Abstract
The present study was carried out to evaluate the effects of partial replacement of soybean with shrimp by-products (SBp) in African catfish (Clarias lazera) diets on productive (growth, digestibility, body composition, dressing yield, blood parameters, immunity) and economic performances. Therefore, 750 fingerlings (~20.0 g) were distributed into five groups of 150 fingerlings/group with three replicates (n = 50) per group. Group 1 was fed a basal diet, while G2 and G3 were fed diets containing 25% SBp (autoclaved and acid-treated, respectively) as soybean replacer for 12 weeks, while, in G4 and G5, SBp level was 50%. All growth and nutrient utilization parameters (body weight, Wg, ADG, PER, FCR, and digestibility), plasma proteins, and immunity significantly increased in G4 and G5. Anemia screening markers recorded insignificant differences between the tested groups and control one, whereas lipid markers of plasma and fish body decreased by autoclaved SBp and increased by acid-treated SBp. The African catfish body dry matter and crude protein percentages were enriched by the addition of SBp. Replacing the soybean meal decreases diet costs and diet costs/1 kg of weight gain. In conclusion, replacing soybean with SBp (especially 50% acid-treated) positively influenced productive and economic performances with friendly effects to avoid the environmental pollution by these wastes.