A Bacillus strain characterized by (i): sensitivity for ampicillin, vancomycin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline and chloramphenicol antimicrobial activity against E. coli and Clostridium perfringens; and (iii) a sporulation percentage of at least 80 when measured after 2 days of incubation. The invention further relates to a method for selecting such strains. Many of the identified strains according to the invention are of the species Bacillus amyloliquefaciens. Some of the Bacillus amyloliquefaciens were further identified as Bacillus amyloliquefaciens subsp. amyloliquefaciens whereas others were identified as amyloliquefaciens subsp. plantarum. A Bacillus strain of the invention may be used as a feed additive to animal feed where it has a probiotic effect.