Fish oil is receiving a lot of attention lately because of its health benefits - particularly those associated with omega-3 fatty acids and the anti-cancer compound CLA (conjugated linoleic acid). And that has researchers looking for ways to pump CLA into our food. One such strategy may be to add fish oil directly to the diet of dairy cattle.

According to research published in the October Journal of Dairy Science, milk from cows fed two fish-oil diets contained almost four times more CLA than milk from cows fed a control diet (see chart below). And, the flavor of milk and butter was similar to that of control cows.

One drawback, however, is fish oil tends to reduce the concentration of milk fat. In this study, for example, cows fed the 2-percent fish oil diet produced milk with about 0.7 percent less fat than milk from control cows.
James, please make chart look pretty.
Concentration of CLA in 3 dairy diets

Diet Concentration of CLA (grams/100 g of fatty acids)
Control (50:50 forage-to-concentrateration) 0.56
2-percent fish oil (on a dry matter basis) 2.3
1-percent fish oil and 1-percent extruded soybeans (on a dry matter basis)2.17