饲料中添加低聚木糖对凡纳滨对虾幼虾消化酶活力、肠道形态及细菌数量的影响

摘要

This experiment was conducted to investigate the effects of dietary xylo?oligosaccharides(XOS)on digestive enzyme activities, intestinal morphology and bacteria numbers of juvenile Litopenaeus vannamei. A total of 800 juvenile Litopenaeus vannamei with an average body weight of(0.67±0.02)g were randomly as?signed to 4 groups with 4 replicates per group and 50 shrimps per replicate. Shrimps in the control group were fed a basal diet, and others in the experimental groups were fed the basal diets supplemented with 200, 400, and 600 mg/kg XOS, respectively. The experiment lasted for 42 days. The results showed as follows: 1) compared with the control group,the intestinal amylase activity and hepatopancreas protease activity of shrimps in experimental groups were significantly increased(P<0.05),the intestinal and hepatopancreas protease activ?ity in 200 mg/kg group, the intestinal and hepatopancreas lipase activity in 400 mg/kg group, and stomach protease activity in 400 mg/kg group were significantly increased(P<0.05). 2)Compared with the control group, the hepatopancreas total protein content, intestinal wall thickness and intestinal villus height of shrimps in 400 mg/kg group were significantly increased(P<0.05). 3)Compared with the control group, the intesti?nal total bacteria and Bifidobacteria numbers of shrimps in experimental groups were significantly increased (P<0.05), while the intestinal vibrio number was significantly decreased(P<0.05). In conclusion, dietary XOS can improve digestive enzyme activities and intestinal morphology, increase intestinal total bacteria and Bifidobacteria numbers, decrease intestinal Vibria number of juvenile Litopenaeus vanname.%本试验旨在研究饲料中添加低聚木糖(XOS)对凡纳滨对虾(Litopenaeus vannamei)消化酶活力、肠道形态及细菌数量的影响.试验选用平均体重为(0.67 ± 0.02)g的凡纳滨对虾幼虾800尾,随机分成4组,每组4个重复,每个重复50尾虾.对照组投喂基础饲料,试验组分别投喂在基础饲料中添加200、400和600 mg/kg XOS的试验饲料.试验期为42 d.结果表明:1)与对照组相比,试验组对虾肠道淀粉酶活力和肝胰腺蛋白酶活力显著提高(P<0.05), 200 mg/kg组肠道和肝胰腺蛋白酶活力、400 mg/kg组肠道和肝胰腺脂肪酶活力、400 mg/kg组胃中蛋白酶活力显著升高(P<0.05).2)与对照组相比,400 mg/kg组对虾肝胰腺总蛋白含量、肠壁厚度和肠绒毛高度均显著升高(P<0.05).3)与对照组相比,试验组对虾肠道总菌和双歧杆菌(Bifidobacterium)数量显著升高(P<0.05),肠道弧菌(Vibrio)数量显著降低(P<0.05).由此可见,饲料中添加XOS能提高凡纳滨对虾幼虾消化酶活力,改善肠道形态,提高肠道总菌和双歧杆菌数量,降低弧菌数量.