Use of Corn Husk Meal in the Development of a Functional Diet for Nile tilapia (Oreochromis niloticus) Fingerlings: Effect on Growth Performance, Antioxidant Status and Intestinal Microbiota

The effect of dietary supplementation of corn husk meal (CHM) on growth performance, liver antioxidant status and intestinal microbiota in Nile tilapia (Oreochromis niloticus) fingerlings was evaluated. Four experimental groups of fish with initial weight 0.47 +/- 0.7 g in triplicate tanks were used; three of them were fed CHM incorporated diets (12.5 g/kg, DH12; 25 g/kg, DH25; and 50 g/kg, DH50), whereas a CHM-free basal diet served as control (DH0). No significant differences were observed in growth performance or feed efficiency in fish fed experimental diets (P > 0.05); however, fish fed the DH50 diet had a significant higher proportion of crude protein of whole-body composition (P < 0.05). Analysis of antioxidant enzyme activity showed significant differences (P < 0.05) with higher superoxide dismutase (SOD) activity in fish fed the DH25 diet, and lower glutathione peroxidase (GPx) activity in fish fed the DH12 diet. No significant differences were found in catalase (CAT) activity between treatments. Fusobacteria, Bacteroidetes and Proteobacteria were the most abundant phyla in all feces samples but no significant differences were found in microbial diversity among diets. Results suggest that CHM is safe for Nile tilapia consumption improving crude protein of whole-body composition and enhancing SOD activity. [GRAPHICS] .