As a Northeast Organic Farming Association (NOFA) board member it was nice to read the February 28 article about our NOFA director. Adrian Hyde has been providing excellent leadership for this organization that provides valuable educational programs for Garden State organic farmers and consumers. I do, however, take exception to your commentary comparing organic and conventional foods.
Consumers frequently ask if there are any meaningful differences in organic versus conventional foods. For plant based foods there has been an ongoing unsettled debate. What is clear is that organic plant based foods have less pesticide residue.
Fewer studies have examined animal-based foods. At least for dairy products the organic versus conventional nutritional differences are measurably evident based on laboratory analysis. A study (Benbrook et al., 2013) compared type of fats in organic vs. conventional milk and found significant differences in the omega 6 / omega 3 fatty acid ratios. The study also reported that conjugated linoleic acid (CLA) in pasture-raised organic milk increases in the spring and summer months in association with having organic dairy cows on pasture. Concentrations of CLA in organic milk are maximized during grazing season while in conventional milk it remains flat regardless of season.
The USDA National Organic Pasture rule (7 C.F.R. pt. 206) requiring grazing for 30 percent or more of dry matter intake can account for the nutritional enhancement of organic milk. The authors of the study concluded that “increasing reliance on pasture and forage-based feeds on dairy farms has considerable potential to improve the FA [fatty acid] profile of milk and dairy products” and “it is far more common — and indeed mandatory on certified organic farms in the U.S. — for pasture and forage-based feeds” and “improvements in the nutritional quality of milk … should improve long-term health status and outcomes, especially for pregnant women, infants, children, and those with elevated CVD [cardiovascular disease] risk.”
Other studies have also reported differences in composition of animal products as a result of pasture feeding. A review by Karsten and Baer (2009) found that in meat, milk, and eggs there are higher levels of CLA, and the fat-soluble vitamins A and E. Smart consumers are becoming increasingly aware of the role of pasture feeding for nutritional quality and for animal welfare.
Conventional producers could also enhance the nutritional quality of meat, milk, and eggs by putting farm animals out on pasture but instead they use confinement feeding to maximize production.
Joseph R. Heckman, Ph.D.
Extension Specialist, Soil Fertility, Rutgers University