Effects of different levels of dietary selenium nanoparticles on growth performance, muscle composition, blood biochemical profiles and antioxidant status of common carp (Cyprinus carpio)

The aim of this study was to assess the effects of different doses of selenium nanoparticles (nano-Se) on growth performance, feed conversion, tissue composition, Se accumulation in muscle and liver, antioxidant response and biochemical blood parameters of common carp, Cyprinus carpio. Nano-Se was added to the experimental basal diets at the rates of 0 (control), 0.5, 1 and 2 mg/kg dry feed weight. Four groups of fish with an average weight of about 10 g were fed one of the experimental diets for 8 weeks. Fish that were fed diet supplemented with 1 mg Se/kg displayed improved (P < 0.05) growth performance, including final weight and weight gain (WG). No significant differences (P > 0.05) in feed conversion ratio (FCR) and survival were observed in fish fed different diets for 8 weeks. Dietary nano-Se had no effects on proximate composition of carps. Fish fed with nanoselenium-supplemented diets showed a higher (P < 0.05) Se content in the muscle and liver tissues compared to that of the control. Liver malondialdehyde (MDA) level was significantly (P < 0.05) lowered in fish fed on diet supplemented with 2 mg nano-Se/kg, whereas the activity of glutathione peroxidase (GPx) and catalase (CAT) in livers of carp fed on diet supplemented with 2 mg nano-Se was significantly (P < 0.05) higher as compared to other experimental diets. The highest superoxide dismutase (SOD) activity was observed in fish fed on 2 mg nano-Se, but it was not significantly (P > 0.05) different from the enzyme activity in the 1 mg nano-Se group. Fish fed on diet supplemented with 2 mg nano-Se showed significantly (P < 0.05) higher total protein and globulin contents but lower albumin level. The serum cholesterol level was significantly (P < 0.05) decreased in fish fed diets containing 2 mg nano-Se/kg. No significant difference (P > 0.05) in serum triglycerides was observed in fish fed different diets. A significant (P < 0.05) decrease in low-density lipoprotein (LDL) was observed in groups receiving 1 and 2 mg nano-Se/kg, whereas serum high-density lipoprotein (HDL) was higher in carp fed on diet with 2 mg nano-Se/kg. Fish fed on 1 and 2 mg nano-Se/kg diets exhibited the highest values of aspartate transaminase (AST) activity as compared to other treatments. The activity of alanine transaminase (ALT) was significantly (P < 0.05) higher in fish fed on 2 mg nano-Se/kg as compared to other test groups. No significant differences (P > 0.05) were found in serum alkaline phosphatase (ALP) activity among the experimental groups. Therefore, the data of the present study recommend adding 1 mg nano-Se per kg diet to improve fish growth and antioxidant defense system. Statement of relevance The data of the present study recommend adding 1 mg nano-e per kg diet to improve carp growth and antioxidant defense system. (C) 2015 Elsevier B.V. All rights reserved.