Importance of and opportunities for the production of nutrient enriched food of animal origin

C. C. Metges, Dummersdorf

Meat, and especially animal fats, are considered to be less healthy. This is reason for producers try to enhance the nutritional quality - and economic value - of the produce by increasing the amount of specific nutrients in meat, milk and eggs. Nutrients contained in food of animal origin are protein, fat, fatty acids, iodine and selenium.

The author provides an overview of feeding strategies to enhance the concentration of desirable nutrients in animal food. Data showing the significance of such products for human nutrition are presented. Naturally, ruminant fat contains a more beneficial n-3/n-6 fatty acid ratio than pork fat. Various feeding strategies including an increase of grass, legume hay and linseed at the expense of grain and concentrate improve the n-3:n-6-fatty acid ratio in meat and milk.

Use of rumen-protected fat may increase the n-3 fatty acid proportion in ruminant fat, but could lead to a depression of milk fat. In pigs, the concentration of n-3 fatty acids should be enhanced, while that of n-6 fatty acids be lowered. This is achieved by increasing the share of n-3 rich oils (linseed, rapeseed, soy, fish) or linseed in the diet. Cis9, trans11-conjugated linoleic acid (CLA) is the prominent CLA isomer in ruminant fat. CLA is generated by biohydrogenation of linoleic acid by rumen bacteria. The CLA content is increased by feeding plant oils or other products (marine algae, fish oil) rich in linoleic acid, and by supplementation with rumen-protected CLA.

In general, in cattle grazing pasture a higher CLA content in milk and beef is achieved which is often related to a reduction of milk performance, however. CLA content in pork and hen’s eggs may also be increased by addition of CLA to the feed. Humans living on a diet containing milk, meat and/or egg products enriched with n-3 fatty acid have been found to show beneficial effects on blood lipids. In some regions of Europe, soils poor in iodine and selenium lead to low contents of these micronutrients in animal products and sometimes even to deficiencies in farm animals.

Feeding strategies including iodine and selenium enriched feedstuffs (marine algae, wheat and grass produced by Se fertilization, Se yeast, Na-selenite) result in an accumulation of substantial amounts of Se and I in milk, beef and pork. For feeding regimen changing the nutritional quality of animal food, research into the efficacy and safety evaluation of these products is needed. Whether these products will be accepted by consumers depends on consumer knowledge of the product properties and on the price and sensory quality of the food.

Keywords: Food of animal origin / nutrient enrichment / changes / production