THE INFLUENCE OF DIET ON INFECTIONS WITH ASCARIS-SUUM AND OESOPHAGOSTOMUM-DENTATUM IN PIGS ON PASTURE

The influence of two diets varying in type and level of carbohydrates on pasture-reared pigs naturally infected with Ascaris suum and Oesoph agostomum dentatum was investigated. Twenty worm-free pigs, from a spe cific pathogen-free farm were divided into two comparable groups and p astured for 20 weeks. The diets consisted of a traditional ground barl ey plus protein feed (diet A) and barley flour plus Raftiline'' plus s ugar beet fibre plus protein (diet B), respectively. The faecal egg ex cretion was followed and subsequently all pigs were slaughtered and wo rm numbers, worm location, sex, developmental stage and female worm fe cundities were determined. A. suum and O. dentatum faecal eggs counts, worm burdens and female worm fecundities were significantly higher in group A than in group B (P <0.001). The diet (A) rich in insoluble no n-starch polysaccharides and lignin apparently provided favourable con ditions for the establishment of A. suum and O. dentatum, whereas diet B low in lignin and with a higher content of soluble non-starch polys accharides, led to significant reduction in worm numbers and female wo rm fecundities.