The intestine is recognized to have important endocrine, metabolic,
immunologic, and barrier functions, as well as nutrient absorption
capacity. In weaned pigs, the change of diet and the aggression and
stress caused by mixing of litters induce decreased feed intake, which
is followed by shortened villi, deepened crypts and other intestinal
problems (Pluske et al., 1997). The architectural and physiological
integrity of the gut is fundamental to its barrier function and serves an
important role in animal health. The barrier functions of the gut include