Effects of High Sugar Diet and Condensed Tannin Supplementation on Growth Performance,Body Composition,Serum Metabolites,Intestinal Short-Chain Fatty Acid Contents and Hormone Gene Expression of Sea Bass(Lateolabrax maculatus)

high sugar diet%condensed tannin%growth performance%glucose metabolism%Lateolabrax macu-latus

This study was conducted to investigate the effects of high sugar diet and condensed tannin(CT)supplementation on growth performance,body composition,serum metabolites,intestinal short-chain fatty acid contents and hormone gene expression of sea bass(Lateolabrax maculatus).A total of 480 healthy sea bass with an initial body weight of(10.85±0.02)g were randomly divided into 3 groups with 4 replicates per group and 40 fish per replicate.Sea bass in the three groups were fed conventional diet(containing 20.0%flour,G1 group),high sugar diet(containing 45.8%flour,G2 group)and high sugar diet supplemented with CT(con-taining 45.8%flour and 0.1%CT,G3 group),respectively.The experiment lasted for 56 days.The results showed as follows:1)compared with G1 group,the final body weight,weight gain rate and specific growth rate of sea bass in G2 group were significantly decreased(P<0.05),and the feed coefficient,condition fac-tor,hepatosomatic index and viscerosomatic index were significantly increased(P<0.05).Compared with G2 group,the final body weight,weight gain rate and specific growth rate in G3 group were significantly in-creased(P<0.05),and the feed coefficient was significantly decreased(P<0.05).2)Compared with Gl group,the contents of moisture,crude protein and crude ash in the whole body of sea bass in G2 and G3 groups were significantly decreased(P<0.05).3)At 1 h after feeding,the serum glucose content of sea bass in G2 group was significantly higher than that in G1 and G3 groups(P<0.05);at 3 and 6 h after feeding,there was no significant difference in serum glucose content among all groups(P>0.05).The serum glutamic oxaloacetic transaminase activity and high-density lipoprotein cholesterol content of sea bass in G2 group were significantly higher than those in G1 and G3 groups(P<0.05),but there were no significant differences in the above indices between G1 and G3 groups(P>0.05).4)The contents of acetic acid,butyric acid and total short-chain fatty acid in intestine of sea bass in all groups were in the order of G1 group>G3 group>G2 group from high to low,and the differences among groups were all significant(P<0.05).5)The mRNA relative ex-pression levels of glucagon-like peptide-1(GLP-1),glucagon-like peptide-2(GLP-2),sodium-dependent glucose cotransporter 1(SGLT1),sodium-dependent glucose cotransporter 2(SGLT2)and glucose transporter 2(GLUT2)in intestine of sea bass in G2 group were significantly lower than those in G1 and G1 groups(P<0.05),the YY peptide(PYY)mRNA relative expression level in intestine in G2 group was significantly high-er than that in G1 and G3 groups(P<0.05),but there were no significant differences between G1 and G3 groups(P>0.05).In conclusion,the high sugar diet can increase the serum glucose content,induce the liver injury,reduce the intestinal short-chain fatty acid content and expression of glucagon-like peptide and glucose transporter genes,and inhibit the growth and nutrient deposition of sea bass.The supplementation of 0.1%CT in the high sugar diet can repair the liver injury,reduce the serum glucose content by regulating the gene ex-pression of intestinal hormone,and improve the growth performance of sea bass.[Chinese Journal of Animal Nutrition,2024,36(8):5254-5268]