Supplementation of probiotic (Bacillus subtilis) for improvement of growth performance and digestive enzymes activity of puntius javanicus under intensive aquaculture system

The experiment was conducted to examine effects of different doses of B. subtilis probiotic supplementation in feed on protein digestibility, growth and activity of digestive enzymes of P. javanicus on intensive farming system. P. javanicus fingerlings used as test animals. The treatments were B. subtilis probiotic on feed. Those were treatments A (0 CFU g^-1 feed), B (0.75 x 10⁷ CFU g^-1 feed), C (1.50 x 10⁷ CFU g^-1 feed) and D (2.25 x 10⁷ CFU g^-1 feed). Observed parameters were protein digestibility (ADC_P), efficiency of feed utilization (EFU), ratio of feed conversion (FCR), ratio of protein efficiency (PER), relative growth rate (RGR), survival rate (SR), digestive enzymes activity and quality of water. The result showed that supplementation of B. subtilis on feeds significantly (P≤0.05) affected ADC_P, EFU, FCR, PER, RGR, SR and digestive enzyme activities. The experiment was conducted under the viable water quality. The optimum supplementation dose of B. subtilis was 1.50 x 107 CFU g^-1 feed resulted in the highest value of ADC_P (75.28%), EFU (74.06%), FCR (1.52), PER (3.78), RGR (3.23% / day), SR (98.33%) and digestive enzymes (protease and amylase) activities were 4.32, 3.42 U g^-1 protein, respectively.