Thanh, B. V. L., Lessard, M., Chorfi, Y. and Guay, F. 2015. The efficacy of anti-mycotoxin feed additives in preventing the adverse effects of wheat naturally contaminated with Fusarium mycotoxins on performance, intestinal barrier function and nutrient digestibility and retention in weanling pigs. Can. J. Anim. Sci. 95: 197-209. This study was designed to determine the effect of feeding deoxynivalenol (DON) contaminated wheat to growing pigs on growth performance, digestibility and retention of nitrogen (N), phosphorus (P) and calcium (Ca). Secondly, we wished to evaluate the potential of four commercial anti-mycotoxin additives in preventing the adverse effects of DON. Sixty piglets (6.0 kg body weight) were assigned to six different corn-soybean meal-wheat diets (control diet: <0.5 mg kg^-1 DON; contaminated diet (DON-contaminated): 4 mg kg^-1; and four contaminated diets supplemented with a different anti-mycotoxin additive: DON GLUC (glucomannan), DON YBP (yeast, live bacteria, enzymes, plant extracts), DON ALU (aluminosilicate) and DON PC (preservation components). Piglets were housed individually in pens for 7 d and then transferred to metabolic crates for urine and feces collection for 7 d. At the end of these 2 wk, mannitol and lactulose doses were given by oral administration. Urine was collected for 24 h for an evaluation of barrier integrity of intestinal mucosa. The piglets were then euthanatized and intestinal samples collected for morphology studies. Feeding DON-contaminated wheat reduced average daily feed intake, average daily gain and G:F ratio compared with the control diet (P<0.05). Only DON PC diet restored the growth performance of piglets fed DON-contaminated diet. Daily retention of N and P was not affected by DON contamination or anti-mycotoxin additives, but retention of Ca was higher in piglets fed the DON-contaminated diets than the control diet. DON-contaminated diet reduced digestibility of dry matter, gross energy and fat, villi height in jejunum, and recovery of mannitol and lactulose compared with the control diet (P<0.05). Finally, DON concentrations in serum from piglets fed the DON-contaminated diets were higher than in the control diet (P<0.05). Piglets fed DON-contaminated wheat had reduced growth possibly caused by impaired jejunal morphology and decreased digestibility of energy and fat.