The use of competitive exclusion in broilers to reduce the level of Salmonella contamination on the farm and at the processing plant.

The effect of a competitive exclusion (CE) product, Broilact, on Salmonella contamination of broiler chickens was studied on the farm and at the processing plant. In the first part of the study, two flocks per week, a CE-treated and an untreated control flock, were placed in similar broiler houses. The CE treatment was administered in the hatchery using a modified spray vaccination cabinet. Salmonella was analyzed from the paper pads of the transport boxes on arrival at the farm and from fecal samples taken 2 wk before slaughter. The results of Salmonella sampling were received for 67 flocks. The other 141 flocks of the company that were reared during the trial period were also sampled for Salmonella and the results were compared to those of treatment and control groups. Broiler performance, including mortality, weight, and feed conversion, was recorded for the trial flocks. In the second part of the study, Salmonella contamination of neck skin samples taken at the processing plant from 18 CE-treated and 28 control flocks was compared. The Broilact-treatment significantly reduced Salmonella contamination both on the farm and at the processing plant. At the level of the farm, the percentage of Salmonella-positive flocks was essentially the same in the control flocks and in other flocks reared during the trial period. An improvement in broiler performance was indicated, although the difference was not significant.