半胱胺盐酸盐对泌乳奶牛血液抗氧化能力的影响

摘要

选择48头健康‘荷斯坦’奶牛,按照泌乳天数、胎次、泌乳量相同或相近的原则随机分成4组(CSH0、CSH3、CSH15、CSH30),每组12头,分别添加半胱胺盐酸盐0、3 g/kg、15 g/kg、30 g/kg(精料干物质基础),研究半胱胺酸盐对泌乳牛血液抗氧化能力的影响.结果表明：试验期第30天的 SOD 活性及整个试验期平均值随添加量的升高呈线性显著升高(P<0.05)；随饲喂时间的延长CSH3组 GSH-Px活性在4个组中提高幅度最大,但四组间差异不显著；试验期第30天,随添加剂量升高,MDA含量呈显著2次变化(P<0.05),随着饲喂时间延长,各组内MDA含量均比试验前降低,以CSH15组降低幅度最大；第30天、60天的 T-AOC 及2次平均值 CSH3组均显著高于CSH0组(P<0.05,P<0.01,P<0.01),而CSH15和 CSH30组T-AOC低于CSH0组,并在第60天达到显著水平(P<0.01),第60天,随添加剂量的提高T-AOC呈显著性二次变化(P<0.05),各组的 T-AOC随试验时间延长均比试验前提高,但CSH3组提高幅度最大；正式期第14、28、42、56天各组间 SCC没有显著差异,随试验时间延长各组内 SCC均比试验前提高,以CSH3组提高幅度最小.试验表明,半胱胺盐酸盐可有效提高泌乳奶牛抗氧化能力,缓解乳体细胞数的增加,但具有剂量依赖性,以3 g/kg精料的添加量效果最好.%This study was conducted to research the effects of cysteamine hydrochloride (CSH )on blood antioxidant ability of lactating dairy cow.Forty-eight healthy Holstein dairy cows were randomly di-vided into four groups (n=1 2/group)according to the principle of similar DIM,parity and milk yield.Cows in four groups were fed a basal diet respectively adding CSH at 0,3,15,30 g/kg.The results indicated that in the 30 th day of the experiment period,the activity of superoxide dismutase (SOD)increased linearly sig-nificant with increasing dietary CSH supplementation(P<0.05),the same as means of the entire experi-ment (P<0.05).The activity of glutathione peroxidase (GSH-Px)in group CSH3 increased higher than other groups with the experiment time extension.In the 30 th day,there was a significantly quadratic change of malonaldehyde (MDA)with increasing dietary CSH administration (P<0.05).The contents of MDA of the four groups were lower than before,and group CSH3 had the highest range.Total antioxidant capacity (T-AOC)of group CSH3 in the 30th day and 60 th day and the means of them were significantly higher than group CSH0 (P<0.05,P<0.01,P<0.01).While T-AOC of group CSH15 and CSH30 were lower than group CSH0,it reached significant level in the 60 th day (P<0.01).A significantly quadratic change of T-AOC with increasing dietary CSH adding appeared in the 60 th day (P<0.05).T-AOC of all groups increased with the experiment time extension,and group CSH3 was the optimum.The milk SCC lev-els of all groups had no significant differences in the 14 th,28 th,42 th and 56th day,but the increasing range of SCC in group CSH3 was the minimum.It is suggested that administration of CSH in diets of lacta-ting cow can efficaciously enhanced blood antioxidant ability and relieved the increasing of milk SCC with a dose dependent.The optimum dose was 3 g/kg.