Peripartum responses of dairy cows fed energy-dense diets for 3 or 6 weeks prepartum.
Peripartum responses of dairy cows fed energy-dense diets for 3 or 6 weeks prepartum.
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DOI：
10.3168/jds.s0022-0302(01)74459-1
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发表时间：
2001
影响因子：
3.5
通讯作者：
D. G. Mashek;D. Beede
中科院分区：
文献类型：
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作者：
D. G. Mashek;D. Beede
两个商业奶牛场的189头怀孕奶牛被随机分配到预期产犊前3周或6周的高能量日粮中。饲喂日粮小于等于26日龄的奶牛为短饲喂组(S)，饲喂大于26日龄的为长饲喂(L)处理组。L的奶牛在产后2周内的能量状况趋于改善，表现为较高的胰岛素浓度和较低的非酯化脂肪酸浓度。治疗不影响血浆β-羟丁酸浓度。L奶牛在干旱期后期身体状况较好。从分娩到产后6wk的总身体状况损失在不同的治疗方法之间没有差异，但在这段时间内变化的速度不同。在产后3周内，S奶牛的产后体重损失比L奶牛多。仅在产后3~6周，L奶牛的产后3~6周的身体状况损失比S奶牛多，子宫炎的发病率更高，第一次服务的间隔时间更长。L奶牛60d产奶量高于S奶牛。此外，L奶牛产奶量比S奶牛少4.4 kg/d，乳脂含量和产奶量较低，体细胞数到150d体细胞数高于S奶牛。增加奶牛产前饲喂高能量饲料的时间在农场1引起了显著的变化，但在农场2效果不大。基于这些结果，L治疗可能会在产后立即改善奶牛的能量状况，但长期效果因农场而异，可能是由于其他未测量的管理差异。
Pregnant cows (n = 189) in two commercial dairy farms were assigned randomly to be fed energy-dense diets for either 3 or 6 wk before expected calving. Cows fed diets for less than or equal to 26 d were designated the short (S) treatment group, and those fed greater than 26 d were the long (L) treatment group. Cows in L tended to have improved energy status during the first 2 wk postpartum, as indicated by higher insulin concentrations and a tendency for lower nonesterified fatty acid concentrations. Treatment did not affect plasma beta-hydroxybutyrate concentrations. Cows in L tended to gain more body condition during the late dry period. Total body condition loss from parturition through 6 wk postpartum was not different between treatments, but the rate of change varied over this period. Cows in S lost more body condition during the first 3 wk postpartum than cows in L. In farm 1 only, cows in L lost more body condition from 3 to 6 wk postpartum and had a higher incidence of metritis and a longer interval to first service than cows in S. Cows in L had higher milk protein content through 60 d in milk compared with cows in S. Additionally, cows in L in farm 1 produced 4.4 kg/d less milk, tended to have lower milk fat content and yields, and higher somatic cell counts through 150 d in milk than cows in S. Overall, increasing the length of time cows were fed the energy-dense diet prepartum elicited significant changes in farm 1, but had little effect in farm 2. Based on these results, L treatment may improve energy status immediately postpartum, but long-term effects varied between farms, perhaps due to other unmeasured management differences.