M01009: Source and spread of particulate and bacterial contamination between cattle during farm to abattoir phase of production

Study Duration: October 1999 to September 2002

Contractor: ADAS Consulting Ltd

Contamination of beef carcasses during slaughter and dressing is unavoidable and work needs to be done to minimise the amount of microbiological contamination present as cattle go to slaughter, as well as in the abattoir. The overall objectives of this project are to establish the incidence of E. coli O157, salmonella and campylobacter on-farm, in markets and abattoir environments, to investigate the spread of particulate and bacterial contamination between cattle along the production/processing chain, and develop intervention measures to reduce these risks.

Contamination of beef carcasses during slaughter and dressing is unavoidable and work needs to be done to minimise the amount of microbiological contamination present when cattle go to slaughter, as well as in the abattoir.

The objective of this project was to establish the incidence of E. coli O157, salmonella and campylobacter on farms, in markets and abattoir environments, to investigate the spread of particulate and bacterial contamination between cattle along the production/processing chain, and develop intervention measures to reduce these risks.

• the incidence of E. coli O157 in faeces from beef farms in England/Wales and Scotland was 1% and 6% respectively, with greater numbers occurring in the autumn rather than the spring sampling
• campylobacter was found in 10% and 25% of faecal samples from farms in England/Wales and Scotland respectively with incidence being higher in spring
• when clean and dirty cattle were mixed during transport, Enterobacteriacae and E.coli counts were higher pre-transport in dirty than in clean cattle, but levels on both were similar post-transport
• the highest counts were recovered from the brisket, a significant area in carcass preparation. Large increases of indicator organisms were also observed on cattle hides following a period of rainfall
• where cattle were fed differential diets prior to transport, animals on the low dry matter diet were cleaner and had the lowest levels of E.coli and Enterobacteriaceae
• a survey carried out on cattle arriving at livestock markets indicated that microbial load on the hide was influenced by: clipping and coat type, diet and dietary change, group size, mixing of cattle groups and lorry bedding. The incidence of E.coli O157 and campylobacter species on cattle in livestock markets was 1% and 8% respectively
• a simulated market study showed clearly that there is considerable transfer of pathogens between animals, both directly from animal to animal and via environmental surfaces
• the prevalence of pathogens on cattle within abattoirs was 29% for E.coli O157, 18% for salmonella species and nil for campylobacter species. Environmental samples detected E.coli O157 at 7%, salmonella species at 6% and campylobacter species at 1%
• routine abattoir cleaning was largely confined to hosing without disinfectants, which was ineffective. The holding pen floor had the highest level of pathogen contamination with 50% of samples testing positive
• the lifespan and growth study of pathogens demonstrated an accumulation of pathogens under certain conditions, but reductions were seen as a result of high temperatures, dry conditions and clean substrates
• investigations into the transfer of pathogens in lairage (a building used to hold animals before slaughter) identified that bacterial contamination was isolated in 30% of animals. This could be transferred onto non-contaminated animals during lairaging and therefore onto carcasses at slaughter. Pathogens can also be transferred to the pen-to-stun environment from which non-contaminated animals can become contaminated
• when low, medium and high dry matter diets were fed to cattle, followed by a change from each diet to either hay or compound, no significant differences were observed in the shedding of indicator organisms between diet combinations

The experiments detailed above culminated in the design of a new Hazard Analysis and Critical Control Point (HACCP) document. Production steps for autumn and spring born dairy-bred and suckled calves have been identified, key hazards recognised and their risks prioritised. Evidence from the findings of the study have identified measures that could be put in place.

The results generated by this project have been used to help formulate the Meat Safety and Clean Cattle on-farm information days on the hygienic production of cattle.

Final report is available from the Agency's Information centre.
To obtain a copy, please contact the Enquiry Desk, Information Services, Food Standards Agency (tel: 020 7276 8181/8182 or email: infocentre@foodstandards.gsi.gov.uk).

Publications

Reid, C.A., Avery, S.M., Hutchison, M.L. and Buncic, S. (2002). Evaluation of sampling methods to assess the microbiological status of cattle hides. Food Control 13 (6-7): 405-410.

Reid, C.A., Small, A., Avery, S.M. and Buncic S. (2002). Presence of food-borne pathogens on cattle hides. Food Control 13 (6-7): 411-415.

Small, A., Reid C.A., Avery S.M., Karabasil N., Crowley C. and Buncic S. (2002). Potential for the spread of Escherichia coli O157, Salmonella and Campylobacter in the lairage environment at abattoirs. Journal of Food Protection 65 (6): 931-937.

Contact: For any enquiries concerning this research project, please contact the relevant programme contact or email: science@foodstandards.gsi.gov.uk