Effect of Different Rates on Growth Performance, Feed Utilization and Body Composition for Mixed Sex Nile Tilapia (Oreochromis Niloticus) Reared in Tanks

The fishes used in this study were mixed Nile tilapia (Oreocheromis niloticus) fingerlings.The experimental fish were transported to the experimental station through Plastic bags and pout in aquarium tanks.Fish were fed on a commercial diet containing (Cp) 30% protein.The experimental system consists of 12 tanks with a total volume of 50 L 3 for each tank.Three replicates were used for each treatment.Each tank was supplied with compressed air pump with tube via air stones.The temperature was adjusted at 27±1 ºC by using thermostatically controlled heaters.The experiment duration was 90 days.The feeding rate was applied in four treatments as 3% (control), 1%,5% and7% of live body weight.Fish were fed 6 day/week the results were summarized as:• By using 3% feeding rate highest survival rate (100%) was obtained, followed by 98 in each feeding rate 5 and 7%, where the least survival was obtained with1%.• Regarding growth parameter: the highest finial weight of tilapia fish without significance difference (P<0.05) with all feeding rates was recorded by using 3% feeding rate.However, least final weight was recorded in fish received 1% feeding levels.specific growth rate(SGR) and condition factor(CF), where fish fed 3% group recorded higher value (P<0.05)compared to the other treatments.• The effect of feeding rate on feed utilization: the highest finial weight (FW) of tilapia fish with significance difference (P<0.05) with all feeding rates was recorded by using 3% feeding rate.So, the NPU% values, the groups fed 3% showed increased value and significantly (P<0.05) with the other tested groups.• The carcass analysis in terms of crude protein (CP) and ash not significantly different between tested feeding rate, where whole fish body lipid was increased by the increasing feeding rate in treatments 5and 7%, without significance difference between the two feeding rates.The present results confirmed an enhancement in growth performance and feed utilization by using 3% feeding rate in Nile.