THE FATTY-ACID COMPOSITION OF MILK-FAT AS INFLUENCED BY FEEDING OILSEEDS

The fatty acid composition of bovine milk fat can be substantially alt ered by feeding lipid sources which alter the fatty acid profile of li pid entering the intestine from the rumen. As long-chain fatty acids o f dietary origin can be incorporated directly into milk fat the opport unity exists to alter the ratio of short and long-chain fatty acids as well as the degree of saturation of milk fat. In practice our ability to alter the fatty acid profile of milk fat is limited not by the syn thetic capacity of the mammary gland, but rather by the challenge of a chieving effective protection of unsaturated dietary fatty acids from biohydrogenation in the rumen, as well as keeping the level of polyuns aturated fatty acids within the range where the organoleptic quality a nd shelf-life of milk and dairy products are not compromised. The fatt y acid composition of oilseeds such as canola are considered desirable from a human health perspective and thus their inclusion in the diet of dairy cattle as a means of achieving a more desirable fatty acid pr ofile in milk fat may enhance the nutritive quality of milk.