Intestinal Damages by F18 and Its Amelioration with an Antibacterial Bacitracin Fed to Nursery Pigs.

This study investigated intestinal oxidative damage caused by F18 and its amelioration with antibacterial bacitracin fed to nursery pigs. Thirty-six weaned pigs (6.31 ± 0.08 kg BW) were allotted in a randomized complete block design. Treatments were: NC, not challenged/not treated; PC, challenged (F18 at 5.2 × 10 CFU)/not treated; AGP challenged (F18 at 5.2 × 10 CFU)/treated with bacitracin (30 g/t). Overall, PC reduced ( < 0.05) average daily gain (ADG), gain to feed ratio (G:F), villus height, and villus height to crypt depth ratio (VH:CD), whereas AGP increased ( < 0.05) ADG, and G:F. PC increased ( < 0.05) fecal score, F18 in feces, and protein carbonyl in jejunal mucosa. AGP reduced ( < 0.05) fecal score and F18 in jejunal mucosa. PC reduced ( < 0.05) populations in jejunal mucosa, whereas AGP increased ( < 0.05) and reduced ( < 0.05) populations in feces. Collectively, F18 challenge increased fecal score and disrupted the microbiota composition, harming intestinal health by increasing oxidative stress, and damaging the intestinal epithelium, ultimately impairing growth performance. Dietary bacitracin reduced reduced F18 populations and the oxidative damages they cause, thereby improving intestinal health and the growth performance of nursery pigs.