酶解棉籽蛋白替代鱼粉及添加单宁酸对斑点叉尾鮰生长性能和肠道健康的影响

Effects of Fish Meal Replaced by Cottonseed Protein Hydrolysate and Dietary Supplementation of Tannic Acid on Growth Performance and Intestinal Health of Channel Catfish(Ictalurus punctatus)

试验研究了酶解棉籽蛋白替代鱼粉及添加单宁酸对斑点叉尾鮰(Ictalurus punctatus)生长性能和肠道健康的影响。设计鱼粉含量为10%的基础饲料,用酶解棉籽蛋白分别替代基础饲料中33.3%、66.6%和100%的鱼粉,并在100%替代组的基础上添加0.5 g/kg和1 g/kg的单宁酸,配制成6组等蛋白饲料(D1、D2、D3、D4、D5组和D6组),饲养初始平均体重为(172.6±1.6)g的斑点叉尾鮰67 d。结果表明:D4、D5和D6组的末体重和增重率较D1组显著下降(P<0.05),D4和D6组的饵料系数较D1组显著增加(P<0.05)。各组斑点叉尾鮰存活率、肥满度、肝体比、脏体比和肌肉常规成分组成均无显著差异(P>0.05)。斑点叉尾鮰后肠肠道微生物群落的优势菌群包括厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidota)、变形菌门(Proteobacteria)和梭杆菌门(Fusobacteria)。对比不同处理组发现,D4组的拟杆菌门相对丰度显著低于D5组(P<0.05),D4组的变形菌门相对丰度显著高于D1、D2和D5组(P<0.05)。各组斑点叉尾鮰肠道的组织结构和微生物多样性无显著差异(P>0.05)。综上所述,在鱼粉含量为10%的基础饲料中,酶解棉籽蛋白可以有效替代66.6%的鱼粉而不会对斑点叉尾鮰的生长性能和肠道健康产生负面影响,0.5 g/kg单宁酸能有效改善无鱼粉组斑点叉尾鮰的肠道微生物群落组成,但对生长性能没有提升效果。

This study was to evaluate the effects of fish meal replaced by cottonseed protein hydrolysate and dietary supplementation of tannic acid on growth performance and intestinal health of channel catfish(Ictalurus punctatus).A basal diet with 10%fish meal was designed,and then cottonseed protein hydrolysate was used to replace 33.3%,66.6%,and 100%of dietary fish meal,and 0.5 g/kg and 1 g/kg tannic acid were added to 100%replacement group to formulate six isonitrogenous diets(D1,D2,D3,D4,D5,D6).The six diets were fed to channel catfish with an average weight of(172.6±1.6)g for 67 days.The results showed that the final body weight and weight gain rate of D4,D5,and D6 groups were significantly lower than those of D1 group,while the feed coefficient of D4 and D6 groups was significantly higher than that of D1 group(P<0.05).There were no significantly differences in survival,condition factor,viscerosomatic index,hepatosomatic index and proximate composition of muscle among all groups(P>0.05).Firmicutes,Bacteroidota,Proteobacteria and Fusobacteria were the dominant microbiome of hind-gut of channel catfish at phylum level.The relative abundance of Bacteroides in D4 group was significantly lower than that in D5 group(P<0.05),while the relative abundance of Proteobacteria in D4 group was significantly higher than that in D1,D2,and D5 groups(P<0.05).There was no significant difference in the histological morphology and microbial diversity in all groups(P>0.05)In summary,in a basal diet containing 10%fish meal,cottonseed protein hydrolysate could replace 66.6%of fish meal without negatively affecting on growth performance and intestinal health of channel catfish,and 0.5 g/kg tannic acid supplementation in no fish meal diet could effectively improve the intestinal microbiota composition of channel catfish,but had no effect on growth performance.