Department of Animal Sciences, University of Florida, Gainesville, FL 32611, USA.
Vet J. 2012 Jul;193(1):140-5. doi: 10.1016/j.tvjl.2011.09.019. Epub 2011 Dec 16.
The objectives of this study were to determine the effects of feeding rumen-protected choline (RPC) to dairy cows on the incidence of disease in early lactation, and on their fertility as measured by return to ovarian cyclicity and pregnancies per insemination (P/AI). In the first experiment, 369 cows were fed 15 g/day of RPC between 25 days pre-calving and 80 days post calving. In the second experiment, 578 primigravid cows were fed 15 g/day of RPC for the last 21 days of gestation only. In both experiments, P/AI were evaluated for the first and second inseminations, and health disorders were monitored daily until 90 days after calving. Return to cyclicity was evaluated in experiment 1 only, on days 51 and 61 post calving. In the first experiment, feeding RPC reduced the incidence of clinical ketosis, mastitis, and morbidity, and the number of cases of mastitis per cow. Feeding RPC did not influence cyclicity and P/AI. In the second experiment, cows fed RPC tended to have greater morbidity than controls because of an increased incidence of metritis and fever, although the incidence of retained fetal membranes was lower. The P/AI for first and second inseminations were similar between treatments. Supplementing the diets of dairy cattle with RPC from before until after calving improved the health of early lactation cows. However, in primigravid cows feeding RPC before calving only had mixed effects on health. Feeding RPC had no beneficial effects on reproduction in either experiment.
本研究的目的是确定在奶牛泌乳早期给与反刍保护胆碱（RPC）对疾病发生率的影响，以及通过卵巢周期恢复和每配种受胎率（P/AI）来衡量的奶牛的繁殖力。在第一个实验中，369 头奶牛在产前 25 天至产后 80 天期间每天喂食 15 克 RPC。在第二个实验中，578 头初产奶牛仅在妊娠的最后 21 天喂食 15 克 RPC。在两个实验中，都评估了第一次和第二次授精的 P/AI，并在产后 90 天内每天监测健康障碍。仅在第一个实验中评估了产后第 51 天和第 61 天的周期恢复情况。在第一个实验中，给与 RPC 可降低临床酮病、乳腺炎和发病的发生率，以及每头奶牛乳腺炎的病例数。给与 RPC 不影响周期恢复和 P/AI。在第二个实验中，由于子宫内膜炎和发烧的发病率增加，给与 RPC 的奶牛比对照组的发病率更高，但胎衣不下的发病率较低。第一次和第二次授精的 P/AI 在处理之间相似。在奶牛产前和产后补充 RPC 可改善泌乳早期奶牛的健康状况。然而，在初产奶牛中，仅在产前给与 RPC 对健康有混合影响。在两个实验中，给与 RPC 对繁殖都没有有益影响。
