Zootechnical Performance, Protease Activity and Proximate Composition of Nile Tilapia Fed Diets Containing Fish Silage Produced from Fish Waste

The present study was carried out to evaluate the impact of fish silage (FS) on the growth performances, protease enzyme activity and muscle compositions of Nile tilapia. In this regard, FS was produced from the waste parts of carp, pangus and tilapia and five iso-nitrogenous (containing 35% crude protein) diets were formulated in which fishmeal (FM) was used as the primary protein source in the control diet (0% FS, T1). The remaining four diets were formulated by replacing 25% (T2), 50% (T3), 75% (T4), and 100% (T5) FM protein with the FS. These diets were fed to tilapia at 8-6% of their body weight rearing them in glass tanks at the density of 15 fish/tank in triplicates. After fifty-days feeding trial, survival (%) of fish remained unaffected among the dietary treatments. Tilapia fed with 75% FS based diet showed improved growth and lower FCR, whereas those fed a diet with 100% FS exhibited lower growth rates. Notably, protease enzyme activity (mg/ml/min) increased with higher levels of FS inclusion. Increased crude protein content was observed in the fish fed the 75% FS diet. These findings underscore the potential of including FS up to 75% to enhance the growth performance of Nile tilapia.