Bovine lymph node microbiological survey.

Summary

​Lymph node examination is routinely performed for all cattle slaughtered in Australia.
With the eradication of bovine tuberculosis the practice requires reassessment, as lymph nodes represent microbiological filters and may therefore be a source of contamination of the carcase during inspection.
A survey of the microbiological status of head and thoracic lymph nodes in cattle was conducted as no microbiological data for cattle nodes existed.
The aim of the project was to determine whether the food safety risk of incising lymph nodes is greater than the benefit gained by detecting pathologies through incision rather than palpation.
A substantial proportion of nodes were found to contain high levels of bacteria, with indications of presence of food-borne pathogens.
There was substantial variation in levels of contamination, associated with a number of factors.
The value of routine lymph node incision needs to be considered in terms of risks associated with microbiological cross-contamination, processing efficiencies, and animal disease surveillance requirements.
Further studies on the role of bovine lymph nodes are required as risks to beef safety will enhance the development of evidence-based, effective, and efficient post-mortem inspection procedures.