A study on the probiotic effects of Bacillus subtilis on broiler chickens infected with Staphylococcus aureus and Salmonella.

Zhang Yaru¹, Liu Xuechun¹, Xue Linlin¹, Zhang Pengzhen¹, Yang Xiaojin², Fan Shouwu², Li Wang¹
1.College of Animal Science and Technology, Henan University of Science and Technology
2.Luoyang Ouke Biotechnology Co., Ltd.

This study aimed to investigate the effects of adding antibacterial Bacillus subtilis to drinking water on growth performance, immune organs, immune factors, and intestinal health in broiler chickens artificially infected with Staphylococcus aureus or Salmonella. 126 one-day-old Arbor Acquired (AA) broiler chickens of similar body condition were randomly divided into four groups: Control, Bacillus subtilis (BS), Staphylococcus aureus (SA), Bacillus subtilis + Staphylococcus aureus (BS+SA), Salmonella (SE), and Bacillus subtilis + Salmonella (BS+SE). Each group had three replicates, with seven chickens per replicate, and the experiment lasted for 21 days. Bacillus subtilis was added to the drinking water at a concentration of 1.8 g/L (5 × 10¹⁰ CFU/g). Staphylococcus aureus (1 × 10⁸ CFU/mL) and Salmonella (1 × 10⁸ CFU/mL) were transmitted via oral gavage. The results showed that: (1) Bacillus subtilis significantly reduced the feed conversion ratio of broilers infected with Staphylococcus aureus and Salmonella (P<0.05). (2) Bacillus subtilis increased the spleen index, bursa of Fabricius index, and thymus index of broilers infected with Staphylococcus aureus and Salmonella (P>0.05). (3) Except for the Salmonella-infected broiler treatment group, the serum IgA, IgG, and IgM levels in the other treatment groups were increased (P>0.05). (4) Bacillus subtilis significantly increased the ileum-villi ratio of broilers infected with Staphylococcus aureus and Salmonella (P<0.05). The results indicate that Bacillus subtilis can inhibit pathogens, improve production performance, and repair intestinal villi in broiler feeding.