Analysis of a poultry slaughter process: Influence of process stages on the microbiological contamination of broiler carcasses

In a large-scale Swiss poultry abattoir, a microbiological process analysis of broiler carcasses was performed. At each selected process stage (scalding, plucking, evisceration, washing, and chilling), 90 carcasses from 30 flocks were sampled and examined for Campylobacter, Salmonella, Escherichia coli, Enterobacteriaceae, and extended-spectrum b-lactamases-producing Enterobacteriaceae. With regard to Campylobacter counts on carcasses, plucking tended to slightly increase the results (on average by 0.4 log CFU/g), whereas mean counts from plucked and chilled carcasses were comparable (3.1 log CFU/g after plucking, 3.0 log CFU/g in the chiller). The Campylobacter results of chilled carcasses are thereby likely to comply with the newly defined requirements of the European Union (process hygiene criterion for Campylobacter). With regard to Escherichia coli and Enterobacteriaceae counts on carcasses, plucking clearly reduced the results (on average by 0.8 and 0.9 log CFU/g), whereas mean counts from plucked and chilled carcasses were comparable (3.4 and 3.5 log CFU/g after plucking, 3.4 log CFU/g in the chiller). In contrast, Salmonella spp. were not detected on broiler carcasses and extended-spectrum b-lactamases- producing Enterobacteriaceae only rarely (1.8%). Such abattoir-specific data are of central importance for assessment of slaughter process performance and if necessary for the implementation of effective measures in the slaughter process.