围产期饲喂过瘤胃胆碱对奶牛生产性能及血液生化指标的影响

本试验旨在研究围产期奶牛饲喂过瘤胃胆碱(RPC)对泌乳性能、血液生化指标及繁殖性能的影响。试验采用单因素试验设计,选用60头年龄、胎次、预产期、上一胎次产奶量相近的健康围产期奶牛,随机分为3组,每组20头。Ⅰ组饲喂基础日粮,Ⅱ组和Ⅲ组在基础日粮上分别添加25 g/d和50 g/d RPC,饲喂期从产前3周至产后3周,共42 d。结果表明:Ⅱ组产奶量在产后1~8周显著高于Ⅰ组和Ⅲ组(P0.05);在产后第2周,Ⅲ组的乳脂率、乳蛋白率显著高于Ⅰ组(P0.05);在整个试验期,Ⅱ组的谷丙转氨酶含量显著低于Ⅰ组(P0.05),Ⅲ组的天门冬氨酸转氨酶显著含量低于Ⅰ组(P0.05);产后第1周和第2周,Ⅱ组的β-羟丁酸、非酯化脂肪酸含量显著低于Ⅰ组(P0.05);Ⅱ组的甘油三酯含量显著高于Ⅰ组和Ⅲ组(P0.05),Ⅲ组的总胆固醇含量显著高于Ⅰ组(P0.05);日粮中添加RPC可以显著提高情期受胎率(P0.05),显著缩减奶牛空怀天数(P0.05),也对产后初次配种时间的缩短和配种次数的降低有影响。日粮中添加RPC可提高围产期奶牛生产性能,对血液生化指标和繁殖性能产生有利影响,本试验条件下RPC最佳添加剂量为每头牛25 g/d。

Dietary Supplement of Rumen-Protected Choline in Transition Cows: Effects on Performance and Plasma Parameters

The experiment was aimed to study the dietary supplemental effects of rumen-protected choline(RPC) on milk performance, blood biochemical parameters and reproductive performance in transition cows. Sixty healthy cows in transition period were selected. According to age, calving time, similar parity and last milk yield, the experimental animals were randomly divided into 3 groups: control group I, treatment group II, treatment group III, and each group included 20 cows. The cows in group I were fed with basal total mixed ration. The cows in group II and group III were fed with the basal ration added by 25 g/d and 50 g/d RPC, respectively. The experiment lasted for 42 days, which started from 21 days before parturition and ended 21 days after parturition. During the first eight weeks, milk yield of group II was greater than that of the group I and the group III(P<0.05); in the second week of postpartum, the milk fat percentage of the group III was greater than that of the group I and the group II(P<0.05); Throughout the trial period, plasma concentrations of aspartate aminotransferase in the group II were lower than thatn of group I(P<0.05); alanine aminotransferase of the group III was lower than thatn of the group I(P<0.05); In the first and second of week postpartum period, β-hydroxybutyric acid and non-esterified fatty acids of the group II were lower than that of the group I(P<0.05), triglycerides(TC) of the group II was significantly higher than group I and group III(P<0.05), total cholesterol of the group III was higher than that of group I(P<0.05); the addition of RPC in TMRs can improve the rate of oestrum fecundation(P<0.05), decrease empty pregnant period(P<0.05). It can reduce the first time of artificial insemination(AI) and AI times in the postpartum period. In conclusion, the addition of RPC in transition period can improve production performance of postpartum cows. Meanwhile, it had a favorable effect on blood biochemical parameters and reproductive performance. This experiment found the appropriate amount of rumen-protected choline was 25 g/d.