Evaluation of the chicken crop as a source of Salmonella contamination for broiler carcasses.

Much previously published research has focused on the role of cecal and intestinal Salmonella contamination of poultry carcasses within commercial processing plants. Presently, we have evaluated the persistence of experimentally inoculated Salmonella enteritidis in the crops and ceca of commercial broiler chickens during the last week of growth (Weeks 6 to 7) and the presence of crop and cecal Salmonella in 7-wk-old broilers in a commercial processing plant. When broilers were inoculated with 1 x 10(6) cfu S. enteritidis at 6 wk of age by oral gavage, the incidence of crop and cecal contamination was equivalent 2d after challenge (30%), with only 1 of 29 crops contaminated and 0 of 29 ceca contaminated at 7 d following challenge. When broilers were inoculated with 1 x 10(8) cfu S. enteritidis at 6 wk of age by oral gavage, 2 d after challenge the crops and ceca were observed to be 57 and 67% positive for S. enteritidis, respectively. Seven days after inoculation with 1 x 10(8) S. enteritidis, the crops and ceca were 37 and 57% positive, respectively, for the challenge organism. At a commercial broiler processing plant, 286 of 550 crops from three flocks were Salmonella-positive, whereas only 73 of 500 ceca from these flocks were contaminated. Furthermore, data from this plant indicated that the crops were far more likely to rupture than ceca (86-fold) during processing, increasing the possibility of carcass contamination with Salmonella derived from crop contents. The results of these studies suggest that the crop may serve as a source of carcass contamination with Salmonella within some processing plants.