Abstract:This study aimed to isolate and screen Bacillus subtilis strains with exceptional probiotic properties,thereby providing a theoretical foundation for the development and application of microbial ecological agents in dairy goat farming.The research team successfully isolated three Bacillus strains from fecal samples of healthy,high-yielding dairy goats in Shenmu city,Shaanxi province,identifying them as Bacillus subtilis through both morphological and molecular biological techniques.Subsequently,the in vitro safety,efficacy,and feasibility of these strains were analyzed,including hemolysis assays,antibiotic susceptibility tests,antibacterial activity assessments,and simulated gastrointestinal tolerance experiments.The results are summarized as follows:(1)The results indicated that none of the strains exhibited hemolytic activity while demonstrating favorable drug sensitivity profiles.(2)They effectively inhibited common mastitis pathogens such as Staphylococcus aureus,Bacillus coagulans and Escherichia coli.(3)These strains displayed robust acid resistance along with significant tolerance to gastric protease and trypsin.In conclusion,the three isolated Bacillus subtilis strains (L1-1,L3-1,and L3-2) exhibit promising in vitro probiotic characteristics that position them as potential candidates for microbial probiotics in goat dairy farming;this offers new opportunities for enhancing both health outcomes and economic benefits within this sector.
