THE ROLE OF DEFEATHERING IN THE CONTAMINATION OF TURKEY SKIN BY SALMONELLA SPECIES AND LISTERIA-MONOCYTOGENES

This study was undertaken to determine whether the incidence of either Salmonella spp. or Listeria monocytogenes on turkeys at three commerc ial processors could be related to the type of defeathering system: 1) conventional, 58 C common bath scald; 2) kosher, 7 C common bath scal d; or 3) steam-spray, 62 C nonimmersion scald. Flocks were sampled bef ore defeathering, after defeathering, and after chill at each facility . The incidence of Salmonella-positive turkeys significantly increased subsequent to conventional defeathering (10 positive out of 14) as co mpared with before defeathering (3/14). The number of Salmonella-posit ive carcasses following kosher (0/14) and steam-spray (2/14) defeather ing were similar to the number of Salmonella-positive carcasses found prior to defeathering (1/14 and 3/14, respectively). The incidence of Salmonella-positive carcasses following chill was slightly lower, but not significantly different than the number of Salmonella-positive car casses found immediately following defeathering at all processors (8/1 4, 0/14, 1/14 for conventional, kosher, and steam-spray processors, re spectively). Although L. monocytogenes was detected on turkeys sampled before chilling (2/10, kosher) and after chilling (8/14, kosher; 1/14 , conventional), no L, monocytogenes was detected on turkeys at any of the processors prior to the evisceration process. Flocks with high ae robic plate counts prior to processing were more likely to contain Sal monella-positive birds throughout processing. Aerobic plate counts of all flocks were similar after chill whether or not Salmonella spp. and L. monocytogenes were detected.