Boosting Growth and Immunity in Labeo rohita: The Role of Bacillus subtilis in Semi-Intensive Aquaculture

Aquaculture plays a major role in rapidly increasing fish production to meet the world's growing protein need. The goal of the current study was to determine the response of Indian major carp Rohu fingerlings (Labeo rohita) in terms of growth, Haematological, and immune parameters after the dietary supplementation with probiotic Bacillus subtilis. An 8-week feeding trial was carried out under semi-intensive culture system. During the trial, fish was fed with three diets including a control diet and two experimental diets with varying concentration of probiotic. Probiotic concentrations in experimental diets were 103, and 106 cfug-1 respectively. All these treatments were applied in triplicates. After the experiment, growth, hematological and immune parameters of fish were evaluated. Results indicated that growth rate, weight gain, and specific growth rate were significantly (P<0.5) higher in fish fed with probiotic containing diet with highest growth observed with diet containing 106 CFU/g of probiotic. Leucocyte, erythrocyte count and glucose content were also high in experimental groups as compared to control groups. Total protein content and Peroxidase activity was significantly higher (P<0.5) in fish fed with highest concentration (106 CFU/g) of probiotic as compared to control and other dietary groups. From these outcomes, Bacillus subtilis can be concluded as a potential probiotic for L. rohita culture under semi-intensive culturing system and can be used for better growth and survival rate of fish in aquaculture practices.