Melinda Hemmelgarn, M.S., R.D.
You've likely heard the popular saying: "You are what you eat." But did you realize this wise old adage applies just as much to cows as it does to humans?
What a cow eats profoundly affects the animal's health, and the nutritional quality of its milk and meat. If you think about human diets at the end of a long food chain, you can understand how the quality of a cow's diet impacts the quality of our diets and ultimately our family's health.
If we continue back along the food chain, we see how the quality of a cow's diet depends on the nature of the soil, water, pasture and forages. That's what makes the organic farmer "outstanding in his/her field." The organic farmer uniquely understands and cares for the entire ecosystem that supports human health.
Compared to conventional meat and dairy, we can expect organic cows that are raised predominantly on a pasture of grass and legumes to contain the healthiest mix of beneficial fats: less saturated fat, more alpha linolenic acid, or ALA (an omega-3 fat), and higher levels of CLA, or conjugated linoleic acid. (1-5) In fact, CLA levels in organic milk from grazing cows may be five times greater than levels in conventional milk. (5)
This is important, because a growing body of evidence supports CLA's potential for disease prevention, including inhibiting tumor development and reducing risk for cancer, inflammation, and heart attack. CLA may also help slow or delay the onset of Type 2 diabetes by increasing our body's sensitivity to insulin. (3,5)
Choosing foods with higher levels of omega-3 fatty acids and less omega-6 fatty acids also holds promise for chronic disease prevention. Artemis Simopoulos, M.D., an expert in the interaction of genes and our environment, explains that today's industrialized diets have too many omega-6 fatty acids and too few omega-3s. (6)
Simopoulos says this imbalance is due in part to a shift in the way we feed our livestock. By feeding animals grains, which are rich in omega-6 fats, instead of more traditional omega-3 rich grasses and hay, the composition of our meat and milk changed from being balanced in essential fatty acids to being depleted in omega-3s, and having mostly omega-6 fats. (6-8)
Unfortunately, when cows are raised in confinement and fed large proportions of grain, the quality of their milk and meat declines. We come up short on beneficial fats, as well as other protective nutrients, such as antioxidants, vitamin E and beta carotene. (1-3,8,9)
Kate Clancy, the author of the Union of Concerned Scientists' "Greener Pastures" report and highly respected human nutritionist advises beef and dairy producers interested in "optimizing levels of omega-3 fatty acids and CLA" to "strive for pasture-based feeding regimens that maximize the number of days their cows spend on pasture.” (1)
To understand how organic, pasture-raised meat and dairy is superior to conventional, we have to take a peek inside the cow. Mother Nature gave cows a unique stomach consisting of four compartments, the first of which is called the "rumen."
Veterinarian Silvia Abel-Caines, DVM, holds a PhD in Ruminant Nutrition. She explains that the fiber in forages, unlike grain, stimulates "vast amounts of saliva." The saliva is key to ruminant digestion because of its buffering effect, which keeps the pH of the rumen at an ideal level for fiber-digesting bacteria residing in the cow's rumen. (9) Those microbes secrete enzymes that digest plant material to form beneficial fats, such as CLA. (4)
Abel-Caines explains when high amounts of grain are introduced into the cow's diet, the pH in the rumen drops, creating a more acidic environment. The change in pH affects the population of rumen bacteria. Starch-digesting bacteria multiply, dominate the fiber-digesting bacteria, and have a negative impact on the cow. (9)
What kind of negative impact? The lack of fiber from fresh pasture and high quality forages, plus the rapidly fermenting grains will cause "chronic lactic acidosis" in dairy cows. This condition impairs the cow's immune system and reproductive performance, increases the likelihood of inflammatory disease, and can even shorten her life. In addition, when the cow's intestinal tract becomes more acidic, it appears more likely to support the more dangerous forms of bacteria, such as the deadly E. coli 0157:H7, which increasingly threatens the safety of our nation's food supply and public health. (9)
The benefits of organic, pasture-raised food and farming systems go beyond improving the health and nutrition of livestock and humans today. According to the Union of Concerned Scientists, well-managed pastures provide environmental benefits to rural communities and generations to come. These include: decreased soil erosion; increased soil fertility; and, reduced air and water pollution. (1, 10)
Bottom line: The highest quality milk (and meat) comes from pasture.
1. "Greener Pastures: How grass-fed beef and milk contribute to healthy eating," Clancey, K. Union of Concerned Scientists, March 2006. http://www.ucsusa.org/food_and_agriculture/solutions/smart_pasture_operations/greener-pastures.html#
2. Healing Foods Pyramid, University of Michigan, Ann Arbor.
3. The Organic Center. State of the Science Reports.
4. Consumer's Guide to Dietary Supplements and Alternative Medicines, W. Marvin Davis, Pharmaceutical Products Press, 2006. Pages 349-50.
5. "Conjugated linoleic acid in adipose tissue and risk of myocardial infarction," Smit.,L.A., et al. Am. J. Clin. Nutrition, May 2010. http://www.ajcn.org/content/early/2010/05/12/ajcn.2010.29524.full.pdf+html
6. "Omega-6/Omega-3 Essential Fatty Acids: Biological Effects," Simopoulos, A. World Rev. Nutr. Diet. 2009.
7. Food Sleuth Radio, interview with Artemis Simopoulos, M.D., September 9, 2010.
8. "Essential fatty acids in health and chronic disease," Simopoulos, A. Am. J. Clin. Nutr. March, 2004.
9. Personal communication with Dr. Silvia Abel-Caines, June 17, 2011.
10. "The Hidden Costs of CAFOs," Union of Concerned Scientists, Sept. 2008.
11. USDA's MyPlate: http://www.choosemyplate.gov/
Cows are miracle machines, able to turn green grass into sweet, creamy milk, and lean, nutritious meat. But dairy cows in particular, have tremendous energy and nutritional needs to maintain healthy pregnancies and produce, on average, 50 pounds of milk per day.
Fred Martz, former professor of animal sciences at the University of Missouri, says when pasture is "low in quality, animals do not gain and grow as they should." That's when cows may need supplements to complement what may be lacking in their high-forage diets.
Just like any lactating momma, a dairy cow puts her babies first. She will rob her own body of energy and nutrients, placing her health at risk, just to create the most nutritious milk for her young. That's why dairy farmers have to be "super stewards"-- constantly working to improve their pasture quality, while meeting their herd's nutritional requirements with a carefully selected balance of grasses and legumes. Supplements, including some organic grains or molasses, may be included in the cow's diet especially during the winter or non-grazing months.
Dr. Silvia Abel-Caines, DVM, PhD, Veterinarian and Ruminant Nutritionist for Organic Valley says, "Meeting a dairy cow's high nutrient and energy requirements with an only-forage diet is possible; if during the grazing season she is allowed to harvest a multispecies-high quality, intensively-managed pasture, and is provided with highly digestible preserved forages during the non-grazing season, the result is the production of milk from a sustainable farming model. But balancing the cow's ration during both season is key to ensure that the nutritious milk she is producing is not taxing her overall health. Supplementation may be necessary until the producers have acquired the level of grazing management and skills as well as the land resources it takes to provide that balanced ration."
Lowell Rheinheimer, Organic Valley's Farm Resources Manager, says "only in very special cases - where the soils are rich in minerals and fertility, the cows have been bred for grass, the farmer is an extraordinary manager and the gazing system is tightly controlled - will a dairy farmer be able to run an economically-successful operation based on grass only."
Organic Valley's "continuous improvement concept" recognizes that it takes time to heal degraded soils and build healthy, nourishing pastures. The process mooves us to "pasture perfect," while creating tremendous environmental benefits for future milk makers and drinkers.
Just as the diet of a breastfeeding mother spices up her milk, a cow's diet passes on the pasture's unique flavors. Think of pasture flavor mooving through to the milk.