Effects of Replacement of Fish Meal with Fermented Fish Processing Wastes on Growth,Hepatic Antioxidant Ability and Intestinal Structure of Juvenile Largemouth Bass(Micropterus salmoides)
A 10-week feeding trial was conducted in indoor culture system to evaluate effects of replacement of fish meal with fermented fish processing wastes(FFPW)on growth,serum biochemical indices,hepatic an-tioxidant ability and intestinal structure of juvenile largemouth bass[initial body weight:(5.87±0.04)g].Four isonitrogenous diets were formulated to replace fish meal by FFPW at 0(FFPW0),10%(FFPW10),20%(FFPW20)and 40%(FFPW40),respectively.A total of 360 fish with similar size were randomly allot-ted to 4 groups,each group consisted of three replicates with 30 fish per replicate,and three tanks of fish were fed for each diet.These results showed that compared with FFPW0 group,replacing 10%to 40%of fish meal with FFPW had no significant effects on survival rate,final body weight,weight gain rate and specific growth rate(P>0.05),however,the final body weight,weight gain rate and specific growth rate in FFPW20 group were significantly higher than those in FFPW40 group(P<0.05),but no significant difference was observed between FFPW20 group and FFPW10 group(P>0.05).Replacing 10%to 40%of fish meal with FFPW had no significant effects on feeding intake,feed coefficient,protein efficiency ratio,condition factor and visceros-omatic index(P>0.05).Fish in FFPW20 group had significantly higher hepatosomatic index than those in FF-PW0 and FFPW40 groups(P<0.05).Fish in FFPW20 group had the lowest moisture and crude protein con-tents of whole body and the highest crude lipid content.The muscle crude lipid content was significantly lower in FFPW0 group than that in FFPW20 and FFPW40 groups(P<0.05).Muscle moisture content in FFPW0 group was significantly higher than that in FFPW replacement groups(P<0.05).With the increase of FFPW replacement level,serum total protein content was gradually increased,while serum glucose and triglyceride contents were gradually decreased,especially the FFPW40 group changed significantly(P<0.05).Replacing 10%to 40%of fish meal with FFPW had no significant effect on hepatic antioxidant enzyme and intestinal di-gestive enzyme activities(P>0.05).The villus length in FFPW0 group was significantly higher than that in FFPW replacement group(P<0.05),while the thickness of muscular layer was significantly lower than that in FFPW40 group(P<0.05).In conclusion,under the experimental conditions,40%of fish meal can be re-placed by FFPW for juvenile largemouth bass without having a negative effect on growth,feed utilization,an-tioxidant and immunity,and intestinal health.[Chinese Journal of Animal Nutrition,2024,36(3):1782-1794]
largemouth bassfish mealfermented fish processing wastesgrowthintestinal structure