Manipulating dietary PUFA in animal feed: implications for human health

Milk, meat and eggs tend not to be regarded as an important source of PUFA. They are disproportionally high in SFA compared with their PUFA content, especially those from cattle and sheep, since their rumen microbes are responsible for the loss of over 90% of PUFA intake by livestock. This need not necessarily be the case since the relative proportion of PUFA in these foods is dictated by livestock management, especially feeding, and this can be manipulated to boost their content of crucial long-chain n-3 fatty acids and conjugated linoleic fatty acids. The present paper considers the fatty acid composition in animal-derived foods and how these can be manipulated to be more conducive for consumers' health. The importance of recognising the effect of livestock production systems on fat composition is also highlighted along with the fact that we may have to compromise between intensive, high levels of production and this particular aspect of food quality.