Administration of some probiotic strains in the rearing water enhances the water quality, performance, body chemical analysis, antioxidant and immune responses of Nile tilapia, Oreochromis niloticus

Abstract The performance, efficiency of consumed feed, body chemical composition, survival rate, antioxidant and immunity parameters of Nile tilapia (Oreochromis niloticus) reared in probiotic-treated water were studied. Two hundred apparently healthy Nile tilapia (20 ± 0.3 g) juveniles were reared for 70 days in five different treatments, with five replications as the control group (clean water) and four test groups with two probiotics strains (Bacillus toyonensis and Geobacillus stearothermophilus) at two different levels (1 or 2 × 105 CFU ml−1) applied in rearing water. Fish reared in water supplemented with G. stearothermophilus at low level demonstrated significantly enhanced (p