Best management practices will facilitate dairy product safety.

Microbial pathogens have long been a concern in dairy production because of their effects on animal health, milk production and economics. In 2003, the USDA-ARS entered a partnership with the Regional Dairy Quality Management Alliance to help validate best management practices (BMPs) that minimize disease risk and ensure the maximum safety of products leaving the farm.

The alliance, a broad coalition of dairy industry interests from across the Northeast and Mid-Atlantic regions, including farmers, veterinarians, processors, academics and regulators, was formed to ensure a healthy and safe food supply, promote animal health and welfare, improve productivity and profitability, and encourage environmental stewardship. Alliance participants and ARS researchers decided to evaluate current BMPs and develop new, more effective ones. The collaborative team consists of investigators at the ARS Environmental Microbial Safety Laboratory; the ARS Antimicrobial Research Laboratory; Cornell University; Pennsylvania State University; and the University of Pennsylvania.

A pilot project, begun in January 2004, involved two dairy herds: a 300-cow herd in New York State and a 100-cow herd in Pennsylvania. A third herd in Vermont was recently added. These herds were selected based on criteria that included known Johne's disease prevalence, Salmonella positive status and on-farm disease recording.

Investigators are collecting biological samples--blood, manure, and bulk tank milk--and environmental samples, such as bird droppings, water, feed and soil. The biological samples are distributed to university and ARS researchers, who test them for the presence of M. avium subspecies paratuberculosis, the bacterium that causes Johne's disease, as well as for Salmonella, E. coli O157:H7, L. monocytogenes and Campylobacter.

In a sampling on one of the test farms, researchers found that although 45% of the cows tested positive for Salmonella, no Salmonella was actually detected in bulk tank milk. They are using molecular genetic techniques to detect particular strains of Salmonella, Listeria and E. coli.

The scientists will use the collected data to determine the location of pathogens on the farms, how they are getting there, how long they survive and how they get into milk. They can then examine the BMPs to determine which ones will truly benefit the dairy farmer

Further information. Jo Ann Van Kessel and Jeffrey Karns, USDA-ARS Environmental Microbial Safety Laboratory, 10300 Baltimore Ave., Building 173, Room 201, Beltsville, MD 20705; phone: [phone]; fax: [phone]; emails: [e-mail]; [e-mail].