蛋氨酸锌对蛋鸡消化酶活性、蛋黄微量元素沉积、抗氧化及免疫指标的影响

Effects of Zinc-Methionine on Digestive Enzyme Activity, Yolk Trace Element Accumulation, Antioxidant Capacity and Serum Immune Indices of Laying Hens

本试验旨在研究饲粮中添加不同水平的蛋氨酸锌对蛋鸡消化酶活性、蛋黄微量元素沉积、抗氧化及免疫指标的影响。选取540只海兰白蛋鸡,随机分成6组,每组6个重复,每个重复15只鸡。Ⅰ组(对照组)饲喂基础饲粮,试验Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ组分别在基础饲粮中添加70、140、350、700、1 400 mg/kg蛋氨酸锌。试验期8周。结果表明:与对照组相比,Ⅱ、Ⅲ组十二指肠淀粉酶(AMY)、蛋白酶(PT)和回肠PT活性显著提高(P<0.05),血清和肝脏铜锌超氧化物歧化酶(CuZn-SOD)活性及总抗氧化能力(T-AOC)显著提高(P<0.05),丙二醛(MDA)含量显著降低(P<0.05),血清免疫球蛋白A(IgA)和免疫球蛋白G(IgG)含量显著升高(P<0.05),Ⅳ、Ⅴ组与对照组差异不显著(P>0.05),而Ⅳ组十二指肠淀粉酶、PT和回肠PT活性极显著降低(P<0.01),血清和肝脏MDA含量极显著升高(P<0.01),CuZn-SOD活性及T-AOC极显著降低(P<0.01),血清IgA和IgG含量极显著降低(P<0.01);与对照组相比,Ⅱ、Ⅲ、Ⅳ和Ⅴ组蛋黄锌含量显著升高(P<0.05),而Ⅵ组蛋黄锌含量极显著升高(P<0.01),蛋黄铜、铁含量极显著降低(P<0.01)。二次曲线拟合分析得出,蛋鸡获得较高的消化酶活性和较好的抗氧化、免疫性能时,蛋氨酸锌的适宜添加水平为60~100 mg/kg。

This experiment was conducted to investigate the effects of different dietary zinc-methionine supplemental levels on digestive activity,yolk trace element accumulation,antioxidant capacity and immune indices of laying hens.Five hundred and forty 20-week-old healthy Hyline White laying hens with similar body weight and laying rate were randomly allocated to 6 groups with 6 replicates per group and 15 birds per replicate.Hens in the control group was fed a basal diet,and hens in experimental groups received the basal diets supplemented with 70,350,700 and 1 400 mg/kg zinc-methionine,respectively.The trail lasted for eight weeks.The results showed as follows:compared with control group,activities of amylase and protease in duodenum and protease ileum were remarkably improved(P<0.05),CuZn-SOD activity and T-AOC were remarkably improved(P<0.05)but MDA content was notably decreased(P<0.05)in serum and liver,IgA and IgG in serum were notably increased(P<0.05)in hens from groupⅡandⅢ,no significant differences were observed among group I,ⅡorⅢ,however,activities of amylase and protease in duodenum and protease ileum were remarkably decreased(P<0.05),CuZn-SOD activity and T-AOC were remarkably reduced(P<0.05)but MDA content was notably increased(P<0.05)in serum and liver,IgA and IgG in serum were notably increased(P<0.05).Compared with control group,zinc content in egg yolk was significantly increased in hens from groupⅡ,Ⅲ,ⅣandⅤ(P<0.05),whereas zinc content was notably increased(P<0.01)and copper and iron contents in yolk were remarkably decreased in hens from groupⅥ(P<0.01).The optimal supplemental level was 60~100 mg/kg while hens acquire high activities of digestive enzymes as well as good antioxidant and immune properties based on quadratic curve fitting analysis.