Abstract

The use of mineral supplementation to enhance the efficacy of aquafeeds is already established. Therefore, the present study was designed to evaluate the effects of various concentrations of dietary copper nanoparticles (CuNPs) on growth performance, Cu retention, antioxidant capacity, and metabolic enzyme status of Nile tilapia (Oreochromis niloticus) by supplementing its diets with CuNPs. Four isoproteic (crude protein; 317 g/kg) and isolipidic (crude lipid; 118 g/kg) dietary treatments were supplemented with CuNPs, viz: D I was set as control (0 mg CuNPs/kg) whereas, D II, D III, and D IV were supplemented with 2, 4 and 6 mg CuNPs/kg, respectively. Three replicates of fish having an initial mean weight of 5.64 ± 0.16 g were hand-fed daily. Significant improved growth performance, feed efficiency ratio (FER), and protein efficiency ratio (PER) was recorded in the group fed with D III (4 mg CuNPs/kg) as compared to the control (D I) as well as other treatment groups, D II and D IV (p < 0.05). The survival rate remained unaffected among all the dietary treatments. Whereas, a significant difference in hepatosomatic and viscerosomatic indices was observed in the group fed with D IV. The significantly improved Cu retention and serum glucose level however, reduced serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity was recorded with dietary treatment D III. Additionally, improved oxidative stability and protease activity (PA) were found in the same nutritional treatment. Based on the results of the present study, supplementation of the fish diet up to 4 mg/kg of CuNPs is suggested to improve growth performance and overall health of O. niloticus by reducing oxidative stress.