16 November 2001

Study focuses on fatty acid content

RELIABLY producing healthier milk requires a means of predicting milk fatty acid content when cows are fed a given ration.

The final phase of a four-year DEFRA-funded study was to test a simple model for predicting milk fatty acid composition, says ADAS Nutritional Sciences Research Units Angela Moss.

"The model, developed by researchers at the National Institute of Animal Science in Denmark, uses the fatty acid content of the diet to predict the concentration of fatty acids in milk."

Using study data, the model predicted the level of palmitic (C16:0) fatty acid in milk reasonably well, which is associated with increased blood cholesterol and coronary heart disease.

"But the model couldnt acurately predict the concentration of linolenic (C18:3) fatty acid in milk from the ration fed."

Dr Moss believes the main reason for the models limited success is that it fails to consider the degree of rumen saturation of polyunsaturated fatty acids in the rumen.

But there is still potential to develop an accurate nutritional model allowing healthier milk to be produced predictably, she adds. &#42