The effect of dietary selenium on growth performance, Carcass Composition, and blood profile of farmed juvenile beluga (Huso huso)

This study was designed to compare the effects of different levels of mineral selenium in diet on growth performance, some blood indices and juvenile beluga carcass composition (Huso huso) within 10 weeks. For this purpose, a number of 315 fry with an average weight of 15.66 ± 0.77 grams were stocked in the twenty-one 500-liter fiberglass tanks (15 per each). Seven diets containing different levels of selenium, including 0, 5, 10, 20, 40, 80 and 160 milligrams per kilogram diet with equal amounts of protein and fat, was formulated and placed at the disposal of the fish. During the breeding period, fish were fed manually three times a day. The process of growth results showed that at the end of breeding period, fish fed with the diets containing 10 to 20 mg of selenium per kg of diet had significantly higher weight gain (WG), condition factor (CF), and Hepato somatic index (HSI) than the fish fed with other diets (P<0.05). In addition, the lowest average of the above mentioned indices was observed in 160 milligram of selenium in diet. Furthermore, the fish fed with the diets containing 10 to 20 mg of selenium per kg of diet had significantly lower feed conversion ratio (FCR) than the fish fed with other diets. By increasing the amount of selenium to 160 mg per kg diet, protein and fat levels of carcass decreased significantly, and the moisture of carcass increased notably. In addition, in comparison to the fish fed with the diets containing 80 to 160 mg of selenium per kg of diet, blood indices (WBC, RBC, Hb, PCV, MCV, MCH, MCHC) of fish fed with the diets containing 10 to 20 mg of selenium per kg of diet improved significantly (P<0.05). According to the results of this study, it can be admitted that, addition of selenium in the diet of young farmed baby beluga, at the levels more than 10 and less than 20 mg/kg of diet, could increase the growth process, improve the nutrition and carcass composition, and reinforce many blood indices