to select the potential blanket materials. The basic criteria include the neutronic performance, tritium-release characteristics, material compatibility, and chemical stability. Three blanket options were analyzed. The first option is based on separate zones for each basic blanket function where the neutron multiplier is kept in a separate zone. The second option is a heterogeneous blanket type with two tritium breeder zones. In the first zone the tritium breeder is assembled in a neutron multiplier matrix behind the first wall while the second zone has a neutron moderator matrix instead of the neutron multiplier. The third blanket option is similar to the second concept except the tritium breeder and the neutron multiplier form a homogeneous mixture

  12. comparative beef production from buli,s, steers and heifers under

    African Journals Online (AJOL)

    steers, although statistically significant, were much srnaller than differences obtained in the present study. Out of a maximum possible grading of 20 points, bulls obtained an average of 12,3 points (Grade I -) which is considerably lower than the grading points obtained by steers (16,3 = Prime) or by heifers (17,5 = Prime+).

  13. Serological response to an indirect and a competitive elisa in heifers vaccinated with Brucella abortus strain 19

    International Nuclear Information System (INIS)

    Carrasco, E.A.; Uzal, F.A.; Echaide, S.

    1998-01-01

    The different serologic techniques for bovine brucellosis diagnosis have different abilities to detect antibodies after vaccination with Brucella abortus strain 19. The humoral response in heifers vaccinated with Brucella abortus strain 19 was evaluated by using several serologic techniques. In the experimental field of INTA, Pilcaniyeu, Rio Negro province, sixteen 5 months old heifers were vaccinated subcutaneously with a standard dose (2ml, containing 20x10 9 to 10x10 9 living organisms) of Brucella abortus strain 19. Sera from all the heifers were obtained on 18 occasions (one 87 days before vaccination, one immediately before vaccination and on 16 occasions after vaccination, during 488 days) and analyzed by buffered plate antigen test, rose bengal test, standard tube agglutination test, 2-mercaptoetanol test, complement fixation test, indirect ELISA, and competitive ELISA. Prior vaccination, 100% of the heifers gave negative results in all the techniques used, while 100% of them gave positive reaction in the first sampling after vaccination to all the techniques, with the exception of standard tube agglutination test that showed agglutinating titters of 1/100 or higher (positive threshold) in only 71.4% of the heifers. The indirect ELISA technique showed a reducing percentage of positive animals up until 316 days after vaccination, after which positive results were obtained. The competitive ELISA gave positive results in a variable number of heifers up to 253 days after vaccination when 100% of the sera were negative to this technique. Buffered plate antigen test was the technique that gave positive results for a longest period, being 100% of the animals negative to this technique at 450 days after vaccination. The other serological techniques assayed gave positive results during variable periods of time, intermediate between standard tube agglutination test and buffered plate antigen test. Although the present results were obtained from a limited number of

  14. Evaluation of the innate immune response of Angus heifers with genetic marker variation for intramuscular fat deposition following a lipopolysaccharide challenge

    Science.gov (United States)

    This study evaluated the effect of genetic selection for markers related to marbling deposition in Angus heifers on the immune response following a lipopolysaccharide (LPS) challenge. Fall-born heifers (n = 19; ~7 months of age, 274 +/- 24 kg) with genetic variation for marbling were utilized inclu...

  15. Coatings for fast breeder reactor components

    International Nuclear Information System (INIS)

    Johnson, R.N.

    1984-04-01

    Several types of metallurgical coatings are used in the unique environments of the fast breeder reactor. Most of the coatings have been developed for tribological applications, but some also serve as corrosion barriers, diffusion barriers, or radionuclide traps. The materials that have consistently given the best performance as tribological coatings in the breeder reactor environments have been coatings based on chromium carbide, nickel aluminide, or Tribaloy 700 (a nickel-base hard-facing alloy). Other coatings that have been qualified for limited applications include chromium plating for low temperature galling protection and nickel plating for radionuclide trapping

  16. Symbiosis of near breeder HTR's with hybrid fusion reactors

    International Nuclear Information System (INIS)

    Seifritz, W.

    1978-07-01

    In this contribution to INFCE a symbiotic fusion/fission reactor system, consisting of a hybrid beam-driven micro-explosion fusion reactor (HMER) and associated high-temperature gas-cooled reactors (HTR) with a coupled fuel cycle, is proposed. This system is similar to the well known Fast Breeder/Near Breeder HTR symbiosis except that the fast fission breeder - running on the U/Pu-cycle in the core and the axial blankets and breeding the surplus fissile material as U-233 in its radial thorium metal or thorium oxide blankets - is replaced by a hybrid micro-explosion DT fusion reactor

  17. Plasma focus breeder

    International Nuclear Information System (INIS)

    Ikuta, Kazunari.

    1981-09-01

    Instead of using linear accelerators, it is possible to breed fissile fuels with the help of high current plasma focus device. A mechanism of accelerating proton beam in plasma focus device to high energy would be a change of inductance in plasma column because of rapid growth of plasma instability. A possible scheme of plasma focus breeder is also proposed. (author)

  18. Management of Waste from the Fusion Experimental Breeder

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    <正> Fusion breeder might be an essential intermediate application of fusion energy at earlier term, which has the potential to provide plenty of commercial fissile fuel. Based on fusion physics and technologies available at present and in near future, the realistic Fusion Experimental Breeder, FEB-E was designed. The obiectives of the FEB-E are to demonstrate the engineering feasibility of

  19. Thermomechanical analysis of solid breeders in sphere-pac, plate, and pellet configurations

    International Nuclear Information System (INIS)

    Blanchard, J.P.; Ghoniem, N.M.

    1986-02-01

    The first configuration studied is called sphere-pac. It features small breeder spheres of three different diameters, thus allowing efficient packing and minimal void fraction. The concept originated as an attempt to minimize thermal stresses in the breeder and improve the predictability of the breeder-structure interface heat conduction. In general the breeder is made as thin as possible, to maximize the breeding ratio, so the cladding's integrity will likely be the life-limiting issue of this concept. The third breeder configuration is in the form of pellets cladded by steel tubes. The major thermomechanical issue of the pin-type designs is cracking, which would impair the thermal performance of the blanket. Fortunately, the pins can be sized to prevent cracking under normal operation. In this report we have treated each blanket generically, dealing with basic issues rather than design specifics. Our basic philosophy is to avoid cracking of the breeder if at all possible. It can be argued that cracking could be allowed, but this would sacrifice predictability of the blanket thermal performance and tritium release characteristics. Proper design can and should minimize breeder cracking

  20. Processing and waste disposal representative for fusion breeder blanket systems

    International Nuclear Information System (INIS)

    Finn, P.A.; Vogler, S.

    1987-01-01

    This study is an evaluation of the waste handling concepts applicable to fusion breeder systems. Its goal is to determine if breeder blanket waste can be disposed of in shallow land burial, the least restrictive method under US Nuclear Regulatory regulations. The radionuclides expected in the materials used in fusion reactor blankets are described, as are plans for reprocessing and disposal of the components of different breeder blankets. An estimate of the operating costs involved in waste disposal is made

  1. Immunological parameters and residual feed intake of Nellore heifers

    Directory of Open Access Journals (Sweden)

    Cleisy Ferreira Nascimento

    2012-12-01

    Full Text Available The residual feed intake (RFI is a parameter used in the identification of animals with respect to more efficient feed utilization. However, physiological basis are still unknown, however, the interrelationships between nutrition an immunity of the animal can contribute to the investigation of biological phenomena relevant to the RFI, since the defense system to oxidative effects caused by free radicals, is formed by acid polyunsaturated fatty acids, water soluble substances and enzymes, which derive mainly from the use of nutrients in the diet. The objective of this study was to evaluate the immunological parameters of Nellore heifers classified according to RFI. It were evaluated 176 heifers (born between 2008 and 2010, Traditional Nellore herd from Instituto de Zootecnia - Sertãozinho/SP, forming three groups of evaluation, submitted to test post weaning feed efficiency and classified into high (> mean + 0.5 SD, n= 55, medium (± 0.5 SD, n= 65 and low RFI (< mean – 0.5 SD, n= 56. The diet was formulated based on Brachiaria decumbens hay, corn, cottonseed meal and mineral mixture (45:55, forage: concentrate. The weight of the animals were performed in fasting blood samples collected by venipuncture vein, using tubes of 10 ml type vacuntainer with EDTA anticoagulant. In the clinical laboratory, we measured the values of leukocytes (LEU; Targeted (SEG and lymphocytes (LIN. The experimental design was a randomized block design using PROC GLM of SAS, considering the fixed effects of year and the age covariate in the statistical model and the averages compared by Tukey test at 5% probability. There was no significant difference (P>0,005 between variables leukocyte (LEU, SEG and LIN and class of RFI (table 1, indicating that there is no distinction between animals more efficient (low RFI and less efficient (high RFI, for inflammatory and immune responses to oxidative effects. Therefore the variables measured leukocytes not explain the differences

  2. Optimising reproductive performance of beef cows and replacement heifers.

    Science.gov (United States)

    Diskin, M G; Kenny, D A

    2014-05-01

    A reproductively efficient beef cow herd is fundamental to meeting the protein and specifically, red meat demand of an ever increasing global population. However, attaining a high level of reproductive efficiency is underpinned by producers being cognisant of and achieving many key targets throughout the production cycle and requires significant technical competency. The lifetime productivity of the beef bred female commences from the onset of puberty and will be dictated by subsequent critical events including age at first calving, duration of the postpartum interval for each successive calving, conception and pregnancy rate and ultimately manifested as length of intercalving intervals and number of calves weaned over her lifetime. Puberty in heifers is a consequence of the interactive effects of genetics and both pre- and post-weaning nutrition. Early onset of puberty is essential to achieving the first main reproductive target for beef cow herds; first calving at 2 years of age. In calved heifers and mature cows, the onset of ovarian activity, postpartum is a key event dictating the calving interval. Again, this will be the product mainly of prepartum nutrition, manifested through body condition and the strength of the maternal bond between cow and calf, though there is increasing evidence of a modest genetic influence on this trait. Following the initiation of postpartum ovarian cyclicity, conception and subsequent pregnancy rate is generally a function of bull fertility in natural service herds and heat detection and timing of insemination in herds bred through artificial insemination. Cows and heifers should be maintained on a steady plane of nutrition during the breeding season, but the contribution of significant excesses or deficiencies of nutrients including protein and trace elements is likely to be minor where adequate pasture is available. While, increased efforts are being made internationally to genetically identify and select for more reproductively

  3. Conceptual design study for a mirror fusion breeder

    International Nuclear Information System (INIS)

    Huang Jinhua; Deng Boquan; Li Guiqing

    1986-01-01

    A mirror fusion breeder, CHD, has been designed for providing plenty of nuclear fuel for light water reactors to meet the needs for rapid development of nuclear power in the first half of next century. The breeder is able to support the nuclear fuel needs for more than 10 LWRs of equal scale in power with fuel enriched directly in CHD without reprocessing. Measures are taken to flatten the power density distribution in the blanket so that fission is suppressed in the region close to the plasma, and by this way fuel production is enhanced for this direct enriched fusion breeder. In order to reduce the MHD pressure drop, LiPb flows in the blanket axially. Though the tritium inventory in the reactor is very low, special material and design have to be developed to reduce the permeation of tritium through the coolant pipes. The cost of electricity from the system, consisting of 11 LWR plants and one fusion breeder is predicted to be 1.05 times of that from a traditional LWR plant. This figure is insensitive both to the cost of CHD and its support ratio

  4. Ingestive behavior of Nellore heifers grazing receiving the supplement based on propolis or monensin

    Directory of Open Access Journals (Sweden)

    Luiz Juliano Valério Geron

    2014-09-01

    Full Text Available We evaluated the effect of additives the basis of propolis and monensin on ingestive behavior (grazing – GRA, rumination lying – RLY, rumination in foot – RFO, rumination – RUM; idleness lying – ILY, idleness in standing – IDS, idleness – IDL, walking – WAL, posture standing – POS, posture lying – PLY, intake of supplement and water – ISW of heifers in Tifton 85 grazing. The treatments were: no additive (NAD; propolis – PRO (33.24 mg animal-1 of total flavonoid in apigenin, and monensin – MON (100 mg animal-1. Were used five heifers treatment-1 for evaluation of ingestive behavior during 12 hours of total valuation, which was divided into three periods. Used a factorial design into 3 x 3 for evaluation of ingestive behavior as a function of the evaluation periods. Were utilized three paddocks of 2.9 acres of grass Tifton 85. The additives and mineral supplement (50 g animal-1 were provided with 200 g of corn meal to 17 hours. For all activities of the ingestive behaviors observed the effect of period on the time spent on of different activities. The activities of GRA and ISW were higher in the third period (15hours to 19hours compared to the first period (7hours at 11hours. For IDL and PLY, there was a higher time in minutes for heifers treatment with PRO in the period of 7hours at 11hours, compared to other treatments (NAD and MON. Thus, it is concluded that the use of the additive based on propolis enables sodium monensin replacement, to heifers maintained on pasture without changing eating behavior as well as providing greater idleness during the day the without affecting animal performance.

  5. Tritium breeders and tritium permeation barrier coatings for fusion reactor

    International Nuclear Information System (INIS)

    Yamawaki, Michio; Kawamura, Hiroshi; Tsuchiya, Kunihiko

    2004-01-01

    A state of R and D of tritium breeders and tritium permeation barrier coatings for fusion reactor is explained. A list of candidate for tritium breeders consists of ceramics containing lithium, for examples, Li 2 O, Li 2 TiO 3 , Li 2 ZrO 3 , Li 4 SiO 4 and LiAlO 2 . The characteristics and form are described. The optimum particle size is from 1 to 10 μm. The production technologies of tritium breeders in the world are stated. Characteristics of ceramics with lithium as tritium breeders are compared. TiC, TiN/TiC, Al 2 O 3 and Cr 2 O 3 -SiO 2 -P 2 O 5 are tritium permeation barrier coating materials. These production methods and evaluation of characteristics are explained. (S.Y.)

  6. Multigenerational effects of a reduced balanced protein diet during the rearing and laying period of broiler breeders. 1. Performance of the F1 breeder generation.

    Science.gov (United States)

    Lesuisse, J; Li, C; Schallier, S; Clímaco, W L S; Bautil, A; Everaert, N; Buyse, J

    2018-05-01

    Studies on mammals and poultry showed that maternal dietary treatments can alter the offspring performance. However, in contrast to rodent studies, little is known about multigenerational dietary manipulations in broiler breeders. The presented research aimed to investigate the effects of a reduction of 25% in the dietary crude protein (CP) level in the F0 generation on the body composition and reproductive performance of F1 broiler breeders. In the F0 generation, breeders were fed either a control (C) or reduced balanced protein (RP) diet, 25% reduction in crude protein and amino acids. Female F0-progeny of each treatment were fed a C or RP diet, resulting in 4 treatments in the F1 breeder generation: C/C, C/RP, RP/C, and RP/RP. The reproductive performance of breeders fed RP diets was negatively influenced by the dietary CP reduction in the F1 generation (P diets in the F0 generation showed a significantly reduced reproductive capacity compared to their control fed counterparts (P diets in the F1 generation were characterized by higher plasma T3 concentrations (P diets in the F0 generation needed lower feed allocations in the laying phase to maintain a similar body weight. Egg weight was reduced for the C/RP and RP/RP breeders. At 34 wk of age, eggs from C/RP and RP/RP breeders showed a reduced proportional albumen weight, whereas no effects on egg composition were found at 42 wk of age. It was concluded that prenatal protein undernutrition triggered hens to relocate more energy towards growth and maintenance and less towards reproductive capacity.

  7. Growth performance and total tract nutrient digestion for Holstein heifers limit-fed diets high in distillers grains with different forage particle sizes

    Science.gov (United States)

    This study evaluated dairy heifer growth performance and total tract nutrient digestion when fed diets high in dried distillers grains with solubles (DDGS) with different forage particle size. An 8-wk randomized complete block design study was conducted utilizing twenty-two Holstein heifers (123 ±...

  8. A worldwide survey of fast breeder reactors

    International Nuclear Information System (INIS)

    Hennies, H.H.

    1986-01-01

    While the completion of the SNR 300 was accompanied by manifold discussions on questions relevant to safety and energy policies in the Federal Republic of Germany and as a result considerable scheduling delays and exceeding of budgets were recorded, breeder reactor technology has been progressing worldwide. The transition from the development phase with small trial reactors to the construction and operation of large performance reactors was completed systematically, in particular in France and the Soviet Union. Even though the uranium supply situation does not make a short-term and comprehensive employment of fast breeder reactors essential, technology has meanwhile been advanced to such a level and extensive operating experience is on hand to enable the construction and safe operation of fast breeder reactors. A positive answer has long been found to the question of the realization of a breeding rate to guarantee the breeding effect. There remain now the endeavors to achieve a reduction in investment and fuel cycle costs. (orig.) [de

  9. Um programa para o planejamento da recria de fêmeas oriundas de rebanhos leiteiros A computer program for planning dairy heifer raising

    Directory of Open Access Journals (Sweden)

    Moisés de Andrade Resende Filho

    2002-01-01

    Full Text Available Alimentação e manejo inadequados das novilhas em recria constituem alguns dos entraves ao incremento da produtividade do rebanho leiteiro no Brasil. Nessa fase, o pecuarista deve decidir entre recriar os animais de reposição, adquiri-los ou terceirizar sua criação. Além disso, em se decidindo por recriar suas próprias novilhas, seria importante encontrar a melhor alternativa em termos econômicos. Visando auxiliar o pecuarista a resolver tal questão, apresenta-se um modelo matemático que permite estimar os custos decorrentes da recria de fêmeas de rebanhos leiteiros até atingir o peso recomendado à cobertura. Tal modelo foi inserido em um programa de computador de maneira a permitir a construção de diferentes cenários, considerando-se peso, raça e ganho de peso diário do lote de novilhas. Assim, após contrastar os cenários gerados com as opções de compra das novilhas ou terceirização da recria, o pecuarista aumenta as chances de tomar uma decisão mais lucrativa. Exemplos de utilização do modelo inserido em um programa de computador são apresentados e avaliados.Inadequate feeding and management when raising heifers are two factors that constrain dairy cattle productivity in Brazil. In order to build their heads, Brazilian dairy farmers must choose between three options: to raise their own heifers to breeding age, to purchase mature heifers from outside sources, or to employ a custom heifer raiser. If the dairy farmer chooses to raise his own heifers, he needs to determine the most economically rational production strategy. To aid the farmer in this determination, a mathematical model was developed to create a budget for raising a group of heifers to their recommended breeding weight. This model was embedded in a computer program making it possible to build different growth scenarios, which can be adjusted by breed, desired daily weight gain, and average weight for a given group of heifers. After contrasting the results

  10. Fertility of Angus cross beef heifers after GnRH treatment on day 23 and timing of insemination in 14-day CIDR protocol.

    Science.gov (United States)

    Kasimanickam, R K; Hall, J B; Whittier, W D

    2017-02-01

    This study compared artificial insemination pregnancy rate (AI-PR) between 14-day CIDR-GnRH-PGF2α-GnRH and CIDR-PGF2α-GnRH synchronization protocol with two fixed AI times (56 or 72 hr after PGF2α). On day 0, heifers (n = 1311) from nine locations assigned body condition score (BCS: 1, emaciated; 9, obese), reproductive tract score (RTS: 1, immature, acyclic; 5, mature, cyclic) and temperament score (0, calm; and 1, excited) and fitted with a controlled internal drug release (CIDR, 1.38 g of progesterone) insert for 14 days. Within herd, heifers were randomly assigned either to no-GnRH group (n = 635) or to GnRH group (n = 676), and heifers in GnRH group received 100 μg of GnRH (gonadorelin hydrochloride, IM) on day 23. All heifers received 25 mg of PGF2α (dinoprost, IM) on day 30 and oestrous detection aids at the same time. Heifers were observed for oestrus thrice daily until AI. Within GnRH groups, heifers were randomly assigned to either AI-56 or AI-72 groups. Heifers in AI-56 group (n = 667) were inseminated at 56 hr (day 32 PM), and heifers in AI-72 group (n = 644) were inseminated at 72 hr (day 33 AM) after PGF2α administration. All heifers were given 100 μg of GnRH concurrently at the time AI. Controlling for BCS (p < .05), RTS (p < .05), oestrous expression (p < .001), temperament (p < .001) and GnRH treatment by time of insemination (p < .001), the AI-PR differed between GnRH treatment [GnRH (Yes - 60.9% (412/676) vs. No - 55.1% (350/635); p < .05)] and insemination time [AI-56 - 54.6% (364/667) vs. AI-72 - 61.8% (398/644); (p < .01)] groups. The GnRH treatment by AI time interaction influenced AI-PR (GnRH56 - 61.0% (208/341); GnRH72 - 60.9% (204/335); No-GnRH56 - 47.9% (156/326); No-GnRH72 - 62.8% (194/309); p < .001). In conclusion, 14-day CIDR synchronization protocol for FTAI required inclusion of GnRH on day 23 if inseminations were to be performed at 56 hr after PGF2α in order to achieve greater AI-PR.

  11. Technical note: whole-pen assessments of nutrient excretion and digestibility from dairy replacement heifers housed in sand-bedded freestalls.

    Science.gov (United States)

    Coblentz, W K; Hoffman, P C; Esser, N M; Bertram, M G

    2013-10-01

    Our objectives were to describe and test refined procedures for quantifying excreta produced from whole pens of dairy heifers. Previous research efforts attempting to make whole-pen measurements of excreta output have been complicated by the use of organic bedding, which requires cumbersome analytical techniques to quantify excreta apart from the bedding. Research pens equipped with sand-bedded freestalls offer a unique opportunity for refinement of whole-pen fecal collection methods, primarily because sand-bedded freestall systems contain no organic bedding; therefore, concentrations of ash within the manure, sand, and feces can be used to correct for contamination of manure by sand bedding. This study was conducted on a subset of heifers from a larger production-scale feeding trial evaluating ensiled eastern gamagrass [Tripsacum dactyloides (L.) L.] haylage (EGG) that was incorporated into a corn silage/alfalfa haylage-based blended diet at rates of 0, 9.1, 18.3, or 27.4% of total DM. The diet without EGG also was offered on a limit-fed basis. Eighty Holstein dairy heifers were blocked (heavy weight, 424 ± 15.9 kg; light weight, 324 ± 22.4 kg) and then assigned to 10 individual pens containing 8 heifers/pen. One pen per block was assigned to each of the 5 research diets, and whole-pen fecal collections were conducted twice for each pen. Grab fecal samples also were gathered from individual heifers within each pen, and subsequent analysis of these whole-pen composites allowed reasonable estimates of OM and NDF excreta output. Under the conditions of our experimental design, pooled SEM for the excreta DM, OM, NDF, and NDF (ash corrected) output were 0.113, 0.085, 0.093, and 0.075 kg·heifer(-1)·d(-1), respectively. For DM excretion, this represented about one-third of the SEM reported for previous whole-pen collections from bedded-pack housing systems. Subsequent calculations of apparent DM and OM digestibilities indicated that the technique was sensitive, and

  12. Influence of temperament score and handling facility on stress, reproductive hormone concentrations, and fixed time AI pregnancy rates in beef heifers.

    Science.gov (United States)

    Kasimanickam, R; Schroeder, S; Assay, M; Kasimanickam, V; Moore, D A; Gay, J M; Whittier, W D

    2014-10-01

    The objectives were (i) to evaluate the effect of temperament, determined by modified 2-point chute exit and gait score, on artificial insemination (AI) pregnancy rates in beef heifers following fixed time AI and (ii) to determine the effect of temperament on cortisol, substance-P, prolactin and progesterone at initiation of synchronization and at the time of AI. Angus beef heifers (n = 967) at eight locations were included in this study. At the initiation of synchronization (Day 0 = initiation of synchronization), all heifers received a body condition score (BCS), and temperament score (0 = calm; slow exit and walk or 1 = excitable; fast exit or jump or trot or run). Blood samples were collected from a sub-population of heifers (n = 86) at both synchronization initiation and the time of AI to determine the differences in serum progesterone, cortisol, prolactin and substance-P concentrations between temperament groups. Heifers were synchronized with 5-day CO-Synch+ controlled internal drug release (CIDR) protocol and were inseminated at 56 h after CIDR removal. Heifers were examined for pregnancy by ultrasound 70 days after AI to determine AI pregnancy. Controlling for synchronization treatment (p = 0.03), facility design (p = 0.05), and cattle handling facility design by temperament score interaction (p = 0.02), the AI pregnancy differed between heifers with excitable and calm temperament (51.9% vs 60.3%; p = 0.01). The alley-way with acute bends and turns, and long straight alley-way had lower AI pregnancy rate than did the semicircular alley-way (53.5%, 56.3% and 67.0% respectively; p = 0.05). The serum hormone concentrations differed significantly between different types of cattle handling facility (p < 0.05). The cattle handling facility design by temperament group interactions significantly influenced progesterone (p = 0.01), cortisol (p = 0.01), prolactin (p = 0.02) and substance-P (p = 0.04) both at the initiation of

  13. 3rd quarterly report 1976 of the Fast Breeder Project

    International Nuclear Information System (INIS)

    1976-12-01

    The report describes activities which were performed within the framework of the Fast Breeder Project at the Gesellschaft fuer Kernforschung mbH Karlsruhe (GfK) or on behalf of the GfK during the third quarter. It contains contributions on the following subjects: Fuel rod development, material studies and development, corrosion tests and coolant analyses, physical experiments, reactor theory, safety of fast breeders, instrumentation and signal processing for core monitoring, environmental impacts, sodium technology tests, thermo- and fluid-dynamic tests in gas, tests concerning gas-cooled breeders. (HR) [de

  14. Influence of dietary component manipulation and feed management strategies on growth and rumen development of weaned dairy heifers

    OpenAIRE

    Dennis, Tana Shea

    2016-01-01

    Well-developed replacement heifers provide a central foundation for the continued success of the dairy industry. Emphasis on improving pre-weaned calf nutrition has predominated in the industry, but opportunities exist to improve post-weaning heifer nutrition and management. We aimed to evaluate common feed management strategies seen in the industry and their effects on growth, feed efficiency (G:F), and rumen development of calves from birth to 8 mo of age using pen- and individually-fed ani...

  15. Productive performance of dairy heifers supplemented in the dry season differed pasture, under two stoking rates

    Directory of Open Access Journals (Sweden)

    Ricardo Dias Signoretti

    2013-01-01

    Full Text Available The objective was to evaluate the characteristics of productive performance of crossbred Holstein x Gir heifers grazing on Brachiaria brizantha differed (Hochst. A. Rich. Stapf. cv. Marandu managed in a rotational stocking, during the dry season of the year. The treatments evaluated were stocking rate of 1.0 UA / ha and 6.0 g / kg body weight (BW / day and stocking rate of 2.0 UA / ha and 12.0 g / kg BW / day-energy protein supplement. The heifers had a average age of 17.46 ± 3.74 months and BW averaging 304.83 ± 33.7 kg and were distributed to a randomized block. The animals were weighed and measured for height at the withers (HW, heart girth (HG, rump length (RL and body condition score (BCS. The BW average batch was used for the calculations to adjust the amount of supplement offered. It was found that the performance of heifers that were subjected to stocking with 2 UA/ha and 12.0 g / kg BW had higher average daily gain (0.579 kg / animal in comparison to those undergoing stocking with 1 UA/ha and 6.0 g / kg BW (0.361 kg / animal. With respect to the development of animal body, it was found that the initial HG, initial and final HW, the initial RL and BCS did not differ between combinations of stocking rates and levels of supplementation. The heifers showed better productive performance in situations differed pastures, with 2 UA/ha and 12.0g/kg BW/day the protein-energetic supplement.

  16. Modelling energy utilisation in broiler breeder hens.

    Science.gov (United States)

    Rabello, C B V; Sakomura, N K; Longo, F A; Couto, H P; Pacheco, C R; Fernandes, J B K

    2006-10-01

    1. The objective of this study was to determine a metabolisable energy (ME) requirement model for broiler breeder hens. The influence of temperature on ME requirements for maintenance was determined in experiments conducted in three environmental rooms with temperatures kept constant at 13, 21 and 30 degrees C using a comparative slaughter technique. The energy requirements for weight gain were determined based upon body energy content and efficiency of energy utilisation for weight gain. The energy requirements for egg production were determined on the basis of egg energy content and efficiency of energy deposition in the eggs. 2. The following model was developed using these results: ME = kgW0.75(806.53-26.45T + 0.50T2) + 31.90G + 10.04EM, where kgW0.75 is body weight (kg) raised to the power 0.75, T is temperature ( degrees C), G is weight gain (g) and EM is egg mass (g). 3. A feeding trial was conducted using 400 Hubbard Hi-Yield broiler breeder hens and 40 Peterson males from 31 to 46 weeks of age in order to compare use of the model with a recommended feeding programme for this strain of bird. The application of the model in breeder hens provided good productive and reproductive performance and better results in feed and energy conversion than in hens fed according to strain recommendation. In conclusion, the model evaluated predicted an ME intake which matched breeder hens' requirements.

  17. stress and adaptation in beef heifers: 1. effect of pen conditions on ...

    African Journals Online (AJOL)

    Korthoring). Bos indicus (Afrikaner) en intermedibre (Bonsmara) tipe, is ingekraal teen. 'n vloer- .... body mass on average, and were in a state of sub-mainte- nance nutrition for 87 /, of the 2l week trial period. (Fig. l). At termination, Afrikaner heifers ...

  18. Neuropeptidome of the Hypothalamus and Pituitary Gland of Indicine × Taurine Heifers: Evidence of Differential Neuropeptide Processing in the Pituitary Gland before and after Puberty.

    Science.gov (United States)

    DeAtley, Kasey L; Colgrave, Michelle L; Cánovas, Angela; Wijffels, Gene; Ashley, Ryan L; Silver, Gail A; Rincon, Gonzalo; Medrano, Juan F; Islas-Trejo, Alma; Fortes, Marina R S; Reverter, Antonio; Porto-Neto, Laercio; Lehnert, Sigrid A; Thomas, Milton G

    2018-05-04

    Puberty in cattle is regulated by an endocrine axis, which includes a complex milieu of neuropeptides in the hypothalamus and pituitary gland. The neuropeptidome of hypothalamic-pituitary gland tissue of pre- (PRE) and postpubertal (POST) Bos indicus-influenced heifers was characterized, followed by quantitative analysis of 51 fertility-related neuropeptides in these tissues. Comparison of peptide abundances with gene expression levels allowed assessment of post-transcriptional peptide processing. On the basis of classical cleavage, 124 mature neuropeptides from 35 precursor proteins were detected in hypothalamus and pituitary gland tissues of three PRE and three POST Brangus heifers. An additional 19 peptides (cerebellins, PEN peptides) previously reported as neuropeptides that did not follow classical cleavage were also identified. In the pre-pubertal hypothalamus, a greater diversity of neuropeptides (25.8%) was identified relative to post-pubertal heifers, while in the pituitary gland, 38.6% more neuropeptides were detected in the post-pubertal heifers. Neuro-tissues of PRE and POST heifers revealed abundance differences ( p pituitary before and after puberty.

  19. Proceedings of the eleventh international workshop on ceramic breeder blanket interactions

    International Nuclear Information System (INIS)

    Enoeda, Mikio

    2004-07-01

    This report is the Proceedings of 'the Eleventh International Workshop on Ceramic Breeder Blanket Interactions' which was held as a workshop on ceramic breeders Under the IEA Implementing Agreement on the Nuclear Technology of Fusion Reactors, and the Japan-US Fusion Collaboration Framework. This workshop was held in Tokyo, Japan on December 15-17, 2003. About thirty experts from China, EU, Japan, Korea, Latvia, Russia and USA attended the workshop. The scope of the workshop included 1) evolutions in ceramic breeder blanket design, 2) progress in ceramic breeder material development, 3) irradiation testing, 4) breeder material properties, 5) out-of-pile pebble bed experiment, 6) modeling of the thermal, mechanical and tritium transfer behavior of pebble beds and 7) interfacing issues of solid breeder blanket. In the workshop, information exchange was performed for designs of solid breeder blankets and test blankets in EU, Russia and Japan, recent results of irradiation tests, HICU, EXOTIC-8 and the irradiation tests by IVV-2M, modeling study on tritium release behavior of Li 2 TiO 3 and so on, fabrication technology developments and characterization of the Li 2 TiO 3 and Li 4 SiO 4 pebbles, research on measurements and modeling of thermo-mechanical behaviors of Li 2 TiO 3 and Li 4 SiO 4 pebbles, and interfacing issues, such as, fabrication technology for blanket box structure, neutronics experiments of blanket mockups by fusion neutron source and tritium recovery system. The 26 of the presented papers are indexed individually. (J.P.N.)

  20. Experiences with fast breeder reactor education in laboratory and short course settings

    International Nuclear Information System (INIS)

    Waltar, A.E.

    1983-01-01

    The breeder reactor industry throughout the world has grown impressively over the last two decades. Despite the uncertainties in some national programs, breeder reactor technology is well established on a global scale. Given the magnitude of this technological undertaking, there has been surprisingly little emphasis on general breeder reactor education - either at the university or laboratory level. Many universities assume the topic too specialized for including appropriate courses in their curriculum - thus leaving students entering the breeder reactor industry to learn almost exclusively from on-the-job experience. The evaluation of four course presentations utilizing visual aids is presented

  1. Performance and meat quality traits of beef heifers fed with two levels of concentrate and ruminally undegradable protein.

    Science.gov (United States)

    Duarte, Marcio de Souza; Paulino, Pedro Veiga Rodrigues; Valadares Filho, Sebastião de Campos; Paulino, Mario Fonseca; Detmann, Edenio; Zervoudakis, Joanis Tilemahos; Monnerat, João Paulo Ismerio dos Santos; Viana, Gabriel da Silva; Silva, Luiz Henrique P; Serão, Nicola Vergara Lopes

    2011-04-01

    The effects of two levels of concentrate and ruminally undegradable protein (RUP) on performance, intake, digestibility, carcass characteristics, meat quality traits, and commercial cuts yield were assessed. Twenty crossbred heifers (240 kg average body weight) were used. At the beginning of the trial, four animals were slaughtered as reference group and the 16 remaining animals were randomly assigned to four treatments, in a 2 × 2 factorial design: two levels of concentrate (40% and 80%, dry matter (DM) basis) and two levels of RUP (48.79% and 27.19% of CP). At the end of the trial, all the animals were slaughtered. There was no interaction (P > 0.05) between concentrate and RUP levels. Dry matter intake and nutrients digestibility was not affected (P > 0.05) by RUP level. Heifers fed the highest RUP level had greater (P  0.05) DMI and ADG. Heifers fed diets with 80% concentrate had greater intake of TDN and EE, and lower intake of NDF (P RUP levels did not affect (P > 0.05) the carcass characteristics and carcass gain composition. Heifers fed 80% concentrate diets had larger (P  0.05) the composition of carcass gain. There was no effect (P > 0.05) of RUP and concentrate levels on meat quality traits and commercial cut yields.

  2. Short communication: Glucose kinetics in dairy heifers limit-fed a low- or high-forage ration at four levels of nitrogen intake

    Science.gov (United States)

    The objective of this research was to evaluate the effect of level of forage and nitrogen (N) intake on glucose kinetics in growing dairy heifers. Eight Holstein heifers (beginning at 362 ± 7 kg body weight (BW) and 12.3 ± 0.4 months of age) were fed eight rations according to a split-plot, 4 x 4 La...

  3. Exploding the myths about the fast breeder reactor

    Energy Technology Data Exchange (ETDEWEB)

    Burns, S.

    1979-01-01

    This paper discusses the facts and figures about the effects of conservation policies, the benefits of the Clinch River Breeder Reactor demonstration plant, the feasibility of nuclear weapons manufacture from reactor-grade plutonium, diversion of plutonium from nuclear plants, radioactive waste disposal, and the toxicity of plutonium. The paper concludes that the U.S. is not proceeding with a high confidence strategy for breeder development because of a variety of false assumptions.

  4. Gas-cooled breeder reactor safety

    Energy Technology Data Exchange (ETDEWEB)

    Chermanne, J.; Burgsmueller, P. [Societe Belge pour l' Industrie Nucleaire, Brussels

    1981-01-15

    The European Association for the Gas-cooled Breeder Reactor (G B R A), set-up in 1969 prepared between 1972 and 1974 a 1200 MWe Gas-cooled Breeder Reactor (G B R) commercial reference design G B R 4. It was then found necessary that a sound and neutral appraisal of the G B R licenseability be carried out. The Commission of the European Communities (C E C) accepted to sponsor this exercise. At the beginning of 1974, the C E C convened a group of experts to examine on a Community level, the safety documents prepared by the G B R A. A working party was set-up for that purpose. The experts examined a ''Preliminary Safety Working Document'' on which written questions and comments were presented. A ''Supplement'' containing the answers to all the questions plus a detailed fault tree and reliability analysis was then prepared. After a final study of this document and a last series of discussions with G B R A representatives, the experts concluded that on the basis of the evidence presented to the Working Party, no fundamental reasons were identified which would prevent a Gas-cooled Breeder Reactor of the kind proposed by the G B R A achieving a satisfactory safety status. Further work carried out on ultimate accident have confirmed this conclusion. One can therefore claim that the overall safety risk associated with G B R s compares favourably with that of any other reactor system.

  5. Potential use of thorium through fusion breeders in the Indian context

    International Nuclear Information System (INIS)

    Srinivasan, M.; Basu, T.K.; Subba Rao, K.

    1991-01-01

    The Indian Nuclear Programme is based on a three stage strategy: the first stage of about 10 GWe comprises of natural uranium fuelled Pressurised Heavy Water Reactors (PHWRs); the second stage would consist of Liquid Metal Cooled Fast Breeder Reactors (LMFBRs) to be fuelled with plutonium generated in the first stage PHWRs and the third stage is envisaged to be based on advanced converters/breeders operating on the Th/U-233 cycle. It has generally been assumed that the initial inventory of U-233 for the third stage reactors would be generated in the blankets of LMFBRs containing thorium. But the success of this strategy depends crucially on the attainment of LMFBR doubling times as short as 14 years. The progress registered in recent years in the magnetic confinement of fusion plasmas has opened up the prospects of developing Fusion Breeders for the direct conversion of fertile 232 Th into fissile 233 U using the 14 MeV neutron released in the (D-T) fusion reaction. A detailed study of the dependence of the 233 U production characteristics as well as energy cost of fissile fuel production of such systems on parameters such as plasma energy gain Q, blanket neutron multiplication has been carried out. The growth rate dynamics of the symbiotic combination of 233 U generating fusion breeders with PHWRs operating on the Th/U-233 cycle in the so called near-breeder regime has been examined. 95% of the energy generated by PHWRs operating with Th/ 233 U fuel would arise from thorium consumption rather than fission of the initially loaded 233 U. A few sub-engineering breakeven fusion breeders producing U-233 at an energy cost well under 200 MeV per atom are adequate to give the requisite nuclear capacity growth rates in conjunction with such near breeder PHWRs. This corresponds to only a 5% diversion of the grid electrical power for the operation of such fusion breeders. In summary the symbiotic combination of a few fusion breeders with a number of PHWRs gives fresh hopes

  6. Safeguards challenges of Fast Breeder Reactor

    International Nuclear Information System (INIS)

    Ko, H. S.

    2010-01-01

    Although the safeguards system of Sodium Fast Reactor (SFR) seems similar to that of Light Water Reactor (LWR), it was raised safeguards challenges of SFR that resulted from the visual opacity of liquid sodium, chemical reactivity of sodium and other characteristics of fast reactor. As it is the basic concept stage of the safeguards of SFR in Korea, this study tried to analyze the latest similar study of safeguards issues of the Fast Breeder Reactor (FBR) at Joyo and Monju in Japan. For this reason, this study is to introduce some potential safeguards challenges of Fast Breeder Reactor. With this analysis, future study could be to address the safeguards challenges of SFR in Korea

  7. Uranium utilization of light water cooled reactors and fast breeders

    International Nuclear Information System (INIS)

    Stojadinovic, Timm

    1991-08-01

    The better uranium utilization of fast breeder reactors as compared with water cooled reactors is one argument in favour of the breeder introduction. This report tries to quantify this difference. It gives a generally valid formalism for the uranium utilization as a function of the fuel burnup, the conversion rate, fuel cycle losses and the fuel enrichment. On the basis of realistic assumptions, the ratio between the utilizations of breeder reactors to that of light water cooled reactors (LWR) amounts to 180 for the open LWR cycle and 100 in case of plutonium recycling in LWRs

  8. Project fast breeder (PSB)

    International Nuclear Information System (INIS)

    1978-01-01

    The annual report of the fast breeder project (PSB) contains contributions of the participating institutes on the four subjects: 1) Development of oxidic fuel rods and materials for the SNR line, 2) Physics and safety investigations for the SNR line, 3) Carbidic fuel elements, and 4) Back-up solution with gaseous coolant. (HK) [de

  9. Growth rates of breeder reactor fuel. Final report

    International Nuclear Information System (INIS)

    Ott, K.O.

    1979-01-01

    During the contract period, a consistent formalism for the definition of the growth rates (and thus the doubling time) of breeder reactor fuel has been developed. This formalism was then extended to symbiotic operation of breeder and converter reactors. Further, an estimation prescription for the growth rate has been developed which is based upon the breeding worth factors. The characteristics of this definition have been investigated, which led to an additional integral concept, the breeding bonus

  10. Light water breeder reactor using a uranium-plutonium cycle

    International Nuclear Information System (INIS)

    Radkowsky, A.; Chen, R.

    1990-01-01

    This patent describes a light water receptor (LWR) for breeding fissile material using a uranium-plutonium cycle. It comprises: a prebreeder section having plutonium fuel containing a Pu-241 component, the prebreeder section being operable to produce enriched plutonium having an increased Pu-241 component; and a breeder section for receiving the enriched plutonium from the prebreeder section, the breeder section being operable for breeding fissile material from the enriched plutonium fuel. This patent describes a method of operating a light water nuclear reactor (LWR) for breeding fissile material using a uranium-plutonium cycle. It comprises: operating the prebreeder to produce enriched plutonium fuel having an increased Pu-241 component; fueling a breeder section with the enriched plutonium fuel to breed the fissile material

  11. Dynamics and control of molten-salt breeder reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sing, Vikram; Lish, Matthew R.; Chvala, Ondrej; Upadhyaya, Belle R. [Dept. of Nuclear Engineering, University of Tennessee, Knoxville (United States)

    2017-08-15

    Preliminary results of the dynamic analysis of a two-fluid molten-salt breeder reactor (MSBR) system are presented. Based on an earlier work on the preliminary dynamic model of the concept, the model presented here is nonlinear and has been revised to accurately reflect the design exemplified in ORNL-4528. A brief overview of the model followed by results from simulations performed to validate the model is presented. Simulations illustrate stable behavior of the reactor dynamics and temperature feedback effects to reactivity excursions. Stable and smooth changes at various nodal temperatures are also observed. Control strategies for molten-salt reactor operation are discussed, followed by an illustration of the open-loop load-following capability of the molten-salt breeder reactor system. It is observed that the molten-salt breeder reactor system exhibits “self-regulating” behavior, minimizing the need for external controller action for load-following maneuvers.

  12. Dynamics and control of molten-salt breeder reactor

    Directory of Open Access Journals (Sweden)

    Vikram Singh

    2017-08-01

    Full Text Available Preliminary results of the dynamic analysis of a two-fluid molten-salt breeder reactor (MSBR system are presented. Based on an earlier work on the preliminary dynamic model of the concept, the model presented here is nonlinear and has been revised to accurately reflect the design exemplified in ORNL-4528. A brief overview of the model followed by results from simulations performed to validate the model is presented. Simulations illustrate stable behavior of the reactor dynamics and temperature feedback effects to reactivity excursions. Stable and smooth changes at various nodal temperatures are also observed. Control strategies for molten-salt reactor operation are discussed, followed by an illustration of the open-loop load-following capability of the molten-salt breeder reactor system. It is observed that the molten-salt breeder reactor system exhibits “self-regulating” behavior, minimizing the need for external controller action for load-following maneuvers.

  13. Respiratory diseases and allergic sensitization in swine breeders: a population-based cross-sectional study.

    Science.gov (United States)

    Galli, Luigina; Facchetti, Susanna; Raffetti, Elena; Donato, Francesco; D'Anna, Mauro

    2015-11-01

    The daily occupation as a swine breeder involves exposure to several bacterial components and organic dusts and inhalation of a large amount of allergens. To investigate the risk of respiratory diseases and atopy in swine breeders compared with the general population living in the same area. A population-based cross-sectional study was conducted in an agricultural area of northern Italy that enrolled a random sample of resident male breeders and non-breeders. Demographic features, comorbidities, and presence of allergic respiratory disease were retrieved through interview. Prick tests for common allergens were performed. An evaluation of pollen and mold in air samples taken inside and outside some swine confinement buildings also was performed. One hundred one male breeders (78 native-born, mean age ± SD 43.0 ± 11.1 years) and 82 non-breeders (43.0 ± 11.1 years) were enrolled. When restricting the analysis to native-born subjects, breeders vs non-breeders showed a lower prevalence of respiratory allergy (12.8% vs 31.1%, respectively, P = .002), asthma (6.4% vs 15.8%, P = .059), rhinitis (16.7% vs 51.2%, P increase, and might decrease, the risk of pollen sensitization and allergic disease. Copyright © 2015 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  14. Study on reproductive performance of Holstein x Lai Sind crossbred dairy heifers and cows at smallholdings in Ho Chi Minh City, Vietnam.

    Science.gov (United States)

    Nguyen-Kien, Cuong; Van Khanh, Nguyen; Hanzen, Christian

    2017-03-01

    The reproductive performance of Holstein x Lai Sind crossbred dairy heifers and cows was evaluated at smallholdings in Ho Chi Minh City (HCMC). The data of 232 heifers and 244 cows (261 lactations) from 35 small dairy farms was collected over a 2-year period, from 2013 to 2014. The overall mean for age at first service (AFS), days between first and last service (DFLS), and age at conception (AC) of heifers was 479 (±80), 38 (±80), and 517 (±114) days, respectively. Average number of services per conception (NSC), conception rate (CR), and conception rate at first service (CRFS) was 1.8 (±1.4), 55, and 58%, respectively. The overall mean for the waiting period (WP), DFLS, and days open (DO) of cows was 109 (±52), 133 (±114), and 242 (±129) days, respectively. The mean for NSC, CR, and CRFS was 4.3 (±2.7), 23, and 14%, respectively. A very significant decrease in AFS and AC according to the year of birth, and a significant increase in AFS according to body weight at first insemination (>320 kg) were observed. The CRFS of heifers inseminated in 2013 was significantly higher than in 2014. Monthly mean CR in heifers and cows was negatively correlated with THI. The WP, DFLS, DO, and NSC of cows significantly decreased according to the year of calving. Cows that calved in rainy season had a significantly longer WP than in dry season. The occurrence of postpartum (PP) diseases was accompanied by an increase in WP, DO, and NSC. A decrease in body condition score (BCS) between calving and 60th day (C60) and also between 60th and 120th day of lactation resulted in a significant increase in WP and DO. A decrease in BCS between C60 was also accompanied by a considerable reduction in CRFS of cows. Season and BCS at insemination had a significant effect on NSC and CR of cows. Reproductive performance was satisfactory for heifers, but poor for cows. Losses of BCS during the first months of lactation and at insemination were the major risk factors for this poor performance

  15. Linear accelerator-breeder (LAB): a preliminary analysis and proposal

    International Nuclear Information System (INIS)

    1976-01-01

    The development and demonstration of a Linear Accelerator-Breeder (LAB) is proposed. This would be a machine which would use a powerful linear accelerator to produce an intense beam of protons or deuterons impinging on a target of a heavy element, to produce spallation neutrons. These neutrons would in turn be absorbed in fertile 238 U or 232 Th to produce fissile 239 Pu or 233 U. Though a Linear Accelerator-Breeder is not visualized as competitive to a fast breeder such as the LMFBR, it would offer definite benefits in improved flexibility of options, and it could probably be developed more rapidly than the LMFBR if fuel cycle problems made this desirable. It is estimated that at a beam power of 300 MW a Linear Accelerator-Breeder could produce about 1100 kg/year of fissile 239 Pu or 233 U, which would be adequate to fuel from 2,650 to 15,000 MW(e) of fission reactor capacity depending on the fuel cycle used. A two-year design study is proposed, and various cost estimates are presented. The concept of the Linear Accelerator-Breeder is not new, having been the basis for a major AEC project (MTA) a number of years ago. It has also been pursued in Canada starting from the proposal for an Intense Neutron Generator (ING) several years ago. The technical basis for a reasonable design has only recently been achieved. The concept offers an opportunity to fill an important gap that may develop between the short-term and long-term energy options for energy security of the nation

  16. Cross-sectional study to identify staphylococcal species isolated from teat and inguinal skin of different-aged dairy heifers.

    Science.gov (United States)

    Adkins, P R F; Dufour, S; Spain, J N; Calcutt, M J; Reilly, T J; Stewart, G C; Middleton, J R

    2018-04-01

    The purpose of this study was to describe the prevalence and distribution of staphylococcal species on the teat and inguinal skin of dairy heifers across the various stages of the heifer life cycle. The cross-sectional study included 106 Holstein heifers with an age range of 0 d to 27 mo that were selected from 11 different groups, based on housing type and age, on a single dairy operation. A composite swabbing sample including all 4 teats and a second composite sample including both inguinal regions of each heifer were collected using gas-sterilized electrostatic dusters (Swiffers; Procter and Gamble, Cincinnati, OH). Swabbing samples were mixed with 10 mL of sterile saline, agitated, and cultured on mannitol salt agar plates. At 24 h, plates were read and up to 10 staphylococcal colonies were saved for further analysis. Staphylococcal isolates were speciated using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or PCR amplification and partial sequencing of rpoB or tuf. The prevalence of staphylococci was compared between the inguinal and teat regions using the chi-squared or Fisher's exact test, as applicable. Logistic regression models were used to investigate the relationship between a heifer's age (treated as a quantitative continuous variable) and the probability of isolating a given staphylococcal species from a given body site (inguinal region or teats). Overall, the most common species identified were Staphylococcus haemolyticus followed by Staphylococcus chromogenes, Staphylococcus xylosus, Staphylococcus devriesei, and Staphylococcus sciuri. Staphylococcus aureus was more prevalent on the teat than in the inguinal region, whereas Staphylococcus arlettae was more prevalent in the inguinal region than on the teat. All other staphylococcal species were as likely to be found on the teat skin as the inguinal region skin. Isolation from the inguinal and teat skin was associated with age for Staphylococcus agnetis, S. chromogenes

  17. Alternative cycles and fast breeders, a look to the future

    International Nuclear Information System (INIS)

    Dahlberg, R.C.

    1979-01-01

    The various nuclear strategies that have been proposed to eke out available uranium are briefly summarised. A recent approach is to develop the concept of a 'transitional symbiosis strategy' which accepts the principle of the fast breeder/advanced converter for the long-range future, and to suggest that advanced converters be designed to be near-breeders. Some of the issues affecting strategic planning in the transitional period are reviewed further. The need for the thorium cycle in both advanced converters (or near breeders) and fast reactors is emphasised. This type of high temperature gas-cooled reactor appears to be the technology most suited for symbiosis with FBRs. (UK)

  18. Modelled female sale options demonstrate improved profitability in northern beef herds.

    Science.gov (United States)

    Niethe, G E; Holmes, W E

    2008-12-01

    To examine the impact of improving the average value of cows sold, the risk of decreasing the number weaned, and total sales on the profitability of northern Australian cattle breeding properties. Gather, model and interpret breeder herd performances and production parameters on properties from six beef-producing regions in northern Australia. Production parameters, prices, costs and herd structure were entered into a herd simulation model for six northern Australian breeding properties that spay females to enhance their marketing options. After the data were validated by management, alternative management strategies were modelled using current market prices and most likely herd outcomes. The model predicted a close relationship between the average sale value of cows, the total herd sales and the gross margin/adult equivalent. Keeping breeders out of the herd to fatten generally improves their sale value, and this can be cost-effective, despite the lower number of progeny produced and the subsequent reduction in total herd sales. Furthermore, if the price of culled cows exceeds the price of culled heifers, provided there are sufficient replacement pregnant heifers available to maintain the breeder herd nucleus, substantial gains in profitability can be obtained by decreasing the age at which cows are culled from the herd. Generalised recommendations on improving reproductive performance are not necessarily the most cost-effective strategy to improve breeder herd profitability. Judicious use of simulation models is essential to help develop the best turnoff strategies for females and to improve station profitability.

  19. Proceedings of the sixth international workshop on ceramic breeder blanket interactions

    International Nuclear Information System (INIS)

    Noda, Kenji

    1998-03-01

    This report is the Proceedings of ''the Sixth International Workshop on Ceramic Breeder Blanket Interactions'' which was held as a workshop on ceramic breeders under Annex II of IEA Implementing Agreement on a Programme of Research and Development on Fusion Materials, and Japan-US Workshop 97FT4-01. This workshop was held in Mito city, Japan on October 22-24, 1997. About forty experts from EU, Japan, USA, and Chile attended the workshop. The scope of the workshop included the following: 1) fabrication and characterization of ceramic breeders, 2) properties data for ceramic breeders, 3) tritium release characteristics, 4) modeling of tritium behavior, 5) irradiation effects on performance behavior, 6) blanket design and R and D requirements, 7) hydrogen behavior in materials, and 8) blanket system technology and structural materials. In the workshop, information exchange was performed for fabrication technology of ceramic breeder pebbles in EU and Japan, data of various properties of Li 2 TiO 3 , tritium release behavior of Li 2 TiO 3 and Li 2 ZrO 3 including tritium diffusion, modeling of tritium release from Li 2 ZrO 3 in ITER condition, helium release behavior from Li 2 O, results of tritium release irradiation tests of Li 4 SiO 4 pebbles in EXOTIC-7, R and D issues for ceramic breeders for ITER and DEMO blankets, etc. The 23 of the papers are indexed individually. (J.P.N.)

  20. Body composition and reproduction in broiler breeders: impact of feeding strategies

    NARCIS (Netherlands)

    Emous, van R.A.

    2015-01-01

    ABSTRACT

    Key words: broiler breeder, feeding strategies, body composition, reproduction, behavior

    Nowadays, welfare issues in broiler breeders associated with nutrition and reproductive characteristics, are becoming increasingly challenging. Due to genetic selection

  1. Comparison of inventory of tritium in various ceramic breeder blankets

    International Nuclear Information System (INIS)

    Nishikawa, M.; Beloglazov, S.; Nakashima, N.; Hashimoto, K.; Enoeda, M.

    2002-01-01

    It has been pointed out by the present authors that it is essential to understand such mass transfer steps as diffusion of tritium in the grain of breeder material, absorption of water vapor into bulk of the grain, and adsorption of water on surface of the grain, together with the isotope exchange reaction between hydrogen in purge gas and tritium on surface of breeder material and the isotope exchange reaction between water vapor in purge gas and tritium on surface, for estimation of the tritium inventory in a uniform ceramic breeder blanket under the steady-state condition. It has been also pointed out by the present authors that the water formation reaction on the surface of ceramic breeder materials at introduction of hydrogen can give effect on behavior of bred tritium and lithium transfer in blanket. The tritium inventory for various ceramic breeder blankets are compared in this study basing on adsorption capacity, absorption capacity, isotope exchange capacity, and isotope exchange reactions on the Li 2 O, LiAlO 2 , Li 2 ZrO 3 , Li 4 SiO 4 and Li 2 TiO 3 surface experimentally obtained by the present authors. Effect of each mass transfer steps on the shape of release curve of bred tritium at change of the operational conditions is also discussed from the observation at out pile experiment in KUR. (orig.)

  2. On the history of the Fast Breeder Project

    International Nuclear Information System (INIS)

    Marth, W.

    1981-07-01

    The evolution of the Fast Breeder Project from its beginning at the Karlsruhe Nuclear Research Center to the present cooperation of various organisations especially in the Federal Republic of Germany, the Netherlands, Belgium and France is described in its historical context. Where as the emphasis was on physical studies of fast neutron cores in the early phase, technological and safety problems gained importance in the subsequent development. The increasing collaboration with industry and the support by government funds resulted in the design and start of construction of the prototype SNR 300. The objectives and the reasoning underlying important intermediate decisions are described. In the meantime, licensing and funding problems have become decisive for the project schedule. The present report also gives an account of the international and national political aspects which influence the breeder reactor development. In the annex all fast breeder publications of the Karlsruhe Nuclear Research Center are listed. (orig.) [de

  3. The metabolic, stress axis, and hematology response of zilpaterol hydrochloride supplemented beef heifers when exposed to a dual corticotropin-releasing hormone and vasopressin challenge

    Science.gov (United States)

    The objective of this study was to determine the metabolic, stress, and hematology cell response of beef heifers supplemented with zilpaterol hydrochloride (ZH) when exposed to an endocrine stress challenge. Heifers (n = 20; 556 ± 7 kg BW) were randomized into two treatment groups: 1) Control (CON):...

  4. Applying ultrasonographic evaluation of antral follicle count to improve reproductive management in heifers

    Science.gov (United States)

    Ultrasonography is a powerful technology that can be used to improve reproductive management in heifers. By counting the number of antral follicles observed on an ultrasound screen the practitioner can gather additional information when reproductive tract scoring, because the number of antral folli...

  5. Using eastern gamagrass to construct diets that limit intake and caloric density for dairy replacement heifers.

    Science.gov (United States)

    Coblentz, W K; Hoffman, P C; Esser, N M; Bertram, M G

    2012-10-01

    Previous research has shown that eastern gamagrass (EGG; Tripsacum dactyloides L.) will survive winter climatic conditions common throughout central Wisconsin, and will produce yields of dry matter (DM) ranging approximately from 7,000 to 10,000 kg/ha annually when managed with a 1-cut harvest system. The objective of this research was to determine whether the fibrous nature of this perennial warm-season grass could be effective in reducing the caloric density and DMI of corn silage/alfalfa haylage diets for replacement dairy heifers. A total of 120 Holstein dairy heifers were blocked by body weight (heavy, 424 ± 15.9 kg; medium, 369 ± 11.8 kg; light, 324 ± 22.4 kg), and then assigned to 15 individual pens containing 8heifers each. Eastern gamagrass forage was harvested, ensiled, and subsequently incorporated into blended corn silage/alfalfa haylage diets at rates of 0, 9.1, 18.3, or 27.4% of the total dietary DM (EGG0, EGG9, EGG18, and EGG27, respectively). These diets were offered during a 105-d evaluation period for ad libitum intake; however, the EGG0 diet also was offered on a limit-fed basis (LF), which was set at 85% of the voluntary intake of EGG0. Serial additions of EGG increased concentrations of neutral detergent fiber in blended diets from 39.6 (EGG0) to 48.7% (EGG27), and simultaneously reduced corresponding estimates of total digestible nutrients (TDN) from 68.2 to 61.3%, and net energy for gain from 1.07 to 0.83 Mcal/kg. Dry matter intakes for all diets offered ad libitum were greater than observed for LF (9.06 vs. 8.07 kg/d); however, DM intakes for diets containing EGG were reduced relative to EGG0 (9.40 vs. 8.94 kg/d). Similarly, intakes of TDN were greater for diets offered for ad libitum intake than for LF (5.84 vs. 5.50 kg/d); however, inclusion of EGG reduced TDN intakes relative to EGG0 (6.41 vs. 5.65 kg/d). This reduction was explained by both linear and quadratic effects of the inclusion rate of EGG in the diet. Over the 105-d trial

  6. Effect of prenatal programming on heifer development.

    Science.gov (United States)

    Funston, Richard N; Summers, Adam F

    2013-11-01

    In beef cattle, the main factors influencing nutrient partitioning between the dam and fetus include age of the dam, number of fetuses, production demand, and environmental stress. These factors play a critical role in programming the fetus for its future environment and available resources. Fetal programming reportedly affects neonatal mortality and morbidity, postnatal growth rate, body composition, health, and reproduction. Two main mechanisms responsible for fetal programming include DNA methylation and histone modifications. Alterations in the genome can be passed through multiple generations. Maternal environment (nutrition, age, physiologic status) can program progeny heifer growth and reproductive performance. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Egg fertility and hatchability in Avians broiler-breeder hens under ...

    African Journals Online (AJOL)

    Impact of temperature and humidity in different month of lay was evaluated on fertility and hatchability in broiler breeder hens reared in Sapele, Nigeria. Six million, six hundred and nineteen thousand, seven hundred and forty six eggs from flocks of Avians broiler-breeder hens reared between 2005 and 2006 in a farm ...

  8. COMPARISON ON ACCURACY OF LOGISTIC, GOMPERTZ AND VON BERTALANFFY MODELS IN PREDICTING GROWTH OF NEW BORN CALF UNTIL FIRST MATING OF HOLSTEIN FRIESIAN HEIFERS

    Directory of Open Access Journals (Sweden)

    L. Budimulyati S.

    2014-10-01

    Full Text Available The body weight records of 1221 heifers were used in this study collected from PT Taurus DairyFarm Sukabumi from year 2001 until 2011. The records that could be used for analysis were 373 out of1221 heifers, having completed data from birth to first mating period. Three different models i.e,Logistic, Gompertz, and von Bertalanffy were performed to analyze the growth rate of heifers. Theresults showed that the three models had different accuracy and heavily depend on age, environment andduration of recording. The body weights of sexual maturity and on certain ages were affected by theduration of recording. The Gompertz model was performed as the simpliest model in form ofcalculation. On the other hand, the Logistic was more difficult to calculate. All models indicated highaccuracy with the determination coefficient (R2 more than 90%. Based on the comparison, theGompertz and Logistic model are recommended for predicting the growth rate of heifers from birth tosexual maturity.

  9. Ingestive Behavior of Heifers Supplemented with Glycerin in Substitution of Corn on Pasture

    Directory of Open Access Journals (Sweden)

    L. M. A. M. Facuri

    2014-11-01

    Full Text Available The objective was to evaluate the ingestive behavior of crossbred heifers finished on a Brachiaria brizantha cv. Marandu pasture receiving four levels of glycerin in their supplementation. Thirty-six crossbred heifers with average initial weight of 264.83±3.83 kg and 20 months of age were distributed into a completely randomized design with four treatments and nine replications: control (0%, 4.82%, 10.12%, and 15.56% glycerin in the dry matter. The grazing time reduced linearly (p0.05. The number of rumination periods reduced linearly (p0.05 whereas the feed efficiency of neutral detergent fiber reduced linearly (p<0.05. Addition of glycerin in substitution of corn in supplements for animals managed on pastures does not influenced feed intake, but reduces the grazing time and increases the idle time. The supplementation also improves feed and rumination efficiencies.

  10. Ovarian dynamics in response to two modified intravaginal progesterone releasing device and oestradiol benzoate based ovulation synchronisation protocols designed for use in Brahman heifers.

    Science.gov (United States)

    Edwards, S A A; Atkinson, P C; Satake, N; Boe-Hansen, G; McGowan, M R

    2014-07-01

    The objective was to investigate the ovarian response of Brahman heifers to two modified ovulation synchronisation protocols developed to increase the proportion of normal synchronous ovulations. Experiment 1 characterised the growth of the ovulatory follicle in heifers (n=19) treated with an intravaginal progesterone releasing device (IPRD) and oestradiol benzoate (ODB), to determine the optimal time to induce ovulation. Using the findings from Experiment 1, Experiment 2 investigated the effect of reducing the duration of IPRD insertion and increasing the interval from IPRD removal to ODB treatment (modified protocol 1 - OPO-6; n=20), and omitting ODB treatment at the time of IPRD insertion (modified protocol 2 - PO-6; n=20). An IPRD (0.78 g progesterone) was inserted at Day 0 (OPO-8) or Day 2 (OPO-6 and PO-6) and all heifers also received 1 mg ODB i.m. Day 8: IPRD removed + 500 μg cloprostenol i.m. At 24 h (OPO-8) and 36 h (OPO-6 and PO-6) post IPRD removal: 1 mg ODB i.m. Fixed-time AI (FTAI) occurred at 54 h for OPO-8 and 72 h for OPO-6 and PO-6, post IPRD removal. After IPRD treatment all OPO-6 and OPO-8 heifers initiated a new follicular wave whereas 25% of PO-6 heifers failed. Diameter of the dominant follicle was larger at FTAI in the PO-6 (11.34 ± 0.50 mm) compared to the OPO-8 protocol (9.74 ± 0.51 mm; P<0.05), but similar to the OPO-6 protocol (10.52 ± 0.51 mm). Proportion of ovulations occurring 12 h prior and 24 h post FTAI was similar for the PO-6 (80%) and OPO-6 (75%) protocols but numerically lower in the OPO-8 heifers (60%). The apparent improvement in ovarian response in heifers treated with the modified protocols needs to be confirmed in larger field studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. The development of the gas cooled fast breeder reactor

    International Nuclear Information System (INIS)

    Dalle Donne, M.; Kernforschungszentrum Karlsruhe

    1975-01-01

    A survey of the present technological state is given on the basis of the developments made so far. Some milestones of development - e.g. the German gas breeder memorandum, the Gas Breeder Reactor Association the results of the BR-2 radiation experiments and of GfK-KWU design and safety studies - are described. The problems connected with a large store of plutonium are also discussed. (UA/AK) [de

  12. Breeder reactors over the world

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    After a short recall on the development of research programs, this paper reviews the fast breeder reactor operating, in construction or in project over the world (USA, France, Italy, RFG, India, Japan and U.K.). Thermal and electrical power output, and operation data are given [fr

  13. Composite beryllium-ceramics breeder pin elements for a gas cooled solid blanket

    International Nuclear Information System (INIS)

    Carre, F.; Chevreau, G.; Gervaise, F.; Proust, E.

    1986-06-01

    Helium coolant have main advantages compared to water for solid blankets. But limitations exist too and the development of attractive helium cooled blankets based on breeder pin assemblies has been essentially made possible by the derivation from recent CEA neutronic studies of an optimized composite beryllium/ceramics breeder arrangement. Description of the proposed toroidal blanket layout for Net is made together with the analysis of its main performance. Merits of the considered composite Be/ceramics breeder elements are discussed

  14. Selection of Breeding Stock among Australian Purebred Dog Breeders, with Particular Emphasis on the Dam

    Directory of Open Access Journals (Sweden)

    Veronika Czerwinski

    2016-11-01

    Full Text Available Every year, thousands of purebred domestic dogs are bred by registered dog breeders. Yet, little is known about the rearing environment of these dogs, or the attitudes and priorities surrounding breeding practices of these dog breeders. The objective of this study was to explore some of the factors that dog breeders consider important for stock selection, with a particular emphasis on issues relating to the dam. Two-hundred and seventy-four Australian purebred dog breeders, covering 91 breeds across all Australian National Kennel Club breed groups, completed an online survey relating to breeding practices. Most breeders surveyed (76% reported specialising in one breed of dog, the median number of dogs and bitches per breeder was two and three respectively, and most breeders bred two litters or less a year. We identified four components, relating to the dam, that were considered important to breeders. These were defined as Maternal Care, Offspring Potential, Dam Temperament, and Dam Genetics and Health. Overall, differences were observed in attitudes and beliefs across these components, showing that there is variation according to breed/breed groups. In particular, the importance of Maternal Care varied according to dog breed group. Breeders of brachycephalic breeds tended to differ the most in relation to Offspring Potential and Dam Genetics and Health. The number of breeding dogs/bitches influenced breeding priority, especially in relation to Dam Temperament, however no effect was found relating to the number of puppies bred each year. Only 24% of breeders used their own sire for breeding. The finding that some breeders did not test for diseases relevant to their breed, such as hip dysplasia in Labrador Retrievers and German Shepherds, provides important information on the need to educate some breeders, and also buyers of purebred puppies, that screening for significant diseases should occur. Further research into the selection of breeding dams

  15. Nuclear data needs for plutonium breeders

    International Nuclear Information System (INIS)

    Hammer, P.

    1979-01-01

    This paper aims at summarizing the present major nuclear data needs for fast breeders. The corresponding requirements are deduced from the target accuracies which are associated to the design, operation and safety related parameters. Due to the fact that these target accuracies may somewhat change from one country to another the requirements quoted here must be considered more as the present order of magnitudes than as precise figures. The maximum admissible uncertainties which are asked presently for the nuclear data are due in particular to: the necessity of reducing the supplementary investment costs which account the present neutronic uncertainties; the necessity of improving the optimization studies devoted to the future commercial fast breeders: these studies involve the comparison of neutronics performances of new concepts, such as the heterogeneous core concept, to the classical one

  16. Superphenix: Is the fast breeder dream over -- or over yonder?

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    A detailed history of France's Superphenix commercial fast breeder reactor project is presented. Important project milestones are discussed from the project's conception in 1971 to its current status. Recommendations of the Castaing Commission on the project and future plans for use of the reactor are outlined. In addition, world wide fast breeder projects are listed and discussed

  17. Proceedings of the sixth international workshop on ceramic breeder blanket interactions

    Energy Technology Data Exchange (ETDEWEB)

    Noda, Kenji [ed.

    1998-03-01

    This report is the Proceedings of `the Sixth International Workshop on Ceramic Breeder Blanket Interactions` which was held as a workshop on ceramic breeders under Annex II of IEA Implementing Agreement on a Programme of Research and Development on Fusion Materials, and Japan-US Workshop 97FT4-01. This workshop was held in Mito city, Japan on October 22-24, 1997. About forty experts from EU, Japan, USA, and Chile attended the workshop. The scope of the workshop included the following: (1) fabrication and characterization of ceramic breeders, (2) properties data for ceramic breeders, (3) tritium release characteristics, (4) modeling of tritium behavior, (5) irradiation effects on performance behavior, (6) blanket design and R and D requirements, (7) hydrogen behavior in materials, and (8) blanket system technology and structural materials. In the workshop, information exchange was performed for fabrication technology of ceramic breeder pebbles in EU and Japan, data of various properties of Li{sub 2}TiO{sub 3}, tritium release behavior of Li{sub 2}TiO{sub 3} and Li{sub 2}ZrO{sub 3} including tritium diffusion, modeling of tritium release from Li{sub 2}ZrO{sub 3} in ITER condition, helium release behavior from Li{sub 2}O, results of tritium release irradiation tests of Li{sub 4}SiO{sub 4} pebbles in EXOTIC-7, R and D issues for ceramic breeders for ITER and DEMO blankets, etc. The 23 of the papers are indexed individually. (J.P.N.)

  18. Uranium alloys for using in fast breeder reactors

    International Nuclear Information System (INIS)

    Moura Neto, C.; Pires, O.S.

    1988-08-01

    The U-Zr and U-Ti alloys are studied, given emphasis to the high solute solubility in gamma phase of uranium, which is suitable for using as metal fuel in fast breeder reactors. The alloys were prepared in electron beam furnaces and submitted to X-ray diffraction, X-ray fluorescence, microhardness, optical metallography, and chemical analysis. The obtained values are good agreements with the literature data. The study shows that the U-Zr presents better characteristics than the U-Ti for using as fuel in fast breeder reactors. (M.C.K.) [pt

  19. Using alfalfa leaf meal as a supplement in late-gestation beef heifer and nursing beef calf diets.

    Science.gov (United States)

    Zehnder, C M; Maddock, T D; DiCostanzo, A; Miller, L R; Hall, J M; Lamb, G C

    2010-06-01

    Two experiments were conducted to investigate using alfalfa leaf meal (ALM; 22% CP, DM basis) in beef cattle diets. In Exp. 1, a total of 24 late-gestation Angus heifers (initial BW 470 +/- 9 kg) were blocked by BW, calving date, and BCS to 1 of 4 dietary treatments in a randomized complete block design. All heifers were offered a basal hay diet (7.4% CP and 67.6% NDF, DM basis). Treatments were arranged as a 2 x 2 factorial consisting of CP supplied at 100 or 112.5% of the recommended daily intake using either soybean meal (SBM) or ALM as the supplemental protein source. Treatments were fed for an average of 100 d before calving. Total DMI was unaffected by supplemental protein source, although heifers consumed more (P Feeding 112.5% of recommended CP to heifers increased precalving rate of BW gain (P = 0.004) and DM digestibility (P = 0.003). Protein source did not affect DM digestibility (P = 0.17). Neither supplemental protein source nor protein amount affected changes in BCS or calving traits. In Exp. 2, replicates of treatments were conducted over 2 consecutive years at 2 locations in northern Minnesota to determine the effects of including ALM in creep-fed supplements on nursing calf performance, supplement BW gain efficiency (GF; BW gain over control/supplement intake), and cow performance. Treatments were control (no supplement), ALM supplement (58% ALM, as-fed basis), or a wheat middling- and soybean hull-based supplement (MIDD). Milk intake (estimated by the weigh-suckle-weigh technique) was similar among treatments. Creep-fed calves had greater (P creep feed DMI than those offered ALM (2.6 vs. 1.3 kg/d, respectively). A year x treatment interaction was noted for GF (P = 0.02). In yr 1, GF for calves offered ALM was greater (P = 0.006) than GF for calves offered MIDD, but in yr 2, there were no differences. Alfalfa leaf meal may substitute for SBM in beef heifer wintering diets and conventional creep feed ingredients. When included in creep feed diets

  20. Economical efficiency estimation of the power system with an accelerator breeder

    International Nuclear Information System (INIS)

    Rublev, O.V.; Komin, A.V.

    1990-01-01

    The review deals with economical indices of nuclear power system with an accelerator breeder producing secondary nuclear fuel. Electric power cost was estimated by the method of discounted cost. Power system with accelerator breeder compares unfavourably with traditional nuclear power systems with respect to its capitalized cost

  1. Intake, digestion, and digestive characteristics of Neotyphodium coenophialum-infected and uninfected fescue by heifers offered hay diets supplemented with Aspergillus oryzae fermentation extract or laidlomycin propionate.

    Science.gov (United States)

    Humphry, J B; Coffey, K P; Moyert, J L; Brazle, F K; Lomas, L W

    2002-01-01

    Tarentaise heifers fitted with a rumen cannula (539 +/- 7.5 and 487 +/- 15.7 kg avg initial BW in Exp. 1 and 2, respectively) were used in two Latin square metabolism experiments having 2 x 2 factorial treatment arrangements to determine the effects of supplementation with Aspergillus oryzae fermentation extract (AO) or laidlomycin propionate (LP) on intake, digestion, and digestive characteristics of Neotyphodium coenophialum-infected (IF) or uninfected (FF) tall fescue (Festuca arundinacea) hay diets consumed ad libitum. Heifers were housed in individual stanchions in a metabolism facility with ambient temperatures controlled to range between 26.7 and 32.2 degrees C daily. Total feces and urine were collected for 5 d following a 21-d dietary adaptation period. In situ DM and NDF disappearance and ruminal fermentation characteristics were also determined. In Exp. 1, DMI was 24% greater (P or = 0.42). In Exp. 2, DMI was 18.9% greater (P < 0.01) by heifers offered FF than by those offered IF (6.6 vs 5.5 kg/d). Heifers fed LP (50 mg/d) consumed 10.6% less (P < 0.05) DM than those not fed LP (5.7 vs 6/5 kg/d). Digestibility of NDF tended to be greater (P = 0.08) and digestibility of ADF was greater (P < 0.05) from FF than from IF. Conversely, apparent N absorption (%) was greater (P < 0.05) from IF than from FF. Heifers fed LP had lower (P < 0.05) ADF digestibility than those not fed LP. In situ degradable DM and NDF fractions were greater (P < 0.01) from IF than from FF. Diets supplemented with LP had higher (P < 0.01) indigestible DM and NDF fractions than those without LP. Propionic acid and total VFA concentrations were greater (P < 0.05) from heifers offered FF than from those offered IF and from heifers fed LP than from those not fed LP. Therefore, it appears the major effect of N. coenophialum was a reduction in forage intake and total-tract fiber digestibility in certain situations. Response to the feed additives was similar whether heifers were offered IF or

  2. Progress on solid breeder TBM at SWIP

    International Nuclear Information System (INIS)

    Feng, K.M.; Pan, C.H.; Zhang, G.S.; Luo, T.Y.; Zhao, Z.; Chen, Y.J.; Ye, X.F.; Hu, G.; Wang, P.H.; Yuan, T.; Feng, Y.J.; Xiang, B.; Zhang, L.; Wang, Q.J.; Cao, Q.X.; Li, Z.X.; Wang, F.

    2010-01-01

    Current progress on the design and R and D of Chinese helium-cooled solid breeder test blanket module, CN HCSB TBM is presented. The updated design on structural, neutronics, thermal-hydraulics and safety analysis has been completed. In order to accommodate the HCSB TBM ancillary system, the design and necessary R and Ds corresponding sub-systems have being developed. Current status on the development of function materials, structure material and the helium test loop are also presented. The Chinese low-activation ferritic/martensitic steels CLF-1, which is the structural material for the HCSB TBM is being manufactured by industry. The neutron multiplier Be and tritium breeder Li 4 SiO 4 pebbles are being prepared in laboratory scale.

  3. Development of Liquid Type Breeder Technology for ITER-TBM

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Ki Sok; Hong, Bong Geun; Lee, Dong Won

    2008-07-15

    In relation to liquid type TBM technology development, various works are performed. We established a test loop concept to test the MHD effects and materials compatibility for the Pb-17Li breeder material. For the loop construction, electromagnetic pump and storage tank for the Pb-17Li loop was manufactured and some technical requirements are summarised. As a reference, technical literatures relevant to the liquid type TBM materials and the tritium extraction from breeder materials are also surveyed.

  4. Major welfare issues in broiler breeders

    NARCIS (Netherlands)

    Jong, de I.C.; Guemene, D.

    2011-01-01

    Under current practices, broiler parent stock (broiler breeders) encounter several welfare problems, such as feed restriction and injury during mating. Intensive selection for production traits, especially growth rate, is associated with increased nutritious requirement and thus feed consumption,

  5. Comparative economics of the breeder and light water reactor

    International Nuclear Information System (INIS)

    Chow, B.G.

    1980-01-01

    The issue of breeder timing is studied in this article via a breakeven analysis in which the key driving variables are conveniently segregated into two groups, with uranium price providing the linkage. In one group, the technical and cost characteristics of reactors and fuel cycles determine the uranium breakeven price. In the other group, nuclear demand projections and the uranium supply schedule determine the time paths of uranium price for a given composition of reactor types. The author finds that, even if proliferation risk is ignored, the breeder is not economically competitive with a 30%-improved once-through light water reactor before the year 2030 in the USA and in the world outside communist areas as a whole in 90% of the cases examined. In the exceptional cases, the penalty of delaying commercial breeder introduction to 2030 is small and well within the noise level of long-term energy planning. (author)

  6. Accelerator breeders, will they replace liquid metal fast breeders (question mark)

    International Nuclear Information System (INIS)

    Grand, P.; Powell, J.R.; Steinberg, M.; Takahashi, H.

    1983-01-01

    Advances in accelerator technology make accelerator breeding of fissile fuel more and more attractive. Brookhaven studies indicate that accelerator breeders could be implemented commercially within twenty years and that the resulting AB-LWR fuel cycle cost is competitive with that of the LMFBR. This cost competitiveness would be greatly enhanced with more advanced converters. Feasibility studies carried out at Brookhaven over the last few years addressed principally the question of neutronics and engineering feasibility of the target system, technical issues of accelerator technology and cost/benefit analysis

  7. Double insemination and gonadotropin-releasing hormone treatment of repeat-breeding dairy cattle.

    Science.gov (United States)

    Stevenson, J S; Call, E P; Scoby, R K; Phatak, A P

    1990-07-01

    Our objective was to determine if double inseminations during the same estrous period of dairy cattle eligible for their third or fourth service (repeat breeders) would improve pregnancy rates equivalent to injections of GnRH given at the time of AI. Repeat-breeding, lactating cows from six herds (five herds in the San Joaquin Valley of central California and one herd in northeast Kansas) were assigned randomly to four treatment groups when detected in estrus: 1) single AI plus no injection, 2) single AI plus 100 micrograms GnRH at AI, 3) double AI plus no injection, or 4) double AI plus 100 micrograms of GnRH at AI. Inseminations were performed according to the a.m.-p.m. rule. The second AI for the double AI treatment was given 12 to 16 h after the first AI. Injections of GnRH were given intramuscularly immediately following the single AI or the first AI of the double AI. Pregnancy rates of cows given a single AI and hormone injection were numerically higher in all six herds than those of their herdmates given only a single AI. In five of six herds, the pregnancy rates of cows given a double AI and hormone injection were numerically higher than pregnancy rates of their herdmates given only a double AI. Overall pregnancy rates for the four treatments were 1) 112/353 (32.1%), 2) 165/406 (41.6%), 3) 119/364 (33.5%), and 4) 135/359 (37.5%). Gonadotropin-releasing hormone increased pregnancy rates of repeat breeders compared with controls given only a single AI. No further benefit beyond the single AI was accrued from the double AI treatment, with or without concurrent hormone administration.

  8. Effect of pregnancy on endometrial sex steroid receptors and on prostaglandin F2α release after uterine biopsy in heifers

    International Nuclear Information System (INIS)

    Meikle, A.; Garofalo, E.G.; Sahlin, L.; Thatcher, W.W.; Kindahl, H.; Forsberg, M.

    2005-01-01

    The effect of pregnancy on oestrogen receptor (ER) and progesterone receptor (PR) endometrial expression in heifers was studied. Holstein heifers were not inseminated (controls, n = 8) or inseminated (n = 21). Endometrial biopsies were taken at Day 17 h from the uterine horn ipsilateral to the corpus luteum. Hourly samples were taken on the day of the biopsy in 12 animals (controls = 4 and inseminated = 8) to analyze 15-ketodihydro-PGF 2α (PGFM) and progesterone concentrations. Pregnancy determined by ultrasonography diagnosed 6 pregnant cows. The uterine biopsy increased PGFM concentrations, which remained high for 2 to 4 hours, followed by a transient decrease in progesterone concentrations, but the procedure neither provoked luteolysis nor blocked pregnancy. PGFM concentrations were higher in cyclic than in pregnant cows. No differences in PR mRNA expression were observed among groups, but ER mRNA in pregnant heifers tended to be lower than controls, suggesting that this pathway is implicated in maintenance of pregnancy. (author)

  9. Effect of Doublesynch and Estradoublesynch protocols on estrus induction, conception rate, plasma progesterone, protein, and cholesterol profile in anestrus Gir heifers

    Directory of Open Access Journals (Sweden)

    N. J. Chaudhary

    2018-04-01

    Full Text Available Aim: This study aimed to evaluate the efficacy of Doublesynch and Estradoublesynch protocols on estrus induction, conception rates, plasma progesterone, protein, and cholesterol profile in anestrus Gir heifers. Materials and Methods: In this study, 50 pubertal anestrus Gir heifers were selected from the field and farm conditions. The heifers were dewormed (injection ivermectin, 100 mg, s/c and supplemented with minerals and vitamins (injection organic phosphorus 800 mg and injection Vitamin AD3E and Biotin 10 ml i/m and multi-mineral bolus at 1 bolus daily for 7 days. The heifers were randomly divided into three groups: Doublesynch (n=20, Estradoublesynch (n=20, and control (n=10. The animals were monitored for estrus response, estrus interval, behavioral signs, and conception rates after induced/first, second, and third cycle post-treatment. Blood samples were obtained on day 0, day 9, day 12, and on day 12 post-artificial insemination (AI for determination of plasma progesterone, protein, and cholesterol profile. Results: The estrus response rate between Doublesynch and Estradoublesynch protocols was similar between treated heifers (85% and 95%. The interval from the second prostaglandin F2α (PGF2α injection to estrus induction did not differ between the groups (63.87±4.19 vs. 58.27±3.83 h. The conception rates following induced estrus (20% vs. 30%, at the second cycle (23.07% vs. 16.66%, at the third cycle (22.22% vs. 30.00%, and the overall conception rate (45% and 55% within 27.89±5.75 and 26.45±5.48 days were the same across the treatment groups. The mean plasma progesterone concentrations were significantly (p<0.01 higher on day 9 (second PGF2α injection and day 12 post-AI compared to day 0 (first PGF2α injection and the day of fixed-timed artificial insemination. The concentrations were also significantly (p<0.05 higher in conceived than non-conceived heifers on day 9 of treatment and day 12 post-AI in both the protocols. The

  10. Effects of breeder turnover and harvest on group composition and recruitment in a social carnivore.

    Science.gov (United States)

    Ausband, David E; Mitchell, Michael S; Waits, Lisette P

    2017-09-01

    Breeder turnover can influence population growth in social carnivores through changes to group size, composition and recruitment. Studies that possess detailed group composition data that can provide insights about the effects of breeder turnover on groups have generally been conducted on species that are not subject to recurrent annual human harvest. We wanted to know how breeder turnover affects group composition and how harvest, in turn, affects breeder turnover in cooperatively breeding grey wolves (Canis lupus Linnaeus 1758). We used noninvasive genetic sampling at wolf rendezvous sites to construct pedigrees and estimate recruitment in groups of wolves before and after harvest in Idaho, USA. Turnover of breeding females increased polygamy and potential recruits per group by providing breeding opportunities for subordinates although resultant group size was unaffected 1 year after the turnover. Breeder turnover had no effect on the number of nonbreeding helpers per group. After breeding male turnover, fewer female pups were recruited in the new males' litters. Harvest had no effect on the frequency of breeder turnover. We found that breeder turnover led to shifts in the reproductive hierarchies within groups and the resulting changes to group composition were quite variable and depended on the sex of the breeder lost. We hypothesize that nonbreeding females direct help away from non-kin female pups to preserve future breeding opportunities for themselves. Breeder turnover had marked effects on the breeding opportunities of subordinates and the number and sex ratios of subsequent litters of pups. Seemingly subtle changes to groups, such as the loss of one individual, can greatly affect group composition, genetic content, and short-term population growth when the individual lost is a breeder. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  11. Effect of Incubator Type and Broiler Breeder Age on Hatchability and Chick Quality

    Directory of Open Access Journals (Sweden)

    ICS Araújo

    Full Text Available ABSTRACT Two experiments were conducted to evaluate the effect of broiler breeder age and incubator type on hatching parameters, hatch window, embryo diagnosis results, and hatchling physical quality. The treatments consisted of a combination of three broiler breeder ages (29, 35 and 59 weeks of age and two incubator types (single stage, SS; or and multiple stage, MS. A completely randomized design in a 3x2 factorial arrangement was applied. In Experiment I, 1,896 eggs were used and 360 eggs in Experiment II. There was an interaction between breeder age and incubator type only for hatchling physical quality score. Independently of incubator type, hatchability rate, late embryo mortality, and egg contamination were higher in the eggs laid by older breeders (59-wk-old. Early mortality (0-4 days was higher in the embryos from young breeders (29-wk-old. A shorter hatch window birth was obtained in the SS incubator, resulting in higher hatchling body weight relative to egg weight, and better hatchling physical quality score. Both types of incubators provide good conditions for embryo development; however, the physical quality of chicks derived from eggs from intermediate-aged breeders (35-wk-old is better when eggs are incubated in SS incubators.

  12. Reducing beryllium content in mixed bed solid-type breeder blankets

    Energy Technology Data Exchange (ETDEWEB)

    Shimwell, J., E-mail: mail@jshimwell.com [Department of Physics and Astronomy, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Lilley, S.; Morgan, L.; Packer, L.; Kovari, M.; Zheng, S. [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); McMillan, J. [Department of Physics and Astronomy, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

    2016-11-01

    Highlights: • The ratio of breeder ceramic to neutron multiplier of breeder blankets was varied linearly with depth. • Blankets with varying composition were found to perform better than uniform composition breeder blankets. • It was also possible to reduce the amount of beryllium required by the blanket. - Abstract: Beryllium (Be) is a precious resource with many high value uses, the low energy threshold (n,2n) reaction makes Be an excellent neutron multiplier for use in fusion breeder blankets. Estimates of Be requirements and available resources suggest that this could represent a major supply difficulty for solid-type blanket concepts. Reducing the quantity of Be required by breeder blankets would help to alleviate the problem to some extent. In addition, it is important that the reduction in the Be quantity does not diminish the blanket's performance in key aspects such as the tritium breeding ratio (TBR), energy multiplication and peak nuclear heating. Mixed pebble bed designs allow for the multiplier fraction to be varied throughout the blanket. This neutronics study used MCNP 6 to investigate linear variations of the multiplier fraction in relation to blanket depth, in order to better utilise the important multiplying Be(n,2n) and breeding reactions. Blankets with a uniform multiplier fraction showed little scope for reduction in Be mass. Blankets with varying multiplier fractions were able to simultaneously use 10% less Be, increase the energy amplification by 1%, reduce the peak heating by 7% and maintaining a sufficient TBR when compared to the performance achievable using a uniform composition.

  13. Contributions of fast breeder test reactor to the advanced technology in India

    International Nuclear Information System (INIS)

    Kapoor, R.P.

    2001-01-01

    Fast Breeder Test Reactor (FBTR) is a 40 MWt/13.2 MWe loop type, sodium cooled, plutonium rich mixed carbide fuelled reactor. Its operation at Indira Gandhi Centre for Atomic Research, since first criticality in 1985, has contributed immensely to the advancement of this multidisciplinary and complex fast breeder technology in the country. It has also given a valuable operational feedback for the design of 500 MWe Prototype Fast Breeder Reactor. This paper highlights FBTR's significant contributions to this important technology which has a potential to provide energy security to the country in future. (author)

  14. Granular Vulvovaginitis Syndrome in Nelore pubertal and post pubertal replacement heifers under tropical conditions: role of Mycoplasma spp., Ureaplasma diversum and BHV-1.

    Science.gov (United States)

    Gambarini, M L; Kunz, T L; Oliveira Filho, B D; Porto, R N G; Oliveira, C M G; Brito, W M E D; Viu, M A O

    2009-10-01

    In order to determine the role of Mycoplasma spp, Ureaplasma diversum and BHV-1 as causal agents of Granular Vulvovaginitis Syndrome in Nelore heifers raised under tropical conditions and based on the hypothesis that stressful conditions during puberty or breeding season would be a determinant factor for the infection, 340 heifers not vaccinated against BHV-1 were divided in Post-pubertal, in the beginning of the first breeding season, and Pubertal heifers. The vaginal lesion score (VLS) Grade 1 to 4 was giving according to lesion area and severity. Vaginal mucus was used to isolate Mycoplasma spp., Ureaplasma diversum and BHV-1. The predominant VLS was 2. No sample was positive for BHV-1; 48% were positive for Mycoplasma spp., Ureaplasma diversum, or both, with predominance of Ureaplasma diversum. Serum neutralization for BHV-1 showed more positive animals in pubertal group (23%); 3 of the paired sera demonstrated seroconversion. These data indicated that post-pubertal and pubertal Nelore heifers raised under extensive conditions are more susceptible to Mycoplasma spp. and Ureaplasma diversum. The hypothesis that the stress of pubertal period could lead to an acute vaginal infection by HBV-1 was not proofed.

  15. Simultaneous subcutaneous and conjunctival administration of the influenza viral vector based Brucella abortus vaccine to pregnant heifers provides better protection against B. abortus 544 infection than the commercial B. abortus S19 vaccine.

    Science.gov (United States)

    Tabynov, Kaissar; Orynbayev, Mukhit; Renukaradhya, Gourapura J; Sansyzbay, Abylai

    2016-09-30

    In this study, we explored possibility of increasing the protective efficacy of our novel influenza viral vector based B. abortus vaccine (Flu-BA) in pregnant heifers by adapting an innovative method of vaccine delivery. We administered the vaccine concurrently via the conjunctival and subcutaneous routes to pregnant heifers, and these routes were previously tested individually. The Flu-BA vaccination of pregnant heifers (n=9) against a challenge B. abortus 544 infection provided protection from abortion, infection of heifers and fetuses/calves by 88.8%, 100% and 100%, respectively (alpha=0.004-0.0007 vs. negative control; n=7). Our candidate vaccine using this delivery method provided slightly better protection than the commercial B. abortus S19 vaccine in pregnant heifers (n=8), which provided protection from abortion, infection of heifers and fetuses/calves by 87.5%, 75% and 87.5%, respectively. This improved method of the Flu-BA vaccine administration is highly recommended for the recovery of farms which has high prevalence of brucellosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Status of fast breeder reactor development in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Horton, K [U.S. Department of Energy, Washington, DC (United States)

    1981-05-01

    The energy policy of the United States is aimed at shifting as rapidly as practicable from an oil dependent economy to one that relies heavily on other fuels and energy sources. Nuclear power Is now and is expected to continue to be an important factor in achieving this goal. If nuclear power is to contribute to a solution of future energy needs, demonstration of the breeder reactor as a viable source of essentially inexhaustible energy supply is essential. The US DOE program for development of the fast breeder reactor has witnessed some notable events in the past year. Foremost among these Is the successful operational testing of the Fast Flux Test Facility (FFTF), located at.the Hanford Engineering Development Laboratory. The reactor reached full design power of 400 MW(t) on December 21, 1980, and has performed remarkably close to design specifications. Design of the Clinch River Breeder Reactor Plant (CRBRP), a 375 MW(e) LMFBR, is now over 80 percent complete. About $530 million in components have been ordered; component deliveries total approximately $124 million; work-in-process totals another $204 million. Construction of the plant, however, has been suspended since 1977. With the concurrence of the U.S. Congress and approvals from the appropriate authorities work on the safety review and site clearing for construction can resume. The Conceptual Design Study for a large, 1000 MW(e) LMFBR Large Developmental Plant was recently completed on a schedule commensurate with submission of a full report to the Congress at the end of March, 1981. This report is the culmination of a study which began in October, 1978 and involved contributions from U.S. reactor manufacturers and US DOE laboratories. The US DOE is carrying forward a comprehensive technology development program. This effort provides direct support to the FFTF and CRBRP projects and to the LDP. It also supports technology development which is generic to the overall LMFBR program. Funding for breeder

  17. Status of fast breeder reactor development in the United States

    International Nuclear Information System (INIS)

    Horton, K.

    1981-01-01

    The energy policy of the United States is aimed at shifting as rapidly as practicable from an oil dependent economy to one that relies heavily on other fuels and energy sources. Nuclear power Is now and is expected to continue to be an important factor in achieving this goal. If nuclear power is to contribute to a solution of future energy needs, demonstration of the breeder reactor as a viable source of essentially inexhaustible energy supply is essential. The US DOE program for development of the fast breeder reactor has witnessed some notable events in the past year. Foremost among these Is the successful operational testing of the Fast Flux Test Facility (FFTF), located at.the Hanford Engineering Development Laboratory. The reactor reached full design power of 400 MW(t) on December 21, 1980, and has performed remarkably close to design specifications. Design of the Clinch River Breeder Reactor Plant (CRBRP), a 375 MW(e) LMFBR, is now over 80 percent complete. About $530 million in components have been ordered; component deliveries total approximately $124 million; work-in-process totals another $204 million. Construction of the plant, however, has been suspended since 1977. With the concurrence of the U.S. Congress and approvals from the appropriate authorities work on the safety review and site clearing for construction can resume. The Conceptual Design Study for a large, 1000 MW(e) LMFBR Large Developmental Plant was recently completed on a schedule commensurate with submission of a full report to the Congress at the end of March, 1981. This report is the culmination of a study which began in October, 1978 and involved contributions from U.S. reactor manufacturers and US DOE laboratories. The US DOE is carrying forward a comprehensive technology development program. This effort provides direct support to the FFTF and CRBRP projects and to the LDP. It also supports technology development which is generic to the overall LMFBR program. Funding for breeder

  18. Stress and immunological response of heifers divergently ranked for residual feed intake following an adrenocorticotropic hormone challenge.

    Science.gov (United States)

    Kelly, A K; Lawrence, P; Earley, B; Kenny, D A; McGee, M

    2017-01-01

    When an animal is exposed to a stressor, metabolic rate, energy consumption and utilisation increase primarily through activation of the hypothalamic-pituitary-adrenal (HPA) axis. Changes to partitioning of energy by an animal are likely to influence the efficiency with which it is utilised. Therefore, this study aimed to determine the physiological stress response to an exogenous adrenocorticotropic hormone (ACTH) challenge in beef heifers divergently ranked on phenotypic residual feed intake (RFI). Data were collected on 34 Simmental weaning beef heifers the progeny of a well characterized and divergently bred RFI suckler beef herd. Residual feed intake was determined on each animal during the post-weaning stage over a 91-day feed intake measurement period during which they were individually offered adlibitum grass silage and 2 kg of concentrate per head once daily. The 12 highest [0.34 kg DM/d] and 12 lowest [-0.48 kg DM/d] ranking animals on RFI were selected for use in this study. For the physiological stress challenge heifers (mean age 605 ± 13 d; mean BW 518 ± 31.4 kg) were fitted aseptically with indwelling jugular catheters to facilitate intensive blood collection. The response of the adrenal cortex to a standardised dose of ACTH (1.98 IU/kg metabolic BW 0.75 ) was examined. Serial blood samples were analysed for plasma cortisol, ACTH and haematology variables. Heifers differing in RFI did not differ ( P  = 0.59) in ACTH concentrations. Concentration of ACTH peaked ( P  response than Low RFI from 40 min to 150 min relative to ACTH administration. Cortisol response was positively associated with RFI status ( r  = 0.32; P  responsiveness of the HPA axis is likely to contribute to appreciable variation in the efficiency feed utilisation of cattle.

  19. The uranium market and its relevance for the fast breeder

    International Nuclear Information System (INIS)

    Marth, W.

    1982-01-01

    Uranium is a very particular element: the technology of light water nuclear power plants is based on its existence, and the doubts with respect to the long-term availability form the basis for the development of fast breeder reactor. At the same time uranium is a merchandise obedient to the laws of the market, which are based on offer and demand, which are however also affected by influences outside the market, particularly in the last time. Here an attempt is made to describe these peculiarities of the uranium market for the past, the presence and the visual future, and to give some insight into the economic field around the breeder reactor, as the uranium market is of great relevance for the introduction of the breeder as an electric power producing system. (orig.) [de

  20. A vision of inexhaustible energy: The fast breeder reactor in Swedish nuclear power history 1945-80

    International Nuclear Information System (INIS)

    Fjaestad, Maja

    2010-01-01

    The fast breeder is a type of nuclear reactor that aroused much attention in the 1950s and 1960s. Its ability to produce more nuclear fuel than it consumes offered promises of cheap and reliable energy, and thereby connected it to utopian ideas about an eternal supply of energy, Furthermore. the ideas of breeder reactors were a vital part of the post-war visions about the nuclear future. This dissertation investigates the plans for breeder reactors in Sweden, connecting them to the contemporary development of nuclear power with heavy or light water and the discussions of nuclear weapons, as well as to the general visions of a prosperous technological future. The history of the Swedish breeder reactor is traced from high hopes in the beginning, via the fiasco of the Swedish heavy water program, partly focusing on the activities at the company AB Atomenergi and investigating how it planned and argued for its breeder program and how this was received by the politicians. The story continues into the intensive environmental movement in the 1970s, ending with the Swedish referendum on nuclear energy in 1980, which can be seen as the final point for the Swedish breeder. The thesis discusses how the nuclear breeder reactor was transformed from an argument for nuclear power to an argument against it. The breeder began as a part of the vision of a society with abundant energy, but was later seen as a threat against the new sustainable world. The nuclear breeder reactor is an example of a technological vision that did not meet its industrial expectations. But that does not prevent the fact that breeder was an influential technology in an age where important decisions about nuclear energy were made. The thesis argues that important decisions about the contemporary reactors were taken with the idea that they in a foreseeable future would be replaced with the efficient breeder. And the last word on the breeder reactor is not said - today, reactor engineers around the world are

  1. Examination of the use of the breeder reactor to enhance security of energy supply. Final report

    International Nuclear Information System (INIS)

    Jones, G.S.; Chow, B.G.

    1980-01-01

    Early commercialization of the breeder reactor has been justified in terms of its promise for lessening a nation's dependence on imported uranium. The relationship between breeder timing (assuming a vigorous but not instantaneous breeder penetration rate) and the reduction in uranium requirements is examined using Japan as an example. Comparing early and delayed breeder introductions (2006 and 2026 respectively in the high growth projections), the difference in cumulative uranium requirements is slight through the year 2045; for both scenarious, annual requirements remain high. The early breeder introduction strategy is more attractive when it incorporates a 30 percent improved LWR. However, given the unlikelihood of sufficient funding for the development of both designs, the optimal strategy for Japan is stockpiling uranium for an improved LWR and delaying introduction of the breeder

  2. Efficiency of fixed-time artificial insemination using a progesterone device combined with GnRH or estradiol benzoate in Nellore heifers

    Directory of Open Access Journals (Sweden)

    Vinícius Antônio Pelissari Poncio

    2015-10-01

    Full Text Available he use of estrogens in artificial insemination protocols for cattle is the least expensive and most efficient method currently available. However, the trend to prohibit the use of estrogens for this purpose has made it necessary to find alternatives that replace estrogens without compromising the reproductive performance of the animals. The objective of this study was to evaluate conception rates in Bos indicus beef heifers treated with a progesterone device (P4 combined with GnRH or an estradiol ester. On day 0, pubertal Nellore heifers (n = 100 received an intravaginal device containing 1 g P4 and were randomly divided into two groups. The GnRH group (n = 49 received an intramuscular injection of 100 µg GnRH, while the E2 group (n = 51 received 2 mg estradiol benzoate (EB. The P4 device was removed after 5 (GnRH group or 8 days (E2 group, followed by an injection of 125 µg of the PGF2α, analog cloprostenol. On that occasion, the E2 group received an additional injection of 300 IU eCG. Twenty-four hours later, the GnRH group received a second injection of 125 µg cloprostenol, while the E2 group received 1 mg EB. The heifers were inseminated 72 (GnRH group or 54 hours (E2 group after removal of the P4 device. At the time of insemination, the GnRH group received additionally an injection of 100 µg GnRH. Estrus was monitored during the period of cloprostenol injection until the time of artificial insemination and pregnancy was diagnosed 40 days after insemination by transrectal ultrasonography. The data were analyzed by Fisher’s exact test. The pregnancy rate was 38.8% and 31.4% in the GnRH and E2 groups, respectively (P>0.05. The ovarian condition of the heifers (estrus or anestrus tended to influence (P=0.07 pregnancy rates in the GnRH group, but not in the E2 group. At the time of artificial insemination, 33.3% of heifers in the GnRH group showed signs of estrus versus 88.2% in the E2 group (P<0.05. However, the time of estrus

  3. An influenza viral vector Brucella abortus vaccine induces good cross-protection against Brucella melitensis infection in pregnant heifers.

    Science.gov (United States)

    Tabynov, Kaissar; Ryskeldinova, Sholpan; Sansyzbay, Abylai

    2015-07-17

    Brucella melitensis can be transmitted and cause disease in cattle herds as a result of inadequate management of mixed livestock farms. Ideally, vaccines against Brucella abortus for cattle should also provide cross-protection against B. melitensis. Previously we created a novel influenza viral vector B. abortus (Flu-BA) vaccine expressing the Brucella ribosomal proteins L7/L12 or Omp16. This study demonstrated Flu-BA vaccine with adjuvant Montanide Gel01 provided 100% protection against abortion in vaccinated pregnant heifers and good cross-protection of the heifers and their calves or fetuses (90-100%) after challenge with B. melitensis 16M; the level of protection provided by Flu-BA was comparable to the commercial vaccine B. abortus S19. In terms of the index of infection and colonization of Brucella in tissues, both vaccines demonstrated significant (P=0.02 to P<0.0001) protection against B. melitensis 16M infection compared to the negative control group (PBS+Montanide Gel01). Thus, we conclude the Flu-BA vaccine provides cross-protection against B. melitensis infection in pregnant heifers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Molten salt breeder reactor

    International Nuclear Information System (INIS)

    1977-01-01

    MSBR Study Group formed in October 1974 has studied molten salt breeder reactor and its various aspects. Usage of a molten salt fuel, extremely interesting as reactor chemistry, is a great feature to MSBR; there is no need for separate fuel making, reprocessing, waste storage facilities. The group studied the following, and these results are presented: molten salt technology, molten salt fuel chemistry and reprocessing, reactor characteristics, economy, reactor structural materials, etc. (Mori, K.)

  5. Characterization of transfer of passive immunity in dairy heifer calves

    International Nuclear Information System (INIS)

    Elizondo-Salazar, Jorge Alberto

    2016-01-01

    The transfer of passive immunity was determined in dairy heifer calves in Costa Rica. The data presented of total serum protein (TSP) have corresponded to measurements obtained in the period between 2010 and 2013, during the months of August and November in 50 dairy farms. 2500 heifer calves born from Holstein cows, Jersey, HolsteinxJersey crosses and others were evaluated. When the TSP concentration has been less than 5,5 g / dl, it was considered as a failure of passive transfer of immunity (FPTI). TSP concentration has ranged between 2,0 and 10,0 g/dl, with an overall mean of 5,9 g/dl. Of all the calves evaluated, 38.8% presented failure of passive transfer of immunity. The animals sampled have presented 38,8% of FPTI. A significantly higher TSP concentration (P<0,05) to the Holstein breed and others were obtained from the animals from the Jersey breed and HolsteinxJersey crosses. When considering calving of the dam, the concentration of TSP of the offsprings remains without significant differences. The offspring of first calving cows have showed the lowest proportion of animals with FPTI. The TSP concentration has varied significantly (P <0,05) between calves that have remained with the dams and were fed with colostrum by bottle. The FPTI has been higher when calves have stayed with their mother (44 vs. 33%). (Author) [es

  6. Detection of bias in animal model pedigree indices of heifers

    Directory of Open Access Journals (Sweden)

    M. LIDAUER

    2008-12-01

    Full Text Available The objective of the study was to test whether the pedigree indices (PI of heifers are biased, and if so, whether the magnitude of the bias varies in different groups of heifers. Therefore, two animal model evaluations with two different data sets were computed. Data with all the records from the national evaluation in December 1994 was used to obtain estimated breeding values (EBV for 305-days' milk yield and protein yield. In the second evaluation, the PIs were estimated for cows calving the first time in 1993 by excluding all their production records from the data. Three different statistics, a simple t-test, the linear regression of EBV on PI, and the polynomial regression of the difference in the predictions (EBV-PI on PI, were computed for three groups of first parity Ayrshire cows: daughters of proven sires, daughters of young sires, and daughters of bull dam candidates. A practically relevant bias was found only in the PIs for the daughters of young sires. On average their PIs were biased upwards by 0.20 standard deviations (78.8 kg for the milk yield and by 0.21 standard deviations (2.2 kg for the protein yield. The polynomial regression analysis showed that the magnitude of the bias in the PIs changed somewhat with the size of the PIs.;

  7. Effects of supplementation with protected polyunsaturated fatty acids on productive and hormonal parameters of embryo recipient heifers

    Directory of Open Access Journals (Sweden)

    Juan Camilo Angel Cardona

    2016-06-01

    Full Text Available Supplementation with protected polyunsaturated fatty acids (PPUFA has positive effects on cow reproduction. Therefore, the aim of this study was to evaluate the effects of adding a source of PPUFA to energy supplements for embryo recipient heifers on productive performance and plasma concentrations of progesterone, cholesterol and insulin. For this purpose, 44 Angus x Hereford embryo recipient heifers (average body weight = 385 kg raised on pasture were studied in a completely randomized design. The effects of PPUFA added to isocaloric energy supplements for 60 days on production parameters and serum concentrations of cholesterol, progesterone and insulin were evaluated. The treatments consisted of individual supplementation with: 1 control (no supplement; 2 corn (corn, 70%; soybean meal, 30%; 3 PPUFA supplement (Megalac-E®, 30%; soybean meal, 20%; commercial ration, 50%. The treatments did not affect (P>0.05 dry matter intake, pregnancy rates, or serum insulin concentration. However, PPUFA supplement increased (P0.05 in dry matter intake between treatments, PPUFA supplement increased (P<0.05 average daily gain compared to the control and corn treatments. The inclusion of PPUFA in energy supplements offered to heifers used in an embryo transfer program increased average daily gain and serum concentrations of cholesterol and progesterone, but did not affect pregnancy rates.

  8. Optimization of electron-cyclotron-resonance charge-breeder ions : Final CRADA Report

    International Nuclear Information System (INIS)

    Pardo, R.

    2009-01-01

    Measurements of 1+ beam properties and associated performance of ECR Charge Breeder source determined by total efficiency measurement and charge state distributions from the ECR Charge Breeder. These results were communicated to Far-Tech personnel who used them to benchmark the newly developed programs that model ion capture and charge breeding in the ECR Charge Breeder Source. Providing the basic data described above and in the discussion below to Far-Tech allowed them to improve and refine their calculational tools for ECR ion sources. These new tools will be offered for sale to industry and will also provide important guidance to other research labs developing Charge Breeding ion sources for radioactive beam physics research.

  9. Ingestive Behavior of Heifers Supplemented with Glycerin in Substitution of Corn on Brachiaria brizantha Pasture.

    Science.gov (United States)

    Facuri, L M A M; Silva, R R; da Silva, F F; de Carvalho, G G P; Sampaio, C B; Mendes, F B L; Lisboa, M M; Barroso, D S; Carvalho, V M; Pereira, M M S

    2014-11-01

    The objective was to evaluate the ingestive behavior of crossbred heifers finished on a Brachiaria brizantha cv. Marandu pasture receiving four levels of glycerin in their supplementation. Thirty-six crossbred heifers with average initial weight of 264.83±3.83 kg and 20 months of age were distributed into a completely randomized design with four treatments and nine replications: control (0%), 4.82%, 10.12%, and 15.56% glycerin in the dry matter. The grazing time reduced linearly (p0.05). The number of rumination periods reduced linearly (p0.05) whereas the feed efficiency of neutral detergent fiber reduced linearly (p<0.05). Addition of glycerin in substitution of corn in supplements for animals managed on pastures does not influenced feed intake, but reduces the grazing time and increases the idle time. The supplementation also improves feed and rumination efficiencies.

  10. Genetic parameters for fertility measurements ind Holstein heifers

    DEFF Research Database (Denmark)

    Sørensen, L. H.; Sørensen, A. C.; Mark, Thomas

    2013-01-01

    first to last insemination (IFL), age at first insemination (AFI), and age at first calving (AFC) in Danish Holstein heifers. The means of the traits were all significantly different between the two groups of herds. Heritabilities for NINS and IFL were lower than 1%, while heritabilities for AFI and AFC...... were 12–29%. Heritabilities were all lower in Heatime herds than in reference herds. The genetic correlations between traits in different environments were high for NINS, AFI, and AFC (>0.88), while the correlation for IFL was 0.68 but with a higher SE (0.313). Thus, IFL seems not to be the same trait...

  11. Updated reference design of a liquid metal cooled tandem mirror fusion breeder

    International Nuclear Information System (INIS)

    Berwald, D.H.; Whitley, R.H.; Garner, J.K.

    1985-09-01

    Detailed studies of key techinical issues for liquid metal cooled fusion breeder (fusion-fission hybrid blankets) have been performed during the period 1983-4. Based upon the results of these studies, the 1982 reference liquid metal cooled tandem mirror fusion breeder blanket design was updated and is described. The updated reference blankets provides increased breeding and lower technological risk in comparison with the original reference blanket. In addition to the blanket design revisions, a plant concept, cost, and fuel cycle economics assessment is provided. The fusion breeder continues to promise an economical source of fissile fuel for the indefinite future

  12. Updated reference design of a liquid metal cooled tandem mirror fusion breeder

    Energy Technology Data Exchange (ETDEWEB)

    Berwald, D.H.; Whitley, R.H.; Garner, J.K.; Gromada, R.J.; McCarville, T.J.; Moir, R.W.; Lee, J.D.; Bandini, B.R.; Fulton, F.J.; Wong, C.P.C.; Maya, I.; Hoot, C.G.; Schultz, K.R.; Miller, L.G.; Beeston, J.M.; Harris, B.L.; Westman, R.A.; Ghoniem, N.M.; Orient, G.; Wolfer, M.; DeVan, J.H.; Torterelli, P.

    1985-09-01

    Detailed studies of key techinical issues for liquid metal cooled fusion breeder (fusion-fission hybrid blankets) have been performed during the period 1983-4. Based upon the results of these studies, the 1982 reference liquid metal cooled tandem mirror fusion breeder blanket design was updated and is described. The updated reference blankets provides increased breeding and lower technological risk in comparison with the original reference blanket. In addition to the blanket design revisions, a plant concept, cost, and fuel cycle economics assessment is provided. The fusion breeder continues to promise an economical source of fissile fuel for the indefinite future.

  13. Genomic association for sexual precocity in beef heifers using pre-selection of genes and haplotype reconstruction.

    Directory of Open Access Journals (Sweden)

    Luciana Takada

    Full Text Available Reproductive traits are of the utmost importance for any livestock farming, but are difficult to measure and to interpret since they are influenced by various factors. The objective of this study was to detect associations between known polymorphisms in candidate genes related to sexual precocity in Nellore heifers, which could be used in breeding programs. Records of 1,689 precocious and non-precocious heifers from farms participating in the Conexão Delta G breeding program were analyzed. A subset of single nucleotide polymorphisms (SNP located in the region of the candidate genes at a distance of up to 5 kb from the boundaries of each gene, were selected from the panel of 777,000 SNPs of the High-Density Bovine SNP BeadChip. Linear mixed models were used for statistical analysis of early heifer pregnancy, relating the trait with isolated SNPs or with haplotype groups. The model included the contemporary group (year and month of birth as fixed effect and parent of the animal (sire effect as random effect. The fastPHASE® and GenomeStudio® were used for reconstruction of the haplotypes and for analysis of linkage disequilibrium based on r2 statistics. A total of 125 candidate genes and 2,024 SNPs forming haplotypes were analyzed. Statistical analysis after Bonferroni correction showed that nine haplotypes exerted a significant effect (p<0.05 on sexual precocity. Four of these haplotypes were located in the Pregnancy-associated plasma protein-A2 gene (PAPP-A2, two in the Estrogen-related receptor gamma gene (ESRRG, and one each in the Pregnancy-associated plasma protein-A gene (PAPP-A, Kell blood group complex subunit-related family (XKR4 and mannose-binding lectin genes (MBL-1 genes. Although the present results indicate that the PAPP-A2, PAPP-A, XKR4, MBL-1 and ESRRG genes influence sexual precocity in Nellore heifers, further studies are needed to evaluate their possible use in breeding programs.

  14. Prevalence of Campylobacter jejuni in poultry breeder flocks

    Directory of Open Access Journals (Sweden)

    Ludovico Dipineto

    2010-01-01

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

  15. [Knowledge and practices concerning taeniasis-cysticercosis in Colombian pig-breeders].

    Science.gov (United States)

    Agudelo-Flórez, Piedad; Restrepo, Berta N; Palacio, Luis G

    2009-01-01

    Describing knowledge and practices regarding taeniasis-cysticercosis and cysticercosis prevalence in the village of Andagoya, Colombia. The study design was qualitative and quantitative. The study population consisted of pig breeders and their families, local groups and pigs. Study participants had partial knowledge of the taeniasis-cysticercosis complex. They considered taeniasis to be an illness resulting from faecal transmission and not caused by becoming infected with cysticercosis after consuming pork. Pig breeding is not carried out in confined conditions and, although breeders know the right measures for controlling some parasitic illnesses, these practices are not observed. There was 8.7% presence of T. solium antibodies in pig breeders and their relatives and 20.9% in the pigs. An educational programme aimed at raising the population's awareness of the taeniasis-cysticercosis complex cycle should be developed; this will facilitate control measures being applied.

  16. Status of fast breeder reactor development in the United States of America - April 1984

    International Nuclear Information System (INIS)

    Horton, K.E.

    1984-01-01

    The Breeder Technology program continues to produce viable information on fuel performance, nuclear systems technology, and power conversion technology. The unique testing capabilities design into the FFTF have resulted in well-validated materials and fuels irradiation information that has confirmed and extended previous data bases. Current directions for the research and development program are to improve the technology for power conversion systems, components, instrumentation, and materials technology to the point where cost reduction and reliability potentials are realized. Operation of the breeder test facility complex at the Hanford Engineering Development Laboratory (HEDL), the Energy Technology Engineering Center (ETEC), and the Argonne National Laboratory (ANL) continues to provide the experience base and test capability for the breeder R and D effort. International cooperation will be even more important in the future than in the past for several reasons. Significant new investments still have to be made in breeder R and D to improve designs, achieve economic competitiveness and to develop practical breeder fuel cycle capabilities. Progress can be accelerated, redundancies avoided, and economics achieved if nations coordinate their programs, and where possible, divide up the work. In addition, there is clear mutual benefit in encouraging the countries involved in breeder development to harmonize standards and regulations related to safety. It is also important that the advanced nations work together closely in assuring that adequate international safeguards, export controls, and national physical security measures keep pace with breeder reactor and fuel cycle developments

  17. Randomised clinical trial evaluating the effect of different timing and number of fixed timed artificial inseminations, following a seven-day progesterone-based protocol, on pregnancy outcomes in UK dairy heifers.

    Science.gov (United States)

    Walsh, John Paul; Coates, Amy; Lima, Fabio; Smith, Rob; Oikonomou, Georgios

    2017-12-01

    The objective of this study was to determine the effect on pregnancy outcome of either inseminating heifers twice (at 48 and 72 hours after withdrawal of a controlled internal drug release insert (CIDR) containing progesterone) or once (56 hours after CIDR withdrawal) following a seven-day CIDR synchronisation protocol. Dairy heifers (n=267) from five farms, with an age range of 388-736 days, were randomly assigned to one of two treatment groups (group A heifers were inseminated twice; group B heifers were inseminated once). Both groups received a CIDR on day (D) 0 and an intramuscular injection of d-cloprostenol on D6; the CIDR was withdrawn on D7. Measurements of withers height, body condition score and hearth girth (used to estimate weight) were taken on D0. The diameter of the largest follicles and corpora lutea was recorded on both D0 and D6. Data were analysed with the use of multivariable logistic regression modelling. Treatment group and farm were not statistically significantly associated with pregnancy per treatment (P/T). Age and dominant follicle size on D6 were significantly associated with P/T. Heifers with the largest dominant follicle sizes (16-22 mm) were 5.54 times less likely to be pregnant than those heifers with the smallest dominant follicles (8-10 mm) on D6. It was shown that the cost associated with inseminating heifers twice after a seven-day CIDR synchronisation protocol is not justified. © British Veterinary Association (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  18. Long-term effect of early nutrition on endocrine parameters and liver and endometrial gene expression of the members of the somatotrophic axis in Hereford heifers.

    Science.gov (United States)

    Guggeri, D; Meikle, A; Carriquiry, M; De Barbieri, I; Montossi, F; Viñoles, C

    2018-04-23

    This study compared the effect of different management systems on endocrine parameters, and gene expression of members of the somatotrophic axis in the liver and endometrium of beef heifers. Twenty-two 709-days-old heifers submitted to Early Weaning (EW, n = 8), Traditional Weaning (TW, n = 7) and TW plus creep feeding (TW+CF, n = 7) were used. Animals were synchronized with two prostaglandin (PG) injections at 11-day interval (Oestrus = Day 0). Blood samples were collected daily for progesterone (P4) determination, and endometrial and liver biopsies on Days 7 and 16 for transcript determination of members of the somatotrophic axis. Progesterone concentrations were greater on Days 15 and 16 (p < .02) of the cycle in TW+CF than TW and EW heifers. On Day 7, TW+CF heifers expressed greater liver total growth hormone receptor transcripts than TW heifers (p = .05) and greater insulin-like growth factor (IGF)-binding protein 3 mRNA than both EW and TW groups (p < .05). On Days 7 and 16, TW+CF expressed more endometrial IGF1 mRNA than the other groups (p < .01). We conclude that increasing the plane of nutrition of nursing calves may have a long-term effect on the functioning of the somatotrophic axis both in the liver and in the endometrium. © 2018 Blackwell Verlag GmbH.

  19. Fast breeder reactors

    International Nuclear Information System (INIS)

    Ollier, J.L.

    1987-01-01

    The first industrial-scale fast breeder reactor (FBR) is the Superphenix I at Crays-Melville. It was designed and built by Novatome, a French company, and Ansaldo, an Italian company. The advantages of FBRs are summarized. The status of Superphenix and the testing schedule is given. The stages in its power escalation in 1986 are given. The article is optimistic about the future for FBRs and expects FBRs to take over from PWRs at the beginning of the 21st Century. To achieve economic viability, European financial cooperation for the research and development programme is advocated. (UK)

  20. The effect of housing on the diurnal behavioural profile of beef heifers

    Directory of Open Access Journals (Sweden)

    Mary Clare Hickey

    2014-02-01

    Full Text Available The objectives were to determine 1. the behaviour of heifers at pasture or housed on slats, and 2. the effect of housing on behavioural adaptation when moved to pasture. Forty-five continental crossbred heifers were assigned to either housing on slats at 3 m2 head-1for 5 months (H, grazing for 5 months (G or housing for 4 months, prior to grazing (HG. Lying and eating behaviour was recorded periodically for H, G and for HG post-turnout. Per day, G animals spent longer (p<0.01 eating and had a greater (p<0.001 number of daily lying bouts than H animals. While there were minor differences between G and HG animals in the 24 h period after turnout, there was no difference between G and HG animals in time spent eating, lying or in the number of lying bouts on day 1, 2, 3 or 10 post turnout. While abnormal lying behaviour was observed in 3 animals before turnout, there was no abnormal lying behaviour in HG animals by 48 h post turnout. The alteration in behaviour due to housing was not permanent.

  1. Effects of month of breeding on reproductive efficiency of Holstein cows and heifers inseminated with sex-sorted or conventional semen in a hot environment.

    Science.gov (United States)

    Mellado, Miguel; Sepulveda, Edgar; Macias-Cruz, Ulises; Avendaño, Leonel; Garcia, Jose E; Veliz, Francisco G; Rodríguez, Alvaro

    2014-01-01

    The main objective of this study was to assess the effect of month of breeding on reproduction performance of Holstein heifers and cows inseminated with sex-sorted or conventional semen in a hot environment. Pregnancy per artificial insemination (P/AI; 64,666 services over an 8-year period) both in heifers (n = 22,313) and cows (n = 42,353) from a large dairy herd in northern Mexico (26°N) were evaluated with the GENMOD procedure of SAS, with respect to month of AI. Overall, P/AI with sex-sorted semen was greater (P sex-sorted semen. While there was no difference in P/AI between the sex-sorted sperm and conventional semen in cows inseminated in July (16 and 18 %, respectively), P/AI plummeted for both groups of cows during the summer and fall (more severe heat stress). P/AI was not different between heifers serviced with sex-sorted or conventional semen during the hottest months of the year (July to October). However, during the coldest month of the year (January and February), P/AI was 10 percentage points greater (P sex-sorted semen. It was concluded that in this hot climate cow and heifer fertility declined in the summer and fall when inseminated with conventional semen. However, the use of sex-sorted semen during summer and fall did not compromise the breeding success in heifers. Thus, this data suggest that sex-sorted semen promotes some embryonic thermoprotective mechanism, which leads to a marginal summer and fall fertility depression with this type of semen in this particular hot environment.

  2. Factors associated with fertility of nulliparous dairy heifers following a 10-day fixed-time artificial insemination program with sex-sorted and conventional semen.

    Science.gov (United States)

    Noonan, E J; Kelly, J C; Beggs, D S

    2016-05-01

    To examine factors associated with fertility on dairy farms that used a common fixed-time artificial insemination (FTAI) program in yearling heifers. Records were analysed from 954 yearling heifers on 10 south-west Victorian dairy farms that used a common FTAI program, involving the insertion of a 1.9-g progesterone-releasing device for 10 days; 2 mg oestradiol benzoate at insertion; 500 µg cloprostenol on day 7; and FTAI 48 h after device removal. Weight, age, expression of oestrus, sire, semen type (frozen sex-sorted or frozen conventional) and timing of insemination were examined for their relationship with first-service conception rates. Heifers over 300 kg body weight were 1.18-fold more likely to express oestrus during the FTAI program. For every extra 1 kg, there was a 1.5% increase in the likelihood of expressing oestrus. First-service conception rates were 40.3% and 56.0% for sex-sorted and conventional semen, respectively, and were significantly higher when oestrus was expressed. The difference was greater for sex-sorted semen (3.4-fold) compared with conventional semen (1.5-fold). The interval from device removal to insemination varied between 47 and 51.4 h and had no significant effect on conception rates. However, there was a trend towards a higher conception rate for sex-sorted semen when inseminations were performed >50 h after device removal. Increased fertility was associated with larger heifers and heifers that expressed oestrus, particularly when sexed-sorted semen was used. Variation in the timing of AI with respect to device removal between 47 and 51.4 h did not adversely affect conception rates. © 2016 Australian Veterinary Association.

  3. Heat production, respiratory quotient, and methane loss subsequent to LPS challenge in beef heifers

    Science.gov (United States)

    Respiration calorimetry was used to measure energy utilization during an acute phase response (APR) to lipopolysaccharide (LPS). Eight Angus heifers (208 +/- 29.2 kg) were randomly assigned to one of two calorimeters in four 2-day periods for measurement of heat production (HP), methane (CH4), and r...

  4. Processing and waste disposal needs for fusion breeder blankets system

    International Nuclear Information System (INIS)

    Finn, P.A.; Vogler, S.

    1988-01-01

    We evaluated the waste disposal and recycling requirements for two types of fusion breeder blanket (solid and liquid). The goal was to determine if breeder blanket waste can be disposed of in shallow land burial, the least restrictive method under U.S. Nuclear Regulatory Commission regulations. Described in this paper are the radionuclides expected in fusion blanket materials, plans for reprocessing and disposal of blanket components, and estimates for the operating costs involved in waste disposal. (orig.)

  5. Growth performance, rumen fermentation, nutrient utilization, and metabolic profile of dairy heifers limit-fed distillers dried grains with ad libitum forage.

    Science.gov (United States)

    Manthey, A K; Anderson, J L

    2018-01-01

    The objective of this study was to determine the effects of feeding a corn- and soybean-product-based concentrate mix or distillers dried grains with solubles concentrate mix with ad libitum grass hay to dairy heifers. A 16-wk randomized complete block design study was conducted using 24 heifers [18 Holstein and 6 Brown Swiss; 219 ± 2 d of age (±standard deviation); 230 ± 4 kg of body weight] to evaluate the effect of diet on dry matter intake (DMI), growth performance, rumen fermentation, metabolic profile, and nutrient digestibility. Treatments were (1) corn and soybean product concentrate mix, and (2) distillers-dried-grains-with-solubles-based concentrate mix (DDG). Both concentrate mixes were limit-fed at 0.8% of body weight and grass hay was offered ad libitum. Heifers were individually fed using Calan gates and orts were recorded daily at feeding. Heifers were weighed every 2 wk and ration concentrate mix offered was adjusted accordingly. Frame measurements and body condition score were recorded every 2 wk. Rumen fluid was collected via esophageal tubing during wk 12 and 16 for pH, ammonia N, and volatile fatty acid analysis. Jugular blood samples were collected every 4 wk for metabolite and metabolic hormone analysis. Total-tract digestibility of nutrients was evaluated during wk 16 by fecal grab sampling. No treatment by week interactions were observed for any of the growth measurements and growth measurements and DMI did not differ between treatments. A treatment by time interaction was observed for rumen butyrate percentage with heifers fed DDG having a greater percentage. Total volatile fatty acid concentration, acetate molar percentage, and acetate:propionate decreased with the DDG treatment, whereas propionate molar percentage increased. No treatment by week interactions were observed for any of the metabolites or metabolic hormones measured. A tendency was observed for glucose and plasma urea nitrogen concentration to decrease with DDG. Plasma

  6. Feeding broiler breeders to improve their welfare whilst maintaining productivity

    DEFF Research Database (Denmark)

    Steenfeldt, Sanna; Nielsen, Birte Lindstrøm

    of their litter may have affected their thermoregulation. This experiment indicates that high fibre diets can alleviate the feeling of hunger currently experienced by broiler breeders, and a high ratio of insoluble fibre can reduce stereotypies and may improve the well-being of the birds.......In the present experiment different types of fibre sources were used in high fibre diets to increase feeding quantity whilst limiting the growth of broiler breeders to industry recommended levels. Using scatter feeding, three diets (CON, commercial control diet; INF, high insoluble fibre content......; and SOF, high soluble fibre content) were each fed to 10 groups of 12 broiler breeder chickens (age: 2 to 15 weeks). Similar growth rates were obtained on different quantities of food (e.g. food allocation in week 14: approx. 80, 100, and 130 g/d for CON, INF, and SOF, respectively) with all birds...

  7. Accelerator breeder: a viable option for the production of nuclear fuels

    International Nuclear Information System (INIS)

    Grand, P.

    1983-01-01

    Despite the growing pains of the US nuclear power industry, our dependence on nuclear energy for the production of electricity and possibly process heat is likely to increase dramatically over the next few deacades. This statement dismisses fusion as being entirely too speculative to be practical within that time frame. Sometime, between the years 2000 and 2050, fissile material will be in short supply whether it is to fuel existing LWR's or to provide initial fuel inventory for FBR's. The accelerator breeder could produce the fuel shortfall predicted to occur during the first half of the 21st century. The accelerator breeder offers the only practical means today of producing, or breeding, large quantities of fissile fuel from fertile materials, albeit at high cost. Studies performed over the last few years at Chalk River Laboratory and at Brookhaven National Laboratory have demonstrated that the accelerator breeder is practical, technically feasible with state-of-the-art technology, and is economically competitive with any other proposed synthetic means of fissile fuel production. This paper gives the parameters of a nearly optimized accelerator-breeder system, then discusses the development needs, and the economics and institutional problems that this breeding concept faces

  8. When celibacy matters: incorporating non-breeders improves demographic parameter estimates.

    Science.gov (United States)

    Pardo, Deborah; Weimerskirch, Henri; Barbraud, Christophe

    2013-01-01

    In long-lived species only a fraction of a population breeds at a given time. Non-breeders can represent more than half of adult individuals, calling in doubt the relevance of estimating demographic parameters from the sole breeders. Here we demonstrate the importance of considering observable non-breeders to estimate reliable demographic traits: survival, return, breeding, hatching and fledging probabilities. We study the long-lived quasi-biennial breeding wandering albatross (Diomedea exulans). In this species, the breeding cycle lasts almost a year and birds that succeed a given year tend to skip the next breeding occasion while birds that fail tend to breed again the following year. Most non-breeders remain unobservable at sea, but still a substantial number of observable non-breeders (ONB) was identified on breeding sites. Using multi-state capture-mark-recapture analyses, we used several measures to compare the performance of demographic estimates between models incorporating or ignoring ONB: bias (difference in mean), precision (difference is standard deviation) and accuracy (both differences in mean and standard deviation). Our results highlight that ignoring ONB leads to bias and loss of accuracy on breeding probability and survival estimates. These effects are even stronger when studied in an age-dependent framework. Biases on breeding probabilities and survival increased with age leading to overestimation of survival at old age and thus actuarial senescence and underestimation of reproductive senescence. We believe our study sheds new light on the difficulties of estimating demographic parameters in species/taxa where a significant part of the population does not breed every year. Taking into account ONB appeared important to improve demographic parameter estimates, models of population dynamics and evolutionary conclusions regarding senescence within and across taxa.

  9. Nuclear and thermal analyses of supercritical-water-cooled solid breeder blanket for fusion DEMO reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yanagi, Yoshihiko; Sato, Satoshi; Enoeda, Mikio; Hatano, Toshihisa; Kikuchi, Shigeto; Kuroda, Toshimasa; Kosaku, Yasuo; Ohara, Yoshihiro [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    2001-11-01

    Within a design study of a fusion DEMO reactor aiming at demonstrating technologies of fusion power plant, supercritical water is applied as a coolant of solid breeder blanket to attain high thermal efficiency. The blanket has multi-layer composed of solid breeder pebbles (Li{sub 2}O) and neutron multiplier pebbles (Be) which are radially separated by cooling panels. The first wall and the breeding region are cooled by supercritical water below and above the pseudo-critical temperature, respectively. Temperature distribution and tritium breeding ratio (TBR) have been estimated by one-dimensional nuclear and thermal calculations. The local TBR as high as 1.47 has been obtained after optimization of temperature distribution in the breeder region under the following conditions: neutron wall loading of 5 MW/m{sup 2}, {sup 6}Li enrichment of 30% and coolant temperature at inlet of breeder region of 380degC. In the case of the higher coolant temperature 430degC of the breeder region the local TBR was reduced to be 1.40. This means that the net TBR higher than 1.0 could be expected with the supercritical-water-cooled blanket, whose temperature distribution in the breeder region would be optimized by following the coolant temperature, and where a coverage of the breeder region is assumed to be 70%. (author)

  10. Reasons for opposition to the breeder reactor

    International Nuclear Information System (INIS)

    Timbal-Duclaux, Louis

    1979-01-01

    The author gives a sociological analysis of the opposition to breeder reactors in France, stressing that the antinuclear groups main thrust of protest against the Super-Phenix has dimished since its apex two years ago [fr

  11. Assessment of the accident response of a light-water-moderated breeder-reactor system: AWBA development program

    International Nuclear Information System (INIS)

    High, H.M.

    1983-05-01

    The predicted accident response for a light water moderated, thorium/U-233 fueled, seed-blanket reactor concept was assessed. The first part of the assessment compared breeder accident response with that of a current commercial pressurized water reactor design for several different types of transients. Based on these comparisons and a review of the various parameter differences between the breeder and a U-235 fueled plant, the second part of the assessment studied the breeder accident behavior in more detail, particularly in areas of potential concern. Based on the two parts of the assessment, it was concluded that the breeder accident response would be very similar to that of present commercial pressurized water reactor plants. The large Doppler and moderator reactivity coefficients of the breeder would significantly reduce the severity of many of the accidents that must be considered. It is expected that the accident response of the breeder can be shown to meet regulatory criteria

  12. Behavior pattern of beef heifers supplemented with different energy sources on oat and ryegrass pasture

    Directory of Open Access Journals (Sweden)

    Luiz Angelo Damian Pizzuti

    2012-08-01

    Full Text Available The objective of this study was to evaluate behavior patterns of heifers grazing on black oat (Avena strigosa Schreb. and ryegrass (Lolium multiflorum Lam., fed supplementation with brown rice meal and/or protected fat. A total of 28 Charolais × Nellore crossbred heifers at average initial age of 18 months and with initial live weight of 274.9±4.97 kg were used in the experiment. Animals were kept in oat + ryegrass pastures and distributed in the following treatments: no supplementation; Megalac (MEG: protected fat supplementation; supplementation with brown rice meal (BRM; and supplementation with BRM + MEG. The neutral detergent fiber (NDF intake of pasture either in kg or in percentage of live weight was not changed by supply of supplement, but increased linearly (0.045 kg per day over grazing periods. Supplementation with BRM and BRM + MEG reduced grazing time, 49.63%, in relation to non-supplemented animals and animals supplemented with MEG, 63.13%. Feeding seasons per minute increased over the experimental period with reduction in time spent in each feeding station. The number of bites per feeding station decreased linearly, with a variation of 34.48% in the late grazing period. Heifers supplemented with BRM and BRM + MEG require less time for grazing and increase their idle time, with no modification in displacement patterns within the paddocks and pasture ingestion. Grazing and idle time does not change in the distinct periods of pasture use, but rumination time increases with days of pasture use and with increase in NDF intake.

  13. Filbe molten salt research for tritium breeder applications

    International Nuclear Information System (INIS)

    Anderl, R.A.; Petti, D.A.; Smolik, G.R.

    2004-01-01

    This paper presents an overview of Flibe (2Lif·BeF 2 ) molten salt research activities conducted at the INEEL as part of the Japan-US JUPITER-II joint research program. The research focuses on tritium/chemistry issues for self-cooled Flibe tritium breeder applications and includes the following activities: (1) Flibe preparation, purification, characterization and handling, (2) development and testing of REDOX strategies for containment material corrosion control, (3) tritium behavior and management in Flibe breeder systems, and (4) safety testing (e.g., mobilization of Flibe during accident scenarios). This paper describes the laboratory systems developed to support these research activities and summarizes key results of this work to date. (author)

  14. The fast breeder reactor: what is security and freedom worth to us

    International Nuclear Information System (INIS)

    1975-01-01

    Risks for governmental and non-governmental proliferation of nuclear weapons as a consequence of the development of fast breeder reactor technology are discussed. Polemological as well as sociological and political analyses together with ecological consequences lead to the conclusion that the fast breeder is not necessary for energy production and socially unacceptable

  15. Relationship between pre-weaning gain, age at puberty, and reproductive tract development in Angus heifers

    Science.gov (United States)

    Beef heifers should initiate reproductive cycles by 12 mo of age to insure multiple estrous cycles before the start of the breeding season to maximize fertility. Previous research indicated that pre-weaning gain positively influenced the onset of puberty and antral follicle numbers. Therefore, the...

  16. The value of reproductive tract scoring as a predictor of fertility and production outcomes in beef heifers.

    Science.gov (United States)

    Holm, D E; Thompson, P N; Irons, P C

    2009-06-01

    In this study, 272 beef heifers were studied from just before their first breeding season (October 15, 2003), through their second breeding season, and until just after they had weaned their first calves in March, 2005. This study was performed concurrently with another study testing the economic effects of an estrous synchronization protocol using PG. Reproductive tract scoring (RTS) by rectal palpation was performed on the group of heifers 1 d before the onset of their first breeding season. The effect of RTS on several fertility and production outcomes was tested, and the association of RTS with the outcomes was compared with that of other input variables such as BW, age, BCS, and Kleiber ratio using multiple or univariable linear, logistic, or Cox regression. Area under the curve for receiver operating characteristic analysis was used to compare the ability of different input variables to predict pregnancy outcome. After adjustment for BW and age, RTS was positively associated with pregnancy rate to the 50-d AI season (P Reproductive tract scoring was a better predictor of fertility than was Kleiber ratio and similar in its prediction of calf weaning weight. It was concluded from this study that RTS is a predictor of heifer fertility, compares well with other traits used as a predictor of production outcomes, and is likely to be a good predictor of lifetime production of the cow.

  17. History and evolution of the breeder reactor

    International Nuclear Information System (INIS)

    Carle, R.

    1989-01-01

    The concept of the breeder reactor is almost as old as the idea of the nuclear reactor itself. From the very first years following the discovery of nuclear fission, scientists and technicians tried to turn mankind's eternal dream into reality; that is, enjoy an abundant source of energy without using up our raw material reserves. Nuclear energy offered several solutions to realize this dream. One of them, fusion, seemed out of our grasp in the near future. But fission of 235 U was possible, and the Manhattan Project soon furnished ample proof of this theory. However, everyone working in this field was conscious of the fact that thermal neutron reactors make very inefficient use of the energy potential contained in natural uranium. The solution was to use in a core sufficiently rich in fissile matter, the excess neutrons to convert the 238 U, so poorly used by other types of reactors, into fissile 239 Pu. Regeneration, or 'breeding' of fuel, can multiply the energy drawn from a ton of uranium by a factor of 50 to 100. This would enable us to ward off the specter of an energy shortage and the rapid depletion of uranium mines. As early as 1945 in Los Alamos, Enrico Fermi stated: 'The country which first develops a breeder reactor will have a great competitive edge in atomic energy.' The development of the breeder reactor in the USA and around the world is discussed

  18. Water storage of liquid-metal fast-breeder-reactor fuel

    International Nuclear Information System (INIS)

    Meacham, S.A.

    1982-01-01

    The purpose of this paper is to present a general overview of a concept proposed for receiving and storing liquid metal fast breeder reactor (LMFBR) spent fuel. This work was done as part of the Consolidated Fuel Reprocessing Program (CFRP) at the Oak Ridge National Laboratory (ORNL). The CFRP has as its major objective the development of technology for reprocessing advanced nuclear reactor fuels. The program plans that research and development will be carried through to a sufficient scale, using irradiated spent fuel under plant operating conditions, to establish a basis for confident projection of reprocessing capability to support a breeder industry

  19. Status of the breeder fuel cycle in the United States

    International Nuclear Information System (INIS)

    Burch, W.D.

    1985-01-01

    This paper reviews the status and plans for the fast reactor fuel cycle in the United States. The United States is undertaking a complete reexamination of its entire breeder program strategy, and the direction of the new program is not yet clear. Studies in progress to examine the associated fuel cycle strategies as they relate to the overall emerging breeder strategy are described. The present status of and recent developments in the fuel cycle R and D programs are summarized

  20. Optimized materials for the future breeder line

    International Nuclear Information System (INIS)

    Ohrt, E.; Heesen, E. te

    1991-01-01

    This paper presents a survey of developments which form part of ongoing activities for the construction of breeder plants. Following a brief introduction it describes the history of an internationally coordinated material for the major components of a European breeder. Some material properties which are of importance for the design are discussed. The task of finding a suitable filler metal for steel 316L(N) (1.4909) is considered in greater detail. In this case too, selection criteria are the mechanical properties of the weld metal, its chemical and thermal resistance and its behaviour during welding. Finally, processes which are absolutely necessary in the construction phase of a power plant are discussed in the outlook. These have not been optimized to date and will therefore be the subject of internationally distributed activities in the subsequent phase. (orig.)

  1. Environmental assessment for Breeder Reprocessing Engineering Test (BRET): Revision 1

    International Nuclear Information System (INIS)

    Lerch, R.E.

    1989-03-01

    This Environmental Assessment (EA) is for the proposed installation and operation of an integrated breeder fuel reprocessing test system in the shielded cells of the Fuels and Materials Examination Facility (FMEF) at Hanford and the associated modifications to the FMEF to accommodate BRET. These modifications would begin in FY-1986 subject to Congressional authorization. Hot operations would be scheduled to start in the early 1990's. The system, called the Breeder Reprocessing Engineering Test (BRET), is being designed to provide a test capability for developing the demonstrating fuel reprocessing, remote maintenance, and safeguards technologies for breeder reactor fuels. This EA describes (1) the action being proposed, (2) the existing environment which would be affected, (3) the potential environmental impacts from normal operations and severe accidents from the proposed action, (4) potential conflicts with federal, state, regional, and/or local plans for the area, and (5) environmental implications of alternatives considered to the proposed action. 41 refs., 10 figs., 31 tabs

  2. Gastrointestinal parasite control during prepuberty improves mammary parenchyma development in Holstein heifers

    OpenAIRE

    Perri, AF; Mejía, ME; Licoff, N; Diab, SS; Formía, N; Ornstein, A; Becú-Villalobos, D; Lacau-Mengido, IM

    2013-01-01

    Parasitism during development impairs normal growth and delays the onset of puberty through altered hormone profiles, including insulin-like growth factor one (IGF-1).Asmammary gland development during prepuberty is strongly dependent on IGF-1, we determined if antiparasitic treatment during this stage of growth improved mammary gland development. One group of Holstein heifers was treated monthly, rotationally with antiparasitic drugs from birth to 70 weeks of age, a secon...

  3. Formation of the research competence of future breeder-geneticists during the practical training

    Directory of Open Access Journals (Sweden)

    Наталія Павлівна Антіпова

    2016-03-01

    Full Text Available In the article were analyzed content, structure and special features of the practical training of the future breeder-geneticists. There was specified that for bachelor breeder-geneticists of the 6.090101 “Agronomy” training direction are provided the following practices: botany, tractors and cars, soil science, agricultural machines, fruit growing, vegetable growing, agriculture, agrochemistry, plant growing, entomology, phytopathology, technology of retreatment and preservation of plant growing production, selection and seed growing of agricultural crops; work practice on agronomy.In the article was grounded the structural-logic scheme of organization of practices of the future breeder-geneticists for forming their professional research competences. There were analyzed functions and methods of scientific-cognitive activity, forms, means and methods of the practical education. According to the types of practices there were elucidated and grounded the structure of practical training of the future breeder-geneticists – natural-technical and special-professional – educational and work practices.The natural-technical, special-professional and production-technological practices form in bachelor agronomists breeder-geneticists professional scientific-research competences: theoretical-analytical ones – geosphere, bio-geo-physical-chemical, meteorological-climatological, informative, fundamental and applied ecological, fundamental-scientific agrosphere; professional competences of professionally oriented and special practical training – agricultural, branch, techno-service, technological, selective, special-genetic-engineering ones; managerial ones

  4. Methodologies for evaluation of ingestive behavior of heifers supplemented in grazing

    Directory of Open Access Journals (Sweden)

    Hermógenes Almeida de Santana Junior

    2014-06-01

    Full Text Available The study was conducted to compare different methodologies for evaluation of ingestive behavior of heifers supplemented in grazing. The experiment was conducted at Princesa do Mateiro farm, Ribeirao do Largo, Bahia. Were used 30 heifers with blood level 5/8 Guzera milk lineage and 3/8 Holstein, with an average of 18 months of age and body weight of 187 ± 13.1 kg. The treatments were: Duration of avaliation (24, 12 and eight hours of observation intervals (10, 20 and 30 minutes; repetitions for observation (three, two and one shifts of observation (two and one. The behavior evaluation was performed on day 25th, 26th, 27th and 28th of each period, then a total of four ratings. The percentage of grazing activity on the duration of 8h and 12h evaluation differed from the standard evaluation period of 24 hours (P0.05. For grazing time, rumination, feeding at the trough, other activities, total feeding and total chewing have not been verified statistical differences between the ranges of observations 20 and 30 minutes compared with 10 minutes (P<0.05. The duration of evaluation of 24 hours is recommended for evaluation of ingestive behavior in terms of nutritional and metabolic parameters, as other promote distortion of the data as a function of the intensity of activities throughout the day.

  5. Secure Automated Fabrication: an overview of remote breeder fuel fabrication

    International Nuclear Information System (INIS)

    Nyman, D.H.; Graham, R.A.

    1983-10-01

    The Secure Automated Fabrication (SAF) line is an automated, remotely controlled breeder fuel pin fabrication process which is to be installed in the Fuels and Materials Examination Facility (FMEF). The FMEF is presently under construction at Hanford and is scheduled for completion in 1984. The SAF line is scheduled for startup in 1987 and will produce mixed uranium-plutonium fuel pins for the Fast Flux Test Facility (FFTF) and the Clinch River Breeder Reactor Plant (CRBRP). The fabrication line and support systems are described

  6. Effects of the tricothecene mycotoxin diacetoxyscirpenol on egg production of broiler breeders.

    Science.gov (United States)

    Brake, J; Hamilton, P B; Kittrell, R S

    2002-12-01

    Three experiments were conducted to determine the effects of 4,15-diacetoxyscirpenol (DAS) on egg quality and egg production of broiler breeders. In Experiment 1, feed containing 0, 1.25, 2.5, or 5.0 mg DAS/ kg was fed from 67 to 69 wk of age followed by a 3-wk recovery period on a slat-litter floor. In Experiment 2, individually caged broiler breeder females were studied from 23 to 31 wk of age. The basal diet containing 0, 5, 10, or 20 mg DAS/kg was fed from 25 to 27 wk of age. In Experiment 3, individually caged broiler breeder hens were studied from 23 to 32 wk of age. DAS was fed at levels of 0 (basal), 5, 10, and 20 mg DAS/kg for 2 wk beginning at Week 24, followed by the basal breeder diet for 7 wk. Egg production was not affected by levels of up to 5 mg DAS/kg in the older hens of Experiment 1. When fed from 25 to 27 wk of age in Experiment 2, DAS decreased egg production at the 20 mg/kg level only. When fed from 24 to 25 wk of age in Experiment 3, DAS had no significant effect on egg production or egg quality. Short-term consumption of DAS at levels that might naturally occur appears to have little effect on broiler breeder egg production.

  7. Solid breeder test blanket module design and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ying, A. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States)]. E-mail: ying@fusion.ucla.edu; Abdou, M. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); Calderoni, P. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); Sharafat, S. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); Youssef, M. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); An, Z. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); Abou-Sena, A. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); Kim, E. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); Reyes, S. [LANL, Livermore, CA (United States); Willms, S. [LANL, Los Alamos, NM (United States); Kurtz, R. [PNNL, Richland, WA (United States)

    2006-02-15

    This paper presents the design and analysis for the US ITER solid breeder blanket test articles. Objectives of solid breeder blanket testing during the first phase of the ITER operation focus on exploration of fusion break-in phenomena and configuration scoping. Specific emphasis is placed on first wall structural response, evaluation of neutronic parameters, assessment of thermomechanical behavior and characterization of tritium release. The tests will be conducted with three unit cell arrays/sub-modules. The development approach includes: (1) design the unit cell/sub-module for low temperature operations and (2) refer to a reactor blanket design and use engineering scaling to reproduce key parameters under ITER wall loading conditions, so that phenomena under investigation can be measured at a reactor-like level.

  8. Reflections on the introduction of fast breeder reactors in the DeBeNeLux states

    International Nuclear Information System (INIS)

    Schroeder, R.; Wagner, J.

    1975-06-01

    This report gives a survey of the impact of introducing sodium-cooled fast breeder reactors in the Federal Republic of Germany and the BeNeLux countries (DeBeNeLux region). The supply situation with respect to electric and thermal energy is studied in particular, together with aspects of economy and environmental impact. The potential and consequences of a breeder economy, the present status and future r+d work are discussed. In addition to sodium-cooled fast breeder reactors with oxide or carbide fuel, alternative solutions are touched: 1) light water and high temperature reactors, 2) helium-cooled fast breeder reactors, 3) geothermal energy, solar energy and fusion energy. (orig.) [de

  9. Performance, carcass and ruminal fermentation characteristics of heifers fed concentrates differing in energy level and cereal type (corn vs. wheat)

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco, C.; Carro, M.D.; Fuentetaja, A.; Medel, P.

    2017-07-01

    A total of 144 beef heifers (218 ± 26.4 kg body weight) were housed in 24 pens (6 animals each) and used in a 168-day feedlot study to evaluate the influence of cereal type and energy level on performance, carcass quality and ruminal fermentation. Four concentrates were formulated according to a 2×2 factorial arrangement of treatments, with two energy levels (1,452 vs. 1,700 kcal net energy/kg) and two main cereals (wheat vs. corn). Concentrate and straw were offered ad libitum. Concentrate intake and body weight were recorded on days 42, 84, 126 and 168. Ruminal fluid was obtained by ruminocentesis from 3 heifers per pen on days 1, 84 and 168; and carcass weight, classification and yield, were determined in the same animals. Heifers fed high-energy diets had lower intake (6.97 vs. 7.29 kg fresh matter/d; p=0.011), and lower concentrate to gain ratio (5.15 vs. 5.66 kg/kg; p=0.002) than those fed low energy concentrates, and tended (p=0.069) to be heavier along the time. Neither carcass yield and classification, nor ruminal pH, volatile fatty acids nor NH3-N concentrations were affected (p>0.050) by energy level. Total volatile fatty acids concentration tended (p=0.070) to be greater in heifers fed corn-based than wheat-based concentrates. No energy level x cereal type interactions were observed. These results indicate that high energy concentrates decreased feed intake and feed conversion but had minor effects on carcass performance. Cereal type had no effects on performance and ruminal fermentation and no interactions between cereal type and energy were detected.

  10. Performance, carcass and ruminal fermentation characteristics of heifers fed concentrates differing in energy level and cereal type (corn vs. wheat)

    International Nuclear Information System (INIS)

    Carrasco, C.; Carro, M.D.; Fuentetaja, A.; Medel, P.

    2017-01-01

    A total of 144 beef heifers (218 ± 26.4 kg body weight) were housed in 24 pens (6 animals each) and used in a 168-day feedlot study to evaluate the influence of cereal type and energy level on performance, carcass quality and ruminal fermentation. Four concentrates were formulated according to a 2×2 factorial arrangement of treatments, with two energy levels (1,452 vs. 1,700 kcal net energy/kg) and two main cereals (wheat vs. corn). Concentrate and straw were offered ad libitum. Concentrate intake and body weight were recorded on days 42, 84, 126 and 168. Ruminal fluid was obtained by ruminocentesis from 3 heifers per pen on days 1, 84 and 168; and carcass weight, classification and yield, were determined in the same animals. Heifers fed high-energy diets had lower intake (6.97 vs. 7.29 kg fresh matter/d; p=0.011), and lower concentrate to gain ratio (5.15 vs. 5.66 kg/kg; p=0.002) than those fed low energy concentrates, and tended (p=0.069) to be heavier along the time. Neither carcass yield and classification, nor ruminal pH, volatile fatty acids nor NH3-N concentrations were affected (p>0.050) by energy level. Total volatile fatty acids concentration tended (p=0.070) to be greater in heifers fed corn-based than wheat-based concentrates. No energy level x cereal type interactions were observed. These results indicate that high energy concentrates decreased feed intake and feed conversion but had minor effects on carcass performance. Cereal type had no effects on performance and ruminal fermentation and no interactions between cereal type and energy were detected.

  11. Relationship among residual feed intake, digestibility and ingestive behavior in Nellore heifers

    Directory of Open Access Journals (Sweden)

    Elaine Magnani

    2013-02-01

    Full Text Available The aim of this study was to evaluate digestibility and feeding behavior of Nellore heifers belonging to different classes of residual feed intake (RFI. Thirty-two heifers ranked high in RFI (0.491± 0.51 kg/d; n=15 and RFI low (- 0.447 ± 0.51 kg/d; n=17 with a mean age of 502 ± 23.61 days and average weight 364 ± 27.96 kg were kept in confinement for 48 days, with formulated diet based on Tifton 85 hay, corn, cottonseed meal and urea, and ratio of forage: concentrate ratio of 45:55%. The parameters analyzed were digestibility, ingestive behavior and their correlation. Animals low RFI showed higher digestibility of dry matter (DMD, neutral detergent fiber (NDF, acid detergent fiber (ADF and cellulose that high RFI animals (49.14% versus 45.38%, 56.65% versus 49.88%, 49.96% versus 45.08%, 61.61% versus 56.40% for DMD, NDFD, ADFD, CELD, respectively. These results indicate that more efficient animals have better food utilization. No differences were found in the variables of ingestive behavior among classes of RFI. Changes in the RFI can be partly explained by the digestibility of nutrients, which is related to ingestive behavior of animals.

  12. Fast Breeder Project status report, 1974

    International Nuclear Information System (INIS)

    Hueper, R.

    A compilation of the papers read at the Status Report of the Fast Breeder Project at the Karlsruhe Nuclear Research Center on March 26, 1974 is presented. The first papers present a general survey of the present state of research and development work performed by the German, Belgian, and Netherlands research centers on the SNR 300 Prototype Fast Breeder Reactor (Kalkar Nuclear Power Station), on the SNR follow-on program, alternative fuels and coolants and basic problems, on work performed by industry with respect to the licensing procedure and construction of the SNR 300, and on commissioning and the planned conversion of KNK, the Compact Sodium Cooled Nuclear Reactor. The detailed papers deal with results elaborated at the institutes of GfK Karlsruhe, SCK/CEN Mol, RCN Petten, and TNO Apeldoorn. Most of these efforts have been concentrated upon fuel pin and materials development and on the physics and safety of fast reactors. The status report concludes with a reference to the future program under the Project. (U.S.)

  13. Digestible Threonine Levels in the Starter Diet of Broilers Derived from Breeders of Different Ages

    Directory of Open Access Journals (Sweden)

    CBGS Tanure

    2015-12-01

    Full Text Available ABSTRACT The aim of this study was to evaluate the effect of digestible threonine supplementation in the starter diet on the performance, intestinal parameters, and nutrient metabolism of broilers derived from breeders of different ages. In total, 480 one-day-old Cobb chicks, derived from 38-or 49-week-oldbreeders, were housed in experimental battery cages until 21 days of age and fed four different threonine levels (800, 900, 1,000, or 1,100 mg/kg in the starter feed. A completely randomized experimental design in a 2x4 factorial arrangement (breeder age x threonine levels was applied, totaling eight treatments with five replicates of 12 birds each. Broilers from older breeders fed 800 mg digestible threonine/kg of diet presented higher weight gain, with a positive linear effect. There was also an interaction between breeder age and threonine levels for the weight gain of 21-d-old broilers supplemented at maximum level of 1,003 mg Thr/kg diet during the starter phase. There was no effect of breeder age or threonine levels on nutrient metabolism during the period of 17-21 days. There was no influence of breeder age or threonine levels in the starter diet on intestinal morphometric measurements, absorption area, or percentage of goblet cells.

  14. Microbial protein synthesis and concentration of urea in dairy heifers fed diets with cactus forage Opuntia

    Directory of Open Access Journals (Sweden)

    Maria do Socorro Mercês Aguiar

    2015-04-01

    Full Text Available The objective was to analyze the influence of increasing levels of forage cactus Opuntia in the diet on the nitrogen balance, the concentrations of urea in urine and plasma and microbial protein synthesis in dairy heifers ¾ Holstein-zebu confined. twenty four heifers were used with initial body weight of 163.00 ± 18 kg, with 8 months old and distributed in a completely randomized design with four treatments and six replications. It was used sorghum silage, concentrate and increasing levels of forage cactus Opuntia in the diet (0, 200, 400 and 600 g kg-1. The nitrogen intake, feces and urine, digested and retained with the addition of forage cactus in the diet showed decreasing linear effect. Nitrogen balance was influenced by the inclusion of forage cactus in the diet of dairy heifers through the values observed for the digested and retained nitrogen, which can be related to similar effects found for the consumption of nitrogen and the nitrogen excretion in feces and urine. Nitrogen digested percentage of intake and nitrogen retention as a percentage of ingested and digested showed no difference with the inclusion of forage cactus in the diet. The concentration of urea nitrogen in the urine of heifers had a quadratic effect point of maximum excretion level of 275.80 g kg-1 of forage cactus in the diet. Consequently, the excretion of urea nitrogen and urea excretion showed similar effect with maximum points excretion levels of 293.75 and 319.00 g kg-1 of forage in the diet. The concentration of ureic nitrogen in plasma showed no difference, with an average value of 13.19 mg dL-1. Synthesis of nitrogen and microbial crude protein adjusted to the quadratic model. The microbial efficiency was not influenced by the inclusion of forage cactus in replacement of sorghum silage and concentrate. The urine volume similar to the treatments, with an average of 5.90 liters of urine per day, proving that the creatinine excretion in urine was not influenced

  15. Effects of flooring and restricted freestall access on behavior and claw health of dairy heifers

    NARCIS (Netherlands)

    Ouweltjes, W.; Werf, van der J.T.N.; Frankena, K.; Leeuwen, van J.L.

    2011-01-01

    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

  16. Evaluations for service-sire conception rate for heifer and cow inseminations with conventional and sexed semen

    Science.gov (United States)

    Service-sire conception rate (SCR), a phenotypic fertility evaluation based on conventional (nonsexed) inseminations from parities 1 through 5, was implemented by USDA in August 2008. Using insemination data from 2005 through 2009, the SCR procedure was applied separately for nulliparous heifer inse...

  17. Modeling delayed neutron monitoring systems for fast breeder reactors

    International Nuclear Information System (INIS)

    Bunch, W.L.; Tang, E.L.

    1983-10-01

    The purpose of the present work was to develop a general expression relating the count rate of a delayed neutron monitoring system to the introduction rate of fission fragments into the sodium coolant of a fast breeder reactor. Most fast breeder reactors include a system for detecting the presence of breached fuel that permits contact between the sodium coolant and the mixed oxide fuel. These systems monitor for the presence of fission fragments in the sodium that emit delayed neutrons. For operational reasons, the goal is to relate the count rate of the delayed neutron monitor to the condition of the breach in order that appropriate action might be taken

  18. Converging on the Clinch River: the politics of the US breeder reactor program

    International Nuclear Information System (INIS)

    Tench, H.G.

    1981-01-01

    For decades the development of nuclear technologies, including the fast breeder, was controlled by the Atomic Energy Commission, the Joint Committee on Atomic Energy, and the nuclear industry, the three pillars of the nuclear technoscience network, the analysis of the formation, culture, growth, and disruption of the network sets the stage for the study of the fast breeder, a program conceived by the scientific estate and carried along and nurtured by the administrative and political estates of the nuclear technoscience network, the early chapters delineate the dimensions of the network. The relationships and influence of its actors, and its unique and secretive culture. The cooperative-client politics of the breeder's deployment ended when the program, for years protected within the interstices of the network, emerged from this protected environment into the larger political system, where it became the subject of Washington's entrepreneurial politics. Under these changed circumstances progress on the LMFBR came to a virtual standstill. Nevertheless, the LMFBR survived the turbulent seventies, when energy and the environment dominate the political agenda, because remnants of the nuclear technoscience network in the executive branch, in Congress, and in the private sector retained sufficient power to prevent the breeder's death. This case study of the politics of the breeder's deployment addresses the dilemma of the experts, their role in the decision-making process as well as the problem of uncertainty within the framework of network theory. This perspective allows for the examination of the multifaceted controversy over the deployment of the fast breeder in the United States, a national debate that eventually converged on the Clinch River

  19. Flow accelerated corrosion and erosion-corrosion of RAFM steel in liquid breeders

    International Nuclear Information System (INIS)

    Kondo, Masatoshi; Muroga, Takeo; Sagara, Akio

    2010-11-01

    Corrosion experiments for RAFM, JLF-1 steel (Fe-9Cr-2w-0.1C) in 3types of flowing liquid breeders (i.e. Li, Pb-17Li and Flinak) were performed at the same conditions, and the compatibility was compared with each other. The weight loss of the specimens in the fluids was evaluated by the corrosion model based on mass transfer. The model can be applied to different test systems with different quantity of liquid breeders and different surface area of the systems. The flow enhanced the dissolution of element of the steel in the fluids. The mechanism of an erosion-corrosion in the liquid breeders was the peeling off of the corroded steel surface by the flow. (author)

  20. Philosophy of safety evaluation on fast breeder reactor

    International Nuclear Information System (INIS)

    1981-01-01

    This is the report submitted from the special subcommittee on reactor safety standard to the Nuclear Safety Commission on October 14, 1980, and it was decided to temporarily apply this concept to the safety examination on fast breeder reactors. The examination and discussion of this report were performed by taking the prototype reactor ''Monju'' into consideration, which is to be the present target, referring to the philosophy of the safety evaluation on fast breeder reactors in foreign countries and based on the experiences in the fast experimental reactor ''Joyo''. The items applicable to the safety evaluation for liquid metal-cooled fast breeder reactors (LMFBR) as they are among the existing safety examination guidelines are applied. In addition to the existing guidelines, the report describes the matters to be considered specifically for core, fuel, sodium, sodium void, reactor shut-down system, reactor coolant boundary, cover gas boundary and others, intermediate cooling system, removal of decay heat, containment vessels, high temperature structures, and aseismatic property in the safety design of LMFBR's. For the safety evaluation for LMFBR's, the abnormal transient changes in operation and the phenomena to be evaluated as accidents are enumerated. In order to judge the propriety of the criteria of locating LMFBR facilities, the serious and hypothetical accidents are decided to be evaluated in accordance with the guideline for reactor location investigation. (Wakatsuki, Y.)

  1. Possible types of breeders with thorium cycle

    International Nuclear Information System (INIS)

    Ishiguro, Y.; Gouveia, A.S. de

    1981-01-01

    Neutronics calculations of simplified homogeneous reactor models show the possibility that metal-fueled LMFBRs and coated particle fueled gas cooled reactors achieve doubling times of around 10 years with the thorium cycle. Three concepts of gas-cooled thorium cycle breeders are discussed. (Author) [pt

  2. Possible types of breeders with thorium cycle

    International Nuclear Information System (INIS)

    Ishiguro, Y.; Gouveia, A.S. de.

    1981-02-01

    Neutronics calculations of simplified homogeneous reactor models show the possibility that metal-fueled LMFBRs and coated particle fueled gas cooled reactors achieve reactor doubling times of around 10 years with the thorium cycle. Three concepts of gas-cooled thorium cycle breeders are discused. (Author) [pt

  3. Effects of Growth Hormone Gene Polymorphism on Lipogenic Gene Expression Levels in Diaphragm Tissues of Japanese Black Heifers

    Directory of Open Access Journals (Sweden)

    Astrid Ardiyanti

    2012-08-01

    Full Text Available Two SNPs, i.e. L127V and T172M, of bovine growth hormone (GH causing the presence of GH gene haplotypes A, B, and C was previously shown to alter intramuscular fatty acid (FA composition in Japanese Black (JB heifers. To determine the SNP effect on somatotropic hormone concentration and lipogenesis, we measured plasma GH, insulin, and insulin-like growth factor-1 (IGF-1 concentrations. We also measured mRNA levels of fatty acid synthase (FASN, stearoyl-coA desaturase (SCD, and sterol regulatory element binding proteins-1 (SREBP-1 and FA composition in diaphragm tissues. Heifers with genotype CC had the lowest plasma insulin concentration and FASN and SCD mRNA levels among genotypes. FASN mRNA levels in haplotype A tended to positively correlate with saturated FA (SFA content and negatively correlated with C18:2 and unsaturated FA (USFA contents. SCD mRNA levels in haplotype A positively correlated with monounsaturated FA (MUFA contents and negatively correlated with C18:0 content. They also tended to positively correlate with C16:1, C18:1, and USFA contents and USFA/SFA ratio and negatively correlate with SFA content. Taken together, GH gene polymorphism affects the lipogenic genes expression levels and their relationships with fatty acid compositions in diaphragm tissues of JB heifers at 31 months of age.

  4. Ultrasonographic reproductive tract measures and pelvis measures as predictors of pregnancy failure and anestrus in restricted bred beef heifers.

    Science.gov (United States)

    Holm, Dietmar E; Nielen, Mirjam; Jorritsma, Ruurd; Irons, Peter C; Thompson, Peter N

    2016-02-01

    Previous reports have shown that reproductive tract score (RTS) can predict reproduction outcomes in seasonally bred beef heifers, although the accuracy can vary. Some ultrasonographic measures of the female reproductive tract and pelvis area have also been associated with reproductive outcome in young heifers. The objectives of this study were to determine which transrectal ultrasound or pelvis measures taken at a single examination are independent predictors of reproductive failure and whether the RTS system can be optimized with this information. In this observational study, year-old beef heifers (n = 488) in 2 birth cohorts were followed from just before the first breeding until confirmation of pregnancy. A single pre-breeding examination included body condition score, RTS, ultrasound measures of the reproductive tract (length and diameter of the left and right ovaries, presence and diameter of a CL, largest follicle diameter and left uterus horn diameter) and transverse and vertical diameters of the pelvis. Additional farm records including dam parity, sire, birth weight and birth date, weaning weight, weaning date, prebreeding body weight, AI dates, and semen used were available. Breeding consisted of 50 days of AI, followed 5 to 7 days later by a 42-day bull breeding period. Pregnancy failure was defined as the failure to become pregnant after the AI and bull breeding periods, while anestrus was defined as the failure to be detected in estrus during the 50-day AI period. From the prebreeding data and farm records, independent predictors of pregnancy failure and anestrus were identified using stepwise reduction in multiple logistic regression models. Age at the onset of breeding was the only consistent independent predictor of pregnancy failure and anestrus in both cohorts of this study (P score, uterus horn diameter, absence of a CL, largest follicle of less than 13 mm, and pelvis area (PA) were the prebreeding examination variables that remained in

  5. Effect of body condition in pregnant dairy heifers on dystocia, calf birth weight, colostral quality and quantity, reproduction, milk yield and health during first lactation

    OpenAIRE

    Adermann, Jenny

    2016-01-01

    Introduction: Involuntary culling of first lactation heifers and as a consequence a reduced productive life span is a central problem in dairy production. A negative influence of poor and excessive body condition on health and production parameters has been elaborately described for multiparous cows, whereas only few studies regarding optimal body condition range of pregnant heifers have been conducted. To investigate the influence of body condition during late pregnancy on health and p...

  6. Effect of consecutive re-synchronization protocols on pregnancy rate in buffalo (Bubalus bubalis) heifers out of the breeding season.

    Science.gov (United States)

    Neglia, Gianluca; Capuano, Massimo; Balestrieri, Anna; Cimmino, Roberta; Iannaccone, Francesco; Palumbo, Francesco; Presicce, Giorgio A; Campanile, Giuseppe

    2018-06-01

    The combined effect of six consecutive timed artificial inseminations (TAIs) on pregnancy rates, following two different synchronization protocols on buffalo heifers, over a period of seven months typically characterized by low breeding performances, were investigated in this study. A total of 2189 TAIs were performed on 1463 buffalo heifers within a large buffalo farm in the south of Italy. Individual animals were allowed to undergo synchronization protocol (either a slightly modified Ovsynch or Progesterone treatment) and TAI until establishment of pregnancy or else for not more than six consecutive times. Semen of seven proven bulls was used throughout the study, which was carried out from March to September of the same year. Therefore, other than the effect given by consecutive TAIs over time, a monthly and a seasonal effect could also be tested, once the entire period was split into a Low Breeding Season (LBS) from March to June, and a Transition to Breeding Season (TBS) from July to September. From the data recorded in this study and the statistical analysis performed, it can be stated that the two protocols for the synchronization of ovulation were similar in efficiency in determining pregnancies with an overall fertility rate of 89.4% when the comparison was run both on a monthly basis or when months were grouped into two different seasons. In addition, an average of 1.83 AI/pregnancy was reported, slightly higher for the Ovsynch when compared to the Progesterone protocol: 1.91 vs 1.70, respectively. Finally, when considering the number of progressive synchronization treatments implemented over time as covariate, neither Ovsynch nor Progesterone treatment significantly affected pregnancy rates following the first of the six synchronization sessions. However, repeating the synchronization procedure, the progesterone based protocol resulted in significantly higher probability of success in terms of established pregnancies during the second and third re

  7. Effectiveness of melatonin and controlled internal drug release device treatment on reproductive performance of buffalo heifers during out-of-breeding season under tropical conditions.

    Science.gov (United States)

    Ramadan, T A; Sharma, R K; Phulia, S K; Balhara, A K; Ghuman, S S; Singh, I

    2014-12-01

    Sixteen Murrah buffalo heifers, divided into control and treatment groups of eight animals each, were used to study the effect of melatonin and controlled internal drug release (CIDR) device treatment on the resumption of ovarian activity during out-of-breeding season (summer solstice). Treated group was implanted with melatonin (18 mg of melatonin per 50 kg of body weight) for 45 days and then heifers of both groups received CIDR for 9 days. All heifers received intramuscular 500 IU eCG on the day before CIDR removal and 10 μg GnRH on the day after CIDR withdrawal. All animals were subjected to estrus detection daily. Blood sampling in conjunction with transrectal ultrasonography were performed twice weekly to determine serum concentrations of melatonin, progesterone, LH, and antioxidant enzyme activities, as well as to monitor the ovarian follicular activity. Melatonin treatment resulted in an increase (P Days 0 and 35 of melatonin treatment. However, melatonin exhibited superior ability to maintain CL at 21 days after artificial insemenation (AI) and increased the percentage of conception to threefold higher than control. In conclusion, melatonin implantation successfully improved the diameter of largest follicles and the ability to maintain CL at 21 days after AI in buffalo heifers during out-of-breeding season under tropical conditions. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Environmental Enrichment for Broiler Breeders: An Undeveloped Field

    DEFF Research Database (Denmark)

    Riber, Anja Brinch; Jong, Ingrid de; van de Werd, Heleen A.

    2017-01-01

    Welfare problems, such as hunger, frustration, aggression, and abnormal sexual behavior, are commonly found in broiler breeder production. To prevent or reduce these welfare problems, it has been suggested to provide stimulating enriched environments. We review the effect of the different types...... of environmental enrichment for broiler breeders, which have been described in the scientific literature, on behavior and welfare. Environmental enrichment is defined as an improvement of the environment of captive animals, which increases the behavioral opportunities of the animal and leads to improvements...... in biological function. This definition has been broadened to include practical and economic aspects as any enrichment strategy that adversely affects the health of animals (e.g., environmental hygiene), or that has too many economic or practical constraints will never be implemented on commercial farms...

  9. Conceptual design of Indian molten salt breeder reactor

    International Nuclear Information System (INIS)

    Vijayan, P.K.; Basak, A.; Dulera, I.V.; Vaze, K.K.; Basu, S.; Sinha, R.K.

    2014-01-01

    The fuel in a molten salt breeder reactor is in the form of a continuously circulating molten salt. Fluoride based salts have been almost universally proposed. A crucial part for achieving reasonable breeding in such reactors is the need to reprocess the salt continuously, either online or in batch mode. This constitutes a major technological challenge for this type of reactors. India has recently started carrying out fundamental studies so as to arrive at a conceptual design of Indian Molten Salt Breeder Reactor (IMSBR). Presently various design options and possibilities are being studied from the point of view of reactor physics and thermal hydraulic design. In parallel fundamental studies as regards various molten salts have also been initiated. This paper would discuss conceptual design of these reactors, as well as associated issues and technologies

  10. US-DOE Fusion-Breeder Program: blanket design and system performance

    International Nuclear Information System (INIS)

    Lee, J.D.

    1983-01-01

    Conceptual design studies are being used to assess the technical and economic feasibility of fusion's potential to produce fissile fuel. A reference design of a fission-suppressed blanket using conventional materials is under development. Theoretically, a fusion breeder that incorporates this fusion-suppressed blanket surrounding a 3000-MW tandem mirror fusion core produces its own tritium plus 5600 kg of 233 U per year. The 233 U could then provide fissile makeup for 21 GWe of light-water reactor (LWR) power using a denatured thorium fuel cycle with full recycle. This is 16 times the net electric power produced by the fusion breeder (1.3 GWe). The cost of electricity from this fusion-fission system is estimated to be only 23% higher than the cost from LWRs that have makeup from U 3 O 8 at present costs (55 $/kg). Nuclear performance, magnetohydrodynamics (MHD), radiation effects, and other issues concerning the fission-suppressed blanket are summarized, as are some of the present and future objectives of the fusion breeder program

  11. Production aspects of broiler breeders submitted to different drinker types

    Directory of Open Access Journals (Sweden)

    LP Colvero

    2014-03-01

    Full Text Available The objective of this study was of evaluate the influence of different drinker types on the egg production, water intake, mortality, poultry litter relative humidity, egg weight, eggshell percentage, and egg specific gravity of broiler breeders. The experiment was carried out in a commercial farm with 37- to 44-wk-old broiler breeders. A randomized block experimental design, consisting of two treatments (bell or nipple drinkers with four replicates of 4.000 females each, was applied. Data were submitted to analysis of variance, and means were compared by the test of Student-Newman-Keuls at 5% significance level. Birds submitted to nipple drinkers presented lower water intake (p0.05 of drinker type on egg production or mortality. Poultry litter relative humidity was lower (p<0.05 under the nipple-drinker system. Birds drinking from bell drinkers produced heavier eggs (p<0.05 between weeks 39 and 40. Hens drinking from bell drinkers laid eggs with higher specific gravity and eggshell percentage. It was concluded that nipple drinkers can be used for broiler breeders during lay.

  12. Progress in tritium retention and release modeling for ceramic breeders

    International Nuclear Information System (INIS)

    Raffray, A.R.; Federici, G.; Billone, M.C.; Tanaka, S.

    1994-01-01

    Tritium behavior in ceramic breeder blankets is a key design issue for this class of blanket because of its impact on safety and fuel self-sufficiency. Over the past 10-15 years, substantial theoretical and experimental efforts have been dedicated world-wide to develop a better understanding of tritium transport in ceramic breeders. Models that are available today seem to cover reasonably well all the key physical transport and trapping mechanisms. They have allowed for reasonable interpretation and reproduction of experimental data and have helped in pointing out deficiencies in material property data base, in providing guidance for future experiments, and in analyzing blanket tritium behavior. This paper highlights the progress in tritium modeling over the last decade. Key tritium transport mechanisms are briefly described along with the more recent and sophisticated models developed to help understand them. Recent experimental data are highlighted and model calibration and validation discussed. Finally, example applications to blanket cases are shown as illustration of progress in the prediction of ceramic breeder blanket tritium inventory

  13. Mortality, diarrhea and respiratory disease in Danish dairy heifer calves

    DEFF Research Database (Denmark)

    Reiten, M.; Rousing, T.; Thomsen, P. T.

    2018-01-01

    system (conventional/organic), season (summer/winter) and calf mortality risk, diarrhea, signs of respiratory disease and ocular discharge, respectively, for dairy heifer calves aged 0–180 days. Sixty Danish dairy herds, 30 conventional and 30 organic, were visited once during summer and once during......Diarrhea and respiratory disease are major health problems for dairy calves, often causing calf mortality. Previous studies have found calf mortality to be higher in organic dairy herds compared to conventional herds. The aim of this study was to investigate the association between production...... variables and in certain age groups, dependent on production system and season....

  14. Reproduction traits, growth traits and age at first calving in Holstein heifers

    Directory of Open Access Journals (Sweden)

    Bruna Silva Marestone

    2014-02-01

    Full Text Available The objective of this study was to verify the reproductive efficiency expressed by traits, interval from first to second calving (IDP, number of services per conception to the first calving (NSC1, number of services per conception for the second calving (NSC2, service period from the first to the second calving (PS and gestation lenght (PG of Holstein heifers. Data from 377 heifers from two herds, one in Santa Cruz do Rio Pardo, São Paulo and another in Rolândia, Paraná were analysed. The statistical model to analyze IDP, NSC1, NSC2, PS and PG included the fixed effect of Contemporary Group (CG. To analyze PG, it was also considered the effect of calf sex. To evaluate the growth performance and age at first calving (AFC, data from 360 Holstein heifers belonging to property in Rolândia were analysed. The model included the fixed effects of contemporary groups (CG and average daily gain from birth to 15 months (ADG. A similar model was used to analyze weigth at 458 dias (W458 and ADG, therefore considering only CG. The overall means of IDP, NSC1, NSC2, PS and PG, were 14.96 ± 3.94 months; 1.35 ± 0.71 services, 2.86 ± 2.37 services, 178.83 ± 118.73 days; 276.67± 5.65 days, respectively. Correlations were observed between the traits IDP and NSC2 of 72% (P<0.0001, between IDP and PS of 98% (P<0.0001 and between NCS2 and PS of 72% (P<0.0001. The gestation length of males and females showed estimated average of 277.53 ± 0.46 days and 276.33 ± 0.40 days, respectively, and the calf sex was source of variation on PG (P<0.05. Average daily gain was a significant source of variation on AFC and CG affected all traits studied. The estimated average for AFC was 24.18 ± 1.59 months, for W458 was 362.33 ± 36.24 kg and ADG was 0.704 ± 0.08 kg.

  15. Genetic analysis of body condition score of lactating Dutch Holstein and Red-and-White heifers

    NARCIS (Netherlands)

    Koenen, E.P.C.; Veerkamp, R.F.; Dobbelaar, P.; Jong, de G.

    2001-01-01

    The aim of this study was to estimate phenotypic and genetic parameters for body condition scores (BCS) from the Dutch type classification system. Data included 108,809 Holstein (H) and 26,208 Red-and-White (R) heifers from 9701 herds that were scored once during lactation on a 1 to 9 scale (1 =

  16. Breeding blanket development. Tritium release from breeder

    International Nuclear Information System (INIS)

    Tsuchiya, Kunihiko; Kawamura, Hiroshi; Nagao, Yoshiharu

    2006-01-01

    Engineering data on neutron irradiation performance of tritium breeders are needed to design the breeding blanket of fusion reactor. In this study, tritium release experiments of the breeders were carried out to examine the effects of various parameters (such as sweep gas flow rate, hydrogen content in sweep gas, irradiation temperature and thermal neutron flux) on tritium generation and release behavior. Lithium titanate (Li 2 TiO 3 ) is considered as a candidate tritium breeder in the blanket design of International Thermonuclear Experimental Reactor (ITER). As for the shape of the breeder material, a small spherical form is preferred to reduce the thermal stress induced in the breeder. Li 2 TiO 3 pebbles of about 170g in total weight and with 0.3 and 2 mm in diameter were manufactured by a wet process, and an assembly packed with the binary Li 2 TiO 3 pebbles was irradiated in Japan Materials Testing Reactor (JMTR). The tritium was generated in the Li 2 TiO 3 pebble bed and released from the pebble bed, and was swept downstream using the sweep gas for on-line analysis of tritium content. Concentration of total tritium and gaseous tritium (HT or T 2 gas) released from the Li 2 TiO 3 pebble bed were measured by ionization chambers, and the ratio of (gaseous tritium)/(total tritium) was evaluated. The sweep gas flow rate was changed from 100 to 900cm 3 /min, and hydrogen content in the sweep gas was changed from 100 to 10000 ppm. Furthermore, thermal neutron flux was changed using a window made of hafnium (Hf) neutron absorber. The irradiation temperature at an outer region of the Li 2 TiO 3 pebble bed was held between 200 and 400degC. The main results of this experiment are summarized as follows. 1) When the temperature at the outside edge of the Li 2 TiO 3 pebble bed exceeded 100degC, the tritium release from the Li 2 TiO 3 pebble bed started. The ratio of the tritium release rate and the tritium generation rate (normalized tritium release rate: R/G) reached

  17. Development of a fresh plutonium fuel container for a prototype fast breeder reactor

    International Nuclear Information System (INIS)

    Ohtake, T.; Takahashi, S.; Mishima, T.; Kurakami, J.; Yamamoto, Y.; Ohuchi, Y.

    1989-01-01

    Japan gives a good deal of encouragement to development of a fast breeder reactor (which is considered as the most likely candidate for nuclear power generation) to secure long-term energy source. And, following an experimental fast breeder reactor Joyo, a prototype fast breeder reactor Monju is now under vigorous construction. Related to development of the prototype fast breeder reactor, it is necessary and important to develop transport container which is used for transporting fresh fuel assemblies from Plutonium Fuel Production Facility to the Monju power plant. Therefore, the container is now being developed by Power Reactor and Nuclear Fuel Development Corporation (PNC). Currently, shipment and vibration tests, handling performance tests, shielding performance tests and prototype container tests are executed with prototype containers fabricated according to a final design, in order to experimentally confirm soundness of transport container and its contents, and propriety of design technique. This paper describes the summary of general specifications and structures of this container and the summary of preliminary safety analysis of package

  18. Precision-feeding dairy heifers a high rumen-degradable protein diet with different proportions of dietary fiber and forage-to-concentrate ratios.

    Science.gov (United States)

    Lascano, G J; Koch, L E; Heinrichs, A J

    2016-09-01

    The objective of this experiment was to determine the effects of feeding a high-rumen-degradable protein (RDP) diet when dietary fiber content is manipulated within differing forage-to-concentrate ratio (F:C) on nutrient utilization of precision-fed dairy heifers. Six cannulated Holstein heifers (486.98±15.07kg of body weight) were randomly assigned to 2 F:C, low- (45% forage; LF) and high-forage (90% forage; HF) diets and to a fiber proportion sequence [33% grass hay and wheat straw (HS), 67% corn silage (CS; low fiber); 50% HS, 50% CS (medium fiber); and 67% HS, 33% CS (high fiber)] within forage proportion administered according to a split-plot, 3×3 Latin square design (16-d periods). Heifers fed LF had greater apparent total-tract organic matter digestibility coefficients (dC), neutral detergent fiber, and cellulose than those fed LC diets. Substituting CS with HS resulted in a linear reduction in dry matter, organic matter, and cellulose dC. Nitrogen dC was not different between F:C or with increasing proportions of HS in diets, but N retention tended to decrease linearly as HS was increased in the diets. Predicted microbial protein flow to the duodenum decreased linearly with HS addition and protozoa numbers HS interacted linearly, exhibiting a decrease as HS increased for LF, whereas no effects were observed for HF. Blood urea N increased linearly as HS was incorporated. The LF-fed heifers had a greater ruminal volatile fatty acids concentration. We noted a tendency for a greater dry matter, and a significantly higher liquid fraction turnover rate for HF diets. There was a linear numerical increase in the liquid and solid fraction turnover rate as fiber was added to the diets. Rumen fermentation parameters and fractional passages (solid and liquid) rates support the reduction in dC, N retention, and microbial protein synthesis observed as more dietary fiber is added to the rations of dairy heifers precision-fed a constant proportion of rumen

  19. Molecular characterization of chicken infectious anemia viruses detected from breeder and broiler chickens in South Korea.

    Science.gov (United States)

    Kim, H-R; Kwon, Y-K; Bae, Y-C; Oem, J-K; Lee, O-S

    2010-11-01

    In South Korea, 32 sequences of chicken infectious anemia virus (CIAV) from various flocks of breeder and commercial chickens were genetically characterized for the first time. Phylogenetic analysis of the viral protein 1 gene, including a hypervariable region of the CIAV genome, indicated that Korean CIAV strains were separated into groups II, IIIa, and IIIb. Strains were commonly identified in great-grandparent and grandparent breeder farms as well as commercial chicken farms. In the field, CIAV strains from breeder farms had no clinical effects, but commercial farm strains were associated with depression, growth retardation, and anemia regardless of the group from which the strain originated. In addition, we identified 7 CIAV genomes that were similar to vaccine strains from vaccinated and unvaccinated breeder flocks. These data suggest that further studies on pathogenicity and vaccine efficacy against the different CIAV group are needed, along with continuous CIAV surveillance and genetic analysis at breeder farms.

  20. Evaluation of treatments with hCG and carprofen at embryo transfer in a demi-embryo and recipient virgin heifer model.

    Science.gov (United States)

    Torres, A; Chagas E Silva, J; Diniz, P; Lopes-da-Costa, L

    2013-08-01

    An in vivo model, combining a low developmental competence embryo (demi-embryo) and a high-fertility recipient (virgin dairy heifer) was used to evaluate the effects of treatment with human chorionic gonadotropin (hCG) and carprofen at embryo transfer (ET) on plasma progesterone (P₄) concentrations of recipients and on embryonic growth and survival. Embryos were bisected and each demi-embryo was transferred to a recipient on Day 7 of the estrous cycle. At ET, heifers (n = 163) were randomly allocated to treatment with hCG (2500 IU im), carprofen (500 mg iv), hCG plus carprofen or to untreated controls. Plasma P₄ concentrations were measured on Days 0, 7, 14 and 21 of all recipients plus on Days 28, 42 and 63 of pregnant recipients. Pregnancy was presumed to be present in recipients with luteal plasma P4 concentrations until Day 21 and confirmed by using transrectal ultrasonography on Days 28, 42 and 63. Embryonic measurements (crown-rump length and width) were obtained on Day 42. Treatment with hCG induced formation of secondary corpora lutea (CL) in 97% of heifers and increased (P carprofen at ET had no significant effects on plasma P₄ concentrations and rate of embryo mortality. Treatment with hCG plus carprofen at ET induced formation of secondary CL in 90% of heifers but decreased the luteotrophic effect of hCG, resulting in no effect on embryo survival. Low developmental competence embryos showed an intrinsic deficiency in overcoming the maternal recognition of pregnancy challenge and in proceeding to further development until Day 28 of pregnancy, whereas mortality beyond this point was residual. Results on pregnancy rates should be confirmed in further experiments involving a larger sample size.

  1. SEROLOGICAL STATUS OF EGG DROP SYNDROME IN BREEDERS AND COMMERCIAL LAYERS IN MANSEHRA DISTRICT

    Directory of Open Access Journals (Sweden)

    S. T. BADAR1, M. SIDDIQUE, R. ALI1 AND M. H. RASOOL

    2006-01-01

    Full Text Available A serological survey was conducted to see the prevalence of antibodies to egg drop syndrome (EDS virus in breeders and commercial layers in Mansehra district. A total of 50 flocks including broiler breeder (30, layer breeder (10 and commercial layers (10 were surveyed from September, 2002 to March, 2003. Paired serum samples were collected at random from 20 birds in each flock at fortnight interval and screened through haemagglutination inhibition (HI test. In broiler breeders, out of 30 flocks, 12(40% were serologically positive for EDS. In layer breeders and commercial layers, 30 and 20% flocks were found to be seropositive, respectively. On the basis of age, maximum seroprevalence (42.85% was observed in birds between 21-40 weeks of age. The seroprevalence was 33.33% in 1-20 weeks, 26.66% in 41-60 weeks and 25.00 % in 61 weeks and above old birds. No specific clinical signs were observed in all three types of birds. A drop in egg production (22.555% was observed in seropositive flocks along with misshapen soft shelled, shell-less and non-pigmented eggs. Based on these findings, the farmers were advised to vaccinate their flocks against EDS between 14-16 weeks of age using killed adjuvanted vaccines.

  2. Evaluation of physical structure value in spring-harvested grass/clover silage and hay fed to heifers

    DEFF Research Database (Denmark)

    Schulze, A.K.S.; Nørgaard, P.; Byskov, M.V.

    2015-01-01

    The physical structure value of conserved grass/clover forages of spring harvest was evaluated by assessing effects of harvest time, conservation method, iNDF/NDF ratio and NDF intake (NDFI) per kg BW on chewing activity and fecal particle size in dairy heifers. A mixed sward consisting of ryegrass...... of 315, 436, 414 and 503 g/kg DM, respectively. Forages were fed as sole feed to four Jersey heifers of 435±30 kg BW in a 4×4 Latin square experiment. Feeding level was 90% of individual ad libitum intake, divided equally across two daily meals offered at 0800 and 1530 h. Chewing activity was estimated...... from recorded jaw movements (JM) oscillations continuously logged for 96 h and summarized per 24 h as mean effective rumination time and eating time. Eating behavior was further observed during four 20-min test meals. Weight proportion of large feces particles (>1.0 mm) and geometric mean fecal...

  3. Ultraviolet light and mating behaviour in domestic broiler breeders.

    Science.gov (United States)

    Jones, E K; Prescott, N B; Cook, P; White, R P; Wathes, C M

    2001-03-01

    1. The perception of UVA light (320 commercial house lighting. One function may be the mediation of sexually related signalling or communication. 2. In experiment 1, two groups of 41 adult broiler breeders (four cockerels, 37 hens) were kept under conventional fluorescent light, with or without fluorescent UVA supplementation amounting to 16.9% of the total spectral power output of the luminaires. Each light environment was approximately iso-illuminant as perceived by the birds. The two groups were exposed to the light environments alternately for five 2-day periods in a cross-over design. Mating behaviour, production measures and time budgets were recorded on the second day of each period. 3. A UVA-enriched environment increased the number of attempted matings (1.27 vs 0.99 matings/cockerel.h) and locomotion (5.3 vs 3.7 min/bird.hour). 4. In a second experiment, 10 hens were allowed to choose between four cockerels lit under different power levels of UVA (1.6%, 14.6%, 43.5%, 57.5% of the total spectral power output of the luminaires) in a four-armed maze. Again, each light environment was approximately iso-illuminant as perceived by the birds. Each hen was allowed to make one choice per day over four days, with the position of the cockerels and the UVA levels interchanged each day. This schedule was repeated with the same hens for two other groups of four cockerels. 5. At a distance of no less than 60 cm from the cockerel, the hens spent most time inspecting whichever cockerel was lit by 1.6% or 14.6% UVA (1.33 vs 1.37 vs 1.22 vs 1.16 log seconds/hen.choice, respectively for increasing UVA level). Similarly, when allowed to approach closer to the cockerels, the hens spent most time in the arm which contained a cockerel lit by 14.6% UVA light, (1.62 vs 1.88 vs 1.69 vs 1.51 log s/hen.choice, respectively for increasing UVA level). 6. UVA is clearly implicated in the transmission of sexual signals or communication which may have implications for the welfare and

  4. Desempenho, características de carcaça e composição química de diferentes cortes comerciais de novilhas mestiças não-gestantes ou gestantes terminadas em confinamento = Performance, carcass characteristics and chemical composition of nonpregnant or pregnant heifers finished in feedlot

    Directory of Open Access Journals (Sweden)

    Lívia Maria Araújo Macedo

    2007-10-01

    Full Text Available Objetivou-se avaliar o efeito da gestação sobre o desempenho, características de carcaça e composição físico-química de cinco cortes de novilhas mestiças em confinamento. Utilizaram-secinco novilhas gestantes e cinco não-gestantes com 20 meses e peso corporal de 323 kg. Não houve diferença (p > 0,05 para peso final, ganho médio diário, consumo, conversão alimentar, peso de carcaça, rendimento de carcaça, área de olho de lombo e espessura de gordura de cobertura entre os tratamentos. O acém das novilhas gestantes teve maiores teores (p This work was carried out to study the effect of pregnancy on performance, carcass characteristics and chemical composition of crossbred heifers in comparison with nonpregnant heifers finished in feedlot. Five pregnant heifers and five nonpregnant heifers, 20 months old and with initial live weight of 327 kg were used. The initial live weight, final weight, average daily gain, intake, feed conversion, carcass weight, hot carcass dressing, Longissimus area and fat thickness (4.21 mm did not differ (p > 0.05 between treatments. Pregnant heifers chuck showed higher levels (p < 0.05 of moisture and ash, and lower levels (p < 0.05 of total fat, than nonpregnant heifers. Pregnant heifers rump showed higher levels (p < 0.05 of moisture. Nonpregnant heifers striploin had the highest level (p < 0.05 of moisture. The fatty acid profile of pregnant heifers chuck had the highest levels (p < 0.05 of 14:0, 16:1n7 and 20:4n6, but showed the lowest level (p < 0.05 of 17:0. Nonpregnant heifers topside showed the highest levels (p < 0.05 of 18:1t11 and 18:2c9t1. Pregnant heifers chuck showed the highest level (p < 0.05 of PUFA. Nonpregnant heifers had higher levels of n-6 fatty acids than pregnant heifers. The striploin of pregnant heifers showed higher percentage (p < 0.05 of n-3.

  5. Ingestive behavior of grazing heifers receiving crude glycerin supplementation during the dry-rainy season transition

    Directory of Open Access Journals (Sweden)

    Vitor Visintin Silva de Almeida

    2014-09-01

    Full Text Available The search to find food alternatives for corn and feeding alternatives that reduce the cost of production has been constant. The use of oleaginous grains to produce ethanol and biodiesel has produced an excess of byproducts, especially biodiesel which produces crude glycerin. The objective of this study was to evaluate the effect of including crude glycerin on the ingestive behavior of crossbred heifers supplemented with pasture. Thirty-six crossbred heifers with an initial mean weight of 301.5 ± 31 kg were distributed in a completely randomized design with four treatments and nine replicates per treatment. The animals were kept in a Brachiaria brizantha (Hochst. ex A. Rich. Stapf 'Marandu' pasture in a rotational-grazing system. The treatments tested were 0.0%, 3.33%, 6.66%, and 9.99% crude glycerin included in total DM to replace corn (Tea mays L. Including crude glycerin reduced the time for grazing and eating at the trough and increased idle time. Rumination was quadratically influenced. Eating time (min kg-1 DM and neutral detergent fiber [NDF] was reduced, while rumination time (min kg-1 DM and NDF was quadratically affected by adding glycerin. The variables, time spent per ruminated bolus and the number of chews per day, were not affected. The number of boluses per day showed a quadratic effect. The number of grazing, idle, ruminating, and eating at the trough periods were not affected by including crude glycerin; means were 15.1, 24.9, and 13.3 and 3.71 periods d-1, respectively. Feed and rumination efficiency (kg h-1 DM and NDF increased when crude glycerin was included in the diet. Including crude glycerin promotes feed and rumination efficiency in grazing heifers.

  6. Assessment of First Wall and Blanket Options with the Use of Liquid Breeder

    International Nuclear Information System (INIS)

    Wong, C.P.C.; Malang, S.; Sawan, M.

    2005-01-01

    As candidate blanket concepts for a U.S. advanced reactor power plant design, with consideration of the time frame for ITER development, we assessed first wall and blanket design concepts based on the use of reduced activation ferritic steel as structural material and liquid breeder as the coolant and tritium breeder. The liquid breeder choice includes the conventional molten salt Li 2 BeF 4 and the low melting point molten salts such as LiBeF 3 and LiNaBeF 4 (FLiNaBe). Both self-cooled and dual coolant molten salt options were evaluated. We have also included the dual coolant leadeutectic Pb-17Li design in our assessment. We take advantage of the molten salt low electrical and thermal conductivity to minimize impacts from the MHD effect and the heat losses from the breeder to the actively cooled steel structure. For the Pb-17Li breeder we employ flow channel inserts of SiC f /SiC composite with low electrical and thermal conductivity to perform respective insulation functions. We performed preliminary assessments of these design options in the areas of neutronics, thermal-hydraulics, safety, and power conversion system. Status of the R and D items of selected high performance blanket concepts is reported. Results from this study will form the technical basis for the formulation of the U.S. ITER test module program and corresponding test plan

  7. Application of discrete element method to study mechanical behaviors of ceramic breeder pebble beds

    International Nuclear Information System (INIS)

    An Zhiyong; Ying, Alice; Abdou, Mohamed

    2007-01-01

    In this paper, the discrete element method (DEM) approach has been applied to study mechanical behaviors of ceramic breeder pebble beds. Directly simulating the contact state of each individual particle by the physically based interaction laws, the DEM numerical program is capable of predicting the mechanical behaviors of non-standard packing structures. The program can also provide the data to trace the evolution of contact characteristics and forces as deformation proceeds, as well as the particle movement when the pebble bed is subjected to external loadings. Our numerical simulations focus on predicting the mechanical behaviors of ceramic breeder pebble beds, which include typical fusion breeder materials in solid breeder blankets. Current numerical results clearly show that the packing density and the bed geometry can have an impact on the mechanical stiffness of the pebble beds. Statistical data show that the contact forces are highly related to the contact status of the pebbles

  8. INCUBATION YIELD AS A FUNCTION OF BROILER BREEDER AGE / RENDIMENTO DE INCUBAÇÃO EM FUNÇÃO DA IDADE DA MATRIZ

    Directory of Open Access Journals (Sweden)

    G. F. da Silva

    2017-09-01

    Full Text Available The factors involved in poultry egg incubation include breeder hen age, which may influence both the external and internal quality of eggs. In this context, this study sought to determine incubation yield among eggs from breeder hens at three ages. A total of 1,728 eggs were obtained from Cobb broiler breeders at three ages (26 weeks, 32 weeks, and 53 weeks and incubated. At the end of the incubation process, eclosion, hatchability, the percentage of infertile eggs, the time of embryo mortality, and chick weight were all analyzed according to breeder hen age. Analysis of variance was applied to the results, and egg fertility was found to be associated with breeder age, since lower rates of eclosion were found in eggs from younger broiler breeders. Chick weight was also found to be influenced by breeder age, since eggs from older broiler breeders hatched into heavier chicks. However, neither mortality nor hatchability were found to be affected by breeder hen age.

  9. Fast breeder reactors: Experience and trends. V. 2

    International Nuclear Information System (INIS)

    1986-01-01

    The IAEA Symposium on ''Fast Breeder Reactors: Experience and Future Trends'' was held, at the invitation of the Government of France, in Lyons, France, on 22-26 July 1985. It was hosted by the French Commissariat a l'energie atomique and Electricite de France. The purpose of the Symposium was to review the experience gained so far in the field of LMFBRs, taking into account the constructional, operational, technological, economic and fuel cycle aspects, and to consider the developmental trends as well as the international co-operation in fast breeder reactor design and utilization. The Symposium was attended by almost 400 participants (340 participants, 35 observers and 20 journalists) from 25 countries and five international organizations. More than 80 papers were presented and discussed during six regular sessions and four poster sessions. A separate abstract was prepared for each of these papers

  10. Evaluation of physical structure value in spring-harvested grass/clover silage and hay fed to heifers

    DEFF Research Database (Denmark)

    Schulze, A.K.S.; Nørgaard, P.; Byskov, M.V.

    2015-01-01

    The physical structure value of conserved grass/clover forages of spring harvest was evaluated by assessing effects of harvest time, conservation method, iNDF/NDF ratio and NDF intake (NDFI) per kg BW on chewing activity and fecal particle size in dairy heifers. A mixed sward consisting of ryegrass...

  11. Advanced liquid metal fast breeder reactor designs

    International Nuclear Information System (INIS)

    Sayles, C.W.

    1978-01-01

    Fast Breeder reactor power plants in the 1000-1200 MW(e) range are being built overseas and are being designed in this country. While these reactors have many characteristics in common, a variety of different approaches have been adopted for some of the major features. Some of those alternatives are discussed

  12. The present status of the fast breeder reactor industrialization in western Europe

    International Nuclear Information System (INIS)

    Dievoet, J.P. van

    1987-01-01

    The development of the liquid metal fast breeder reactor in Europe started in the mid-fifties, after the successful operation of EBR-1 at ARCO, Idaho, in 1951. A more and more integrated development among the countries of the European Community culminated in 1986 with the beginning to power of the 1200 MWe SUPERPHENIX plant at Creys-Malville, France. The road is now open towards the full industrialization of the liquid metal fast breeder reactor at the moment, in 2005, when the first European thermal neutron power reactor station will have to be decommissioned and replaced. The European programme aims at providing the utilities at that time with a clear choice between thermal neutron reactors and fast breeder reactors, both economical but very different in their use of the limited natural resource that uranium is. (author)

  13. Comparison of metabolic, hematological, and peripheral blood leukocyte cytokine profiles of dairy cows and heifers during the periparturient period.

    Science.gov (United States)

    Jonsson, N N; Fortes, M R S; Piper, E K; Vankan, D M; de Cisneros, J Prada J; Wittek, T

    2013-04-01

    The periparturient period presents major physiological challenges for the dairy cow. It is a period that is affected by metabolic stressors, major changes in endocrine status, and altered immune function, which together result in an increased risk of disease. Immunological, hematological, and metabolic profiles from the periparturient period of heifers (primipara) were compared with those of cows (pluripara) to test the hypothesis that at the time of calving they have qualitatively different peripheral blood profiles. Blood samples were collected from 22 Holstein-Friesian animals on 3 occasions: approximately 2 wk before calving, within 24h after calving, and approximately 2 wk after calving. Quantitative PCR was used to measure the expression of a selected set of cytokines and receptors by peripheral blood leukocytes. Additional analyses included hemoglobin concentration, red cell, platelet and white cell counts (total and differentiated), and clinical diagnostic biochemical profiles. Total leukocyte counts, neutrophils, and lymphocytes were higher in heifers than cows before calving and within 24h after calving. Alkaline phosphatase was consistently higher in heifers than cows and several significant differences were observed between the 2 groups with regards to cytokine and cytokine-receptor mRNA expression. The results warrant further investigation from the perspective of identifying risk factors for metabolic and parturient disease in dairy cattle. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Local host response following an intramammary challenge with Staphylococcus fleurettii and different strains of Staphylococcus chromogenes in dairy heifers.

    Science.gov (United States)

    Piccart, Kristine; Verbeke, Joren; De Visscher, Anneleen; Piepers, Sofie; Haesebrouck, Freddy; De Vliegher, Sarne

    2016-05-12

    Coagulase-negative staphylococci (CNS) are a common cause of subclinical mastitis in dairy cattle. The CNS inhabit various ecological habitats, ranging between the environment and the host. In order to obtain a better insight into the host response, an experimental infection was carried out in eight healthy heifers in mid-lactation with three different CNS strains: a Staphylococcus fleurettii strain originating from sawdust bedding, an intramammary Staphylococcus chromogenes strain originating from a persistent intramammary infection (S. chromogenes IM) and a S. chromogenes strain isolated from a heifer's teat apex (S. chromogenes TA). Each heifer was inoculated in the mammary gland with 1.0 × 10(6) colony forming units of each bacterial strain (one strain per udder quarter), whereas the remaining quarter was infused with phosphate-buffered saline. Overall, the CNS evoked a mild local host response. The somatic cell count increased in all S. fleurettii-inoculated quarters, although the strain was eliminated within 12 h. The two S. chromogenes strains were shed in larger numbers for a longer period. Bacterial and somatic cell counts, as well as neutrophil responses, were higher after inoculation with S. chromogenes IM than with S. chromogenes TA. In conclusion, these results suggest that S. chromogenes might be better adapted to the mammary gland than S. fleurettii. Furthermore, not all S. chromogenes strains induce the same local host response.

  15. Be-Breeder - an application for analysis of genomic data in plant breeding

    OpenAIRE

    Matias,Filipe Inácio; Granato,Italo Stefanine Correa; Dequigiovanni,Gabriel; Fritsche-Neto,Roberto

    2017-01-01

    Abstract Be-Breeder is an application directed toward genetic breeding of plants, developed through the Shiny package of the R software, which allows different phenotype and molecular (marker) analysis to be undertaken. The section for analysis of molecular data of the Be-Breeder application makes it possible to achieve quality control of genotyping data, to obtain genomic kinship matrices, and to analyze genome selection, genome association, and genetic diversity in a simple manner on line. ...

  16. Fast breeder fuel cycle, worldwide and French prospects

    International Nuclear Information System (INIS)

    Rapin, M.

    1982-01-01

    A review is given of fast breeder fuel cycle development from both the technological and the economical points of view. LMFBR fuel fabrication, reactor operation, spent fuel storage and transportation, reprocessing and fuel cycle economics are topics considered. (U.K.)

  17. Combined system of accelerator molten-salt breeder (AMSB) apd molten-salt converter reactor (MSCR)

    International Nuclear Information System (INIS)

    Furukawa, K.; Kato, Y.; Ohmichi, T.; Ohno, H.

    1983-01-01

    A design and research program is discUssed of the development of accelerator molten-salt breeder (AMSB) consisting of a proton accelerator and a molten fluoride target. The target simultaneously serves as a blanket for fissionable material prodUction. An addition of some amoUnt of fissile nuclides to a melt expands the AMSB potentialities as the fissionable material production increases and the energy generation also grows up to the level of self-provision. Besides the blanket salts may be used as nuclear fuel for molten-salt converter reactor (MSCR). The combined AM SB+MSCR system has better parameters as compared to other breeder reactors, molten-salt breeder reactors (MSBR) included

  18. Installation of the Light-Water Breeder Reactor at the Shippingport Atomic Power Station (LWBR Development Program)

    International Nuclear Information System (INIS)

    Massimino, R.J.; Williams, D.A.

    1983-05-01

    This report summarizes the refueling operations performed to install a Light Water Breeder Reactor (LWBR) core into the existing pressurized water reactor vessel at the Shippingport Atomic Power Station. Detailed descriptions of the major installation operations (e.g., primary system preconditioning, fuel installation, pressure boundary seal welding) are included as appendices to this report; these operations are of technical interest to any reactor servicing operation, whether the reactor is a breeder or a conventional light water non-breeder core

  19. Installation of the Light-Water Breeder Reactor at the Shippingport Atomic Power Station (LWBR Development Program)

    Energy Technology Data Exchange (ETDEWEB)

    Massimino, R.J.; Williams, D.A.

    1983-05-01

    This report summarizes the refueling operations performed to install a Light Water Breeder Reactor (LWBR) core into the existing pressurized water reactor vessel at the Shippingport Atomic Power Station. Detailed descriptions of the major installation operations (e.g., primary system preconditioning, fuel installation, pressure boundary seal welding) are included as appendices to this report; these operations are of technical interest to any reactor servicing operation, whether the reactor is a breeder or a conventional light water non-breeder core.

  20. Present status of the Liquid Breeder Validation Module for IFMIF

    International Nuclear Information System (INIS)

    Casal, Natalia; Mas, Avelino; Mota, Fernando; García, Ángela; Rapisarda, David; Nomen, Oriol; Arroyo, Jose Manuel; Abal, Javier; Mollá, Joaquín; Ibarra, Ángel

    2013-01-01

    Highlights: • The LBVM will be used to perform irradiation experiments on functional materials for fusion reactors. • It houses 16 experimental rigs, each one containing a EUROFER capsule partially filled with lithium lead, at 300–550 °C. • A helium purge gas will sweep the tritium permeated through the capsule walls to a tritium measuring station. • A helium cooling system will keep tritium diffusion within safe margins and guarantee its mechanical integrity. • Thermal hydraulic and mechanical calculations, the module instrumentation and aspects as safety or RAMI are presented. -- Abstract: One of the objectives of IFMIF (International Fusion Materials Irradiation Facility), as stated in its specifications, is the validation of breeder blanket concepts for DEMO design. The so-called Liquid Breeder Validation Module (LBVM) will be used in IFMIF to perform experiments under irradiation on functional materials related to liquid breeder concepts for future fusion reactors. This module, not considered in previous IFMIF design phases, is currently under design by CIEMAT in the framework of the IFMIF/EVEDA project. In this paper, the present status of the design of the LBVM is presented

  1. Present status of the Liquid Breeder Validation Module for IFMIF

    Energy Technology Data Exchange (ETDEWEB)

    Casal, Natalia, E-mail: natalia.casal@ciemat.es [Laboratorio Nacional de Fusión por Confinamiento Magnético – CIEMAT, 28040 Madrid (Spain); Mas, Avelino; Mota, Fernando; García, Ángela; Rapisarda, David [Laboratorio Nacional de Fusión por Confinamiento Magnético – CIEMAT, 28040 Madrid (Spain); Nomen, Oriol [Institut de Recerca en Energia de Catalunya (IREC), Barcelona (Spain); Centre de Disseny d’Equips Industrials (CDEI), Technical University of Catalonia (UPC), Barcelona (Spain); Arroyo, Jose Manuel [Laboratorio Nacional de Fusión por Confinamiento Magnético – CIEMAT, 28040 Madrid (Spain); Abal, Javier [Fusion Energy Engineering Laboratory (FEEL), Technical University of Catalonia (UPC) Barcelona-Tech, Barcelona (Spain); Mollá, Joaquín; Ibarra, Ángel [Laboratorio Nacional de Fusión por Confinamiento Magnético – CIEMAT, 28040 Madrid (Spain)

    2013-10-15

    Highlights: • The LBVM will be used to perform irradiation experiments on functional materials for fusion reactors. • It houses 16 experimental rigs, each one containing a EUROFER capsule partially filled with lithium lead, at 300–550 °C. • A helium purge gas will sweep the tritium permeated through the capsule walls to a tritium measuring station. • A helium cooling system will keep tritium diffusion within safe margins and guarantee its mechanical integrity. • Thermal hydraulic and mechanical calculations, the module instrumentation and aspects as safety or RAMI are presented. -- Abstract: One of the objectives of IFMIF (International Fusion Materials Irradiation Facility), as stated in its specifications, is the validation of breeder blanket concepts for DEMO design. The so-called Liquid Breeder Validation Module (LBVM) will be used in IFMIF to perform experiments under irradiation on functional materials related to liquid breeder concepts for future fusion reactors. This module, not considered in previous IFMIF design phases, is currently under design by CIEMAT in the framework of the IFMIF/EVEDA project. In this paper, the present status of the design of the LBVM is presented.

  2. Dounreay: more is at stake than just the fast breeder

    International Nuclear Information System (INIS)

    Holmes, A.

    1988-01-01

    The British government's policy on nuclear power is to support and encourage an expansion of the nuclear energy programme. However, the Conservative government has said it will withdraw its funding from the fast breeder reactor research programme based at Dounreay in Scotland. Once the Electricity supply industry has been privatised it will not finance the fast breeder reactor programme either. So it seems likely that the research will be discontinued after 5 years and the reprocessing plant planned for Dounreay will never be built. This highlights the basic ambiguity that has existed for a long time over the fast breeder programme and has forced a decision. A similar problem exists generally with the United Kingdom Atomic Energy Authority which has continued to thrive despite many failures. The reasons for this are explained. Privatisation may be the spur to the demise of the UKAEA so it no longer enjoys such a favoured position. The decision to kill off the FBR is just one consequence of this. Others may be a change of attitude to the decommissioning of the Windscale prototype advanced gas cooled reactor, and the fusion project, including JET. (U.K.)

  3. Growth performance and fatty acid profiles of intramuscular and subcutaneous fat from Limousin and Charolais heifers fed extruded linseed

    Czech Academy of Sciences Publication Activity Database

    Bartoň, L.; Marounek, Milan; Kudrna, V.; Bureš, D.; Zahrádková, R.

    2007-01-01

    Roč. 76, 3 (2007), 517-523 ISSN 0309-1740 Institutional research plan: CEZ:AV0Z50450515 Keywords : heifers * linseed * fatty acids Subject RIV: GH - Livestock Nutrition Impact factor: 2.006, year: 2007

  4. Inherent safe fast breeder reactors and actinide burners, metallic fuel

    International Nuclear Information System (INIS)

    Dorner, S.; Schumacher, G.

    1991-04-01

    Nuclear power without breeder strategy uses the possibilities for the energy supply only to a small extend compared to the possibilities of fast breeder reactors, which offer an energy supply for thousands of years. Moreover, a fast neutron device offers the opportunity to run an actinide-burner that could improve the situation of waste management. Within this concept metallic fuel could play a key role. The present report shows some important aspects of the concept like the pyrometallic reprocessing, the behaviour of metallic fuel during a core meltdown accident and others. The report should contribute to the discussion of these problems and initialize further work

  5. Effect of supplemental nutrient source on heifer growth and reproductive performance, and on utilization of corn silage-based diets by beef steers.

    Science.gov (United States)

    Howlett, C M; Vanzant, E S; Anderson, L H; Burris, W R; Fieser, B G; Bapst, R F

    2003-09-01

    Two experiments were conducted to determine effects of oilseeds or soybean hulls on growth and reproductive performance of heifers and utilization of corn silage diets by growing beef cattle. In Exp. 1, 96 beef heifers (249 kg of BW) were used in a randomized complete block design. Treatments were as follows: 1) corn and soybean meal (CON) at 56% of the DMI; 2) whole linted cottonseed at 15% of the DMI (COT); 3) whole raw soybeans at 15% of the DMI (SB); or 4) pelleted soyhulls at 30% of the DMI (SH). Diets were formulated to be isonitrogenous (13.8% CP) and fed to achieve target weights equal to 65% of expected mature BW at the time of AI. Estrus was synchronized and heifers were inseminated by AI in response to detected estrus. Because the energy value for SH was underestimated, cumulative ADG for SH (1.03 kg/d) was greater (P 0.10) the proportion of pubertal heifers at the beginning of the breeding season: CON (60%), COT (53%), SB (69%), SH (71%), or first-service conception rates: CON (37%); COT (38%); SB (57%); SH (42%). In Exp. 2, crossbred steers (387 kg) were used in a 6 x 6 Latin square design to evaluate the effects of supplemental nutrient source on utilization of corn silage diets. Treatments included diets used in Exp. 1, plus a negative control (soybean meal at 10% of the DMI; SIL) and whole raw soybeans at 25% of the DMI (SB25). Diets were formulated to be isonitrogenous (13.8% CP) except SB25 (17% CP), and were fed twice daily at 1.8 x NEm. Oilseed inclusion decreased (P tract NDF digestibilities. The CON and SH diets had the greatest (P tract OM digestibilities. Microbial efficiencies were greatest (P reproductive performance of heifers. Although oilseed additions increased total fatty acid flow to the duodenum, a high degree of biohydrogenation occurred, greatly increasing C18:0, with only marginal increases in unsaturated fatty acid flow. Depending on diet and feeding conditions, inclusion of whole oilseeds may not be an effective means of

  6. Report to the Congress: liquid metal fast breeder reactor program--past, present, and future, Energy Research and Development Administration

    International Nuclear Information System (INIS)

    1975-01-01

    The past, present, and future of the liquid metal fast breeder reactor (LMFBR) program, the Nation's highest priority energy program, are studied. ERDA anticipates that the operation of the first large commercial breeder will start in 1987, and that 186 commercial-size breeders will be in operation by the year 2000. The breeder program is made up of six major areas, each dealing with an important element of technology: reactor physics; fuels and materials; fuel recycle; safety; component development; plant experience; and facilities used in the LMFBR program. ERDA is implementing a new system for administering, managing, and controlling the breeder program that will provide increased program visibility and control. Federal funding for breeder development was $168 million in FY 1971, accounting for 40% of the total Federal R and D energy budget; in FY 1976 Federal funding for this program will be $474 million, only 26% of total Federal funding for energy research. Besides Federal funds, over half a billion dollars have been or will be invested by industry over the next 5 to 10 years to develop the breeder and to build a demonstration plant. Five other nations--the United Kingdom, France, Japan, West Germany, and the Soviet Union--have a high priority national energy program for developing the LMFBR. These foreign breeder programs could contribute important data and information to the U.S. program

  7. Environmental Enrichment for Broiler Breeders: An Undeveloped Field

    NARCIS (Netherlands)

    Riber, Anja B.; Jong, de Ingrid; Weerd, van de Heleen A.; Steenfeldt, Sanna

    2017-01-01

    Welfare problems, such as hunger, frustration, aggression, and abnormal sexual behavior, are commonly found in broiler breeder production. To prevent or reduce these welfare problems, it has been suggested to provide stimulating enriched environments. We review the effect of the different types of

  8. The broiler breeder paradox: ethical, genetic and physiological perspectives, and suggestions for solutions.

    Science.gov (United States)

    Decuypere, E; Bruggeman, V; Everaert, N; Li, Yue; Boonen, R; De Tavernier, J; Janssens, S; Buys, N

    2010-10-01

    1. Due to intensive selection, broiler chickens became the most efficient meat-producing animals because of their fast growth, supported by a virtually unlimited voluntary feed intake. These characteristics cause many problems in the management of broiler breeder hens because of the negative correlation between muscle growth and reproduction effectiveness. 2. This problem, namely the fast muscle growth versus reproduction health paradox, induces a second paradox, acceptable reproduction and health versus hunger stress and impaired welfare, because broiler breeder hens require dedicated programmes of feed restriction (1) to maximise egg and chick production and (2) to avoid metabolic disorders and mortality in broiler breeders. 3. Given that poultry selection is a global large-scale business and chickens are a prolific species, improvement in profit can only be obtained by selecting on feed conversion and/or for higher breast meat percentage, which will intensify the broiler-breeder paradox. 4. New feeding strategies are being studied, but it is questionable if the paradox can be solved by management tools alone. Because breeding and selection are long-term processes, involving animals, farmers, consumers, industry, environment etc., a more sustainable breeding goal needs to be determined by a multidisciplinary approach and an open debate between several actors in the discussion. 5. Using dwarf broiler breeder hens could be one alternative, because dwarf hens combine relatively good reproductive fitness with ad libitum feeding. Another possibility is to accept lower broiler productivity by assigning economic values to welfare and including integrity traits in an extended breeding goal.

  9. Consideration on risk reduction of future breeder reactors

    International Nuclear Information System (INIS)

    Vossebrecker, H.

    1990-09-01

    An overall concept of risk minimization of future sodium-cooled fast breeder reactors is presented in this report. Since shutdown reliability is of vital importance for the breeder safety, a so-called third shutdown level is proposed in addition to the two independent fast shutdown systems. It is basically a group of passive and active measures, which are capable to bring the reactor to safe conditions in all conceivable accident-initiating events and in case of total failure of the two actual shutdown systems. Core disruptions as a result of shutdown failure are therefore beyond the scope of technical imagination. Measures are also foreseen to combat other conceivable causes of core disruption, in particular to achieve residual heat removal with essentially passive systems by making use of the good natural circulation capacity of sodium. On top of that, since absolute safety can never be claimed, damage-limiting containment measures are discussed

  10. Gas-cooled fast breeder reactor

    International Nuclear Information System (INIS)

    Yoshida, Hiroyuki

    1982-07-01

    Almost all the R D works of gas-cooled fast breeder reactor in the world were terminated at the end of the year 1980. In order to show that the R D termination was not due to technical difficulties of the reactor itself, the present paper describes the reactor plant concept, reactor performances, safety, economics and fuel cycle characteristics of the reactor, and also describes the reactor technologies developed so far, technological problems remained to be solved and planned development schedules of the reactor. (author)

  11. Chemical surveillance of commercial fast breeder reactors

    International Nuclear Information System (INIS)

    Stamm, H.H.; Stade, K.Ch.

    1988-01-01

    After BN-600 (USSR) and SUPERPHENIX (France) were started succesfully, the international development of LMFBRs is standing at the doorstep of commercial use. For commercial use of LMFBRs cost reductions for construction and operation are highly desirable and necessary. Several nations developing breeder reactors have joined in a common effort in order to reach this aim by standardization and harmonization. On the base of more than 20 years of operation experience of experimental reactors (EBR-II, FFTF, RAPSODIE, DFR, BR-5/BR-10, BOR-60, JOYO, KNK-II) and demonstration plants (PHENIX, PFR, BN-350), possibilities for standardization in chemical surveillance of commercial breeder reactors without any loss of availability, reliability and reactor safety will be discussed in the following chapters. Loop-type reactors will be considered as well as pool-type reactors, although all commercial plants under consideration so far (SUPERPHENIX II, BN-800, BN-1600, CFBR, SNR-2, EFR) include pool-type reactors only. Table 1 gives a comparison of the Na inventories of test reactors, prototype plants and commercial LMFBRs

  12. Effects of straw processing and pen stocking density on holstein dairy heifers: ii) behavior and hygiene

    Science.gov (United States)

    The effects of pen-stocking density and straw processing on the daily behavior traits and hygiene of Holstein dairy heifers housed in a freestall system are not understood. Our objective was to evaluate these factors in a trial with a 2 × 3 factorial arrangement of straw-processing (GOOD or POOR) an...

  13. The effects of selecting for the myostatin F94L polymorphism on reproductive traits in pubertal heifers

    Science.gov (United States)

    The myostatin F94L polymorphism influences carcass traits in steers; however, the influence of this polymorphism on female reproductive performance should be characterized as part of using it for marker assisted selection. Results from USMARC indicate that heifers that are homozygous for the L allel...

  14. Solid tritium breeder materials-Li2O and LiAlO2: a data base review

    International Nuclear Information System (INIS)

    Liu, Y.Y.; Billone, M.C.; Clemmer, R.G.; Fischer, A.K.; Hollenberg, G.W.; Tam, S.W.

    1985-01-01

    The fabrication, properties, and irradiation behavior of Li 2 O and γ-LiAlO 2 are reviewed and assessed to determine the potential of these materials to satisfy the basic solid breeder blanket performance requirements. Based on the data analysis and theoretical modeling, a set of major technical uncertainties is identified. These uncertainties include: fabricability of sphere-pac solid breeders; high fluence and burnup effects on thermal conductivity and microstructural stability; high fluence and burnup effects on tritium diffusion coefficients at low temperature; relationship among purge flow chemistry, surface adsorption, and species of released tritium; and mechanical properties and the loads imposed on the structural materials by the breeder during blanket operation. Resolution of these issues is important in assuring that solid breeder blankets can be designed with confidence

  15. Partial budget analysis of prepartum antimicrobial therapy and Escherichia coli J5 vaccination of dairy heifers and their effect on milk production and milk quality parameters

    Directory of Open Access Journals (Sweden)

    Renison T. Vargas

    2016-02-01

    Full Text Available Abstract: This study aimed to determine whether prepartum antimicrobial and/or Escherichia coli J5 vaccination in dairy heifers influence the milk production, milk quality, and estimate their economic benefit. Thus, 33 dairy heifers were enrolled in four groups using a split-splot design. Groups were: (G1 prepartum antimicrobial infusion and vaccination with an E. coli J5 bacterin, (G2 prepartum antimicrobial infusion, (G3 vaccination with an E. coli J5 bacterin, and (G4 control heifers. Composite milk samples for somatic cell count, total bacteria count and milk composition were collected 15 days after calving and every 15 days until the end of the experiment. Bacteriological analysis was carried out at the end of study. The milk production and the incidence of clinical cases of mastitis, as well as the costs associated with them were recorded. The results demonstrate a reduction on clinical mastitis rates by preventive strategies, which implicated in lower volume of discarded milk (0.99, 1.01, 1.04 and 3.98% for G1, G2, G3 and G4, respectively and higher economic benefit. Thus, in well-managed dairy herds the prevention of heifer mastitis by vaccination or antimicrobial therapy can reduce the amount of antimicrobials needed to treat clinical mastitis cases and the days of discarded milk.

  16. Role of the consolidated fuel reprocessing program in the United States Breeder Reactor Program

    International Nuclear Information System (INIS)

    Ballard, W.W.; Burch, W.D.

    1980-01-01

    While present US policy precludes the commercial reprocessing of LWR fuels and the recycle of plutonium, the policy does encompass the need to continue a program to develop the technology for reprocessing breeder fuels. Some questions have again risen this year as to the pace of the entire breeder program, including recycle, and the answers are evolving. This paper and the other companion papers which describe several aspects of the Consolidated Fuel Reprocessing Program take a longer-range perspective on the total program. Whether the program is implemented in the general time frame described is dependent on future government actions dedicated to carrying out a systematic program that would permit breeders to be commercialized early in the next century

  17. Repellent effectiveness of seven plant essential oils, sunflower oil and natural insecticides against horn flies on pastured dairy cows and heifers.

    Science.gov (United States)

    Lachance, S; Grange, G

    2014-06-01

    Plant essential oils (basil, geranium, balsam fir, lavender, lemongrass, peppermint, pine and tea tree), mixed with either sunflower oil or ethyl alcohol, were applied at 5% concentrations to the sides of Holstein cattle. Pastured cattle treated with essential oils diluted in sunflower oil had less flies than the untreated control for a 24-h period. However, the essential oil treatments were not significantly different than the carrier oil alone. Barn-held heifers treated with essential oils and sunflower oil alone had significantly less flies than the untreated control for up to 8 h after treatment. Basil, geranium, lavender, lemongrass and peppermint repelled more flies than sunflower oil alone for a period ranging from 1.5 to 4 h after treatments applied to heifers. All essential oils repelled > 75% of the flies on the treated area for 6 and 8 h on pastured cows and indoor heifers, respectively. Geranium, lemongrass and peppermint stayed effective for a longer duration. Essential oils mixed with ethyl alcohol demonstrated less repellence than when mixed with the carrier oil. Safer's soap, natural pyrethrins without piperonyl butoxide and ethyl alcohol alone were not efficient at repelling flies. Essential oils could be formulated for use as fly repellents in livestock production. © 2013 The Royal Entomological Society.

  18. Comparative assessment of nuclear fuel cycles. Light-water reactor once-through, classical fast breeder reactor, and symbiotic fast breeder reactor cycles

    International Nuclear Information System (INIS)

    Hardie, R.W.; Barrett, R.J.; Freiwald, J.G.

    1980-06-01

    The object of the Alternative Nuclear Fuel Cycle Study is to perform comparative assessments of nuclear power systems. There are two important features of this study. First, this evaluation attempts to encompass the complete, integrated fuel cycle from mining of uranium ore to disposal of waste rather than isolated components. Second, it compares several aspects of each cycle - energy use, economics, technological status, proliferation, public safety, and commercial potential - instead of concentrating on one or two assessment areas. This report presents assessment results for three fuel cycles. These are the light-water reactor once-through cycle, the fast breeder reactor on the classical plutonium cycle, and the fast breeder reactor on a symbiotic cycle using plutonium and 233 U as fissile fuels. The report also contains a description of the methodology used in this assessment. Subsequent reports will present results for additional fuel cycles

  19. The influence of oestrous substances on cyclicity and oestrous behaviour in dairy heifers

    Directory of Open Access Journals (Sweden)

    Nordéus Kristina

    2012-04-01

    Full Text Available Abstract Background Declining fertility is a major concern for dairy farmers today. One explanation is shorter and weaker expression of oestrus in dairy cows making it difficult to determine optimal time for artificial insemination (AI. Chemical communication is of interest in the search for tools to detect oestrus or to synchronise or enhance oestrous periods. Pheromones, used in chemical communication within species, can influence reproduction in different ways. The aim here was to investigate whether oestrous cycle length, and duration and intensity of oestrous expression in dairy heifers could be manipulated through exposure to pheromones in oestrual substances from other females. Methods Beginning on day 16 of two consecutive control oestrous cycles, ten heifers of the Swedish Red Breed (SRB were exposed to water. During the two following cycles the heifers were exposed to urine and vaginal mucus, obtained from cows in oestrus. Cyclicity parameters were monitored through hormone measurements, oestrus detection and ultrasonographic examination. Results We found no difference in cycle length or in duration of standing oestrus between control and treatment. We did, however, find a tendency of interaction between type of exposure (control or treatment and cycle number within type of exposure for cycle length (p = 0.068, with the length differing less between the treatment cycles. We also found a tendency of effect of type of exposure on maximal concentration (p = 0.073 and sum of concentrations (p = 0.063 of LH during the LH surge, with values being higher for the control cycles. There were also significant differences in when the different signs of oestrus occurred and in the intensity of oestrous expression. The score for oedema and hyperaemia of external genitalia was significantly higher (p = 0.004 for the control cycles and there was also a significant interaction between type of exposure and time period for restlessness (p = 0.011, with

  20. Fast breeder reactor at Kalkar. Pt. 2

    International Nuclear Information System (INIS)

    Degen, G.

    1979-02-01

    After a brief description of the previous development of the case the legal decisions are documented and commented on. The concept of the then FDP-Minister of Economy of North Rhine Westphalia (Riemer, Pu-combustion plant) is presented and the prospects and risk for the fast breeder reactor after the 3. partial construction license are discussed. (orig./HP) [de

  1. Compatibility of 316L stainless steel with tritium breeders for fusion reactors

    International Nuclear Information System (INIS)

    Broc, M.; Fauvet, P.; Flament, T.; Sannier, J.

    1986-06-01

    Compatibility problems with structural materials are a concern for the choice of the tritium breeder for fusion reactors. In the frame of the European Programme on Fusion Technology, two types of blankets are considered: liquid (eutectic lithium-lead alloy at 0.68 wt % Li: 17Li83Pb) and solid (lithium aluminate or silicate) breeders. This paper is devoted to compatibility studies of 316L stainless steel with 17Li83Pb alloy and γ-LiA10 2 ceramic

  2. Effects of rumen-undegradable protein on intake, performance, and mammary gland development in prepubertal and pubertal dairy heifers

    NARCIS (Netherlands)

    Silva, A.L.; Detmann, E.; Dijkstra, J.; Pedroso, A.M.; Silva, L.H.P.; Machado, A.F.; Sousa, F.C.; Santos, dos G.B.; Marcondes, M.I.

    2018-01-01

    The objective of this study was to evaluate the influence of different amounts of rumen-undegradable protein (RUP) on intake, N balance, performance, mammary gland development, carcass traits, and hormonal status of Holstein heifers at different physiological stages (PS). Sixteen prepubertal (PRE)

  3. Influence of different levels of concentrate and ruminally undegraded protein on digestive variables in beef heifers.

    Science.gov (United States)

    Pina, D S; Valadares Filho, S C; Tedeschi, L O; Barbosa, A M; Valadares, R F D

    2009-03-01

    This experiment evaluated the effect of 2 levels of diet concentrate (20 and 40% of DM) and 2 levels of ruminally undegraded protein (RUP: 25 and 40% of CP) on nutrient intake, total and partial apparent nutrient digestibility, microbial protein synthesis, and ruminal and physiological variables. Eight Nellore heifers (233 +/- 14 kg of BW) fitted with ruminal, abomasal, and ileal cannulas were used. The animals were held in individual sheltered pens of approximately 15 m(2) and fed twice daily at 0800 and 1600 h for ad libitum intake. Heifers were allocated in two 4 x 4 Latin square designs, containing 8 heifers, 4 experimental periods, and 4 treatments in a 2 x 2 factorial arrangement. All statistical analyses were performed using PROC MIXED of SAS. Titanium dioxide (TiO(2)) and chromic oxide (Cr(2)O(3)) were used to estimate digesta fluxes and fecal excretion. Purine derivative (PD) excretion and abomasal purine bases were used to estimate the microbial N (MN) synthesis. No significant interaction (P > 0.10) between dietary levels of RUP and concentrate was observed. There was no effect of treatment (P = 0.24) on DMI. Both markers led to the same estimates of fecal, abomasal, and ileal DM fluxes, and digestibilities of DM and individual nutrients. Ruminal pH was affected by sampling time (P RUP, whereas a quadratic effect (P RUP. The higher level of dietary concentrate led to greater MN yield regardless of the level of RUP. The MN yield and the efficiency of microbial yield estimated from urinary PD excretion produced greater (P RUP and concentrate were observed for ruminal and digestive parameters. Neither RUP nor concentrate level affected DMI. Titanium dioxide showed to be similar to Cr(2)O(3) as an external marker to measure digestibility and nutrient fluxes in cattle.

  4. Effect of high energy intake on carcass composition and hypothalamic gene expression in Bos indicus heifers

    Directory of Open Access Journals (Sweden)

    Juliane Diniz-Magalhães

    Full Text Available ABSTRACT The objective of this study was to evaluate the effect of high or low energy intake on carcass composition and expression of hypothalamic genes related to the onset of puberty. Twenty-four prepubertal Nellore heifers, 18-20- months-old, with 275.3±18.0 kg body weight (BW, and 4.9±0.2 (1-9 scale body condition score (BCS were randomly assigned to two treatments: high-energy diet (HE and low-energy diet (LE. Heifers were housed in two collective pens and fed diets formulated to promote average daily gain of 0.4 (LE or 1.2 kg (HE BW/day. Eight heifers from each treatment were slaughtered after the first corpus luteum detection - considered as age of puberty. The 9-10-11th rib section was taken and prepared for carcass composition analyses. Samples from hypothalamus were collected, frozen in liquid nitrogen, and stored at −80 °C. Specific primers for targets (NPY, NPY1R, NPY4R, SOCS3, OXT, ARRB1, and IGFPB2 and control (RPL19 and RN18S1 genes were designed for real-time PCR and then the relative quantification of target gene expression was performed. High-energy diets increased body condition score, cold carcass weight, and Longissimus lumborum muscle area and decreased age at slaughter. High-energy diets decreased the expression of NPY1R and ARRB1 at 4.4-fold and 1.5-fold, respectively. In conclusion, the hastening of puberty with high energy intake is related with greater body fatness and lesser hypothalamic expression of NPY1 receptor and of β-arrestin1, suggesting a less sensitive hypothalamus to the negative effects of NPY signaling.

  5. Metagenomic analysis of rumen microbial population in dairy heifers fed a high grain diet supplemented with dicarboxylic acids or polyphenols.

    Science.gov (United States)

    De Nardi, Roberta; Marchesini, Giorgio; Li, Shucong; Khafipour, Ehsan; Plaizier, Kees J C; Gianesella, Matteo; Ricci, Rebecca; Andrighetto, Igino; Segato, Severino

    2016-02-19

    The aim of this study was to investigate the effects of two feed supplements on rumen bacterial communities of heifers fed a high grain diet. Six Holstein-Friesian heifers received one of the following dietary treatments according to a Latin square design: no supplement (control, C), 60 g/day of fumarate-malate (organic acid, O) and 100 g/day of polyphenol-essential oil (P). Rumen fluid was analyzed to assess the microbial population using Illumina sequencing and quantitative real time PCR. The P treatment had the highest number of observed species (P PCoA with unweighted Unifrac distance showed a separation among dietary treatments (P = 0.09), above all between the C and P (P = 0.05). The O and P treatments showed a significant increase of the family Christenenellaceae and a decline of Prevotella brevis compared to C. Additionally, the P treatment enhanced the abundance of many taxa belonging to Bacteroidetes, Firmicutes and Tenericutes phyla due to a potential antimicrobial activity of flavonoids that increased competition among bacteria. Organic acid and polyphenols significantly modified rumen bacterial populations during high-grain feeding in dairy heifers. In particular the polyphenol treatment increased the richness and diversity of rumen microbiota, which are usually high in conditions of physiological rumen pH and rumen function.

  6. Status of EC solid breeder blanket designs and R and D for demo fusion reactors

    International Nuclear Information System (INIS)

    Proust, E.; Anzidei, L.; Moons, F.

    1994-01-01

    Within the European Community Fusion Technology Program two solid breeder blankets for a DEMO reactor are being developed. The two blankets have various features in common: helium as coolant and as tritium purge gas, the martensitic steel MANET as structural material and beryllium as neutron multiplier. The configurations of the two blankets are however different: in the B.I.T. (Breeder Inside Tube) concept the breeder materials are LiAlO 2 or Li 2 ZrO 3 in the form of annular pellets contained in tubes surrounded by beryllium blocks, the coolant helium being outside the tubes, whereas in the B.O.T. (Breeder out of Tube) the breeder and multiplier material are Li 4 SiO 4 and beryllium pebbles forming a mixed bed placed outside the tubes containing the coolant helium. The main critical issues for both blankets are the behavior of the breeder ceramics and of beryllium under irradiation and the tritium control. Other issues are the low temperature irradiation induced embrittlement of MANET, the mechanical effects caused by major plasma disruptions, and safety and reliability. The R and D work concentrate on these issues. The development of martensitic steels including MANET is part of a separate program. Breeder ceramics and beryllium irradiations have been so far performed for conditions which do not cover the peak values injected in the DEMO blankets. Further irradiations in thermal reactors and in fast reactors, especially for beryllium, are required. An effective tritium control requires the development of permeation barriers and/or of methods of oxidation of the tritium in the main helium cooling systems. First promising results have been obtained also in field of mechanical effects from plasma disruptions and safety and reliability, however further work is required in the reliability field and to validate the codes for the calculations of the plasma disruption effects. (authors). 8 figs., 2 tabs., 53 refs

  7. Status of advanced tritium breeder development for DEMO in the broader approach activities in Japan

    International Nuclear Information System (INIS)

    Hoshino, Tsuyoshi; Oikawa, Fumiaki; Nishitani, Takeo

    2010-01-01

    DEMO reactors require ' 6 Li-enriched ceramic tritium breeders' which have high tritium breeding ratios (TBRs) in the blanket designs of both EU and JA. Both parties have been promoting the development of fabrication technologies of Li 2 TiO 3 pebbles and of Li 4 SiO 4 pebbles including the reprocessing. However, the fabrication techniques of tritium breeders pebbles have not been established for large quantities. Therefore, these parties launch a collaborative project on scaleable and reliable production routes of advanced tritium breeders. In addition, this project aims to develop fabrication techniques allowing effective reprocessing of 6 Li. The development of the production and 6 Li reprocessing techniques includes preliminary fabrication tests of breeder pebbles, reprocessing of lithium, and suitable out-of-pile characterizations. The R and D on the fabrication technologies of the advanced tritium breeders and the characterization of developed materials has been started between the EU and Japan in the DEMO R and D of the International Fusion Energy Research Centre (IFERC) project as a part of the Broader Approach activities from 2007 to 2016. The equipment for production of advanced breeder pebbles is planned will be installed in the DEMO R and D building at Rokkasho, Japan. The design work in this facility was carried out. The specifications of the pebble production apparatuses and related equipment in this facility were fixed, and the basic data of these apparatuses was obtained. In this design work, the preliminary investigations of the dissolution and purification process of tritium breeders were carried out. From the results of the preliminary investigations, lithium resources of 90% above were recovered by the aqueous dissolving methods using HNO 3 and H 2 O 2 . The removal efficiency of 60 Co by the addition in the dissolved solutions of lithium ceramics were 97-99.9% above using activated carbon impregnated with 8-hydroxyquinolinol. In this report

  8. Unidentified Factors in Jojoba Meal Prevent Oviduct Development in Broiler Breeder Females.

    Science.gov (United States)

    Vermaut; Onagbesan; Bruggeman; Verhoeven; Berghman; Flo; Cokelaere; Decuypere

    1998-01-19

    Supplementation of feed with jojoba meal, as a means for autonomous feed restriction, was successful in depressing feed intake and controlling body weight of broiler breeder pullets to the extent recommended by the breeder company. However, these broiler breeders never produced eggs. At the level of ovary, normal follicle development and maturation did occur. A considerable number of ovulations occurred which were not followed by oviposition. After ovulation, the ova could not be captured by the oviduct, because of the small size of the oviduct, resulting in "internal laying". The virtual absence of oviduct development cannot be explained presently but it must be due to some yet unidentified factor(s) in jojoba meal which prevent(s) the normal development of the oviduct. These factors may be acting by abnormally increasing plasma progesterone or triiodothyronin levels and/or directly by themselves interfering with oviduct development. The nature of these factors requires further investigations.

  9. Japanese contributions to ITER testing program of solid breeder blankets for DEMO

    International Nuclear Information System (INIS)

    Kuroda, Toshimasa; Yoshida, Hiroshi; Takatsu, Hideyuki; Maki, Koichi; Mori, Seiji; Kobayashi, Takeshi; Suzuki, Tatsushi; Hirata, Shingo; Miura, Hidenori.

    1991-04-01

    ITER Conceptual Design Activity (CDA), which has been conducted by four parties (Japan, EC, USA and USSR) since May 1988, has been finished on December 1990 with a great achievement of international design work of the integrated fusion experimental reactor. Numerous issues of physics and technology have been clarified for providing a framework of the next phase of ITER (Engineering Design Activity; EDA). Establishment of an ITER testing program, which includes technical test issues of neutronics, solid breeder blankets, liquid breeder blankets, plasma facing components, and materials, has been one of the goals of the CDA. This report describes Japanese proposal for the testing program of DEMO/power reactor blanket development. For two concepts of solid breeder blanket (helium-cooled and water-cooled), identification of technical issues, scheduling of test program, and conceptual design of test modules including required test facility such as cooling and tritium recovery systems have been carried out as the Japanese contribution to the CDA. (author)

  10. Past and present role of fast breeder reactors in Italy

    International Nuclear Information System (INIS)

    Castelli, G.; Cicognani, G.; Ghilardotti, G.; Musso, B.

    1978-01-01

    The paper describes the programme that is under development in Italy for fast breeder reactors. The Italian engagement in the construction of the Creys-Malville plant is discussed as well as the work at present under way in R and D activities and on the PEC reactor. The roles of the different organizations involved in the fast breeder reactor programme are also considered with particular attention to the activities carried out by AGIP NUCLEARE, CNEN, ENEL, NIRA and by the manufacturing companies. An overall picture of the different agreements between European countries is also given with reference to the construction of the Creys-Malville plant and to research and industrial development activities. (author)

  11. Selenium Status in Heifers, Late Pregnancy Cows and Their Calves in the Šumava Region, Czech Republic

    Directory of Open Access Journals (Sweden)

    P. Slavík

    2007-01-01

    Full Text Available The objective of this study was to ascertain selenium status in beef cattle in different stages of production in the Šumava region. In the region, blood collections and analyses for selected metabolic variables were performed in 54 animals in different production stages (18 heifers, 18 cows in late pregnancy and 18 calves aged 3 weeks on the average. Three herds were studied. The selenium status was determined both directly by measuring serum selenium (Se contents and indirectly by measuring glutathione peroxidase (GSH-Px activity in whole blood. The mean serum selenium concentration in all the animals under study (n = 54 was 30.6 μg/l +/- 2.91, and mean GSH-Px activity was 167.01 μkat/l +/- 92.39. In heifers, mean serum selenium concentration was 34.81 μg/l +/- 13.84; mean GSHPx activity was 186.96 μkat/l +/- 112.15. In late pregnancy cows, mean serum selenium concentration was 26.58 μg/l +/- 8.01, mean GSH-Px activity was 94.55 +/- 35.72 μkat/l. In calves, mean serum selenium concentration and GSH-Px activity were 30.41 μg/l +/- 12 and 219.54 μkat/l +/- 64.41, respectively. There was a statistically significant difference between the heifers and late pregnancy cows in both variables under study. However, between the late pregnancy cows and the calves, only the difference in GSH-Px activity was significant. The results indicate severe Se deficiency in the animals under study. It means apart from other things that mineral licks used did not provide enough minerals to meet the basic requirements of the animals.

  12. The fast breeder reactor Rapsodie (1962)

    International Nuclear Information System (INIS)

    Vautrey, L.; Zaleski, C.P.

    1962-01-01

    In this report, the authors describe the Rapsodie project, the French fast breeder reactor, as it stands at construction actual start-up. The paper provides informations about: the principal neutronic and thermal characteristics, the reactor and its cooling circuits, the main handling devices of radioactive or contaminated assemblies, the principles and means governing reactor operation, the purposes and locations of miscellaneous buildings. Rapsodie is expected to be critical by 1964. (authors) [fr

  13. The French liquid metal fast breeder reactor programme

    International Nuclear Information System (INIS)

    Rapin, M.

    1980-01-01

    The strong French LMFBR development and the corresponding success obtained up to now show that there is no technical insuperable barrier to fast breeder construction. This satisfactory evolution is in fact the conjunction of a strong incentive due to the lack of other resources, a firm and permanent stand of the government, and an obstinate effort of all the teams involved in the LMFBR field. The changeover to industrial level should be helped by the simplicity of the French organization for fast breeder. Finally, the development of LMFBR on a larger scale is helped by international agreements through which the present French know-how can be put at the disposal of other partners, and the general knowledge can be improved by setting common R and D programmes. A quite successful example of such agreements is given by the German-French agreement, and we hope that new partners will join us soon. (orig.) [de

  14. Design and development of ceramic breeder demo blanket

    International Nuclear Information System (INIS)

    Enoeda, M.; Sato, S.; Hatano, T.

    2001-01-01

    Ceramic breeder blanket development has been widely conducted in Japan from fundamental researches to project-oriented engineering scaled development. A long term R and D program has been launched in JAERI since 1996 as a course of DEMO blanket development. The objectives of this program are to provide engineering data base and fabrication technologies of the DEMO blanket, aiming at module testing in ITER currently scheduled to start from the beginning of the ITER operation as a near-term target. Two types of DEMO blanket systems, water cooled blanket and helium cooled blanket, have been designed to be consistent with the SSTR (Steady State Tokamak Reactor) which is the reference DEMO reactor design in JAERI. Both of them utilize packed small pebbles of breeder Li 2 O or Li 2 TiO 3 as a candidate) and neutron multiplier (Be) and rely on the development of advanced structural materials (a reduced activation ferritic steel F82H) compatible with high temperature operation. (author)

  15. Analysis of mechanical effects caused by plasma disruptions in the European breeder out of tube solid breeder blanket design with MANET as structural material

    International Nuclear Information System (INIS)

    Boccaccini, L.V.; Ruatto, P.

    1995-01-01

    In this paper we deal with some aspects related to the mechanical behaviour of the European breeder out of tube solid breeder blanket for the DEMO reactor during plasma disruptions. The first aspect regards the properties of the martensitic steel MANET which has been chosen as structural material. MANET is a magnetic material and its fracture toughness properties degrade considerably under irradiation. These two features have been taken into account in the calculation of magentic forces and in the assessment of conditions of unstable crack propagation respectively. As second aspect, a comparison between an electrically segmented and a continuous blanket design has been performed. The analysis reveals lower mechanical stresses for the second design during the DEMO reference disruption and in case of faster disruptions. (orig.)

  16. Breeder Spent Fuel Handling (BSFH) cask study for FY83. Final report

    International Nuclear Information System (INIS)

    Diggs, J.M.

    1985-01-01

    This report documents a study conducted to investigate the applicability of existing LWR casks to shipment of long-cooled LMFBR fuel from the Clinch River Breeder Reactor Plant (CRBRP) to the Breeder Reprocessing Engineering Test (BRET) Facility. This study considered a base case of physical constraints of plants and casks, handling capabilities of plants, through-put requirements, shielding requirements due to transportation regulation, and heat transfer capabilities of the cask designs. Each cask design was measured relative to the base case. 15 references, 4 figures, 6 tables

  17. Fission-suppressed hybrid reactor: the fusion breeder

    International Nuclear Information System (INIS)

    Moir, R.W.; Lee, J.D.; Coops, M.S.

    1982-12-01

    Results of a conceptual design study of a 233 U-producing fusion breeder are presented. The majority of the study was devoted to conceptual design and evaluation of a fission-suppressed blanket and to fuel cycle issues such as fuel reprocessing, fuel handling, and fuel management. Studies in the areas of fusion engineering, reactor safety, and economics were also performed

  18. Effect of dietary canthaxanthin and 25-hydroxycholecalciferol supplementation on the performance of duck breeders under two different vitamin regimens.

    Science.gov (United States)

    Ren, Zhouzheng; Jiang, Shizhen; Zeng, Qiufeng; Ding, Xuemei; Bai, Shiping; Wang, Jianping; Luo, Yuheng; Su, Zhuowei; Xuan, Yue; Yao, Bing; Cisneros, Fernando; Zhang, Keying

    2016-01-01

    Dietary canthaxanthin (CX), 25-hydroxycholecalciferol (25-OH-D 3 ) and vitamins have been widely reported to be involved in productive and reproductive performance of broiler breeders. However, limited information is available for duck breeders. In this study, a total of 1,560 Cherry Valley SM3 duck breeder females and 312 males were used to assess if the addition of CX and 25-OH-D3 could increase the performance of duck breeders under two different dietary vitamin regimens. Four diets were used under a 2 × 2 factorial arrangement with 2 kinds of vitamin premixes (REGULAR and HIGH; HIGH premix had higher levels of all vitamins except K3 than REGULAR premix), and with or without the supplementation of the mixture of CX (6 mg/kg) and 25-OH-D3 (0.069 mg/kg). The ducks were fed ad libitum with pelleted diets based on corn-soybean meal from 38 to 77 wk of age. HIGH vitamin premix decreased malondialdehyde (MDA) level (P vitamin premix together with the mixture of CX and 25-OH-D3 decreased cracked egg rate and increased shell thickness of duck breeders. Serum phosphorus was decreased in duck breeder females fed REGULAR vitamin premix without the addition of the CX and 25-OH-D3 mixture. Dietary HIGH vitamin premix increased antioxidant status of eggs and breeder males, and increased hatchability. The mixture of CX and 25-OH-D3 enhanced egg shell quality, and promoted pigmentation and antioxidant status of eggs and breeder males.

  19. Breeding nuclear fuels with accelerators: replacement for breeder reactors

    International Nuclear Information System (INIS)

    Grand, P.; Takahashi, H.

    1984-01-01

    One application of high energy particle accelerators has been, and still is, the production of nuclear fuel for the nuclear energy industry; tantalizing because it would create a whole new industry. This approach to producing fissile from fertile material was first considered in the early 1950's in the context of the nuclear weapons program. A considerable development effort was expended before discovery of uranium ore in New Mexico put an end to the project. Later, US commitment to the Liquid Metal Fast Breeder Reactors (LMFBR) killed any further interest in pursuing accelerator breeder technology. Interest in the application of accelerators to breed nuclear fuels, and possibly burn nuclear wastes, revived in the late 1970's, when the LMFBR came under attack during the Carter administration. This period gave the opportunity to revisit the concept in view of the present state of the technology. This evaluation and the extensive calculational modeling of target designs that have been carried out are promising. In fact, a nuclear fuel cycle of Light Water Reactors and Accelerator Breeders is competitive to that of the LMFBR. At this time, however, the relative abundance of uranium reserves vs electricity demand and projected growth rate render this study purely academic. It will be for the next generation of accelerator builders to demonstate the competitiveness of this technology versus that of other nuclear fuel cycles, such as LMFBR's or Fusion Hybrid systems. 22 references, 1 figure, 5 tables

  20. Plant dynamics and safety analysis of fast breeder reactors

    International Nuclear Information System (INIS)

    Ertel, V.

    1982-01-01

    Some general features of sodium cooled fast breeders which influence the thermohydraulics and differ from LWR'S are discussed. Using the SNR-300 as a reference, some thermohydraulic transients from normal operation and from design accidents are presented. (orig.)

  1. Conceptual design of solid breeder blanket system cooled by supercritical water

    International Nuclear Information System (INIS)

    Enoeda, Mikio; Akiba, Masato; Ohara, Yoshihiro

    2001-12-01

    This report is a summary of the design works, which was discussed in the design workshop held in 2000 for the demonstration (DEMO) blanket aimed to strengthen the commercial competitiveness and technical feasibility simultaneously. The discussion of the Fusion Council in 1999 updated the assessment of the mission of DEMO blanket. Updated mission of the DEMO blanket is to be the prototype of the commercially competitive power plant. The DEMO blanket must supply the feasibility and experience of the total design of the power plant and the materials. From such standing point, the conceptual design study was performed to determine the updated strategy and goal of the R and D of the DEMO blanket which applies the supercritical water cooling proposed in A-SSTR, taking into account the recent progress of the plasma research and reactor engineering technology. The DEMO blanket applies the solid breeder materials and supercritical water cooling. The product tritium is purged out by helium gas stream in the breeder region. In the breeder region, the pebble bed concept was applied to withstand instable cracking of the breeder and multiplier materials in high neutron irradiation and high temperature operation. Inlet temperature of the coolant is planned to be 280degC and final outlet temperature is 510degC to obtain high energy conversion efficiency up to 43%. Reduced activation ferritic steel, F82H and ODS ferritic steel were selected as the structural material. Lithium ceramics, Li 2 TiO 3 or Li 2 O were selected as the breeder materials. Beryllium or its inter-metallic compound Be12Ti was selected as the neutron multiplier materials. Basic module structure was selected as the box type structure which enables the remote handling replacement of the module from in-vessel access. Dimension of the box is limited to 2 m x 2 m, or smaller, due to the dimension of the replacement port. In the supercritical water cooling, the high coolant temperature is the merit for the energy

  2. Cellular proliferation rate and insulin-like growth factor binding protein (IGFBP)-2 and IGFBP-3 and estradiol receptor alpha expression in the mammary gland of dairy heifers naturally infected with gastrointestinal nematodes during development.

    Science.gov (United States)

    Perri, A F; Dallard, B E; Baravalle, C; Licoff, N; Formía, N; Ortega, H H; Becú-Villalobos, D; Mejia, M E; Lacau-Mengido, I M

    2014-01-01

    Mammary ductal morphogenesis during prepuberty occurs mainly in response to insulin-like growth factor-1 (IGF-1) and estradiol stimulation. Dairy heifers infected with gastrointestinal nematodes have reduced IGF-1 levels, accompanied by reduced growth rate, delayed puberty onset, and lower parenchyma-stroma relationship in their mammary glands. Immunohistochemical studies were undertaken to determine variations in cell division rate, IGF-1 system components, and estradiol receptors (ESR) during peripubertal development in the mammary glands of antiparasitic-treated and untreated Holstein heifers naturally infected with gastrointestinal nematodes. Mammary biopsies were taken at 20, 30, 40, and 70 wk of age. Proliferating cell nuclear antigen immunolabeling, evident in nuclei, tended to be higher in the parenchyma of the glands from treated heifers than in those from untreated. Insulin-like growth factor binding proteins (IGFBP) type 2 and type 3 immunolabeling was cytoplasmic and was evident in stroma and parenchyma. The IGFBP2-labeled area was lower in treated than in untreated heifers. In the treated group, a maximal expression of this protein was seen at 40 wk of age, whereas in the untreated group the labeling remained constant. No differences were observed for IGFBP3 between treatment groups or during development. Immunolabeling for α ESR (ESR1) was evident in parenchymal nuclei and was higher in treated than in untreated heifers. In the treated group, ESR1 peaked at 30 wk of age and then decreased. These results demonstrate that the parasite burden in young heifers negatively influence mammary gland development, affecting cell division rate and parameters related to estradiol and IGF-1 signaling in the gland. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  3. Experimental Breeder Reactor I Preservation Plan

    Energy Technology Data Exchange (ETDEWEB)

    Julie Braun

    2006-10-01

    Experimental Breeder Reactor I (EBR I) is a National Historic Landmark located at the Idaho National Laboratory, a Department of Energy laboratory in southeastern Idaho. The facility is significant for its association and contributions to the development of nuclear reactor testing and development. This Plan includes a structural assessment of the interior and exterior of the EBR I Reactor Building from a preservation, rather than an engineering stand point and recommendations for maintenance to ensure its continued protection.

  4. A model for an economically optimal replacement of a breeder flock.

    Science.gov (United States)

    Yassin, Hurria; Velthuis, Annet G J; Giesen, Gerard W J; Oude Lansink, Alfons G J M

    2012-12-01

    A deterministic model is developed to support the tactical and operational replacement decisions at broiler breeder farms. The marginal net revenue approach is applied to determine the optimal replacement age of a flock. The objective function of the model maximizes the annual gross margin over the flock's production cycle. To calculate the gross margin, future egg production, fertility, or hatchability of the eggs, revenues and variable costs of a flock were estimated. For tactical decisions, the optimal laying length is the age at which the average gross margin of an average flock is maximal. For operational decisions, a flock should be replaced when the marginal gross margin of a replaceable flock is less than the average gross margin of an average flock. To demonstrate the model, a broiler breeder flock from a Dutch breeder farm was used. A sensitivity analysis showed that the optimal replacement decision, for both tactical and operational management, is sensitive to the decrease in the weekly egg production after the peak and the prices of feed and hatching eggs. The effect of the decrease in weekly fertility after the peak on the replacement decision is related to the payment system for hatching eggs.

  5. Survey of creep data on structural materials of fast breeder reactor

    International Nuclear Information System (INIS)

    Yoshida, S.

    1977-11-01

    The reactor vessels and other components of fast breeder reactor is affected by high neutron irradiation at elevated temperatures. However, in this regard, related test data on creep property of component materials and welds at elevated temperatures are a few in Japan, and especially, there are no data available on the irradiation effect. It will take 3 to 7 years before the results of currently planned research and development on prototype fast breeder become available. On the other hand, establishment of design base for prototype fast breeder and other needs call for early solution to such problems. The Committee should, therefore, collect from documents the latest data on experiments on structural materials overseas and in our country, and survey and analyze the problems in order to proceed with the future research and development in the most effective way. It was for this purpose that the Fourth Subcommittee at Technical Research Association for Integrity of Structures at Elevated Service Temperatures was commissioned by Power Reactor and Nuclear Fuel Development Corporation to conduct the examination and study of related data by establishing Group 41G. This collection of data is the compilation of the above results. (author)

  6. Coincidence measurements of FFTF breeder fuel subassemblies

    International Nuclear Information System (INIS)

    Eccleston, G.W.; Foley, J.E.; Krick, M.; Menlove, H.O.; Goris, P.; Ramalho, A.

    1984-04-01

    A prototype coincidence counter developed to assay fast breeder reactor fuel was used to measure four fast-flux test facility subassemblies at the Hanford Engineering Development Laboratory in Richland, Washington. Plutonium contents in the four subassemblies ranged between 7.4 and 9.7 kg with corresponding 240 Pu-effective contents between 0.9 and 1.2 kg. Large count rates were observed from the measurements, and plots of the data showed significant multiplication in the fuel. The measured data were corrected for deadtime and multiplication effects using established formulas. These corrections require accurate knowledge of the plutonium isotopics and 241 Am content in the fuel. Multiplication-corrected coincidence count rates agreed with the expected count rates based on spontaneous fission-neutron emission rates. These measurements indicate that breeder fuel subassemblies with 240 Pu-effective contents up to 1.2 kg can be nondestructively assayed using the shift-register electronics with the prototype counters. Measurements using the standard Los Alamos National Laboratory shift-register coincidence electronics unit can produce an assay value accurate to +-1% in 1000 s. The uncertainty results from counting statistics and deadtime-correction errors. 3 references, 8 figures, 8 tables

  7. Grazing as an alternative for utilization of saline-sodic soils in the San Joaquin Valley: Selenium accretion and performance of beef heifers

    Energy Technology Data Exchange (ETDEWEB)

    Juchem, Sergio O., E-mail: sdjuchem@gmail.com [Department of Animal Science, University of California, Davis, CA 95616 (United States); Department of Plant Science, California State University, Fresno, CA 93740-8033 (United States); Benes, Sharon E. [Department of Plant Science, California State University, Fresno, CA 93740-8033 (United States); Robinson, P.H. [Department of Animal Science, University of California, Davis, CA 95616 (United States); Grattan, Stephen R. [Department of Land and Water Resources, University of California, Davis, CA 95616 (United States); Vasquez, Pablo [Department of Plant Science, California State University, Fresno, CA 93740-8033 (United States); Chilibroste, Pablo [Instituto Nacional de Investigacion Agropecuaria, Paysandu (Uruguay); Brito, Martin [Department of Plant Science, California State University, Fresno, CA 93740-8033 (United States)

    2012-03-01

    Two experiments were conducted to evaluate Se accumulation and health of non-pregnant, non-breeding beef cattle grazing on forages with a high Se content due to irrigation with saline drainage water. Heifers grazed experimental pastures of 'Jose' tall wheatgrass (TWG; Thinopyrum ponticum var. 'Jose') and creeping wildrye (CWR; Leymus triticoides var. 'Rio') for190 days in Experiment 1 (2007) and for 165 days in Experiment 2 (2008). In experiment 1, mean Se concentrations were similar in TWG and CWR herbage (4.0 versus 3.7 {+-} 0.26 mg/kg dry weight; p = 0.34) as was crude protein (113 versus 114 {+-} 7.9 g/kg dry weight; p = 0.94). Concentrations of Se in blood increased by 300% during the grazing period, and were similar for heifers grazing the TWG or CWR pastures (0.94 versus 0.87 {+-} 0.03 mg/kg; p = 0.89). Heifers grazing on TWG gained more body weight than did heifers grazing on CWR (0.59 versus 0.27 {+-} 0.07 kg/days; p < 0.01). In experiment 2, concentration of Se (4.0 versus 2.8 mg/kg {+-} 0.19 mg/kg dry weight; p < 0.01) and crude protein (79 versus 90 {+-} 5.6 g/kg dry weight; p < 0.01) differed, for TWG and CWR, respectively. Within 20 days, Se concentrations in blood had increased by 300% and by nearly 200% in heifers grazing on TWG or CWR. All data cited are least square means {+-} standard error of the mean. Data from our two grazing seasons are consistent in demonstrating the safety of grazing beef cattle for a period of up to 6 months on TWG and CWR forages having high levels of Se due to irrigation with saline drainage water. This suggests that forage production using saline drainage water is a viable alternative for saline soils with limited potential for producing high value, salt-sensitive, crops. - Highlights: Black-Right-Pointing-Pointer Forages irrigated with saline drainage water may contain high levels of selenium. Black-Right-Pointing-Pointer High concentration of selenium in forages can be toxic to grazing

  8. Grazing as an alternative for utilization of saline-sodic soils in the San Joaquin Valley: Selenium accretion and performance of beef heifers

    International Nuclear Information System (INIS)

    Juchem, Sérgio O.; Benes, Sharon E.; Robinson, P.H.; Grattan, Stephen R.; Vasquez, Pablo; Chilibroste, Pablo; Brito, Martin

    2012-01-01

    Two experiments were conducted to evaluate Se accumulation and health of non-pregnant, non-breeding beef cattle grazing on forages with a high Se content due to irrigation with saline drainage water. Heifers grazed experimental pastures of “Jose” tall wheatgrass (TWG; Thinopyrum ponticum var. “Jose”) and creeping wildrye (CWR; Leymus triticoides var. “Rio”) for190 days in Experiment 1 (2007) and for 165 days in Experiment 2 (2008). In experiment 1, mean Se concentrations were similar in TWG and CWR herbage (4.0 versus 3.7 ± 0.26 mg/kg dry weight; p = 0.34) as was crude protein (113 versus 114 ± 7.9 g/kg dry weight; p = 0.94). Concentrations of Se in blood increased by 300% during the grazing period, and were similar for heifers grazing the TWG or CWR pastures (0.94 versus 0.87 ± 0.03 mg/kg; p = 0.89). Heifers grazing on TWG gained more body weight than did heifers grazing on CWR (0.59 versus 0.27 ± 0.07 kg/days; p < 0.01). In experiment 2, concentration of Se (4.0 versus 2.8 mg/kg ± 0.19 mg/kg dry weight; p < 0.01) and crude protein (79 versus 90 ± 5.6 g/kg dry weight; p < 0.01) differed, for TWG and CWR, respectively. Within 20 days, Se concentrations in blood had increased by 300% and by nearly 200% in heifers grazing on TWG or CWR. All data cited are least square means ± standard error of the mean. Data from our two grazing seasons are consistent in demonstrating the safety of grazing beef cattle for a period of up to 6 months on TWG and CWR forages having high levels of Se due to irrigation with saline drainage water. This suggests that forage production using saline drainage water is a viable alternative for saline soils with limited potential for producing high value, salt-sensitive, crops. - Highlights: ► Forages irrigated with saline drainage water may contain high levels of selenium. ► High concentration of selenium in forages can be toxic to grazing cattle. ► Cattle accumulated high levels of selenium in blood, liver and muscle

  9. Project of a binary breeder reactor and its inherent safety

    International Nuclear Information System (INIS)

    Nascimento, J.A. do; Dias, A.F.; Ishiguro, Y.

    1983-01-01

    A core layout for the binary breeder reactor (BBR) is developed based on the results of preliminary burnup calculations. The apparent breeding ratio, in the U 233 /Th fueled inner core, is low due to the accumulation of Pa-233 in the first few months of operation. The loss of reactivity during this time is around 3%. The BBR requires more reactivity control than Pu/U-fueled LMFBRs and the core layout developed has 19 control rod assemblies in the inner core. Three aspects related to the inherent safety of the Binary Breeder Reactor have been studied: the radial distribution of the sodium-void reactivity zone-wise Doppler reactivity and the fractions of delayed neutrons. The results show excellent characteristics for the BRB safety. (Author) [pt

  10. Some safety considerations of liquid lithium as a fusion breeder material

    International Nuclear Information System (INIS)

    Jeppson, D.W.; Muhlestein, L.D.

    1986-01-01

    Test results and conclusions are presented for the reaction of steam with a high temperature lithium pool and for the reaction of high temperature lithium spray with a nitrogen atmosphere. The reactions are characterized and evaluated in regard to the potential for mobilization of radioactive species associated with the liquid breeder under postulated fusion reactor accident conditions. These evaluations include measured lithium temperature responses, atmosphere temperature and pressure responses, gas consumption and generation, aerosol quantities and particle size characterization, and potentially radioactive species releases. Conclusions are made as to the consequences of these safety considerations for the use of lithium as a fusion reactor breeder material

  11. Breeder nutrition and offspring performance

    Directory of Open Access Journals (Sweden)

    F Calini

    2007-06-01

    Full Text Available Vertical integration in poultry industry strongly emphasizes the importance of cost control at all levels. In the usual broiler production operations, the costs involved with the production of the hatching egg or the day old chick are negligible if seen in the perspective of the cost per kg of live bird. From a research point of view, anyway, the greatest attention is usually given to the performance of broiler breeders, and most of the research in the field is focused on the improvement of their relative performance, mainly in terms of saleable chicks produced per hen, while less attention has been given to the quality of the chick and to the improvement of its growth performances, even if these last parameters have an effective impact on the overall economics of the poultry growing business. Most of the data available is quite dated, as can be seen from some recent reviews, and in general little attention is given to the impact of parental nutrition on the subsequent broiler performance. It is in fact more usual to find data about dam nutrition influence on egg fertility and hatchability than on subsequent progeny performance. The objectives of this review were to assess, on the basis of published reports, the effects of selected nutrients and anti-nutrients normally prevailing in commercial broiler breeder feeds - vitamins, micro-minerals, mycotoxins, - trying to pinpoint which could be the positive and the negative effects of both on the subsequent broiler performance, with a particular attention to the impact on immune function and carcass yield.

  12. Activation analysis of tritium breeder lithium lead irradiated by fusion neutrons in FDS-II

    International Nuclear Information System (INIS)

    Mingliang Chen

    2006-01-01

    R-and-D of fusion materials, especially their activation characteristics, is one of the key issues for fusion research in the world. Research on activation characteristics for low activation materials, such as reduced activation ferritic/martensitic steels, vanadium alloys and SiCf/SiC composites, is being done throughout the world to ensure the attractiveness of fusion power regarding safety and environmental aspects. However, there is less research on the activation characteristics of the other important fusion materials, such as tritium breeder etc.. Lithium lead (Li 17 Pb 83 ) is presently considered as a primary candidate tritium breeder for fusion power reactors because of its attractive characteristics. It can serve as a tritium breeder, neutron multiplier and coolant in the blanket at the same time. The radioactivity of Li 17 Pb 83 by D-T fusion neutrons in FDS-II has been calculated and analyzed. FDS-II is a concept design of fusion power reactor, which consists of fusion core with advanced plasma parameters extrapolated from the ITER (International Thermonuclear Experimental Reactor) and two candidates of liquid lithium breeder blankets (named SLL and DLL blankets). The neutron transport and activation calculation are carried out based on the one-dimensional model for FDS-II with the home-developed multi-functional code system VisualBUS and the multi-group data library HENDL1.0/MG and European Activation File EAF-99. The effects of irradiation time on the activation characteristics of Li 17 Pb 83 were analyzed and it concludes that the irradiation time has an important effect on the activation level of Li 17 Pb 83 . Furthermore, the results were compared with the activation levels of other tritium breeders, such as Li 4 SiO 4 , Li 2 TiO 3 , Li 2 O and Li etc., under the same irradiation conditions. The dominant nuclides to dose rate and activity of Li 17 Pb 83 were analyzed as well. Tritium generated by Li has a great contribution to the afterheat and

  13. Operability design review of prototype large breeder reactor (PLBR) designs. Final report, September 1981

    International Nuclear Information System (INIS)

    Beakes, J.H.; Ehman, J.R.; Jones, H.M.; Kinne, B.V.T.; Price, C.M.; Shores, S.P.; Welch, J.K.

    1981-09-01

    Prototype Large Breeder Reactor (PLBR) designs were reviewed by personnel with extensive power plant operations experience. Fourteen normal and off-normal events, such as startup, shutdown, refueling, reactor scram and loss of feedwater, were evaluated using an operational evaluation methodology which is designed to facilitate talk-through sessions on operational events. Human factors engineers participated in the review and assisted in developing and refining the review methodologies. Operating experience at breeder reactor facilities such as Experimental Breeder Reactor-II (EBR-II), Enrico Fermi Atomic Power Plant - Unit 1, and the Fast Flux Test Facility (FFTF) was gathered, analyzed, and used to determine whether lessons learned from operational experience had been incorporated into the PLBR designs. This eighteen month effort resulted in approximately one hundred specific recommendations for improving the operability of PLBR designs

  14. Ultrasonographic reproductive tract measures and pelvis measures as predictors of pregnancy failure and anestrus in restricted bred beef heifers

    NARCIS (Netherlands)

    Holm, Dietmar E; Nielen, Mirjam; Jorritsma, Ruurd; Irons, Peter C; Thompson, Peter N

    Previous reports have shown that reproductive tract score (RTS) can predict reproduction outcomes in seasonally bred beef heifers, although the accuracy can vary. Some ultrasonographic measures of the female reproductive tract and pelvis area have also been associated with reproductive outcome in

  15. Do traditional sheep breeders perform conscious selection? An example from a participatory breeding program of Morada Nova sheep.

    Science.gov (United States)

    Arandas, Janaina Kelli Gomes; Alves, Ângelo Giuseppe Chaves; Facó, Olivardo; Belchior, Ernandes Barboza; Shiotsuki, Luciana; de Arruda Leite, Paulo Márcio Barbosa; Ribeiro, Maria Norma

    2017-10-01

    The implementation of sustainable breeding programs requires genetic breeding strategies that are appropriate for the reality production systems. It is also essential that the choice of animal selection criteria be based on breeders' knowledge and objectives. This work is an ethno-zootechnical study of the Morada Nova sheep breed and its crossbreeds. The goals of this study were to register and analyze indigenous breeders' knowledge and practices regarding animal selection criteria and to generate technical information to support a participatory breeding program of the breed. This study was conducted in the Morada Nova municipality in the state of Ceará, Brazil. Semi-structured interviews were evaluated using two groups of individuals, purebred Morada Nova sheep breeders (RMN, n = 13) and breeders of Morada Nova crossbreeds (MMN, n = 48). Interview questions were used to identify local selection criteria adopted by each group in the choice of animals for breeding. Data from the interviews were submitted to frequency distribution analysis and the Shapiro-Wilk test to verify their distribution. Later, the Kruskal-Wallis test was used to compare the two groups of farmers based on that information, in addition to multivariate statistical analysis and evaluation of Smith salience index. Breeders in the RMN group used selection criteria related to breed standards, such as pelage color. In contrast, breeders of the MMN group used criteria related to productivity, such as body conformation and milk production. Breeders should be engaged in the development of breeding programs, and it is important to consider their preferences and objectives when evaluating breeding animals.

  16. Prototype fast breeder reactor main options

    International Nuclear Information System (INIS)

    Bhoje, S.B.; Chellapandi, P.

    1996-01-01

    Fast reactor programme gets importance in the Indian energy market because of continuous growing demand of electricity and resources limited to only coal and FBR. India started its fast reactor programme with the construction of 40 MWt Fast Breeder Test Reactor (FBTR). The reactor attained its first criticality in October 1985. The reactor power will be raised to 40 MWt in near future. As a logical follow-up of FBTR, it was decided to build a prototype fast breeder reactor, PFBR. Considering significant effects of capital cost and construction period on economy, systematic efforts are made to reduce the same. The number of primary and secondary sodium loops and components have been reduced. Sodium coolant, pool type concept, oxide fuel, 20% CW D9, SS 316 LN and modified 9Cr-1Mo steel (T91) materials have been selected for PFBR. Based on the operating experience, the integrity of the high temperature components including fuel and cost optimization aspects, the plant temperatures are recommended. Steam temperature of 763 K at 16.6 MPa and a single TG of 500 MWe gross output have been decided. PFBR will be located at Kalpakkam site on the coast of Bay of Bengal. The plant life is designed for 30 y and 75% load factor. In this paper the justifications for the main options chosen are given in brief. (author). 2 figs, 2 tabs

  17. Effects of dietary sulfur concentration and forage-to-concentrate ratio on ruminal fermentation, sulfur metabolism, and short-chain fatty acid absorption in beef heifers.

    Science.gov (United States)

    Amat, S; McKinnon, J J; Penner, G B; Hendrick, S

    2014-02-01

    This study evaluated the effects of dietary S concentration and forage-to-concentrate ratio (F:C) on ruminal fermentation, S metabolism, and short-chain fatty acid (SCFA) absorption in beef heifers. Sixteen ruminally cannulated heifers (initial BW 628 ± 48 kg) were used in a randomized complete block design with a 2 × 2 factorial treatment arrangement. The main factors included F:C (4% forage vs. 51% forage, DM basis) and the S concentration, which was modified using differing sources of wheat dried distillers grains with solubles (DDGS) to achieve low- and high-S diets (LS = 0.30% vs. HS = 0.67% S on a DM basis). Elemental S was also added to increase the S content for the HS diets. Serum sulfate concentration from blood, sulfide (S(2-)), and SCFA concentrations from ruminal fluid, hydrogen sulfide (H2S) concentration from the ruminal gas cap, and urinary sulfate concentration were determined. Continuous rumen pH and SCFA (acetate, butyrate, and propionate) absorption were measured. There were no interactions between S concentration and F:C. The F:C did not affect DMI (P = 0.26) or ruminal S metabolite concentrations (P ≥ 0.19), but ruminal pH was lower (P ruminal pH (P ruminal H2S (P Ruminal H2S was positively correlated with serum sulfate (r = 0.89; P Ruminal acetate concentration was not affected (P = 0.26) by dietary S concentration. Heifers fed the HS diet had lower (P = 0.01) ruminal propionate concentration and tended to have lower (P = 0.06) butyrate concentration than heifers fed the LS diet. Ruminal acetate was greater (P = 0.01) and butyrate was less (P < 0.01) with the high F:C diet than the low F:C diet. Both HS (P = 0.06) and low F:C (P = 0.07) diets tended to reduce urine output. Feeding HS diets reduced SCFA absorption (P < 0.05). In summary, S metabolism in beef heifers was not influenced by the F:C, but HS reduced DMI, inhibited SCFA absorption, and increased urinary S excretion.

  18. Particle flow of ceramic breeder pebble beds in bi-axial compression experiments

    International Nuclear Information System (INIS)

    Hermsmeyer, S.; Reimann, J.

    2002-01-01

    Pebble beds of Tritium breeding ceramic material are investigated within the framework of developing solid breeder blankets for future nuclear fusion power plants. For the thermo-mechanical characterisation of such pebble beds, bed compression experiments are the standard tools. New bi-axial compression experiments on 20 and 30 mm high pebble beds show pebble flow effects much more pronounced than in previous 10 mm beds. Owing to the greater bed height, conditions are reached where the bed fails in cross direction and unhindered flow of the pebbles occurs. The paper presents measurements for the orthosilicate and metatitanate breeder materials that are envisaged to be used in a solid breeder blanket. The data are compared with calculations made with a Drucker-Prager soil model within the finite-element code ABAQUS, calibrated with data from other experiments. It is investigated empirically whether internal bed friction angles can be determined from pebble beds of the considered heights, which would simplify, and broaden the data base for, the calibration of the Drucker-Prager pebble bed models

  19. Effects of Physically Effective Neutral Detergent Fiber Content on Intake, Digestibility, and Chewing Activity in Fattening Heifer Fed Total Mixed Ration

    Directory of Open Access Journals (Sweden)

    Mi Rae Oh

    2016-12-01

    Full Text Available The objective of this study was to determine the effects of physically effective neutral detergent fiber (peNDF content in total mixed ration (TMR on dry matter intake, digestibility, and chewing activity in fattening Hanwoo (Bos taurus coreanae heifers. The experiment was designed as a replicated 3×3 Latin square using 12 heifers. Fattening heifers were offered one of three diets [high (T1, medium (T2, and low (T3 peNDF] obtained by different mixing times (3, 10, and 25 min for the same TMR feed. The peNDF content of TMR was determined by multiplying the proportion of dry matter retained by a 1.18 mm-screen in a Penn State Particle Separator by the dietary NDF content. The peNDF1.18 content was 30.36%, 29.20%, and 27.50% for the T1, T2, and T3 diets, respectively (p<0.05. Dry matter intake was not affected by peNDF content in TMR. Total weight gain in T1 group was significantly higher (p<0.05 than in T2 and T3 groups. However, weight gain did not differ between T2 and T3 groups. The feed conversion ratio decreased with an increase in the peNDF content (T1: 12.18, T2: 14.17, and T3: 14.01 g/g. An increase in the peNDF content of TMR was associated with a linear increase in the digestibility of dry matter, crude protein, crude fiber, neutral detergent fiber, and acid detergent fiber (p<0.05. Also, an increase in peNDF content of the TMR resulted in a linear increase in the number of chews in eating and ruminating (p<0.05, and consequently in the number of total chews (p<0.05. These results indicate that peNDF content affects digestibility and chewing activity. Consequently, the peNDF content of TMR should be considered for improving feed efficiency, digestibility, body weight gain, and performance in fattening heifers.

  20. Effect of increasing the level of alfalfa hay in finishing beef heifer diets on intake, sorting, and feeding behavior.

    Science.gov (United States)

    Madruga, A; González, L A; Mainau, E; Ruíz de la Torre, J L; Rodríguez-Prado, M; Manteca, X; Ferret, A

    2018-02-15

    Eight rumen cannulated Simmental heifers (BW = 281.4 ± 7.28 kg) were randomly assigned to one of four experimental treatments in a 4 × 4 replicated Latin square design to ascertain the effects of increasing levels of alfalfa hay on intake, sorting, and feeding behavior in comparison to barley straw as forage source. Treatments tested were four total mixed rations with: 1) 10% barley straw (10BS) with 7.0% NDF from forage, 2) 13% alfalfa hay (13AH) and less NDF from forage (5.7%) than 10BS, 3) 16% alfalfa hay (16AH) and the same NDF from forage (7.0%) as 10BS, and 4) 19% alfalfa hay (19AH) and more NDF from forage (8.3%) than 10BS. Each experimental period consisted of 3 wk for adaptation and 1 wk for sampling. Increasing the proportion of alfalfa hay in the diet linearly increased (P comparison to the 10BS diet. In the same way, intake of long, medium, and short particle size was greater in this diet. Moreover, heifers fed 19AH sorted for medium particle size and tended to sort for long and short particles size, and against fine particle size. Sorting behavior and meal length increased in the 19AH diet, which leads us to think that sorting feed ingredients requires time and therefore lengthens the meal. Time spent ruminating was greater in heifers fed 19AH, thus reducing the risk of ruminal acidosis when animals are fed high concentrate diets.

  1. Nycterohemeral eating and ruminating patterns in heifers fed grass or corn silage: analysis by finite Fourier transform.

    Science.gov (United States)

    Deswysen, A G; Dutilleul, P; Godfrin, J P; Ellis, W C

    1993-10-01

    Average daily and within-day nycterohemeral patterns of eating and ruminating behavior were determined in six Holstein-Friesian heifers (average BW = 427 kg) given ad libitum access to either corn or grass silage in a two-period crossover design. Rhythm components (number of cycles/24 h) were characterized by finite Fourier transform of the 24-h mastication activities as measured during 4 d by continuous jaw movement recordings. Average daily voluntary intake of corn silage was 8.2% greater (P = .05) than that for grass silage and was associated (P finite Fourier transform was reparameterized to express the amplitude (as periodograms) and phase of each rhythm component. Rhythm Components 1, 3, and 4 contributed primarily to explaining the total dispersion of the 24-h series of time spent eating and ruminating, for both silage types and individual heifers. Relative importance of Rhythm Component 1 of time spent eating, indicative of a main circadian pattern, was related positively to pedigree value for milk production (P = .01) and negatively to milk protein concentration (P = .09).(ABSTRACT TRUNCATED AT 250 WORDS)

  2. The tripartite fast breeder programme: a utility/industry view

    International Nuclear Information System (INIS)

    Brandstetter, A.; Eitz, A.W.

    1976-01-01

    The first phase of fast breeder development in Europe was conducted mainly on an independent basis but from the size of major national RandD programmes the desirability of broadening the basis of participation became evident. In 1968 inter-governmental agreements between Germany, Belgium and Holland led the research centres to enter into cooperation agreements, and utilities and industries to form organisation structures for building and operating breeder power stations with the SNR 300 as prototype. The SNR 300 is a turnkey contract incorporating many commercial features and requiring a firm basis of cooperation between the utility and the manufacturer. It is also subject to very strict licensing procedure. The unique contractual and licensing aspects, and the important consequences of both, are examined. Costs are discussed. The importance of increased collaborate efforts for demonstration plants is stressed and participation agreements relative to Superphenix and SNR-2 are illustrated. (U.K.)

  3. Real time simulation method for fast breeder reactors dynamics

    International Nuclear Information System (INIS)

    Miki, Tetsushi; Mineo, Yoshiyuki; Ogino, Takamichi; Kishida, Koji; Furuichi, Kenji.

    1985-01-01

    The development of multi-purpose real time simulator models with suitable plant dynamics was made; these models can be used not only in training operators but also in designing control systems, operation sequences and many other items which must be studied for the development of new type reactors. The prototype fast breeder reactor ''Monju'' is taken as an example. Analysis is made on various factors affecting the accuracy and computer load of its dynamic simulation. A method is presented which determines the optimum number of nodes in distributed systems and time steps. The oscillations due to the numerical instability are observed in the dynamic simulation of evaporators with a small number of nodes, and a method to cancel these oscillations is proposed. It has been verified through the development of plant dynamics simulation codes that these methods can provide efficient real time dynamics models of fast breeder reactors. (author)

  4. Role of the breeder in long-term energy economics

    International Nuclear Information System (INIS)

    Kosobud, R.F.; Daly, T.A.; Chang, Y.I.

    1982-01-01

    Private and public decisions affecting the use of nuclear and other energy technologies over a long-run time horizon were studied using the ETA-MACRO model which provides for economic- and energy-sector interactions. The impact on the use of competing energy technologies of a public decision to apply benefit-cost analysis to the production of carbon dioxide that enters the atmosphere is considered. Assuming the public choice is to impose an appropriate penalty tax on those technologies which generate CO 2 and to allow decentralized private decisions to choose the optimal mix of energy technologies that maximize a nonlinear objective function subject to constraints, the study showed that breeder technology provides a much-larger share of domestically consumed energy. Having the breeder technology available as a substitute permits control of CO 2 without significant reductions in consumption or gross national product growth paths

  5. Status of French breeder development and German-French cooperation

    International Nuclear Information System (INIS)

    Vendryes, G.

    1978-01-01

    The development of fast breeder reactors in France is at present characterized by the successful operation of the 250 MW reactor, Phenix, and the speedy progress made in construction of the 1200 MW Superphenix plant. The technical concept of Superphenix is a logical extension of the Phenix concept, i.e., the pool type sodium cooled breeder reactor. While the only change in the primary system has been an increase in capacity, the main modification over Phenix is the change from small modular steam generators to four large units. The development of the work to date does not cast any doubt upon the envisaged date of first criticality in the second half of 1982. The basis of German-French cooperation is a joint declaration by the then Ministers for Research of the two countries on February 13, 1976 in which the Ministers had expressed themselves in favor of close cooperation between both countries in the development of safe, reliable and economic fast breeder reactors. On this basis, the two governments, the research centers and the industrial partners in the two countries, including the previous partners in Belgium, the Netherlands and Italy, agreed on the general principles of this cooperation. Meanwhile, the cooperation formalized in 1977 has been activated. Both in research and development and among planning and building industries the exchange of know-how and cooperation is in full swing. The joint company, SERENA, is the pool for the know-how introduced by the partners and the sole representative of the partners in the scheme. (orig.) 891 UA [de

  6. Modeling of tritium behavior in ceramic breeder materials

    International Nuclear Information System (INIS)

    Kopasz, J.P.; Tam, S.W.; Johnson, C.E.

    1988-11-01

    Computer models are being developed to predict tritium release from candidate ceramic breeder materials for fusion reactors. Early models regarded the complex process of tritium release as being rate limited by a single slow step, usually taken to be tritium diffusion. These models were unable to explain much of the experimental data. We have developed a more comprehensive model which considers diffusion and desorption from the grain surface. In developing this model we found that it was necessary to include the details of the surface phenomena in order to explain the results from recent tritium release experiments. A diffusion-desorption model with a desorption activation energy which is dependent on the surface coverage was developed. This model provided excellent agreement with the results from the CRITIC tritium release experiment. Since evidence suggests that other ceramic breeder materials have desorption activation energies which are dependent on surface coverage, it is important that these variations in activation energy be included in a model for tritium release. 17 refs., 12 figs

  7. Instrumentation and control of the fast breeder reactors

    International Nuclear Information System (INIS)

    Juengst, U.

    1982-01-01

    Generally the Liquid Metal Fast Breeder Reactor (LMFBR) in comparison to the Leight Water Reactors hasn't exceptionally different requirements to the instrumentation and control systems. There fore the paper restricts itself to outline the peculiarities of LMFBR's exemplified at the design of the German Breeder SNR-300 beeing under construction. The special sodium instrumentation for temperature level, flow and pressure in the main systems is described. The automatic control system enabled the plant to follow the bad demand of the grid immidiately. The nuclear power production itself is stabilized by inherent coefficients of the core. An exceptional high reliability of the shut down systems is necessary; there fore all LMFBR's have two completely independant and diverse shut down systems. In the SNR-300 also the control of decay heat removal and the active safety systems for enclosure of radioactivity are distributed to two independent and diverse plant protection systems (PPS) so that the first system covered the accidents due to internal events and the second systems managed the external events such as earthquake and aircraft crash. (orig.)

  8. Mechanical design of a light water breeder reactor

    International Nuclear Information System (INIS)

    Fauth, W.L. Jr.; Jones, D.S.; Kolsun, G.J.; Erbes, J.G.; Brennan, J.J.; Weissburg, J.A.; Sharbaugh, J.E.

    1976-01-01

    In a light water reactor system using the thorium-232--uranium-233 fuel system in a seed-blanket modular core configuration having the modules arranged in a symmetrical array surrounded by a reflector blanket region, the seed regions are disposed for a longitudinal movement between the fixed or stationary blanket region which surrounds each seed region. Control of the reactor is obtained by moving the inner seed region thus changing the geometry of the reactor, and thereby changing the leakage of neutrons from the relatively small seed region into the blanket region. The mechanical design of the Light Water Breeder Reactor (LWBR) core includes means for axially positioning of movable fuel assemblies to achieve the neutron economy required of a breeder reactor, a structure necessary to adequately support the fuel modules without imposing penalties on the breeding capability, a structure necessary to support fuel rods in a closely packed array and a structure necessary to direct and control the flow of coolant to regions in the core in accordance with the heat transfer requirements. 4 claims, 24 drawing figures

  9. Programme and current status of fast breeder reactor development in Japan

    International Nuclear Information System (INIS)

    Suita, T.; Oyama, A.

    1977-01-01

    In 1967 the Japan Atomic Energy Commission revised her long term programme after a two year study for giving principles to her nuclear energy development programme, which indicated the dominant role of nuclear energy mid 1980's in the electric power generation and stressed the necessity of developing fast breeder reactors. It also recommended to organize a nucleus to undertake this nation-wide project, bringing together the total capability available throughout the country. Accordingly, the Power Reactor and Nuclear Fuel Development Corporation (PNC) was established in 1967 to develop two sodium-cooled fast reactors, an experimental fast reactor of about 100 MW thermal and a prototype fast breeder reactor of about 300 MW electrical, both using mixed oxide fuels. Construction of the experimental fast reactor started in 1970 and was essentially completed at the end of in 1974. The precommissioning test was followed in parallel with re-evaluating quality assurance of all systems. Physics test will be initiated around the end of 1976. The conceptual design of the prototype fast breeder reactor is now toward its final stage. Surveys on its proposed site have just started. Construction will start in 1978. Beside R and D works conducted by many organizations in Japan as well as under the international cooperation, several key test facilities were installed by PNC itself to conduct in-sodium test of full-size prototype components including 50 MW steam generators and post-irradiation-examination of fuels and materials. Recently an interim report was issued to an ad-hoc committee organized by JAEC to evaluate future prospect of the fuel cycle and power reactors. This recommended start of construction of the prototype reactor as scheduled and the large demonstration reactor to be followed to the prototype. Thus the fast breeder reactor is indicated as the most indispensable in 1990's

  10. Conceptual design of solid breeder blanket system cooled by supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Enoeda, Mikio; Akiba, Masato [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Ohara, Yoshihiro [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment] [and others

    2001-12-01

    This report is a summary of the design works, which was discussed in the design workshop held in 2000 for the demonstration (DEMO) blanket aimed to strengthen the commercial competitiveness and technical feasibility simultaneously. The discussion of the Fusion Council in 1999 updated the assessment of the mission of DEMO blanket. Updated mission of the DEMO blanket is to be the prototype of the commercially competitive power plant. The DEMO blanket must supply the feasibility and experience of the total design of the power plant and the materials. From such standing point, the conceptual design study was performed to determine the updated strategy and goal of the R and D of the DEMO blanket which applies the supercritical water cooling proposed in A-SSTR, taking into account the recent progress of the plasma research and reactor engineering technology. The DEMO blanket applies the solid breeder materials and supercritical water cooling. The product tritium is purged out by helium gas stream in the breeder region. In the breeder region, the pebble bed concept was applied to withstand instable cracking of the breeder and multiplier materials in high neutron irradiation and high temperature operation. Inlet temperature of the coolant is planned to be 280degC and final outlet temperature is 510degC to obtain high energy conversion efficiency up to 43%. Reduced activation ferritic steel, F82H and ODS ferritic steel were selected as the structural material. Lithium ceramics, Li{sub 2}TiO{sub 3} or Li{sub 2}O were selected as the breeder materials. Beryllium or its inter-metallic compound Be12Ti was selected as the neutron multiplier materials. Basic module structure was selected as the box type structure which enables the remote handling replacement of the module from in-vessel access. Dimension of the box is limited to 2 m x 2 m, or smaller, due to the dimension of the replacement port. In the supercritical water cooling, the high coolant temperature is the merit for

  11. Status of fast breeder reactor development in the United States of America

    International Nuclear Information System (INIS)

    Horton, K.E.

    1983-01-01

    The goal of the United States Liquid Metal Fast Breeder Reactor (LMFBR) program is to develop the technology to the point that the private sector can deploy a safe, economic breeder reactor. The LMFBR will provide virtually inexhaustible supplies of electrical energy for the long term and will provide additional confidence to LWR nuclear deployment in the near term. The LMFBR program consists of a streamlined research and development effort focussing on those actions needed to enable private sector financing of industrial deployment including plant demonstration and technology efforts in reactor fuels, components, materials, physics, and safety

  12. Comparison of lithium and the eutectic lead lithium alloy, two candidate liquid metal breeder materials for self-cooled blankets

    International Nuclear Information System (INIS)

    Malang, S.; Mattas, R.

    1994-06-01

    Liquid metals are attractive candidates for both near-term and long-term fusion applications. The subjects of this comparison are the differences between the two candidate liquid metal breeder materials Li and LiPb for use in breeding blankets in the areas of neutronics, magnetohydrodynamics, tritium control, compatibility with structural materials, heat extraction system, safety, and required R ampersand D program. Both candidates appear to be promising for use in self-cooled breeding blankets which have inherent simplicity with the liquid metal serving as both breeders and coolant. The remaining feasibility question for both breeder materials is the electrical insulation between liquid metal and duct walls. Different ceramic coatings are required for the two breeders, and their crucial issues, namely self-healing of insulator cracks and radiation induced electrical degradation are not yet demonstrated. Each liquid metal breeder has advantages and concerns associated with it, and further development is needed to resolve these concerns

  13. Numerical characterization of thermo-mechanical performance of breeder pebble beds

    International Nuclear Information System (INIS)

    An, Zhiyong; Ying, Alice; Abdou, Mohamed

    2007-01-01

    A numerical approach using the discrete element method (DEM) has been applied to study the thermo-mechanical properties of ceramic breeder pebble beds. This numerical scheme is able to predict the inelastic behavior observed in a loading and unloading operation. In addition, it demonstrates that the average value of contact force increases linearly with overall pressure, but at a much faster rate, about 3.4 times the overall pressure increase rate. In this paper, the thermal creep properties of two different ceramic breeder pebble materials, Li 4 SiO 4 and Li 2 O, are also examined by the current numerical code. The difference found in the properties of candidate materials is reflected numerically in the overall strain in the pebble bed when the stress magnitude becomes smaller

  14. Numerical characterization of thermo-mechanical performance of breeder pebble beds

    International Nuclear Information System (INIS)

    An, Zhiyong; Ying, Alice; Abdou, Mohamed

    2008-01-01

    A numerical approach using the discrete element method (DEM) has been applied to study the thermo-mechanical properties of ceramic breeder pebble beds. This numerical scheme is able to predict the inelastic behavior observed in a loading and unloading operation. In addition, it demonstrates that the average value of contact force increases linearly with overall pressure, but at a much faster rate, about 3.4 times the overall pressure increase rate. In this paper, the thermal creep properties of two different ceramic breeder pebble materials, Li 4 SiO 4 and Li 2 O, are also examined by the current numerical code. The difference found in the properties of candidate materials is reflected numerically in the overall strain in the pebble bed when the stress magnitude becomes smaller. (author)

  15. Effects of high fibre diets on gut fill, behaviour and productivity in broiler breeders

    DEFF Research Database (Denmark)

    Steenfeldt, Sanna; Nielsen, Birte Lindstrøm

    , and the higher water content of their litter may have affected their thermoregulation. In exp. II, four diets based on different fibre sources were given to broiler breeders from day 12 to 19 weeks of age to increase feed quantity. Diet A (commercial control diet: 10.7MJ/kg), B (42% dietary fibre (DF); 7.25MJ...... groups of 12 broiler breeder chickens (age: 2 to 15 weeks). Similar growth rates were obtained on different quantities of food (e.g. food allocation in week 14: approx. 80, 100, and 130 g/d for A, B, and C, respectively) with all birds reaching commercial target weight at 15 weeks of age. Birds fed A ate...... stereotypic behaviour, indicating an improvement in the well-being of the birds, who may experience less hunger than commercially fed broiler breeders....

  16. Overview of pool hydraulic design of Indian prototype fast breeder ...

    Indian Academy of Sciences (India)

    Flow sheet of prototype fast breeder reactor. ... over, the main vessel that houses radioactive primary sodium is free of any ..... with superficial velocity components in porous media. ..... The attenuation within thermal boundary layer was found.

  17. Increasing levels of crude protein in multiple supplements for grazing beef heifers in rainy season

    Directory of Open Access Journals (Sweden)

    Lívia Vieira de Barros

    2015-06-01

    Full Text Available The objective was to evaluate the effect of multiple supplements with differents levels of crude protein (CP or mineral supplements on the nutritional parameters and performance of beef heifers grazing Uruchloa decumbens in the rainy season. A complete random design was employed. The treatments were made up of increasing levels of CP in the multiple supplements and a control treatment (MM in which animals were offered only mineral mixture. Multiple supplements contained 17; 30; 43 and 56% of CP, for treatments CP17; CP30; CP43 and CP56, respectively. Average daily gain (ADG (g was 447.7; 554.6; 638.4; 587.9; 590.4, for treatments MM, CP17; CP30; CP43 and CP56, respectively. A quadratic effect of the levels of crude protein was found (p< 0.10 on ADG. A greater intake of dry matter (DM, organic matter (OM, CP, ether extract (EE, non-fibrous carbohydrates (NFC, total digestible nutrients (TDN, and digested dry matter (p< 0.10 was found in animals supplemented with multiple supplements. Multiple supplements increased the apparent digestibility coefficient of DM, CP, EE and NFC. Supply of multiple multiple supplements for heifers grazing in medium to high quality pastures in the rainy season improves the performance of the animals.

  18. OPINIONS EXPRESSED BY CATTLE BREEDERS ON HUMAN-ANIMAL RELATIONS AND THE CONDITIONS IN WHICH ANIMALS ARE KEPT

    Directory of Open Access Journals (Sweden)

    Beata SITKOWSKA

    2012-03-01

    Full Text Available The survey included 69 Polish farmers running private farms which focus on cattle breeding. Based on the survey results, and answers given by dairy and beef cattle breeders, it was found that the majority of respondents present the right attitude towards animals, and that they understand the influence of the person being in charge of a herd on the behaviour of animals and production results. The majority of the surveyed breeders continue to keep their cattle in stall barns, with more than 70% believing that this system provides good conditions for animals, and approximately 10% believe this is the best system possible. Approximately 80% of breeders is of the opinion that the animal housing system used has an effect on the condition of animals’ legs. The majority of breeders say that their animals are kept in either good or very good environmental conditions.

  19. Metabolic cues for puberty onset in free grazing Holstein heifers naturally infected with nematodes.

    Science.gov (United States)

    Díaz-Torga, G S; Mejia, M E; González-Iglesias, A; Formia, N; Becú-Villalobos, D; Lacau-Mengido, I M

    2001-07-01

    Leptin is a new plausible candidate for the molecular link between nutritional status and the reproductive axis. In previous studies we described that continuous natural nematode infections in heifers retarded growth and delayed the onset of puberty, and that the insulin-like growth factor I (IGF-I) was involved. In the present study we monitored the leptin levels during development in heifers naturally parasitized versus those chronically treated with ivermectin and we investigated whether growth hormone (GH) accounted for the differences in IGF-I previously noted. Insulin levels were also measured. Prolactin hormone was recorded as an indicator of immune system activation. We found a direct correlation between leptin and body weight during development and a prepubertal surge of the hormone 2 weeks before the first progesterone peak that indicates the onset of puberty. This suggests that leptin may act as a signal for this event. Insulin did not vary during growth and prepuberty. On the other hand, GH as not responsible for diminished IGF-I levels in parasitized animals as levels were similar in both groups. The GH levels were high at birth and then diminished rapidly and remained constant during development and puberty. The last hormone studied, prolactin, followed seasonal changes of sunlight duration and presented sporadic bursts in infected animals. These were related to high nematode infection and are probably involved in the immune response of the host.

  20. Automated manufacturing of breeder reactor fuels

    International Nuclear Information System (INIS)

    Nyman, D.H.; Benson, E.M.; Bennett, D.W.

    1983-09-01

    The Secure Automated Fabrication (SAF) line is an automated, remotely controlled breeder fuel pin fabrication process which is to be installed in the Fuels and Materials Examination Facility (FMEF). The FMEF is presently under construction at Hanford and is scheduled for completion in 1984. The SAF line is scheduled for startup in 1987 and will produce mixed uranium-plutonium oxide fuel pins for the Fast Flux Test Facility (FFTF). Radiological protection requirements, computer control equipment, use of robotics, and the fabrication process is described