酵母铬对围产后期奶牛免疫功能和泌乳性能的影响

Effects of Dietary Cr-Yeast Supplementation on Immune Function and Milk Performance in Postpartum Dairy Cows

本试验旨在研究日粮中添加不同水平的酵母铬对围产后期奶牛免疫功能和泌乳性能的影响,为奶牛业科学应用铬制剂提供参考。选用20头胎次和分娩期相近的中国荷斯坦奶牛,随机分为4组,对照组为基础日粮,3个处理组在基础日粮中分别添加3.0、6.0、9.0 g/d的酵母铬。试验期从分娩当天持续到产后14 d。结果表明:与对照组相比,添加酵母铬可以提高外周血淋巴细胞转化能力,提高了IgM、IgG和IgA的含量(P<0.01);添加酵母铬对乳脂率、乳蛋白率、乳糖率、尿素氮和干物质没有显著影响。本试验条件下,围产后期奶牛日粮添加酵母铬对奶牛的泌乳性能影响不大,但可以提高免疫功能,基础日粮添加9.0 g/d的酵母铬,使铬添加水平为0.8 mg Cr/kg DM时,效果较好并且是安全的。

This trial was conducted to investigate the effects of dietary Cr-Yeast supplementation at different levels on immune function and milk performance in diary cows during postpartum period, which would offer references to the application of chromiumin the milk cow industry. A total of 20 health Chinese Hosltein dairy cows with similar number of parturition and delivery date were randomly assigned to four different treatments. The four treatments were basal diet （the control, without any Cr addition）, basal diet ＋ 3.0 g/d Cr-Yeast, basal diet ＋ 6.0 g/d Cr-Yeast, and basal diet ＋ 9.0 g/d Cr-Yeast, respectively. The experimental period was 2 weeks, from the day of delivery to the 14th day after delivery. The results showed that compared with the control group, with the supplement of Cr-Yeast , peripheral blood lymphoid transformation, serum IgM, IgG and IgA concentration increased （P〈0.01）, the milk protein, lactose, milk urea nitrogen and total solids didn＇t change. Under the conditions of this experiment, we found that the basal diet with 0.8 mg Cr/kg DM which supplied in form of Cr-Yeast（9.0 g/d） had better improvement on immune function , the milk performance didn＇t change a lot and the dose was safe.