Identifying important routes of carcass contamination

Summary

​Good hygiene practices on the slaughter floor are essential in ensuring low microbial counts on carcases.
Previous studies have compared systems using relatively poor practices with systems using combinations of animal washing, sterile gloves, face masks and strict knife sanitation at all stations, and only considered the end-product. 
Baseline studies on carcase microbiology in Australian plants have identified that there is a wide range in the microbiological status of carcases produced at different plants. 
This study aimed to examine the amount of microbial transfer from the initial surface to the carcase at individual operations, and how much is picked up by the tools and hands of the operator during the operation.
The results indicated that for the skinning operations, the hide was the most significant potential source of contamination, carrying the greatest microbial load, and the greatest numbers and prevalence of both E. coli and S. aureus. 
There was no correlation between hide total viable count at either legging or brisket clearing and the carcase total viable count at ESAM sampling. 
By understanding the dynamics of cross-contamination at an individual operation, it is possible to identify the relative importance of particular components of the operation, such as manual handling versus implement.
This study did not identify any apparent relationship between the operations at each individual dressing station and the final microbial load on the carcases at ESAM sampling; further work is needed to elicit the true sources of this contamination.