An Investigation of Calf Carcass Contamination by Escherichia coli from the Gut Contents at Slaughter

The degree of carcass contamination at slaughter of three groups of calves (a total of 36 animals) was studied and the O-antigen types of Escherichia coli found on the carcass surface and in rectal contents were determined. In one-third of the animals E. coli strains found on the surface of a carcass belonged to the same O-serotype as those found in the rectal sample of the same calf. Nearly all the O-serotypes found on the carcasses were also found in the rectal contents of at least one calf, showing that cross-contamination of carcasses had occurred. The E. coli isolated from the rectal contents were all resistant to at least one antibacterial agent.