Feeding of Bacillus Subtilis as a potential probiotic feed supplement in broiler chicken

This study was aimed to investigate the efficacy of Bacillus subtilis (BS) as a potential probiotic against control and antibiotic supplemented broiler chickens. Three experimental diets viz. T1 (control-Basal diet), T2 (BD + 50 g BS/ton diet), and T3 (BD + 250 mg Bacitracin methylene disalicylate- BMD/kg diet) were supplemented to broiler chickens distributed in three groups which were further divided into three replicates each for period of six weeks (0–6 weeks). BS supplemented birds had significantly higher (P<0.001) body weight gain compared to BMD and control birds, whereas feed intake was intermediate to BMD and control birds. The feed conversion ratio of control birds was significantly (P<0.001) higher as compared to probiotic or BMD supplemented birds, which did not differ significantly from each other. Production efficiency factor and energy efficiency ratio at 6^th week of age was higher in BS supplemented birds compared to other two groups. In contrary, protein efficiency ratio was lower in control group compared to the others. In control group, humoral immunity was significantly (P<0.05) lower compared to other groups. The H:L ratio was lower in BS supplemented birds compared to others. The morphometry of intestinal epithelium of probiotic supplemented birds was superior to BMD fed and control birds. Therefore, it has been concluded that, the BS probiotic may serve as a viable alternative to antibiotic growth promoter in broiler chickens considering superior growth performance, immunity and gut health.