芽孢杆菌有氧发酵豆粕替代鱼粉对大口黑鲈幼鱼生长性能、血清生化指标及肠组织结构的影响

芽孢杆菌(Bacillus)有氧发酵豆粕的肽类和活菌等含量丰富,为研究其替代鱼粉对大口黑鲈(Micropterus salmoides)幼鱼的养殖效果,配制鱼粉含量为50％的大口黑鲈基础饲料,在基础饲料中用芽孢杆菌有氧发酵豆粕分别替代0、10％、20％、30％和40％的鱼粉,配制成5种等氮、等能实验饲料进饲养实验.实验...

Effects of replacing fish meal with Bacillus aerobically fermented soybean meal on the growth performance, serum biochemical indices and intestinal histology of largemouth bass (Micropterus salmoides)

This experiment was conducted to study the effects of Bacillus aerobically fermented soybean meal (FSBM) on the growth performance, serum biochemical indices, and intestinal structure of largemouth bass (Micropterus salmoides). Five isoproteic and isoenergetic diets were formulated. A high fish meal (FM) diet containing 50% white fish meal was used as a control diet (0); FSBM was used to replace 10%, 20%, 30%, and 40% of the FM in the control diet to obtain the other experimental four diets. Largemouth bass [with initial body weight of (19.83±0.33) g] were randomly divided into five groups and reared in an indoor cage system for 75 d. Each group had 3 replicates, and each replicate contained 30 fish. The results showed that the weight gain rates of the 20% and 30% trial groups were significantly higher than that of the control group (P<0.05), but there was no significant difference in feed efficiency and survival rate in all experimental groups (P>0.05). There were no significant differences in either condition factor or hepatosomatic index between all trial groups (P>0.05); but the viscerosomatic index was significantly lower than that of the control group (P<0.05). There was no significant difference in serum albumin in all trial groups (P>0.05); the total protein and globulin of experimental groups were significantly higher than those of the control group (P<0.05); the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities of the trial groups were significantly higher than those of the control group (P<0.05); In the 30% and 40% FSBM treatments, the intestinal muscular layer appeared thinner and villi integrity dropped. These results indicate that at least 20% of dietary FM protein in the diets of juvenile largemouth bass can be replaced by FSBM without having any adverse effect on growth performance, physical fitness, and intestinal health.