Your glass of milk and pat of butter may have more beneficial fats if the cow that produced them grazed on grass. Milk, butter, and cream from grass fed cows are high in the heart-healthy, cancer-fighting, and lean muscle-building conjugated linoleic acid (CLA). A study published in the Journal of Dairy Science found that a tablespoon of butter from a cow on a grass diet contained 250 milligrams of CLA, whereas a tablespoon of butter from a cow in confinement contained less than 50 milligrams of this beneficial fat. In the United States, most dairy cows live in confinement, though dairies that are certified organic are required to provide cows with access to pasture.
How do you know how much grass is in the diet of the cows producing your milk? Your best bet is to ask your dairy farmer. We have a buyer’s guide available with our posts-by-email sign-up designed for raw milk consumers that would help you understand the issue and know what to look for at a dairy, but it would be useful for buyers of small production pasteurized milk as well.