Bacillus subtilis on survival, growth, biochemical constituents and energy utilization of the freshwater prawn Macrobrachium rosenbergii post larvae

This experiment was carried out to evaluate the effects of the probiotic Bacillus subtilis on survival, growth, biochemical constituents and energy utilization in Macrobrachium rosenbergii PL. Experimental diets were the same in all, except for the variation in probiotic levels. The probiotic B. subtilis was used at 0% (diet 1), 1% (diet 2), 2.0% (diet 3), 3.0% (diet 4) and 4.0% (diet 5) inclusion in the experimental diets. These diets were fed to M. rosenbergii PL for a period of 90 days. The growth parameters, such as survival, weight gain, specific growth rate, feed conversion efficiency and protein efficiency rate were significantly (P < 0.05) higher in 3% B. subtilis incorporated diet fed PL followed by other experimental groups than the control. Similarly the biochemical constituents of the protein, amino acid, carbohydrate, lipid and ash content were significantly (P < 0.05) higher in 3% B. subtilis incorporated diet fed PL. The energy utilization parameters, such as feeding rate, absorption rate, conversion rate and metabolic rate were significantly (P < 0.05) higher in 3% B. subtilis incorporated diet fed PL. From the results of this experiment, we conclude that B. subtilis can be used as a probiotic in M. rosenbergii culture, to enhance the survival, growth and improved energy utilization performance.