A study was conducted to find the potential sources of microorganisms that are found on cull cow hides and to investigate the entry/contamination points of pathogens on the carcass during the slaughter/dressing process. Eighty cull cows were slaughtered over a 4-day period. Fresh fecal samples and hide surface sponge samples (brisket area) were taken and evaluated for the presence of E. coli O157:H7 and Salmonella. The fecal samples yielded no E. coli O157:H7 or Salmonella. The brisket sponge sample had no E. coli O157:H7 but tested positive for Salmonella at a rate of 13.8 %.
The highest incidence of Salmonella was at pre-evisceration at 1.9% with post final wash and post 24-hour chill having incidence rates of 1%. The brisket location had the highest incidence rate on the carcass at 1.4% for Salmonella. Lameness and hide cleanliness were evaluated with lamer animals having higher overall microbial counts and dirtier hides having higher microbial counts. These conditions did not affect pathogen levels. Although this study is limited in scope, it reaffirms that the presence of pathogens in slaughter cattle, in this case cull cows, is at a very low incidence rate.