添喂两种植物雌激素对奶牛乳成分、血液生化指标和抗氧化性能的影响

试验旨在研究日粮中添喂两种植物雌激素及其组合物对奶牛乳成分、血液生化指标和抗氧化性能的影响。选取健康、年龄及泌乳期相近的40头荷斯坦奶牛，随机分为4组：1个对照组、3个试验组，每组10头。对照组饲喂全混合日粮，试验组在饲喂全混合日粮的基础上添加2.5 g大豆黄酮（试验Ⅰ组）、35 g芒柄花素（试验Ⅱ组）、1.25 g大豆黄酮和17.5 g芒柄花素（试验Ⅲ组）。预试期7 d，正试期120 d。分别于试验的第0、30、60、90、120天采集乳样，测定乳成分；颈静脉采集血液样品，3 500 r/min离心15 min，分离血浆，－20 ℃保存备用。结果表明，与对照组相比，试验Ⅰ、Ⅲ组产奶量、乳蛋白产量均显著提高（P< 0.05）；试验Ⅰ、Ⅱ、Ⅲ组乳糖产量显著提高（P< 0.05）；试验Ⅲ组T-AOC显著提高（P< 0.05）；试验Ⅱ、Ⅲ组GSH-Px活性显著提高（P< 0.05）；试验Ⅰ、Ⅱ组MDA含量极显著降低（P< 0.05）；乳脂产量、乳糖率及TP、ALB、GLB含量均无显著差异（P> 0.05）；CAT、SOD活性均有一定程度的提高。由此可见，日粮中添喂两种植物雌激素及其组合物能够在一定程度上提高荷斯坦奶牛的产奶量、乳蛋白含量和乳糖含量，能够提高奶牛机体抗氧化能力，增强免疫功能。

Effect of Two Kinds of Phytoestrogens on Milk Composition,Blood Biochemical Index and Antioxidant Capacity of Dairy Cows

This experiment was conducted to investigate the effect of feeding phytoestrogens on milk composition, blood biochemical index and antioxidant capacity of dairy cows.A total of 40 Holstein cows were selected and randomly divided into 4 groups by health, age and lactation stage. The cows in control group was fed total mixed rations(TMR), and the other in 3 trial groups were fed TMR supplemented with 2.5 g dainzein(group Ⅰ), 35 g formononetin (group Ⅱ), 1.25 g dainzein and 17.5 g formononetin (group Ⅲ), respectively. The total duration of the trial was 127 d, the first 7 d of the trial was the preliminary period and the formal trial lasted for 120 d. The milk samples were collected in the trial of 0, 30, 60, 90, 120 d, respectively, and determination of milk composition. The blood samples were collected by jugular vein in the trial, and plasma was separated by 15 min, 3 500 r/min centrifugation, and saved at －20 ℃ for later use. The result showed as follows: Compared with the control group, the milk yield and milk protein yield in groups Ⅰ and Ⅲ were significantly increased (P< 0.05),the lactose yield in groups Ⅰ,Ⅱ and Ⅲ were significantly increased (P< 0.05), the T-AOC activity of blood in group Ⅲ was significantly increased (P< 0.05), the GSH-Px activity of blood in groups Ⅱ and Ⅲ were significantly increased (P< 0.05), the MDA activity of blood in groups Ⅰ and Ⅱ were significantly decreased (P< 0.05), the milk fat yield,lactose rate and TP, ALB, GLB of blood were not significantly increased (P> 0.05),the CAT, SOD activity of blood in trail groups had a upward trent. It was concluded that feeding phytoestrogens could enhance the milk yield, milk protein yield, lactose yield, the body's antioxidant capacity and immune function of Holstein cows.