The effect of dietary carbohydrates with different digestibility on the populations of Oesophagostomum dentatum in the intestinal tract of pigs

An experiment was undertaken to study the effect of dietary carbohydrates w ith different digestibility on the populations of Oesophagostamum dentatum in the intestinal tract of pigs. Sixty-four worm-free pigs from a specific pathogen-free farm were randomly divided into 8 equal groups. The animals i n 4 groups were assigned to a diet with partially undegradable carbohydrate s (diet 1), while the pigs in the 4 remaining groups were given a diet with fermentable carbohydrates (diet 2). Diet 1 was comprised of barley flour, oat husk meal, soybean meal, vitamins and minerals and diet 2 of barley flo ur, inulin and sugar beet fibre, soybean meal, vitamins and minerals. The p igs in 6 of the groups (n=48) were inoculated with 6000 infective larvae of O. dentatum. To determine O. dentatum populations at the early stage of in fection, 16 pigs were slaughtered 3 weeks p.i., while the remaining 4 group s continued on the diets for a further 9 weeks after which they were slaugh tered. In a diet cross-over experiment 6 weeks after inoculation, 8 pigs ch anged from diet 1 to diet 2 (diet 1 > diet 2), and 8 pigs from diet 2 to di et 1 (diet 2 > diet 1). The results showed that partially undegradable carb ohydrates provided favourable conditions not only for parasite establishmen t and sustainability, but also for already established O. dentatum infectio n while, in contrast, the diet composed of highly degradable carbohydrates decreased worm establishment, size and female fecundity. The implications f or pastured pigs or pigs fed different complex carbohydrate diets is discus sed.