The present invention relates to novel subspecies of Bacillus. The novel subspecies can improve health and performance of production animals. In one embodiment the Bacillus subtilis subspecies has activity against Clostridium perfringens and/or E. coli. The invention further relates to compositions comprising one or more strains of the Bacillus subtilis subspecies and to use of the strain(s) of the Bacillus subtilis subspecies in an animal feed.