Effects of vitamin E deficiency on dietary vitamin C requirement in Siberain Sturgeon (Acipenser Baerii)

A 2×5 factorial design was used to evaluate the effects of different dietary vitamin C and vitamin E levels on growth, feed utilization, haemato-biochemical status and immune response in Siberain sturgeon, Acipenser baerii. Ten diets were formulated to contain two dietary vitamin E levels of 0 and 200 mg dl-tocopheryl acetate (TA) and 5 dietary L-ascorbic acid (AA) in the form of L-ascorbyl-2-monophosphate (AMP(levels of 0, 100, 200, 400, and 800 mg/kg. Thus, the diets with 0 mg/kg vitamin E were designated as E0 C0, E0 C100, E0 C200, E0 400, E0 C800 while the diet with 200 mg/kg vitamin E were designated as E200 C0, E200 C100, E200 C200, E200 C400, E200 C800. 300 fish with an average weight of 29.8±1.6 g (mean ± SD) were fed each of the 10 experimental diets in triplicate groups for 12 weeks. At the end of experimental period, weight gain (WG) in fish fed E0C400 and E0C800 diets were significantly higher than those fed E0C0 and E0C100 (P<0.05). Growth performance, feed utilization, haemato-biochemical status and immune response significantly improved with an increase in dietary vitamin E level. However, there were no significant differences in those parameters among fish fed E20 C100, E200C200, E200C400 and E200C800 diets (P>0.05). The results showed sparing effect of dietary vitamin E on vitamin C. Meanwhile, there was no significant difference in survival of fish fed diets supplemented with vitamin C. Deficiency symptoms such as retarded growth and anorexia were observed in fish fed vitamin C of 0 mg/kg at either of the dietary vitamin E levels. These results showed that dietary vitamin C requirement is 200 mg AA/kg diet when juvenile Siberain sturgeon, Acipenser Baerii fed a vitamin E deficiency diet while vitamin C requirement is 100 mg AA/kg diet when fish fed a diet supplemented with 200 mg/kg vitamin E.