3 April 1998

Grass role in fat reduction

Healthier milk and meat is the aim of MAFF-funded research

which is finding out how to meet the Health of the Nation

objectives in which the medical profession wishes to see a

reduction in total fat intake. This Special details progress

to date on altering animal diets to produce milk and meat

which is even healthier. Robert Davies reports

WITHIN a few years consumers may be able to buy what they perceive as healthier milk containing more polyunsaturated fatty acids.

Research at the Institute of Grassland and Environmental Research at Aberystwyth has indicated that some grass species are better sources than others of favourable long chain acids such as alpha linolenic acid. Leaves also contain more than stems, and both flowering and ensiling reduce levels.

Now funding is being sought to investigate how choice of grass and management might be used to manipulate milk fatty acid composition. Work is already under way, in association with Bristol University on using diet to optimise the fatty acid composition of the intramuscular or marbling fat of beef cattle.

The potential of different dietary fatty acid sources, such as grass, linseed and fish oil, to produce low fat:high polyunsaturated beef is being examined. Ability of different breeds to respond to the sources is being looked at, and beef flavour comparisons being made.

Aberystwyth researcher Richard Dewhurst is hoping to pinpoint fatty acid composition variations between and within grass species, and come up with a management blueprint to exploit them to modify the nature of milk fat. He anticipates there could be strong consumer interest in reducing the risk of coronary heart disease.

Grass breeders will have an important long-term role. They could produce varieties with enhanced amounts of favourable fatty acids, in which flowering is suppressed. Work is also needed on what happens to the acids during wilting and ensiling and the inter-relationship between the fatty acids in grass and those in other components of cows rations.

Some grass species contain more favourable long chain fatty acids such as alpha linolenic acid. Research is investigating how choice of grass and management might be used to manipulate milk fatty acid composition.

HEALTHY OPTION

&#8226 Increase long chain fatty acid .

&#8226 Some grasses better sources of these.

&#8226 Management blueprint to exploit their benefits.