Summary
Meat has been criticised in the past for its high content of saturated fatty acids, which are damaging to health. Modification of diets offered to animals can allow beneficial unsaturated fatty acids to pass into meat and also milk and eggs.
Unsaturated fatty acids are believed to have positive implications for human health by reducing the risk of cardiovascular disease and they may also reduce the incidence of some cancers, asthma, diabetes and a number of other conditions.
The possibility of consuming a greater proportion of these fatty acids as part of an every day diet will appeal to the public, rather than consuming dietary supplements.
This report encompasses a review of the literature in relation to dietary sources of beneficial fatty acids (linseed, hemp, chia seed, marine algae, fish oil/meal, lupins, oilseed rape, soya, grass and clover) available for feeding animals and their subsequent availability in milk, meat (beef, lamb, pork, poultry) and eggs. Overall, inclusion of these feeds in the diet improves the fatty acid profile of milk, meat and eggs by increasing conjugated linoleic acid levels and decreasing the ratio of n-6:n-3 fatty acids. Care must be taken when introducing these feeds into diets as some may reduce milk yield, fat and protein concentrations in dairy cows. Furthermore, increased levels of polyunsaturated fatty acids in meat can occasionally lead to a more rapid colour change from red to brown, due to oxidation. The effects of inclusion of polyunsaturated fatty acids on flavour parameters in meat are not clear cut, with some authors finding no effects and others reporting deleterious effects.
Further research is required on the effect of fatty acid enrichment of animal diets on meat eating quality. Producing for niche markets will become increasingly essential in future farming systems as a consequence of the Common Agricultural Policy.
The development of specialist animal diets rich in unsaturated fats could play a valuable role in creating niche markets for animal products. However, consumer perception and acceptance will be the driving force behind the success of niche market products.
