254 Intestinal Oxidative Damages By F18+Escherichia Coli and Its Amelioration with an Antibacterial Bacitracin Fed to Nursery Pigs

Abstract

Abstract This study investigated the intestinal oxidative damages caused by F18+Escherichia coli and its amelioration with an antibacterial bacitracin fed to nursery pigs. Thirty-six weaned pigs (6.31 ± 0.08 kg BW) were allotted in RCBD. Treatments were: NC, not challenged/not treated; PC, challenged (F18+E. coli at 5.2 × 109 CFU)/not treated; AGP, challenged (F18+E. coli at 5.2 × 109 CFU)/treated with bacitracin (30 g/t). The F18+E. coli was orally inoculated to pigs on challenged treatments at d 7. The unchallenged pigs received an oral dose of sterile saline solution. The fecal score was recorded daily. Body weight and feed intake were recorded weekly. On d 14 and 28, fecal and blood samples were collected. On d 28, all pigs were euthanized to collect intestinal samples. F18+E. coli counting, microbiota composition, and intestinal health variables were analyzed. Data were analyzed using the mixed procedure on SAS 9.4. Overall, PC reduced (P < 0.05) ADG (353 to 282 g), G:F (0.71 to 0.55), villus height (527 to 394 µm), and VH:CD (2.22 to 1.58), whereas AGP increased (P < 0.05) ADG (298 to 344 g), and G:F (0.55 to 0.61). PC increased (P < 0.05) fecal score from d 7 to 14 (3.0 to 4.6), from 14 to 21 (2.8 to 3.9), and from d 21 to 28 (2.5 to 3.2); increased F18+E. coli (5.9 to 7.5 log DNA) in feces at d 14, and protein carbonyl (2.15 to 3.61 nmol/mg protein) in jejunal mucosa. AGP reduced (P < 0.05) fecal score from d 7 to 14 (4.6 to 4.0) and from d 14 to 21 (3.9 to 3.4) and reduced F18+E. coli (4.3 to 3.9 log DNA) in jejunal mucosa. PC reduced (P < 0.05) Prevotella stercorea (5.1 to 1.5%) population in jejunal mucosa, whereas AGP increased (P < 0.05) Phascolarctobacterium succinatutens (3.0 to 10.0%) and reduced (P < 0.05) Mitsuokella jalaludinii (8.7 to 2.0%) populations in feces. Collectively, F18+E. coli 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 oxidative damages caused by F18+ E. coli thereby protecting intestinal health by reducing F18+E. coli population in jejunal mucosa and fecal score, consequently improving the growth performance of nursery pigs.