Risks to farm animals from pathogens in composted catering waste containing meat

Abstract

Uncooked meat may contain animal pathogens, including bovine spongiform encephalopathy, foot-and-mouth disease virus, African swine fever virus and classical swine fever virus, and to prevent outbreaks of these diseases in farm animals, the disposal of meat from catering waste is controlled under the Animal By-Products Regulations. This paper estimates the risks to farm animals of grazing land on to which compost, produced by the composting of catering waste containing meat, has been applied. The factors controlling the level of risk are the separation of the meat at source, the efficiency of the composting process, and the decay and dilution of the pathogens in soil. The net pathogen destruction by the composting process is determined largely by the degree of bypass, and to accommodate the possibility of large joints or even whole carcases being discarded uncooked to catering waste, a time/temperature condition of 60°C for two days is recommended. Where data are lacking, worst-case assumptions have been applied. According to the model, classical swine fever virus constitutes the highest risk, but the assessment shows that a two-barrier composting approach, together with a two-month grazing ban, reduces the risk to one infection in pigs every 190 years in England and Wales. This work defined the operational conditions for the composting of catering waste as set out in the Animal By-Products Regulations 2003 (SI 1482).