甘露寡糖对欧洲鳗鲡(Anguilla anguilla)生长、消化酶活性及非特异性免疫的影响

Effect of mannan oligosaccharides on growth performance,activities of digestive enzymes and nonspecific immunity response in Anguilla anguilla

为探讨甘露寡糖（MOS）对欧洲鳗鲡生长、体组成、消化酶活性及非特异性免疫的影响，选取540尾初重为（5．82±0．02）g幼鳗，随机分为6组，每组3个重复，在基础饲料中分别添加不同含量的甘露寡糖（0、0．10％、0．20％、0．30％、0．40％、0．50％），连续投喂42d。实验结果表明，0．40％组和0．50％组鳗鲡增重率分别比对照组提高了28．01％、23．85％（P〈0．05），肝体指数和肥满度于各组间均无显著差异（P〉0．05）。相比对照组，MOS添加组鱼体水分含量显著降低，粗蛋白和粗灰分含量显著提高，但各组之间粗脂肪含量差异不显著（P〉0．05）。0．20％～0．50％的MOS能够提高鳗鲡肠道胰蛋白酶、淀粉酶和脂肪酶活性。随着MOS含量的增加，血清超氧化物歧化酶（SOD）、溶菌酶（LZM）、碱性磷酸酶（AKP）活性均呈先增后降趋势，0．30％～0．40％添加组欧鳗血清SOD活性显著高于对照组且达各组最高水平（P〈0．05），0．40％组LZM和AKP活性达各组最高水平，血清TP随MOS含量的增加不断升高，并于0．5％组达最大值。综上所述，饲料添加MOS有促进鳗鲡生长、增强肠道消化酶活性和提高鳗鲡非特异性免疫力的作用，本实验条件下MOS的适宜添加量为0．4％。研究结果为欧洲鳗鲡在养殖过程中甘露寡糖适宜添加量的确定提供理论参考。

The objective of this study was to determine the effects of mannan oligosaccharides （MOS） on growth per- formance, activities of digestive enzymes and immune response in Anguilla anguilla. Juveniles [ body weight （5.82 ± 0.02） g ] were randomly divided into 6 groups （with 3 replicates each）. Six experimental diets were administered （ adding 0%, 0.10%, 0.20%, 0.30%, 0.40%, 0.50% MOS）, respectively for 42 d. The results showed that the weight gain ratios for 0.40% and 0.50% groups were higher than those of the control group by 28.01% and 23.85 %. However, no significant difference was found among all hepatosomatic indexes or condition factors. Mannan oligosaccharides decreased the body moisture, while significantly increasing the crude protein and ash content. There was no significant difference among crude lipid contents compared with the control group. The feeds added with 0.20%, 0.3%, 0.4% ,0.50% mannan oligosaccharides significantly increased the activities of intestinal trypsin, amylase, lipase. The activities of serum superoxide dismutase, lysozyme and alkaline phosphatase increased and then decreased with increasing mannan oligosaccharides in diets. The activities of superoxide dismutase for additions of 0.30%, 0.40% mannan oligosaccharides were significantly higher than that for the control group ; activities of lyso- zyme and alkaline phosphatase of 0.40% group were higher than other treatments. With the increase of added mannan oligosaccharides, the concentration of serum total protein was raised, and the highest value was found in 0.40% 0.50% MOS given in discrete fashion, and cannot be in the form of a range. In conclusion, the feed added with 0.40% multi- enzyme can promote the growth performance, digestibility and nonspecific immunity response of An- guilla anguilla. The results provided a scientific reference for suitable addition amount of MOS in Anguilla anguilla.