Benfotiamine counteracts the negative effects of a high dietary carbohydrate on growth and ammonia toxicity resistance in post larval Penaeus monodon

The present study aimed to evaluate the effects of high carbohydrate diet in the absence of presence of dietary benfotiamine on growth and immune response against ammonia toxicity (50 mg NH4Cl L-1, average ambient temperature=27oC, pH 8.3) of post larval Penaeus monodon. A feeding trial involving three dietary treatments followed by an ammonia toxicity tests and a feed attractability test were conducted separately. During the feeding trial, shrimps were fed three experimental diets, namely, (1) a diet containing 15% starch (C), (2) a diet with 25% corn starch (high carbohydrate diet, HC) and (3) a diet containing both 25% starch supplemented with 0.2 g kg-1 benfotiamine (HCB). At the termination of the feeding trial, the shrimps were subjected to ammonia toxicity test to determine the effects of the diets on the immune response of the post larval shrimps. Attractability tests using customized aquaria showed that the HCB diet elicited significantly the highest attractability even after 10 min of feed placement in the feeding chamber. In the feeding trial that lasted for 60 days, results showed that shrimps fed with diet containing HCB exhibited significantly the highest growth rate (p<0.05) among all groups of shrimps in terms of final average body weight (FABW), weight gain (WG), and specific growth rate (SGR); they also exhibited significantly the highest feed intake (p<0.05). Upon challenge of the shrimps with 50 mg L-1 ammonia, shrimps fed with the HCB diet exhibited significantly the highest cumulative survival rate of 60% after 72 h while those fed with diet C and HC exhibited lower survival rates of 33% and 40%, respectively, and were not significantly different from each other. In conclusion, benfotiamine enhances attractability of the feed, growth performance and immune response against ammonia toxicity at the level of 0.2 g kg-1.