Microbiological contamination of cattle carcasses at different stages of slaughter in two abattoirs

• A microbial process analysis of cattle slaughtering was performed in two abattoirs.
• Carcasses were examined for aerobic colony counts (ACC) and Enterobacteriaceae.
• After skinning, microbial results were low (average ACC: 1.5 log CFU cm− 2).
• Mainly minor changes occurred during slaughtering (exception: blast chilling).
• Carcass-hide ratios allow comparing process performance in the daily practice.

Cattle carcasses from two abattoirs were examined at selected stages of slaughter (skinning, evisceration, trimming, washing, blast chilling) for aerobic colony counts (ACC) and Enterobacteriaceae. At each stage and abattoir, 50 carcasses were sampled by swabbing at the neck, brisket, flank and rump. After skinning, average ACC on carcasses was 1.5 log CFU cm− 2 and Enterobacteriaceae frequencies at sites were ≤ 6%. From skinned to washed carcasses, certain abattoir- and site-specific changes occurred. Blasting clearly reduced ACC and Enterobacteriaceae results on carcasses from abattoir B, but reductions were limited or lacking in abattoir A. In addition, 100 hides and corresponding chilled carcasses were examined. On hides, average ACC was 5.6 log CFU cm− 2 and Enterobacteriaceae frequencies at sites ranged from 74 to 96%. Average carcass–hide ratios of the two abattoirs were comparable for ACC (0.0182–0.0202%) but differed for Enterobacteriaceae counts (abattoir A: 0.4627%; abattoir B: 0.0941%). Such ratios allow comparing process performance between abattoirs in the daily practice.