This experiment was conducted to compare the effects of different sources of selenium (Se) on growth, muscle Se concentration, muscle proximate composition, blood enzymes and antioxidant status of common carp, Cyprinus carpio. Organic Se (selenomethionine, SeMet), inorganic Se (sodium selenite, Na2SeO3), or nanoselenium were each added to the basal diet at 0.7 mg Se kg−1 diet. Four groups of fish with an average weight of 9.69 ± 0.12 g were fed one of the experimental diets for 8 weeks. Nano-Se diet resulted in better growth performance (P < 0.05). Fish fed with Se-supplemented diets showed a higher (P < 0.05) Se content in the muscle and liver tissues. Fish fed nano-Se had the highest liver glutathione peroxidase, superoxide dismutase and catalase activities (P < 0.05). Liver malondialdehyde level was significantly (P < 0.05) lower in fish fed on SeMet and nano-Se diets as compared to control. The carp fed on nano-Se diet had the lowest values of aspartate transaminase and alanine transaminase. Lactate dehydrogenase activity was significantly lower in fish fed on SeMet and nano-Se diets. This study shows that nano-Se acts more efficiently on growth performance and antioxidant defence system of common carp than organic and inorganic sources of Se.
