Evaluation of probiotic adequacy, immunomodulatory effects and dosage application of Bacillus coagulans in formulated feeds for Catla catla (Hamilton 1822)

Hydrophobicity Probiotic properties Phagocytic ratio Indian carp.


June 25, 2020


The present study was conducted to study the probiotic properties, antagonistic effect against pathogenic Aeromonas hydrophila of Bacillus coagulans isolated from intestine of healthy Catla catla Hamilton, 1822; and its optimum dosage for growth promotion and immunostimulation. The isolated B. coagulans from the gastrointestinal tract of C. catla was first assessed for its probiotic properties viz., antagonism towards pathogen and cell surface adhesion. A feeding trial of 90 days was conducted to optimize the inclusion level of B. coagulans in diets and C. catla fingerlings (avg. wt. 0.30±0.03g) were fed on feed supplemented with 1x103 (diet D1), 2x103 (diet D2), 3x103 (diet D3) and 5x103 (diet D4) B. coagulans  CFU g-1 of feed in triplicate treatments. The growth and digestibility parameters, intestinal enzyme activities were significantly higher in group of fish fed on feed D3 (3x103 CFU g-1) in comparison to other dietary treatments except for food conversion ratio which was significantly higher in control group. Significantly higher value of carcass protein level, lower excretion of metabolites (ammonia and phosphates), enhancement of non-specific immune response and increase of total Erythrocyte count (TEC) and total Leucocyte Count (TLC) were observed in fish fed with probiotics supplemented diets. The results obtained in the present study support the use of B. coagulans for better growth and proper nutrient utilization. The broken line analysis was carried out and polynomial fit curve further suggest that the optimum concentrations of B. coagulans as high as 3000 (3x103) CFU g-1 of feed is required for improving the overall physiological performance and enhancement of defense mechanisms in the fingerlings of C. catla.