Growth performance, feed utilization, digestive enzyme activity, innate immunity and protection against Vibrio harveyi of freshwater prawn, Macrobrachium rosenbergii fed diets supplemented with Bacillus coagulans

The present study was conducted to investigate the effects of dietary supplementation of Bacillus coagulans on growth, feed utilization, digestive enzyme activity, innate immune response and disease resistance of freshwater prawn Macrobrachium rosenbergii. Three treatment groups (designated as T1, T2 and T3) and a control group (C), each in triplicates, were established. The prawn in the control were fed a basal diet and those in T1, T2 and T3 were fed basal diet containing B. coagulans at 105, 107 and 109 cfu g−1, respectively. After 60 days, growth performance and feed utilization were found significantly higher (P < 0.05) in prawn fed T3 diet. The specific activities of protease, amylase and lipase digestive enzymes were significantly higher (P < 0.05) for T3. Innate immunity in terms of lysozyme and respiratory burst activities were significantly elevated (P < 0.05) in all the probiotic treatment groups as compared to control. Challenge study with Vibrio harveyi revealed significant increase (P < 0.05) in disease resistance of freshwater prawn in T2 and T3 groups. The results collectively suggested that supplementation of B. coagulans as probiotic in the diet at approximately 109 cfu g−1 can improve the growth performance, feed utilization, digestive enzyme activity, innate immune response and disease resistance of freshwater prawn.