The microbial condition of Scottish wild deer carcasses collected for human consumption and the hygiene risk factors associated with Escherichia coli and total coliforms contamination

Abstract

Wild deer hunting is necessary in Scotland to control deer population density, with most carcasses being processed for human consumption. As limited information is available on the microbial condition of Scottish venison, we studied the variation of total coliforms and Escherichia coli (E. coli) on 214 wild deer carcasses collected from six approved establishments. Samples were collected from the hide, body cavity and external surface of each carcass and mean values were determined following bacterial plate counts. The mean log10/cm2 coliforms were 5.78 (hide), 6.80 (body cavity) and 6.36 (external surface). The mean log10/cm2E. coli were 1.82 (hide), 2.27 (body cavity) and 2.17 (external carcass). Significantly higher coliforms counts were associated with storage-to-dressing times above 6 days and with longer transport distances. Risk factors that increased E. coli were red deer species, ambient temperature above 7 °C during hunting, dirty hides, faecal contamination and moisture or slimy film on the carcass. Although the bacterial counts obtained in this study indicated some hygienic processing, for around half of the carcasses, the E. coli counts were above 2 log10/cm2. Therefore, the above risk factors suggest a few handling hygiene practices that should be further improved to enhance quality and safety.