Effects of Dietary Glutathione on Growth Performance,Serum Biochemical Indices and Body Composition of Juvenile grass carp(Ctenopharyngodon idella)

An 8 weeks feeding trial was conducted to study the effects of dietary glutathione on growth performance,serum biochemical indices and body composition of juveniles grass carp,Ctenopharyngodon idella.Seven hundred and twenty grass carps with an average body weight of(4.10±0.02) g were randomly allocated into 6 groups with 4 replicates of 30 fish.Group Ⅰ,as the control group,was fed with the basal diet,while groupⅡ,Ⅲ,Ⅳ,Ⅴ and Ⅵ,as trial groups,were fed with the basal diet added with 100,200,300,400 and 500 mg/kg GSH respectively.The results showed that when compared with the control group,WGR and SGR were improved at 4th week and showed a significant increase in group Ⅱ(P0.05).Adding high levels of GSH(≥300 mg/kg)to diet reduced serum UN content and showed a significant decrease in group Ⅳ(P0.05).Activity of serum CHO was increased and showed a significant increase in group Ⅳ and Ⅵ(P0.05).Adding GSH to diet could improve serum content GPT and showed a significant increase in group Ⅳ(P0.05).Whole-fish protein content was increased and showed a significant increase in group Ⅴ and Ⅵ(P0.05).Whole-fish dry matter,lipid,ash and relative weight of organs were not influenced by adding different levels of GSH(P0.05).In conclusion,early growth performance,nutrition metabolism and whole-fish protein content could be improved by adding GSH,while relative weight of organs were not affected significantly.However,adding high levels of GSH in diet could result in impaired liver function in fish.