THE IMPACT OF DIETS VARYING IN CARBOHYDRATES RESISTANT TO ENDOGENOUS ENZYMES AND LIGNIN ON POPULATIONS OF ASCARIS-SUUM AND OESOPHAGOSTOMUM-DENTATUM IN PIGS

The impact of diets varying in type and level of carbohydrates resista nt to endogenous enzymes and lignin on the establishment and location of Ascaris suum and Oesophagostomum dentatum was investigated experime ntally. 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 pe r pig. The diets consisted of a traditional ground barley plus protein feed (diet A), commercial full-constituent pelleted feed (diet B), ba rley flour plus protein (diet C), barley flour, inulin (Raftiline(R) S T, ORAFTI, Tienen, Belgium), sugar beet fibre plus protein (diet D), a nd barley flour, wheat bran, and protein (diet E). The faecal egg excr etion was followed and the pigs were slaughtered at 8 weeks p.i. and s amples taken from the small and large intestine. Intestinal contents w ere 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 polysaccharide s (NSP) and organic acids. In all diet groups A. suum worm burdens wer e low and comparable, whereas the O. dentatum worm burdens were signif icantly higher in pigs fed the diets with high levels of NSP and ligni n (diets A and E) than in pigs fed diets B, C, and D. The present stud y suggests that a diet rich in lignin and insoluble NSP's provides fav ourable conditions for the establishment of O. dentatum in the large i ntestine of pigs while it is unlikely that the concentration of short- chain fatty acids and pH plays any major role.