Department of Dairy Science, University of Wisconsin, Madison 53706, USA.
J Anim Sci. 2010 Mar;88(3):1048-60. doi: 10.2527/jas.2009-2206. Epub 2009 Oct 23.
The present study evaluated the interaction of pregnancy type [PT; single (S) vs. twin (T)] and dry period feeding management [D; close-up (CU) diet (NE(l) = 1.54 Mcal/kg of DM)] throughout the entire dry period (8W) vs. far-off (FO) diet (NE(l) = 1.32 Mcal/kg of DM) from 60 to 21 d before expected calving date (ECD) followed by CU diet until calving (3W). Treatments were arranged in a 2 x 2 factorial with a randomized block design with primiparous (n = 8) and multiparous (n = 39) Holstein cows. We hypothesized that increasing the duration of feeding a CU diet would improve metabolic status and lactation performance for cows with T, but not for cows with S. All cows were fed similarly in late lactation (90 to 60 d before ECD; diet NE(l) = 1.58 Mcal/kg of DM) and in early lactation (calving to 105 DIM; diet NE(l) = 1.71 Mcal/kg of DM). Prepartum DMI as percentage of BW did not differ (P > 0.10) with D but tended to be greater (P = 0.10) for cows with S than with T. Cows with T tended to have greater (P = 0.08) BW than cows with S, but conceptus-free BW was less (P = 0.001) for cows with T than for cows with S. No differences (P > 0.10) were detected in prepartum BCS or BCS change with PT or D. Energy balance (EB) was greater for cows with S than with T (P < 0.001) and for cows fed 8W vs. 3W (P = 0.01). Cows with T had greater (P < 0.001) NEFA and a tendency for greater liver triglycerides (TG; P = 0.07) and plasma beta-hydroxybutyrate (BHBA; P = 0.06) than cows with S. Prepartum cows fed 3W had greater (P = 0.01) liver TG and greater (P = 0.02) plasma NEFA, but less (P = 0.02) plasma BHBA than cows fed 8W. Plasma glucose (P < 0.004) and liver glycogen (P = 0.02) were less for cows with T but were not affected (P > 0.10) by D. Postpartum, there was no effect (P > 0.1) of PT or D on mean DMI as percentage of BW, BW, and BCS, but there was an interaction (P = 0.02) of PT x D for mean BCS. Cows that calved T were in a more positive (P = 0.004) EB than cows that calved S. Milk production was 5.2 kg/d greater (P = 0.04) for cows fed 8W; however, they were in less (P = 0.01) EB than cows that received 3W. Postpartum cows that calved T had decreased concentrations of plasma NEFA (P = 0.02) and liver TG (P = 0.04) but greater concentrations of plasma glucose (P = 0.03) than cows that calved S. Plasma BHBA (P = 0.07) and NEFA tended (P = 0.06) to be greater for cows that received 8W than 3W. Neither PT nor D affected (P > 0.1) plasma glucose and liver glycogen. There was a tendency for an interaction of PT x D for plasma NEFA and liver TG. In contrast to our hypothesis, response to D was independent of PT. Based on milk production data from the present experiment, 8W is a more desirable feeding strategy than 3W.
本研究评估了妊娠类型[PT；单胎（S）与双胎（T）]和干奶期饲养管理[D；限饲（CU）日粮（NE(l) = 1.54 Mcal/kg DM）持续整个干奶期（8 周）与远饲（FO）日粮（NE(l) = 1.32 Mcal/kg DM）从预计分娩日期前 60 天至 21 天，然后饲喂 CU 日粮至分娩（3 周）]之间的相互作用。处理方案采用两因素完全随机区组设计，包括初产（n = 8）和经产（n = 39）荷斯坦奶牛。我们假设，增加饲喂 CU 日粮的时间将改善 T 型牛的代谢状况和泌乳性能，但对 S 型牛没有影响。所有奶牛在泌乳后期（从预计分娩日期前 90 天至 60 天；日粮 NE(l) = 1.58 Mcal/kg DM）和泌乳早期（分娩至 105 DIM；日粮 NE(l) = 1.71 Mcal/kg DM）的采食量相似。干奶前期 DMI 占体重的百分比不受 D 的影响（P > 0.10），但 S 型牛的 DMI 占体重的百分比高于 T 型牛（P = 0.10）。T 型牛的体重倾向于大于 S 型牛（P = 0.08），但 T 型牛的无胎衣体重低于 S 型牛（P = 0.001）。PT 或 D 对干奶前期体况评分（BCS）或 BCS 变化没有影响（P > 0.10）。S 型牛的能量平衡（EB）大于 T 型牛（P < 0.001）和 8 周与 3 周（P = 0.01）。T 型牛的 NEFA 和肝甘油三酯（TG）的趋势（P = 0.07）以及血浆 β-羟丁酸（BHBA；P = 0.06）高于 S 型牛。3 周干奶的奶牛的肝 TG 和血浆 NEFA 更高（P = 0.01），血浆 BHBA 更少（P = 0.02），而 8 周干奶的奶牛则相反。T 型牛的血浆葡萄糖（P < 0.004）和肝糖原（P = 0.02）低于 S 型牛，但不受 D 的影响（P > 0.10）。产后，PT 或 D 对平均 DMI 占体重的百分比、体重和 BCS 均无影响（P > 0.1），但对平均 BCS 有交互作用（P = 0.02）。T 型牛分娩的奶牛处于更有利的能量平衡（P = 0.004）中。与 S 型牛相比，8 周干奶的奶牛产奶量多 5.2 kg/d（P = 0.04），但 3 周干奶的奶牛能量平衡更好（P = 0.01）。产后 T 型牛分娩的奶牛的血浆 NEFA（P = 0.02）和肝 TG（P = 0.04）浓度降低，但血浆葡萄糖（P = 0.03）浓度升高。与 S 型牛相比，T 型牛分娩的奶牛的血浆 BHBA（P = 0.07）和 NEFA 有升高的趋势（P = 0.06）。8 周干奶的奶牛的血浆 NEFA 和肝 TG 有增加的趋势（P = 0.06）。PT 或 D 对血浆葡萄糖和肝糖原没有影响（P > 0.1）。PT x D 对血浆 NEFA 和肝 TG 有交互作用。与我们的假设相反，D 的反应与 PT 无关。根据本实验的产奶量数据，8 周干奶期的饲养策略优于 3 周。
