SOURCES OF SALMONELLAE IN BROILER-CHICKENS IN ONTARIO

Abstract

Sources of salmonellae infecting broiler chicken flocks in Ontario, Canada, were investigated from July, 1975-April, 1976. Three broiler flocks were investigated on each of 4 farms which received chicks from a common hatchery. Samples of feed and new litter were preenriched in nonselective broth subcultured to Salmonella-selective enrichment broth and plated on Salmonella-selective differential agar. Samples of used litter, water, culled chicks, insects, mice, wild birds and environmetnal swabs were not cultured initially in the nonselective broth. Fecal samples from principal and occasional flock attendants were examined for salmonellae. Salmonella infection, as judged by contaminated flock litter was detected in 6 flocks on 2 of the farms while the flocks on the other farms remained negative. Salmonellae were isolated from 23 of 412 feed samples (9 serotypes), 6 of 35 new wood shaving samples (4 serotypes), 1 of 29 pools of culled chick viscera (1 serotype) and 44 of 267 used litter samples (14 serotypes). Apparently broiler chicken flocks were infected with diverse salmonellae introduced in day old chicks, pelleted feeds, wood shavings and residual contamination from the preceding flock.