Diarrhea: the nemesis of the artificially reared, early weaned piglet and a strategy for defense.

Rearing early weaned piglets artificially for the purpose of increasing the efficiency of the sow is an attractive management concept. However, high death losses resulting from diarrhea in artificially reared piglets have dampered enthusiasm for early weaning. Enterotoxigenic Escherichia coli, transmissible gastroenteritis virus and rotavirus are the three main enteropathogens responsible for causing the diarrhea. The enteropathogens infect the small intestine, which produces a secretory or malabsorptive diarrhea. In nature, the nursing piglet is protected from the enteropathogens by antibody bathing his gut. The source of the antibody is the dam's colostrum and milk. It should be possible to protect artificially reared, early weaned piglets from enteropathogens by feeding them diets that contain antibodies to putative enteropathogens.