INCREASED CONCENTRATIONS OF OMEGA-3-FATTY-ACIDS IN MILK AND PLATELET-RICH PLASMA OF GRASS-FED COWS

Epidemiological data indicate that omegy-3 fatty acids protect from ca rdiovascular diseases and hyperlipidemia. Cold water fish is the major recognized source of omega-3 fatty acids but fish is not a staple foo d in many countries. Since terrestrial green plants may also represent a source of omega-3 fatty acids we tested the hypothesis that platele t rich plasma and milk from cows feeding exclusively on green grass co ntains more omega-3 fatty acids than milk from cows fed conserved gras s. The relative concentrations of linolenic acid ; (18:3) and eicosape ntaenoic acid (20:5) and the ratio of eicosapentaenoic acid to arachid onic acid (20:4) which is critical for the formation of omega-3 derive d eicosanoids were significantly higher in milk from grass fed cows. S imilar changes were seen in the fatty acid composition of platelets. H alf a liter of milk from grass fed cows provides approximately 191 mg 18:3 and 14 mg 20:5. In this regard milk from grass fed cows may be nu tritionally superior fo milk from cows eating conserved grass.