EFFECT OF PROTEIN AND ENERGY LEVELS IN COMMERCIAL DIETS ON GROWTH PERFORMANCE OF JUVENILE NILE TILAPIA (OREOCHROMIS NILOTICUS)

An experiment was carried out to determine the optimum protein to energy ratio for maximum growth, diet utilization and body composition of juvenile Nile tilapia (Qreochromis niloticus) (3,6g initial body weight) raised in glass aquaria. A 4 x 2 factorial design was employed in which eight diets containing 12, 16, 20 or 24% protein each with 245 or 262 kcal metabolizable energy (ME)/I00g were used. Each treatment was replicated in three glass aquaria. Results revealed that. increasing dietary crude protein increased final body weight (FBW) significantly (P < 0.05). Fish that maintained at 20 or 24% protein levels exhibited significantly the greater mean FBW compared to that fed 12% protein. Also, increasing dietary energy significantly (P < 0.05) increased FBW. Interaction between dietary protein and energy indicated that the 20 % protein level with 245 kcal ME/lOOg (81.6 mg P /kcal ME) showed the best P/E ratio for growth and feed utilization. The results also showed that feed intake increased as dietary protein increased, however dietary energy seemed to have no influence on this trait. Feed conversion ratio