Effects of different sources of dietary - antioxidants (vitamin E, co-enzyme Q10 and selenium forms) on growth performance and biochemical indices in rainbow trout (Onchorhynchus mykiss) fingerlings

In the present study, the effects of different levels of dietary antioxidant supplements on growth performance and biochemical indices in rainbow trout (Oncorhynchus mykiss) fingerlings were investigated. For this aim, nine experimental diets were formulated and supplemented with different combinations of three antioxidants including vitamin E (VE) at levels of 0, 100 and 150 mg kg-1 diet), coenzyme Q10 (CoQ10) at levels of 0, 10 and 20 mg kg-1 diet and selenium forms (mineral, organic and nano-selenium (Nano-Se)) at levels of 0, 0.3 and 0.5 mg kg-1 diet. The fish were randomly divided into these diets with stocking density of 25 per replicate and fed for 56 days. Based on the results, a relative increase was observed in the growth indices of fish fed with the treatment containing 0.5 mg Nano-Se + 100 mg VE. The highest of glucose content was obtained in supplemented treatment with 0.5 mg Nano-Se + 100 mg VE. For cholesterol and triglyceride, the highest values were reported in fish fed with treatments containing 0.5 mg mineral Se + 150 mg VE + 20 mg CoQ10 and 0.5 mg Nano-Se + 100 mg VE, respectively. Similarly, the highest values ​​of HDL and VLDL indices were observed fish fed with 0.5 mg Nano-Se + 100 mg VE. In contrast, the control treatment showed the highest LDL value. The results of this study revealed that supplemented diet with Nano-Se at level of 0.5 mg and VE at level of 100 mg can be effective in improving the growth and blood biochemical indices of rainbow trout.