The practice of supplementing direct fed microbial and prebiotic additives to domestic animals during growth is becoming more widespread in food animal production. Beneficial effects particularly in cattle, pigs and poultry, including improved general health, foodborne pathogen reduction, more efficient food utilization, faster growth rate and increased milk and egg production are common results. The success associated with direct fed microbial and prebiotic applications in multiple species ensures their continued commercialization and the widespread use of such additives. However, several...