The Impact of an Extended Bleed-to-evisceration Interval on the Microbiological Quality of On-farm Slaughtered Cattle Carcasses

Abstract

The uncertainties surrounding the microbiological risks of an extended exsanguination-to-evisceration interval have limited the implementation of on-farm slaughter in Europe. On-farm slaughter is increasingly advocated by farmers, consumers, and policymakers as a humane alternative to traditional slaughterhouse operations. However, concerns about hygiene and food safety, particularly bacterial contamination, have led to stringent time limits imposed by Member States on the interval between bleeding and evisceration. Microbiological standards for bovine carcasses in the European Union are governed by Commission Regulation (EC) No 2073/2005, which sets process hygiene criteria for aerobic colony count and Enterobacteriaceae. To investigate whether extending the bleed-to-evisceration interval compromises meat safety, five Holstein dairy cattle were slaughtered on-farm, with samples collected from the internal paralumbar area in contact with the intestines for up to 4 h postmortem. The samples were analyzed for Enterobacteriaceae, aerobic colony count, and Escherichia coli. None of the samples exceeded the established thresholds of 1.5 and 3.5 log CFU/cm² for aerobic colony count and Enterobacteriaceae, respectively, as defined by Belgian health authorities for the nondestructive sampling method. These preliminary findings suggest that on-farm slaughter with evisceration occurring up to 4 h post-mortem does not pose increased microbiological risks to human health. However, further research is necessary, particularly under warmer environmental conditions and with a larger sample size, to confirm these results and to explore additional factors that may influence bacterial translocation and digestive tract wall integrity.