The impact of diets varying in type and level of carbohydrates
resistant to endogenous enzymes and lignin on the
establishment and location of Ascaris suum and Oesophagostomum
dentatum was investigated experimentally. Fifty worm-free pigs, from a
specific pathogen-free farm were used. The animals were assigned randomly to
5 diets and infected with
600 infective A. suum eggs and 6000 infective larvae of O. dentatum
per pig. The diets consisted of a traditional ground
barley plus protein feed (diet A), commercial full-constituent pelleted feed
(diet B), barley flour plus protein (diet C),
barley flour, inulin (Raftiline® ST, ORAFTI, Tienen, Belgium), sugar beet fibre
plus protein (diet D), and barley flour,
wheat bran, and protein (diet E). The faecal egg excretion was followed and
the pigs were slaughtered at 8 weeks p.i. and
samples taken from the small and large intestine. Intestinal contents were
analysed for worm burdens, worm location and
female worm fecundity along with the concentration of insoluble
(chromic oxide) and soluble (polyethylene glycol-4000)
markers, lignin, non-starch polysaccharides (NSP) and organic acids. In all
diet groups A. suum worm burdens were low
and comparable, whereas the O. dentatum worm burdens were significantly
higher in pigs fed the diets with high levels
of NSP and lignin (diets A and E) than in pigs fed diets B, C, and D. The
present study suggests that a diet rich in lignin
and insoluble NSP's provides favourable conditions for the
establishment of O. dentatum in the large intestine of pigs
while it is unlikely that the concentration of short-chain fatty acids and
pH plays any major role.