The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Henri Seegers - One of the best experts on this subject based on the ideXlab platform.
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Influence of herd structure and type of virus introduction on the spread of bovine viral diarrhoea virus (BVDV) on the spread of bovine viral diarrhoea virus (BVDV) within a dairy herd
Veterinary Research, 2008Co-Authors: Pauline Ezanno, Christine Fourichon, Henri SeegersAbstract:A herd is a population structured into groups not all equally in contact, which may influence within-herd spread of pathogens. Herd structure varies among cattle herds. However, published models of the spread of bovine viral diarrhoea virus (BVDV) assume no herd structure or a unique structure chosen as a representative. Our objective was to identify - for different index cases introduced into an initially BVDV - free dairy herd - risky (favourable) herd structures, which increased (decreased) BVDV spread and persistence compared to a reference structure. Classically, dairy herds are divided into calves, young Heifers, bred Heifers, lactating cows and dry cows. In the reference scenario, groups are all equally in contact. We evaluated the effect of isolating or merging groups. Three index cases were tested: an open persistently-infected (PI) heifer, an open transiently-infected heifer, an immune heifer carrying a PI foetus. Merging all groups and merging calves and lactating cows were risky scenarios. Isolating each group, isolating lactating cows from other groups, and merging calves and young Heifers were favourable scenarios. In most structures, the most risky index cases were the following: first, the entry of a PI heifer; second, the birth of a PI calf; last, the entry of a transiently-infected heifer. Recommendations for dairy herds are to raise young animals together before breeding and to isolate lactating cows from others as much as possible. These recommendations will be less efficient if a PI adult enters into the herd.
A J Heinrichs - One of the best experts on this subject based on the ideXlab platform.
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symposium review strategies to improve the efficiency and profitability of heifer raising
Journal of Dairy Science, 2020Co-Authors: Peter S Erickson, J L Anderson, K F Kalscheur, G J Lascano, M S Akins, A J HeinrichsAbstract:ABSTRACT Regional Research Project NC-2042 has a main objective to study calf and heifer nutrition. Within this objective, feeding the postweaned heifer is considered a major priority to improve the profitability and sustainability of US dairy farms. Through optimizing nutrient utilization by precision feeding, using alternative feeds, high-fiber diets, and feed additives, this research group has worked to enhance dairy heifer nutrition. Research has focused on precision feeding Heifers and incorporating high- and low-fiber diets into this system of feeding. This is accomplished by meeting the nutrient needs of the heifer for a desired rate of growth while enhancing total-tract nutrient digestibility, reducing waste and improving profitability. High-fiber forages have been studied as a means of controlling ad libitum dry matter intakes and thus weight gain in Heifers. These results provide producers with a means of feeding Heifers while reducing costs. Similarly, utilizing alternative feedstuffs in heifer diets has also been a major research area for this group including comprehensive research on distillers co-products, and new protein sources such as camelina and carinata meals. Results indicated that these products can be satisfactorily incorporated into heifer diets. Studying feed additives has also been a function of the research group. Research with Ascophyllum nodosum and cinnamaldehyde indicated that calves find these additives unpalatable and that supplementing cinnamaldehyde to postweaned Heifers showed no benefit. However, sodium butyrate and yeast supplementation proved to be beneficial in the growth and feed efficiency of Heifers. Research from this group has an effect on heifer feeding, resulting in new information that can aid in the sustainability of dairy farms. This review will focus on the area of postweaned heifer nutrition.
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a 100 year review a century of dairy heifer research
Journal of Dairy Science, 2017Co-Authors: A J Heinrichs, G J Lascano, G I Zanton, C M JonesAbstract:The years 1917 to 2017 saw many advances in research related to the dairy heifer, and the Journal of Dairy Science currently publishes more than 20 articles per year focused on Heifers. In general, nutrition and management changes made in rearing the dairy heifer have been tremendous in the past century. The earliest literature on the growing heifer identified costs of feeding and implications of growth on future productivity as major concepts requiring further study to improve the overall sustainability of the dairy herd. Research into growth rates and standards for body size and stature have been instrumental in developing rearing programs that provide Heifers with adequate nutrients to support growth and improve milk production in first lactation. Nutrient requirements, most notably for protein but also for energy, minerals, and vitamins, have been researched extensively. Scientific evaluation of heifer programs also encouraged a dramatic shift toward a lower average age at first calving over the past 30 yr. Calving at 22 to 24 mo best balances the cost of growing Heifers with their production and lifetime income potential. Increasingly, farms have become more progressive in adopting management practices based on the physiology and nutrient needs of the heifer while refining key economic strategies to be successful. Research published in the Journal of Dairy Science has an integral role in the progress of dairy heifer programs around the world.
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identifying efficient dairy heifer producers using production costs and data envelopment analysis1
Journal of Dairy Science, 2013Co-Authors: A J Heinrichs, C M Jones, S M Gray, P A Heinrichs, S A Cornelisse, R C GoodlingAbstract:Abstract 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.
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Growth of Holstein Dairy Heifers in the United States
Journal of Animal Science, 1998Co-Authors: A J Heinrichs, Willard C LosingerAbstract:Data were collected on the heart girth (n = 8,565; a measure of body weight) and height at withers (n = 8,568) of Holstein dairy Heifers from 659 dairy farms as part of the National Dairy Heifer Evaluation Project during 1991 and 1992. Means and standard deviations for weight and height were determined for ages .5 to 23.5 mo. Third-order polynomial regression equations were derived to study the relationship of weight and height to age. Stepwise mixed-model regression, using REML estimation, was used to identify factors associated with Holstein heifer growth and to build a multivariate model describing Holstein heifer growth across the United States. Holstein Heifers on the sample of dairy farms in this study were heavier and taller at the withers than standards published 30 to 50 yr ago. Increased rolling herd average milk production was associated with a greater rate of growth in Holstein Heifers. Holstein Heifers in the West and Midwest were larger at a given age than those in the Northeast and Southeast.
Pauline Ezanno - One of the best experts on this subject based on the ideXlab platform.
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Influence of herd structure and type of virus introduction on the spread of bovine viral diarrhoea virus (BVDV) on the spread of bovine viral diarrhoea virus (BVDV) within a dairy herd
Veterinary Research, 2008Co-Authors: Pauline Ezanno, Christine Fourichon, Henri SeegersAbstract:A herd is a population structured into groups not all equally in contact, which may influence within-herd spread of pathogens. Herd structure varies among cattle herds. However, published models of the spread of bovine viral diarrhoea virus (BVDV) assume no herd structure or a unique structure chosen as a representative. Our objective was to identify - for different index cases introduced into an initially BVDV - free dairy herd - risky (favourable) herd structures, which increased (decreased) BVDV spread and persistence compared to a reference structure. Classically, dairy herds are divided into calves, young Heifers, bred Heifers, lactating cows and dry cows. In the reference scenario, groups are all equally in contact. We evaluated the effect of isolating or merging groups. Three index cases were tested: an open persistently-infected (PI) heifer, an open transiently-infected heifer, an immune heifer carrying a PI foetus. Merging all groups and merging calves and lactating cows were risky scenarios. Isolating each group, isolating lactating cows from other groups, and merging calves and young Heifers were favourable scenarios. In most structures, the most risky index cases were the following: first, the entry of a PI heifer; second, the birth of a PI calf; last, the entry of a transiently-infected heifer. Recommendations for dairy herds are to raise young animals together before breeding and to isolate lactating cows from others as much as possible. These recommendations will be less efficient if a PI adult enters into the herd.
Richard N Funston - One of the best experts on this subject based on the ideXlab platform.
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heifer calving date positively influences calf weaning weights through six parturitions
Journal of Animal Science, 2013Co-Authors: R A Cushman, Richard N Funston, L K Kill, Eric M Mousel, G. A. PerryAbstract:Longevity and lifetime productivity are important factors influencing profitability for the cow- calf producer. Heifers that conceive earlier in the breeding season will calve earlier in the calving season and have a longer interval to rebreeding. Calves born earlier in the calving season will also be older and heavier at weaning. Longevity data were collected on 2,195 Heifers from pro- ducers in South Dakota Integrated Resource Management groups. Longevity and weaning weight data were col- lected on 16,549 individual Heifers at the U.S. Meat Animal Research Center (USMARC). Data were lim- ited to Heifers that conceived during their first breeding season. Heifers were grouped into 21-d calving periods. Heifers were determined to have left the herd when they were diagnosed not pregnant at the end of the breeding season. Heifers that left the herd for reasons other than reproductive failure were censored from the data. Heifers that calved with their first calf during the first 21-d period of the calving season had increased (P < 0.01) longev- ity compared with Heifers that calved in the second 21-d period, or later. Average longevity for South Dakota Heifers that calved in the first or later period was 5.1 ± 0.1 and 3.9 ± 0.1 yr, respectively. Average longevity for USMARC Heifers that calved in the first, second, or third period was 8.2 ± 0.3, 7.6 ± 0.5, and 7.2 ± 0.1 yr, respec- tively. Calving period as a heifer influenced (P < 0.01) unadjusted weaning BW of the first 6 calves. Estimated postpartum interval to conception as a 2-yr-old cow was greater for females that calved in the first period as heif- ers but did not differ between heifer calving periods in subsequent calving seasons. In summary, Heifers that calved early in the calving season with their first calf had increased longevity and kilograms weaned, compared with Heifers that calved later in the calving season.
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Effect of Development System on Heifer Performance and Primiparous Heifer Grazing Behavior
2013Co-Authors: Adam F. Summers, T. L. Meyer, Jacqueline Musgrave Musgrave, Stetson P. Weber, Richard N FunstonAbstract:The effect of heifer development system on primiparous heifer performance grazing corn residue during late gestation was investigated. Weaned Heifers grazing corn residue tended to have reduced final BW after corn residue grazing compared to Heifers grazing winter range. However reproductive performance for the two treatments was similar. When grazing corn residue as pregnant Heifers during late gestation, Heifers developed on corn residue had improved ADG compared to drylotdeveloped Heifers and tended to have increased ADG compared to winter range-developed Heifers. Adaptation to corn residue grazing as a developing heifer improves primiparous heifer performance grazing corn residue during late gestation.
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joint alpharma beef species symposium implications of beef heifer development systems and lifetime productivity
Journal of Animal Science, 2013Co-Authors: R L Endecott, Richard N Funston, J T Mulliniks, A J RobertsAbstract:Research emphasis has been placed on heifer development strategies in recent years, comparing traditional, more intensive systems to more extensive systems using less feed and relying on compensatory gain to reach a target BW. Recent research has indicated that developing Heifers to a lighter target BW at breeding (i.e., 50 to 57% of mature BW compared with 60 to 65% BW) reduced development costs and did not impair reproductive performance. Research published through the late 1980s demonstrated greater negative effects of limited postweaning growth on age at puberty and pregnancy rates whereas more recent studies demonstrate less of a negative impact of delayed puberty on pregnancy rate. A limitation of most research concerning influences of nutrition on heifer development and cow reproductive performance is little or limited consideration of long-term implications. Longevity has relatively low heritability; therefore, heifer development and other management strategies have a greater potential to impact cow retention. Establishing the impact of heifer development protocols on longevity is complex, requiring consideration of nutritional factors after the start of breeding and through subsequent calvings. Lower-input heifer development, where all Heifers are managed together after the postweaning period, did not impair rebreeding, but continued subsequent restriction in the form of marginal winter supplementation resulted in decreased retention in the breeding herd. Therefore, the compensatory BW gain period for restricted-growth Heifers may be important to longevity and lifetime productivity. Adequate growth and development to ensure minimal calving difficulty can be of critical importance for longevity; however, providing additional supplemental feed during postweaning development to accomplish this may be less efficient than later in development. Restricting gain during postweaning development by limiting DMI or developing Heifers on dormant winter forage resulted in increased economic advantages compared with developing Heifers at greater rates of ADG to achieve a greater target BW. Implications of heifer development system on cow longevity must be considered when evaluating economics of a heifer enterprise; however, studies evaluating the effects of heifer development systems on cow longevity are extremely limited.
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Effect of Calving Period on Heifer Progeny
2012Co-Authors: Richard N Funston, T. L. Meyer, Jacqueline A. Musgrave, Dan M. LarsonAbstract:Records from 1997 through 2009 were used to determine the effect of calving date on ADG, reproduction, and first-calf characteristics in spring born heifer calves at University of Nebraska– Lincoln Gudmundsen Sandhills Laboratory. Heifers were classified as born in the first, second, or third 21day period of the calving season. Heifer calves born during the first 21 days had greater weaning, pre-breeding, and pre-calving BW; greater percent cycling before breeding, and pregnancy rates compared to Heifers born in the third period. First-calf progeny had earlier birth date and greater weaning BW. Calving period of heifer progeny impacts development and first-calf characteristics.
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heifer development systems a comparison of grazing winter range or corn residue
Journal of Animal Science, 2011Co-Authors: D M Larson, Andrea S Cupp, Richard N FunstonAbstract:Two experiments at 2 Nebraska loca- tions evaluated effects of heifer development system on growth and pregnancy rate. In Exp. 1, Heifers (n = 270, BW = 225 ± 2 kg) grazed winter Sandhills range (WR) or west central Nebraska corn residue (CR) with a sup- plement (0.45 kg/animal; 31% CP; 80 mg·animal −1 ·d −1 of monensin). In Exp. 2, Heifers (n = 180, BW = 262 ± 3 kg) grazed eastern Nebraska WR or CR with a supplement (0.45 to 0.90 kg/d; 31% CP; 80 to 160 mg·animal −1 ·d −1 of monensin). The CR Heifers tended to have less (P = 0.10) ADG compared with WR Heifers before breeding in Exp. 1; however, prebreeding ADG was similar (P = 0.77) in Exp. 2. Prebreeding BW, percentage of mature BW at breeding, and pregnancy determination BW were similar (P ≥ 0.14) for CR and WR in both experiments. Percentage of Heifers puber- tal at breeding, AI conception, and AI pregnancy rate (Exp. 2) and final pregnancy rate in both experiments were also similar (P ≥ 0.27) for CR and WR Heifers. Precalving BW, percentage of calves born in the first 21 d, calf birth date, calf birth BW, and dystocia score were all similar (P ≥ 0.21) for CR and WR Heifers in both experiments. Cow BW at weaning, calf weaning BW, adjusted 205-d calf BW, and second season preg- nancy rates were not affected (P ≥ 0.16) by treatment. Heifer development system did not affect (P ≥ 0.56) the cost of producing 1 pregnant heifer in Exp. 1 or 2. Development on CR may reduce ADG before breeding, but did not affect pregnancy rate. Heifer development using CR or WR postweaning resulted in similar repro- ductive performance and development cost.
Christine Fourichon - One of the best experts on this subject based on the ideXlab platform.
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Influence of herd structure and type of virus introduction on the spread of bovine viral diarrhoea virus (BVDV) on the spread of bovine viral diarrhoea virus (BVDV) within a dairy herd
Veterinary Research, 2008Co-Authors: Pauline Ezanno, Christine Fourichon, Henri SeegersAbstract:A herd is a population structured into groups not all equally in contact, which may influence within-herd spread of pathogens. Herd structure varies among cattle herds. However, published models of the spread of bovine viral diarrhoea virus (BVDV) assume no herd structure or a unique structure chosen as a representative. Our objective was to identify - for different index cases introduced into an initially BVDV - free dairy herd - risky (favourable) herd structures, which increased (decreased) BVDV spread and persistence compared to a reference structure. Classically, dairy herds are divided into calves, young Heifers, bred Heifers, lactating cows and dry cows. In the reference scenario, groups are all equally in contact. We evaluated the effect of isolating or merging groups. Three index cases were tested: an open persistently-infected (PI) heifer, an open transiently-infected heifer, an immune heifer carrying a PI foetus. Merging all groups and merging calves and lactating cows were risky scenarios. Isolating each group, isolating lactating cows from other groups, and merging calves and young Heifers were favourable scenarios. In most structures, the most risky index cases were the following: first, the entry of a PI heifer; second, the birth of a PI calf; last, the entry of a transiently-infected heifer. Recommendations for dairy herds are to raise young animals together before breeding and to isolate lactating cows from others as much as possible. These recommendations will be less efficient if a PI adult enters into the herd.
