Two experiments were performed in two or three way factorial design on Nile tilapia hybrid (O. niloticus x O. aureus) at the El kanater El khairyia Experimental Fish Research Station belonging to NIOF. The three experiments
were carried out in outdoor concrete tanks, each of 10m3 total water volume.Both experiments lasted 20 weeks after start and fish initial weights for the first and second experiments were 30.24 and 31.76 g, respectively.
The first trial aimed to test the interaction between protein (25 or 30 % p25 or p30) and dietary energy levels (15.70; 16.74 or 18.84 Kj g-1 dry diet) on growth performance of hybrid tilapia. In the second experiment, three feeding
rates (2, 4 or 6% biomass of fish R2 ;R4 or R6) within each rate two feeding frequencies (2 or 3 times /day F2 or F3 ) within each two stocking densities (25 or 50 fish /m3 D25 or D50) were tested for their effects on growth performance
of hybrid tilapia. Results of the first experiment revealed that the maximum growth performance of hybrid tilapia was obtained using the diet P25% E16.74KJ, which is recommended for hybrid tilapia. Results of the second trial recommended the feeding rate; frequency and stocking density of 4%; two times feeding at 25 fish/ mi density, respectively for best growth performance of hybrid tilapia.