酵母铬对围产后期奶牛抗氧化能力的影响

选用20头胎次相近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和9．0g／a的酵母铬。试验期为2周，从分娩当天持续到产后14d。结果表明，（1）与对照组相比，添加酵母铬可以提高血清中总抗氧化能力（T—AOC），超氧化物歧化酶（SOD）和谷胱苷肽过氧化物酶（GSHPx）的活力（P〈0．01），降低丙二醛的浓度；（2）酵母铬降低了皮质醇含量，提高了胰岛素活性。本试验条件下，发现基础日粮添加9．0g／d的酵母铬，使铬添加水平为0．8mgCr／kg时，效果较好。为研究在日粮中添加不同水平的酵母铬对围产后期奶牛抗氧化性能的影响提供依据。

Effects of dietary Cr-yeast supplementation on antioxidation function in postpar- tum dairy cows

This trial was conducted to investigate the effects of dietary Cr-yeast supplementation at different levels on antioxidation performance in diary cows during postpartum period. 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 including basal diet （the con- trol,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. The experimental period lasts for 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, the serum total antioxidative capacity （T-AOC）, superoxide dismutase （SOD） and glutathione peroxidase capacity （GSH-PX） increased （P〈0. 01） ,the concentration of maleic dialdehyde decreased. The serum glucocorticoid decreased and the serum insulin activity in creased. Under the conditions of this experiment,we found that the basal diet with 0.8 mg Cr/kg DM as Cr-yeast （9.0 g/d）had better improvement on antioxidation function of postpartun dairy COWS.