Theres no significant nutritional differences between organic and regular milk, or in the health of cows on the two types of dairy farms, according to new research by Oregon State University and other academics.
Nearly 300 small dairy farms in Oregon, New York and Wisconsin participated in the study, funded by a $1 million grant from the National Institute of Food and Agriculture in the U.S. Department of Agriculture.
Researchers also found that many organic and conventional dairies did not meet cattle welfare standards in three commonly used programs: the American Humane Association's Animal Welfare Standards for Dairy Cattle, Farmers Assuring Responsible Management, and the Canadian Codes of Practice.
"While there are differences in how cows are treated on organic farms, health outcomes are similar to conventional dairies," said Mike Gamroth, co-author of the study and professor emeritus in OSU's College of Agricultural Sciences. "Few dairies in this study performed well in formal criteria used to measure the health and well-being of cows."
Researchers found that milk from organic herds occasionally had higher omega-3 fatty acids, which may improve heart health. Some organic herds also showed a strain of bacteria known as Strep. g., which conventional herds eliminated long ago via use of antibiotics.
Some organic farms perform better in some areas of health, such as fewer hock lesions leg injuries that stem from being housed for long periods.
"Nearly seven in 10 organic farms previously operated conventional herds, which explains the lack of differences between them," Gamroth said. "Many organic farmers operate in a similar fashion to when they raised conventional herds, from milking procedures, to using the same facilities, to caring for sick cattle."
The five-year study included 192 organic dairies and 100 conventional ones, including 24 of each category in Oregon.
Among the other findings:
Cows on organic farms produced 43 percent less milk per day than conventional non-grazing cattle, and 25 percent less than conventional grazing herds.
Only one in five herds met standards for hygiene, a measure of animal cleanliness.
Only 26 percent of the organic herds, and 18 percent of the conventional herds, meet recommendations for pain relief during dehorning.
The study was done by OSU, Pamela Ruegg of the University of Wisconsin-Madison, Linda Tikofsky and Ynte Schukken of Cornell University, and Charles Benbrook of the Organic Centre in Oregon.
Follow Sustainable Life at facebook.com/portland.sustainable.life.