Effects of dietary curcumin on growth performance, body composition and serum antioxidant enzyme activity in juvenile turbot (Scophthalmus maximus)
A 77-d feeding trial was conducted to evaluate the effects of dietary curcumin on growth performance,body composition and serum antioxidant enzyme activity in junvenile turbot (Scophthalmus maximus) [initial body weight (5.12±0.04) g].Four isonitrogenous and isoenergetic practical diets (50.66% protein,17.36% lipid) were formulated to contain graded levels (0,0.02%,0.04% and 0.06% dry weight) of curcumin.Each diet was randomly assigned to triplicate groups of 35 fish and the fish were fed twice daily to apparent satiation.The results showed that survival rate (SR),specific growth rate (SGR),feed intake (FI),hepatosomatic index (HSI) and viserosomatic index (VSI) were not significantly affected by the dietary curcumin levels.There were no significant differences observed in whole body moisture content among all treatments.Lipid content in whole body significantly decreased,while lipid content in liver and muscle significantly increased with increasing dietary curcumin levels.Fish fed diet with 0.04% curcumin showed lower protein content in whole body than other groups.The activity of serum SOD increased with increasing dietary curcumin levels,and fish fed diet with 0.06% curcumin had significantly higher value than the control group.The activity of serum CAT was opposite to the trend of serum SOD activity,and the group fed diet with 0.06% curcumin had higher value than the control group.The serum MDA content and GSH content were significantly decreased with increasing dietary curcumin levels.In conclusion,the results from the present study indicated that 0.06% dietary curcumin improved the serum antioxidation ability of juvenile turbot,but did not affect the growth offish.