Competitive exclusion of Salmonella typhimurium in broilers fed with vermicompost and complex carbohydrates

Vermicompost (VC) was produced by earthworms fed with fresh chicken faeces, and was earth-like in appearance and odour. In three experiments, VC was sprinkled on the first feed of newly-hatched broiler chicks. Treated and control groups were challenged on day 6 by the addition of seeder chicks that had been inoculated orally with Salmonella typhimurium. Chickens were killed at intervals during a 6-week period and were tested for colonization of the pathogen in the crop, caecum and internal organs. The VC-treated groups were significantly more resistant (p < 0.01) to colonization by S. typhimurium than the untreated controls. In one experiment, the VC treatment appeared to have conferred complete protection against colonization of both the crop and caecum. Colonization of the crop was increased transiently by addition to the diet of 2.5% fructooligosaccharide, xylo-oligosaccharide or transgalactosylated oligosaccharide. The influence of these carbohydrates on colonization of the caecum was variable.