Effects of adding three different small peptides to feed on growth,digestive,and immune function of Micropterus salmoides juveniles

CHEN Yushu; ZHANG Xinyan; ZHANG Jingjing; CHEN Duhuang; FAN Haiping; LIN Wanhua; ZHANG Wen; XUE Lingzhan

doi:10.13557/j.cnki.issn1002-2813.2025.21.016

Abstract：The experiment aimed to investigate the effects of different small peptides on the growth performance,digestive enzyme activity,antioxidant capacity,and immune function of Micropterus salmoides juveniles.A total of 360 Micropterus salmoides with an average weight of(38.43±3.17)g were selected and randomly divided into three groups,with three replicates per group and 30 fish per replicate.The control group(group N)was fed a basal diet,while the groups DI,DYT and KZ added 0.1％DI,DYT and KZ small peptides to the basal feed,respectively.The pre-test period was three days,and the formal test period was 50 days.The results showed that compared with group N,the final weight,specific growth rate(SGR),and protein efficiency(PER)in group DI were significantly increased by 7.64％,16.48％,and 58.95％,respectively(P＜0.05),while the feeding rate(FR)and feed coefficient(FCR)were significantly decreased by 8.17％and 37.24％,respectively(P＜0.05).Compared with group N,the activities of gastric protease andα-amylase in group DI were significantly increased by 39.06％and 65.74％,respectively(P＜0.05),while the activity ofα-amylase in group KZ was significantly increased by 93.19％(P＜0.05).Compared with group N,the activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),and total antioxidant capacity(T-AOC)in the liver in group DI were significantly increased by 35.59％,12.44％,and 60.53％,respectively(P＜0.05),the activity of serum alanine aminotransferase(ALT)was significantly decreased by 59.56％(P＜0.05),while the activities of acid phosphatase(ACP),alkaline phosphatase(ALP),and lysozyme(LZM)were significantly increased by 58.65％,179.58％,and 29.38％,respectively(P＜0.05).The study indicates that DI small peptide can significantly improve the growth performance and digestive enzyme activity of Micropterus salmoides juveniles,as well as enhance immunity,and can be used for large-scale production of Micropterus salmoides fry.