TRFs useful for identifying strains of interest are provided. A method of identifying one or more strain that can be used as a direct-fed microbial is also provided. One or more strain identified by the method is additionally provided. A method is also provided for administering to an animal an effective amount of the one or more strain. Additionally provided is an isolated strain chosen from at least one of Lactobacillus acidophilus strain P1B c6 (NRRL B-50103), Lactobacillus salivarius strain o246e 33w (NRRL B-50102), Pediococcus acidilactici strain o246e 42 (NRRL B-50171), and Pediococcus acidilactici strain P1J e3 (NRRL B-50101). An isolated strain having all of the identifying characteristics of one of the strains listed above is also provided. One or more strain can be administered as a direct-fed microbial to an animal. Methods of preparing a direct-fed microbial are also provided.