Effect of dietary Bio-fermented selenium on growth performance, nonspecific immune enzyme, proximate composition and bioaccumulation of zebrafish (Danio rerio)

A four-weeks feeding trial was conducted to evaluate the effects of dietary Bio-fermented selenium (Bio-Se) on zebrafish (Danio rerio). Effects of three Se diets containing basal diet (1.63 mg Se/kg), L-Se diet (3 mg Se/kg), and H-Se diet (10 mg Se/kg) on growth performance, nonspecific immune enzyme activities, proximate composition, and selenium accumulation of zebrafish were tested. The results indicate that body weight gain (BWG), specific growth rate (SGR), and nonspecific immune enzyme [glutathione peroxidase (GPx), superoxide dismutase (SOD), and alkaline phosphatase (ALP)] activities of fish fed with L-Se diet were significantly highest among all the groups. However, increased H2O2 content and decreased SOD activity indicates oxidative stress when fish was fed with H-Se diet. Dietary Se did not affect the proximate composition of zebrafish. The Se concentration in muscle increased in a dose-dependent manner, and the highest Se concentration was recorded in H-Se diet. In summary, the growth performance and nonspecific immunity of zebrafish fed with L-Se diet improved, but exposure to higher concentrations of Bio-Se severely affects the health status of fish. Keywords: Bio-fermented selenium, Zebrafish, Growth performance, Nonspecific immune enzyme, Bioaccumulatio