Do dairy cows raised on organic farms produce different amounts of milk or suffer from less disease? A $1 million grant from the U.S. Department of Agriculture (USDA) will study 300 dairy farms -- of which 200 meet organic standards -- in Wisconsin, New York and Oregon to find out.

The research team, which will use the data to develop recommendations for keeping dairy cows healthy while optimizing income and the quality of the milk, includes investigators from Cornell's College of Veterinary Medicine, the University of Wisconsin-Madison, Oregon State University and the Organic Centre in Oregon.

"This is one of the largest, if not the largest applied research project on organic milk production on U.S. dairy farms," said Linda Tikofsky a co-principal investigator and senior extension associate at Cornell's Vet College.

The study will compare conventional dairy farms with organic farms and provide data on herd factors that are associated with disease and well-being. Researchers will spend the next two years visiting each farm to make observations, review farm records and administer a questionnaire. During the visits, they'll see how many cows are pregnant, check for lameness, measure body fat and rate the cleanliness of the cows' udders. They also will collect milk samples to count bacteria and screen for common infectious diseases. In particular, they'll look for mastitis, a costly infection of the mammary gland. Farmers also will collect and submit data about diseases and their economic impact on their business.

Organic dairy farming is a rapidly growing sector of the U.S. dairy industry. Organically managed farms allow their cows to graze and do not use antibiotics, pesticides or hormones in their day-to-day management of cows and calves.

The project's principal investigator is Pamela Ruegg at the University of Wisconsin-Madison; co-investigators include Ynte Schukken at Cornell.

Stephanie Specchio is director of communications in the College of Veterinary Medicine.