Effects of sodium selenite, selenium methionine, and selenium yeast on growth performance, carcass composition, blood biochemistry, and antioxidant status of intensively reared Hypophthalmichthys molitrix

The current study aimed to assess the effects of various selenium(Se) sources on the growth performance, blood biochemistry, and antioxidant status of intensively reared silver carp. For this, (N = 420) fingerlings with an average body weight of 13 +/- 1.5 g were randomized into 21 aquariums (20 fish/100 L aquaria) and was subjected to one of the seven dietary treatments under completely randomized design. The dietary treatments were control(C), with 0.5 mg/kg sodium selenite(N-0.5), 1 mg/kg sodium selenite(N-1), 0.5 mg/kg Se methionine(M0.5), 1 mg/kg Se methionine(M-1), 0.5 mg/kg Se yeast(Y-0.5), and 1 mg/kg Se yeast(Y-1). The experiment was of two-weeks of fish acclimatization to ponds followed by 12-weeks of feeding trial. The source of Se influenced the growth performance and the group M-0.5supplemented diet achieved the highest(P < 0.05) final body weight (BW), final length, BW gain, and specific growth rate than others. The selenium concentration of liver, kidney, and muscle was significantly higher(P < 0.05) in methionine fed groups compared to others. However, concentrations of Se in liver, kidney and muscle were similar (P > 0.05) in fish supplemented with M-0.5 and M-1. The dry matter, fat, ash and protein contents of the fish meat were similar (P > 0.05) in all. The WBCs, HGB, HCT, and MCHC were higher (P < 0.05) in the M-0.5 supplemented group than the rest of the treatment groups. Similarly, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were also higher (P < 0.05) in the M-0.5 supplemented group compared with others. However, TBARS for liver and serum were not influenced (P > 0.05) by Se supplementation. Similarly, levels of superoxide dismutase, catalase, and peroxidase enzymes in the fish whole body, muscle, and liver were also remained unchanged (P > 0.05). From the findings, we can conclude that Se methionine is the best source, and 0.5 mg/kg dietary supplementation improved the growth performance, organs enrichment, and antioxidant status of silver carp.