Cows, milk and omega-3

For several decades, the omega-6 / omega-3 ratio has been increasing in the consumer base ... and in the dairy cows' base with the reduction of grazing. However, a balance between these two families of polyunsaturated fatty acids is essential to the proper functioning of the organism. The precursor of long-chain omega-3 (α-linolenic acid), which can not be synthesized by animals, must be supplied by the diet. Researchers from the Inra-Oniris BIOEPAR UMR have studied the effects of the supply of extruded linseed, rich in α-linolenic acid, based on data from 21 studies in the scientific literature, on the quality of milk fat, and simultaneously on animal performance.
Milk derived from dairy cows that have ingested extruded linseed contains less saturated fatty acids, more oleic acid, and more polyunsaturated fatty acids including rumenic acid and α-linolenic acid. The higher the linseed intake, the greater the effect. This modification of the lipid composition of milk follows the recommendations of the National Program of Health Nutrition. No effect of linseed dose on cow ingestion was observed. An average increase in milk production was observed when the linseed dose did not exceed zootechnician recommendations. Finally, the fat content of milk can be reduced if linseed is combined with rations rich in corn silage or if it is brought in too much.
These results help to evaluate the technico-economic effect of the use of extruded linseed on the scale of the dairy cattle farm, for example by simulating a better value of this milk, naturally enriched in omega-3.

Associated publication : Meignan, T., C. Lechartier, G. Chesneau, and N. Bareille. 2017. Effects of feeding extruded linseed on production performance and milk fatty acid profile in dairy cows: A meta-analysis. J. Dairy Sci. 1–15. doi:10.3168/jds.2016-11850.

Contact(s)

Scientific Contact:

• Thomas Meignan
• Nathalie Bareille UMR BIOEPAR