Dietary influence on a desirable fatty acid composition in milk from dairycattle

Milk components, with respect To the potential for improving health and the prevention of health problems, are intermediate products of the biohydroge nation of poly-unsaturated fatty acids in the rumen of cattle. Dairy produc ts are a major source of conjugated linoleic acids (CLA) in the human diet. It has been demonstrated that CLA can suppress carcinogenesis, modulate th e immune system, and can have an anti-obesity effect, while reducing athero genesis and diabetes. Controlled intervention studies showed that trans fat ty acids have a significant adverse effect on the LDL cholesterol level. Th e aim must therefore be to have a high content of poly-unsaturated fatty ac ids and CLA in milk, while concurrently having a low content of trans-9 and trans-10 C-18:1 fatty acids. The high correlation between CLA and the sum of all trans fatty acids of r = 0.88 in milk fat demonstrates that this goa l is not easy to achieve. New feeding strategies for lactating ruminants in which an independent regulation of the different C-18:1 isomers is conside red as pasture feeding, concentrate to roughage management, use of protecte d plant oils and use of milk fat low-sensitive cows have to be developed.