Abstract
The study evaluated the growth performance and body composition of Oreochromis niloticus fed isonitrogenous and isocaloric diets containing different levels of wheat bran (0 %, 6 %, 12 % and 18 %). Significant (P < 0.05) differences were observed in the total weight gain, body condition factor, specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER) and net protein retention (NPR) values of fish fed different levels of wheat bran. The inclusion of wheat bran at 6 % or 12 % levels in the diets, significantly improved the weight gain, body condition factor, SGR, FCR, PER and NPR values as compared to those fed control diet (without wheat bran). The diet containing 18 % of wheat bran showed the poorest feed intake, weight gain, SGR and body condition factor. Although the FCR and PER values for the diet containing 18 % of wheat bran were significantly (P < 0.05) lower than those containing 6 % or 12 % of wheat bran, they did not differ (P > 0.05) as compared to that of control diet (without wheat bran). The best net protein retention values were observed for the diet containing 12 % of wheat bran. Significant differences (P < 0.05) were also observed in the body composition of fish fed different levels of wheat bran. The diet containing 18 % of wheat bran produced fish with the highest body moisture but with the lowest fat, ash and energy contents. The highest body crude protein content was observed in fish fed diet containing 12 % of wheat bran. The body lipid contents decreased with the increasing level of wheat bran in the diet. It is concluded that wheat bran when added up to a level of 12 % in the diets of Oreochromis niloticus will improve their growth performance, body condition factors, FCR, PER and NPR values.