Campylobacter isolation trends of cage versus floor broiler chickens: a one-year study.

An experiment was carried out over a 1-yr period with broiler chickens to assess the influence of cage and floor rearing environments on the isolation trends of Campylobacter jejuni. The study used 36 7-wk-old broiler chickens that were raised in floor pens and naturally infected with or exposed to C. jejuni during the growout period. These broilers were then leg-banded and split into two groups with 18 per group. The groups were placed in wire cages or in a floor pen with unused litter in separate houses on the same farm. Each broiler was swabbed cloacally monthly to determine the presence of C. jejuni. The yearly average percentage isolation rates were significantly (P < 0.05) higher for the broilers held in the litter floor pen (130/185;66%) when compared to the broilers kept in wire cages (67/193;35%). There was a trend for higher isolation rates in the fall for caged and floor broilers and a decrease in rates near the end of the experimental year (summer) in the caged broilers. Isolation rates for both treatments reached their lowest level for the month of March. No caged broilers tested positive during the last 4 mo of the trial. The long-term cage isolation was linked to a reduced prevalence of C. jejuni. The results from this study suggest that housing environment and time spent in that environment play a major role in the continuing shedding and isolation of C. jejuni in broiler chickens.