低聚木糖对草鱼非特异性免疫功能的影响

Effects of Xylo-oligosaccharides on Non-specific Immune Function of Grass Carp(Ctenopharyngodon idellus)

本试验旨在研究低聚木糖对草鱼非特异性免疫功能的影响。将525尾规格、体重基本一致的健康草鱼随机分为5组(每组设3个重复,每个重复35尾),分别饲喂在基础饲料中添加0(A0组)、1(A1组)、2(A2组)、4(A3组)和6 g/kg(A4组)低聚木糖的饲料。分别于试验第0天、第7天、第14天、第28天、第56天检测草鱼血液中白细胞吞噬活性,血清溶菌酶、超氧化物歧化酶活性和补体C3含量。在养殖试验(56 d)结束后连续攻毒14 d,计算各组试验鱼攻毒后死亡率。结果表明,与对照组相比,在整个试验期内,各试验组草鱼的各项免疫指标均有不同程度的提高。其中,A3组的白细胞吞噬活性,血清溶菌酶、超氧化物歧化酶活性和补体C3含量均显著高于A0组(P<0.05),并分别于第28天、第28天、第7天、第28天达到最大值,而且其攻毒后死亡率最低。结果提示,饲料中添加低聚木糖可提高草鱼非特异性免疫功能,其最佳添加量为4 g/kg。

This experiment was conducted to study the effects of xylo-oligosaccharides on non-specific immune function of grass carp（Ctenopharyngodon idellus）.Five hundred and twenty-five healthy grass carp with basically the same size and body weight were randomly assigned to 5 groups with 3 replicates in each group and 35 fish in each replicate.Grass carp in 5 groups were fed with the basal diets supplemented with 0（group A0）,1（group A1）,2（group A2）,4（group A3） and 6 g/kg（group A4） xylo-oligosaccharides,respectively.The activities of blood leukocyte phagocytic,serum lysozyme,and serum superoxide dismutase,and the content of serum complement C3 were determined on day 0,7,14,28 and 56,respectively.Calculating the mortality after 14 d of challenge test when the culture experiment（lasted for 56 d） was finished.The results showed that the immune indices of experimental groups were enhanced compared with the control group in the whole experiment.Among them,the leukocyte phagocytic activity,serum lysozyme activity,serum superoxide dismutase activity and serum complement C3 content in group A3 were significantly higher than those in the control group（P0.05）,which reached to the top level on day 28,28,7,28 of the experiment,respectively.The group A3 also had the lowest mortality rate among the 5 groups.These results indicate that xylo-oligosaccharides can enhance the non-specific immune function of grass carp,and the optimum addition level is 4 g/kg.