Grass feeding is a practice not yet familiar to all consumers. 100% grass-fed cow’s milk comes from cows who have grazed in pasture year-round rather than being fed a processed diet for much of their life. Grass feeding improves the quality of cow’s milk, and makes the milk richer in omega-3 fats, vitamin E, beta-carotene, and CLA (a beneficial fatty acid named conjugated linoleic acid). (For more detailed information about grass feeding, please click here.) Just how important is grass feeding for cow’s milk quality? As you will see in the chart below, we have included grass feeding as one of our top-level recommendations for anyone who plans to include cow’s milk in their meal plan:
Shopping for Cow’s Milk
Stick with organic
Organic standards help lower risk of contaminated feed and organic cow’s milk usually has higher nutrient quality. However, remember that organic by itself does not guarantee a natural lifestyle for the dairy cows.
Ask for 100% grass-fed
Go beyond organic by asking for 100% grass-fed. Don’t get sidetracked by the confusing array of labeling terms like natural” or “pasture-raised.” Labeling laws allow products to display these terms even if dairy cows spend little or no time outdoors in a pasture setting. Unfortunately, even the term “grass-fed” is not sufficient since grass-fed dairy cows may have spent a relatively small amount of time grass feeding. The standard to look for on the label is “100% grass-fed.” Talk to your grocer or the dairy cow farmer and find out how the animals were actually raised. In addition, if you would like more information about the practice of grass feeding, please click here.
Consider local farms
Organic, 100% grass-fed cow’s milk may be available from local farms with small flocks, which provide a natural lifestyle for their dairy cows. Two websites that can help you find small local farms in your area are www.localharvest.org and www.eatwild.com. Both sites are searchable by zip code.
One thing you’ll notice about the chart above is an absence of recommendations about percent fat. Provided that you keep your serving size for grass-fed cow’s milk at 4 ounces or less, we recommend that you consume it in the form of whole milk. Not only is whole milk the least processed form of milk (placing it in the category of a whole, natural food), it’s also the form of grass-fed milk that will provide you with the most omega-3s and other key nutrients. Traditionally, health organizations have not recommended whole milk in the diet but rather reduced fat milk, including 2%, skim, and nonfat milk. Since too much total fat, too much saturated fat, and too many calories in a daily meal plan can raise the risk of certain health problems, this traditional approach makes sense for individuals who cannot make room in their daily meal plan for the amount of total fat, saturated fat, and calories contained in whole milk. However, we believe that many people who may want to include a 4-ounce serving of grass-fed milk in their meal plan will be able to include it in the form of whole milk while still remaining within the guidelines for intake of total fat, saturated fat, and calories.
What’s New and Beneficial About Grass-Fed Cow’s Milk
CLA (conjugated linoleic acid) is a type of fat associated with a wide variety of health benefits, including immune and inflammatory system support, improved bone mass, improved blood sugar regulation, reduced body fat, reduced risk of heart attack, and maintenance of lean body mass. According to recent studies, you’ll find yourself getting at least 75 milligrams of CLA from an 8-ounce serving of grass-fed cow’s milk. (In some cases, you may even get two to three times this amount. The amount of CLA in cow’s milk tends to increase along with consumption of fresh grasses by the cows, and when cows have had ample access to fresh pasture, you are likely to get increased amounts of CLA.) Since the CLA content of milk from 100% grass-fed cows is typically two to fives times greater than the CLA content of milk from conventionally fed cows, 100% grass-fed milk can provide you with increased health benefits in the areas described above.
Improved intake of omega-3 fat is another health benefit that can be obtained from 100% grass-fed cow’s milk. The omega-3 fat content of grass-fed cow’s milk can vary widely, due to the wide variety of forage crops that can be planted in pastures (or that grow on pastureland in the wild). This omega-3 content also varies with the age, breed, and health of cows and seasonal plant cycles in pastureland. At the lower end of the spectrum, recent research shows 50-65 milligrams of omega-3s (in the form of alpha-linolenic acid, or ALA) in 8 ounces of grass-fed cow’s milk. At the higher end of the spectrum, those same 8 ounces may provide 120-150 milligrams of omega-3s. While these amounts of ALA are not large, they’re going to be helpful to many individuals who are deficient in omega-3s. The relatively low ratio of omega-6s to omega-3s in 100% grass-fed cow’s milk may also enhance the benefits that you get from these omega-3s. This ratio typically falls between 2:1 and 3:1—quite unlike the ratio in milk from traditionally fed cows, which often fall into the range of 8:1 or higher. Since omega-6 metabolism can interfere with omega-3 metabolism, the relatively reduced amounts of omega-6s in 100% grass-fed cow’s milk may help improve the metabolism of omega-3s in your body after you’ve consumed the milk.
Based on recent research studies, the overall fat composition of 100% grass-fed milk is not what you might think. There are about 8 grams of total fat in 8 ounces of whole grass-fed cow’s milk. About 2 grams (or 25%) come from monounsaturated fat in the form of oleic acid. This omega-9 fatty acid is the primary fatty acid found in olive oil, and when it replaces other types of fat in the diet, it’s been linked to reduction in high blood pressure as well as reduction in high blood cholesterol levels. About 4.5 grams (or 56%) come from saturated fat – a type of fat that we often associate with unwanted health consequences. However, the type of saturated fat in 100% grass-fed cow’s milk does not fully fit the “unwanted” fat category. About 6-7% of this saturated fat is “short-chain” saturated fat and it can function as a “probiotic” that supports the health of friendly bacteria in the intestine. Nearly half of the saturated fat is “medium chain” saturated fat—the kind that is predominant in coconut oil. Medium chain saturated fat is more easily digested and metabolized in the body, and in some studies, it’s been associated with immune system benefits. Within the 4.5 grams of saturated fat in 8 ounces of 100% grass-fed whole milk, only 25-30% come from palmitic acid—a long chain fat that’s been more closely associated with heart disease risk than other saturated fats. When taken as a whole, the fat composition of 100% grass-fed whole cow’s milk is much more balanced in terms of health risks and benefits than many people assume.

Source: Why do we recommend grass-fed cow's milk? : WH Foods