Atkinson D J, von Keyserlingk M A G, Weary D M
Animal Welfare Program, Faculty of Land and Food Systems, University of British Columbia, 2357 Main Mall, Vancouver, BC, V6T 1Z4 Canada.
Animal Welfare Program, Faculty of Land and Food Systems, University of British Columbia, 2357 Main Mall, Vancouver, BC, V6T 1Z4 Canada.
J Dairy Sci. 2017 May;100(5):3773-3782. doi: 10.3168/jds.2016-11800. Epub 2017 Feb 23.
Poor health and growth in young dairy calves can have lasting effects on their development and future production. This study benchmarked calf-rearing outcomes in a cohort of Canadian dairy farms, reported these findings back to producers and their veterinarians, and documented the results. A total of 18 Holstein dairy farms were recruited, all in British Columbia. Blood samples were collected from calves aged 1 to 7 d. We estimated serum total protein levels using digital refractometry, and failure of passive transfer (FPT) was defined as values below 5.2 g/dL. We estimated average daily gain (ADG) for preweaned heifers (1 to 70 d old) using heart-girth tape measurements, and analyzed early (≤35 d) and late (>35 d) growth separately. At first assessment, the average farm FPT rate was 16%. Overall, ADG was 0.68 kg/d, with early and late growth rates of 0.51 and 0.90 kg/d, respectively. Following delivery of the benchmark reports, all participants volunteered to undergo a second assessment. The majority (83%) made at least 1 change in their colostrum-management or milk-feeding practices, including increased colostrum at first feeding, reduced time to first colostrum, and increased initial and maximum daily milk allowances. The farms that made these changes experienced improved outcomes. On the 11 farms that made changes to improve colostrum feeding, the rate of FPT declined from 21 ± 10% before benchmarking to 11 ± 10% after making the changes. On the 10 farms that made changes to improve calf growth, ADG improved from 0.66 ± 0.09 kg/d before benchmarking to 0.72 ± 0.08 kg/d after making the management changes. Increases in ADG were greatest in the early milk-feeding period, averaging 0.13 kg/d higher than pre-benchmarking values for calves ≤35 d of age. Benchmarking specific outcomes associated with calf rearing can motivate producer engagement in calf care, leading to improved outcomes for calves on farms that apply relevant management changes.
犊牛健康状况不佳和生长发育不良会对其发育及未来生产产生持久影响。本研究对一组加拿大奶牛场的犊牛饲养结果进行了基准评估，将这些结果反馈给养殖户及其兽医，并记录了相关结果。总共招募了18个荷斯坦奶牛场，均位于不列颠哥伦比亚省。采集了1至7日龄犊牛的血样。我们使用数字折射仪估算血清总蛋白水平，被动转运失败（FPT）定义为低于5.2 g/dL的值。我们使用胸围测量带估算断奶前小母牛（1至70日龄）的平均日增重（ADG），并分别分析早期（≤35日龄）和晚期（>35日龄）的生长情况。在首次评估时，农场的平均FPT率为16%。总体而言，ADG为0.68 kg/d，早期和晚期生长率分别为0.51和0.90 kg/d。在提供基准报告后，所有参与者自愿接受第二次评估。大多数（83%）养殖户至少对初乳管理或喂奶方式做出了1项改变，包括首次喂奶时增加初乳量、缩短首次喂初乳的时间，以及增加初始和最大每日喂奶量。做出这些改变的农场取得了更好的结果。在11个为改善初乳喂养而做出改变的农场中，FPT率从基准评估前的21±10%降至做出改变后的11±10%。在10个为改善犊牛生长而做出改变的农场中，ADG从基准评估前的0.66±0.09 kg/d提高到做出管理改变后的0.72±0.08 kg/d。ADG的增加在早期喂奶期最为显著，对于≤35日龄的犊牛，平均比基准评估前的值高出0.13 kg/d。对与犊牛饲养相关的特定结果进行基准评估，可以促使养殖户关注犊牛护理，从而使实施相关管理改变的农场的犊牛取得更好的结果。
