Impact of Bacillus Subtilis Probiotic on Growth Performance, Bone Health, Intestinal Morphology, and Cecal Microbiota in Cobb Broiler Chicks

Abstract

Alternatives to antibiotics have attracted widespread attention in poultry farming, particularly after the ban on antibiotic growth promoters. Probiotics, in particular, have shown promising results in enhancing poultry health and productivity when used as a feed additive. The study aimed to evaluate the effects of probiotics ( Bacillus subtilis) on growth performance, bone health, cecal microbiota, and gut morphology in broilers. Day-old Cobb broiler chicks (n=900) were randomly divided into three experimental groups for 35 days, with each group comprising four replicates and n=75 chicks per replicate by following a completely randomized design. Group A served as the control group fed on the basal diet, while the Group B and Group C groups were given flavomycin (10 g/ per ton of feed) and Bacillus subtilis (500 g/ton of feed) along with the basal diet, respectively. Growth parameters, such as body weight gain, feed intake, and feed conversion ratio, were measured weekly, whereas bone strength, cecal microbiota, and gut morphology were recorded at 35 days after randomly selecting three birds from each replicate. The probiotic-supplemented diet (PSD) significantly (P<0.05) improved the growth performance of birds throughout the trial period, increased villus length and crypt depth compared with other groups, and reduced Clostridium perfringes, Escherichia coli, and Staphylococcus aureus populations in the cecum compared to the control group (P<0.05). Moreover, the PSD improved calcium and phosphorus deposition, as well as tibia strength and ash percentage (P<0.010). In conclusion, Bacillus subtilis based probiotics may be a better alternative to antibiotic growth promoters.