This invention relates to a process to improve the feed efficiency and carcass characteristics of (1) animals that are not showing clinical signs of disease or other microbial challenge and (2) animals that are not expected to show clinical signs of disease or other microbial challenge (that is, within the next 1-2 weeks or less) because of known management practices, such as weaning of piglets. The process of this invention can be used to decrease the cost of animal diets, to improve performance of animals and to improve the percentage of carcass in animals.
