Effects of Oesophagostomum dentatum and dietary carbohydrates on morphology of the large intestine of pigs

The effects of Oesophagostomum dentatum infection and dietary carbohydrates on the morphology and epithelial cell proliferation in the gastrointestinal tract of pigs were investigated experimentally. Thirty-two worm-free pigs (n=32) from a specific pathogen-free farm were randomly divided into four groups (A-D), of eight animals each. Pigs in groups A (control) and B (infected) were fed Diet 1, and pigs in groups C (control) and D (infected) were fed Diet 2. The two diets were formulated: Diet 1 (%) contained barley flour, oat husk meal plus soya bean meal (55:21:24) and Diet 2 (%) contained barley flour, inulin and sugar beet fibre (SBF) (80.1:7:12.9) plus soya bean meal (3:1) to contain carbohydrates from inulin and sugar beet fibre (SBF) that were readily fermentable in the large intestine. The two infected pig groups (16 pigs total) were inoculated with 6000 infective larvae of O. dentatum and all pigs, including the controls, were slaughtered 12 weeks p.i. The combination of O. dentatum infection and highly fermentable dietary carbohydrates affected the mucosal architecture, the epithelial cell proliferation and mucin secretion of the large intestine. Infection had a significant influence on the crypt volume, height and density, and on muscularis externa at the proximal and middle colon. The changes in the affected gut sections were proportional to the number of worms present. However, these parameters appeared unaffected by those diets alone. In pigs without infection non-digestible dietary carbohydrates significantly influenced the tissue weight of colon.