Effects of dietary zinc on the growth, digestive enzyme activities, muscle biochemical compositions, and antioxidant status of the giant freshwater prawn Macrobrachium rosenbergii

Current study was made to assess the dietary zinc (Zn) on the growth, activity of digestive enzymes, muscle biochemical compositions, antioxidant and metabolic enzyme status of the freshwater prawn, Macrobrachium rosenbergii. Zn was supplemented at 0, 10, 20, 40, 60, and 80 mg kg− 1 with the basal diet, and the concentrations of Zn in Zn supplemented diets were 31.45, 42.10, 53.80, 65.70, 92.80, and 113.50 mg kg− 1 respectively. M. rosenbergii were fed these Zn supplemented diets for a period of 90 days. Results showed that prawns fed with 10-60 mg kg− 1 Zn supplemented diets attained significant (P < 0.05) improvement in survival, growth, digestive enzyme activities, and muscle biochemical compositions. However, the prawns fed with 80 mg Zn kg− 1 showed poor performance. The enzymatic antioxidants, metabolic enzymes and lipid peroxidation status in muscle and hepatopancreas showed no significant (P > 0.05) alterations in prawns fed with 10-60 mg Zn kg− 1 supplemented diets. However, prawns fed 80 mg of Zn kg− 1 supplemented feed PL showed significant (P < 0.05) alterations in these antioxidant and metabolic enzymes activities suggesting toxic effects of this dose. Hence, the present study suggests that 60 mg Zn kg− 1 can be supplemented for regulating better survival, growth and production of M. rosenbergii.