日粮中添加不同水平的酵母硒对围产后期奶牛抗氧化能力和免疫机能的影响

Effects of dietary Se-Yeast supplementation at different levels on anti-oxidation performance and immune response in postpartum dairy cows

研究在日粮中添加不同水平的酵母硒对围产后期奶牛抗氧化性能和免疫机能的影响,选用20头体况和预产期相近的奶牛,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3.2、6.4和9.6 g/d的酵母硒。试验结果表明:添加酵母硒显著提高了全血硒和乳硒的含量(P<0.05),在产后第7和14天,随着酵母硒添加量的增加,谷胱甘肽过氧化物酶(GSH-px)活性表现分别由78.44和101.04 U/mL逐渐上升到149.69和152.90 U/mL,而在产后21 d,GSH-px活性表现为先升高后降低趋势,当添加6.4 g/d酵母硒时,其活性达到最高点(132.19 U/mL);血清总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)和外周血淋巴细胞刺激指数(SI)都有不同程度的提高(P<0.05),并随着添加水平的增加,有先升高后下降的趋势;而且酵母硒的添加显著影响了血清中的免疫球蛋白IgM、IgG和IgA的含量,当添加量为3.2 g/d时,产后7 d的血清IgM、IgG和IgA均处于最高水平(0.86、1.35和0.13 g/L;P<0.05),产后14 d的免疫球蛋白(IgM、IgG和IgA)含量并不受影响,而在产后21 d,9.6 g/d的酵母硒添加水平具有最高的血清IgM,IgG和IgA浓度(P<0.05),对照组和添加6.4 g/d组最低(P<0.05)。由此得出结论,日粮中添加酵母硒显著改善了围产后期奶牛抗氧化能力及免疫机能,综合考虑,在基础日粮中添加6.4 g/d的酵母硒效果较明显。

This trial was conducted to investigate the effects of dietary Se-Yeast supplementation at different levels on anti-oxidation performance and immune response in diary cows during postpartum period.A total of 20 Chinese Hosltein dairy cows with similar body condition and calving date were randomly assigned to four different treatments.The four treatments were：1） basal diet（the control,without any Se addition）;2） basal diet ＋3.2 g/d Se-Yeast;3） basal diet ＋6.4 g/d Se-Yeast;and 4） basal diet ＋9.6 g/d Se-Yeast.The results showed that compared with the control group,the supplement of Se-Yeast increased selenium concentration in both blood and milk significantly（P〈0.05）;Glutathione peroxidase capacity（GSH-px） was increased from 78.44 and 101.04 U/mL to 149.69 and 152.90 U/mL when the inclusion level of Se-Yeast increased to 9.6 g/d in 7 and 14 d after calving and was firstly enhanced and then declined in 21 d after calving（the capacity reached 132.19 U/mL when added 6.4 g/d Se-Yeast to the ration）;Serum total anti-oxidative capacity（T-AOC）,superoxide dismutase（SOD） and lymphoid transformation were in the similar tendency with GSH-px;IgM,IgG and IgA were altered by treatment significantly.Seven days after calving,cows fed basal diet with 3.2 g/d had the highest concentration of IgM,IgG and IgA（0.86,1.35 and 0.13 g/L;P〈0.05）.However,the content of IgM,IgG and IgA were respectively in the highest and lowest levels in 21d after calving as the supplementation level was 9.6 and 6.4 g/d（P〈0.05）.It was concluded that supplementation with Se-Yeast improved anti-oxidantion performance and immune response in postpartum diary cows,where the treatment with basal diet of 6.4 g/d Se-Yeast had the best performance.