A considerable amount of evidence has accumulated in supporting the view that conjugated linoleic acids (CLA) and omega-3 fatty acids (FA) have beneficial health properties and that the consumption levels of these FA is insufficient in most western diets. In view of their benefits, there has been a considerable interest in enhancing milk and dairy food products with these beneficial FA. The objective of the first trial was to determine the effect of supplementing grazing dairy cows' diet with fish oil (FO) and linseed oil (LSO) on milk c9, t11 CLA and omega-3 FA. The objective of the second trail was to examine the temporal changes in milk c9, t11 CLA content of grazing dairy cows fed FO and LSO for an extended period of time. Results from the two trials show that supplementing grazing cows' diets with LSO and FO enhances milk c9, t11 CLA and omega-3 FA content and could be used as a practical approach to broaden dairy market by increasing their competitiveness in the U.S. healthy food market.