“…Of the large animal group, the intestinal flora of the pig has been most extensively studied (36,84,103,121,122,124,151,152,162,246,248). It is evident from these and other publications (66,67,73,94,201) that the relationship between various bacterial species in the intestine and their distribution varies greatly in the normal animal and is influenced by such factors as age, diet, pH, oxidation-reduction potentials in the various portions of the intestine, and antagonisms and synergisms between and within the bacterial species involved.…”