Raw materials used in feed manufacture are contaminated with high (>104 cfu/g) levels of enterobacteriaceae indicating the potential for contamination with pathogenic bacteria such as salmonella (Wood et al. 2001). There is urgent need to reduce the contamination of animal feed with zoonoses such as salmonella and campylobacter. During manufacture of feedingstuffs, heat and moisture are used to process and sterilise feed but this can also provide conditions for microbial growth. High temperature treatment used to sterilise feed will not protect feedingstuffs from recontamination, if residual microbial contamination remains in the feed mill. It is essential to understand the influence of feed processing and the feed mill environment on the microbial contamination of feed.