The effects of l-arginine (Arg) supplementation on intestinal mucosal immune barrier function in weaned pigs after Escherichia coli LPS challenge were evaluated. Twenty-four weaned pigs were allotted to four treatments including: (i) non-challenged control; (ii) LPS-challenged control; (iii) LPS + 0.5% Arg; and (iv) LPS + 1.0% Arg. On d 16, pigs in the LPS, LPS + 0.5% Arg and LPS + 1.0% Arg groups were challenged by injection with 100 μg/kg of body mass LPS, whereas the control group were given sterile saline. At 48 h post-challenge, all pigs ...