A five-year study by Oregon State University of nearly 300 small dairy farms—192 organic and 100 conventional—found few differences in cow health or in the nutritional content of milk.
The study was funded by a $1 million grant from the U.S. Department of Agriculture (USDA) and was based on criteria from three commonly used cattle welfare programs: The American Humane Association’s Animal Welfare Standards for Dairy Cattle, Farmers Assuring Responsible Management and the Canadian Codes of Practice. However, the dairies surveyed for the study were not committed to these standards, reports Feedstuffs.
Dairy cow health, including nutrition, lameness, udder cleanliness and the use of veterinarians were studied. Results showed organic herds performed better in some areas of cow health, such as fewer injuries to legs from being housed and calves weaned at an older age.
Milk samples were screened for bacteria and common diseases. Some organic herds showed Strep. ag. bacteria, which was purged in conventional herds long ago with the use of antibiotics. Few milk nutritional differences were found between organic and non-organic herds. Occasionally, organic milk can contain more omega-3 fatty acids, which may improve heart health. However, those increases come from seasonal grazing and are not present when cattle are fed stored forage.
Most organic farms previously ran as conventional and both use the same milking procedures, the same facilities and similarly tend to sick cows—this likely is the reason for the slight differences between the two practices.