This study aims to evaluate dietary phytases from three Bacillus spp. for Oreochromis mossambicus on growth, feed utilization and nutrient deposition. Plant-based diets were supplemented with 500 FTU kg-1 of B. pumilus, B. megaterium and B. licheniformis phytases (Bpum, Bmeg and Blic, respectively) while diet without supplementation and the commercial diet (NoP and ComD, respectively) served as negative and positive controls, respectively. Bmeg, Blic and Bpum diets did not have marked effect on growth performance. Carcass ash was significantly the highest in the Bmeg and Blic groups while carcass P and Ca were significantly increased by all supplemented diets. Scale ash was increased significantly by both the Bmeg and Blic diets while scale P and Ca by all three supplemented diets. Bone P and Mg were significantly the highest in Bmeg and Blic diet groups; bone Ca were highest in the Bmeg group. P retention was significantly increased in the three supplemented diets. P load were significantly the lowest in all supplemented diets. All the supplemented diets were effective in significantly reducing fecal P. In conclusion, the Bmeg and Blic phytases were most effective in hydrolyzing phytate P and in ameliorating water quality.
