Growth Performance, Feed Utilization and Body Composition of the Nile and Red Hybrid Tilapia Fingerlings Reared in Mono and Polycultures

The present work aimed to investigate the impact of stocking density of two types of fish species, the Nile tilapia (NT) and the red hybrid tilapia (RHT) fingerlings, reared in monoculture or polyculture, on their growth performance, feed utilization and chemical body composition. The experimental groups were designed as the following: G₁: contained 40 fingerlings of NT that stand for 100% of  NT; G₂: contained 30 fingerlings of NT and 10 fingerlings of RHT, representing a portion of 75% of NT and 25% of RHT; G₃: contained 10 fingerlings of NT and 30 fingerlings of RHT, providing a portion of 25% of NT and 75% of RHT, and G₄: contained 40 fingerlings of RHT that were a 100% of RHT. All tested groups received the same diet of 32.2% crude protein and 4638 kcal for 60 days. The result showed that polyculture (G₂ and G₃)showed the highest final weight (FW), total body weight gain (TBWG) and average daily gain (ADG) in comparison with monocultures (G₁ or G₄). Survival ratio was decreased with rearing two types of fingerlings together in one hap (polyculture), compared to the other two fingerlings reared in monoculture for NT or RHT. Mono or polycultures affected significantly (P<0.05) their TBWG, FI, FCR; CPI and PER. While the body composition was not affected by the type of reared haps (mono or polycultures). G₁ recorded the highest value of energy retention (ER %, 108.10%); meanwhile, G₄ recorded the lowest value (66.61%). Protein productive value (PPV %) was a significant (P<0.05) affecting factor among the different groups. It can be mentioned that reared fingerlings of the Nile tilapia or the red hybrid tilapia together in one hap (polyculture) can be realized successfully without occurring any adverse effect on growth performance, feed utilization, and body composition.