Protecting chicks and poults from Salmonellae by oral administration of "normal" gut microflora.

Resistance of young chicks and poults to salmonella exposure was substantially increased by early oral administration of intestinal contents or feces from selected adult chickens. Protection was secured also by administering anaerobic broth cultures of intestinal microflora from selected donor birds. Protection, was substantial for 63 days, the longest period tested, although it could be overcome by severe exposure. The protective mechanism appears to be a consequence of competitive exclusion of salmonella by "normal" microflora of the gastrointestinal tract.