Abstract
Postweaning colibacillosis in piglets is associated with proliferation and colonisation of β-haemolytic entertoxigenic Escherichia coli in the small intestine. The pathogenesis of this disease is complex, with dietary composition being an important contributing factor. In this experiment the interaction between dietary fibre and intestinal β-haemolytic E. coli populations was studied in 33 experimentally infected newly-weaned piglets. A source of soluble fibre (guar gum) was added to the base diet (cooked rice/ animal protein) to increase the dietary soluble fibre content from 1 to 6% on a dry matter basis. The base diet and the guar gum diet were fed to a separate group of piglets for a week from weaning. Experimental inoculation with haemolytic E. coli took place 48 hours after weaning, and all intestinal samples were taken 6-7 days postweaning. Pigs fed the guar gum diet had significantly higher (p<0.05) number of colony-forming units (CFU) of β-haemolytic E. coli per gram of mucosal scraping at 50% along the length of the small intestine (8.0 x 10 9 compared to 1.3 x 10 4 CFU/gram mucosal scraping). No significant differences in haemolytic E. coli numbers were found in the large intestine between diets. Addition of guar gum to the base diet also resulted in reduced weight gain after weaning (p<0.0001). Soluble fibre in the diet appears to be detrimental to growth and health of pigs in the first week postweaning.