Separating calves from cows immediately after birth reduces the potential of the newborns ingesting Mycobacterium avium subspecies paratuberculosis, the causative agent of Johne's disease, from their mothers' milk.
The Department of Agriculture has renewed funding for the Johne's Disease Integrated Program—providing $4.8 million for four years of research on control programs for bovine infection with Mycobacterium avium subspecies paratuberculosis.
Currently, the USDA estimates that such infections are present in almost 70 percent of U.S. dairy herds as well as a smaller percentage of beef herds.
"Johne's is a serious disease affecting large numbers of beef and dairy cattle and accounts for more than $200 million in economic losses," said Gale Buchanan, USDA undersecretary for research, education, and economics.
The USDA Cooperative State Research, Education, and Extension Service initially funded Johne's integrated research in 2004 with a three-year, $4.4 million grant. The continuation of the coordinated agricultural project will focus on developing new tests, vaccines, and strategies to help producers manage, control, and prevent the disease.
"This influx of monies is a good thing, as research dollars for food animals are drying up in spite of the increasing pressures of zoonotic and foreign animal diseases in the United States," said Dr. Michael Bolton, president of the American Association of Bovine Practitioners.
Johne's has a potential link with Crohn's disease in humans, though the cause of Crohn's remains unclear.
Congress established a control program for Johne's disease in cattle with the 2002 Farm Bill, authorizing appropriations as necessary through 2007. A provision in the 2007 Farm Bill, which Congress passed at press time by overriding a veto, authorizes appropriations until 2012.
In addition to the Johne's coordinated agricultural project, the USDA has helped develop the Voluntary Bovine Johne's Disease Control Program. Another pertinent USDA program is the National Johne's Disease Demonstration Herd Project.
Dr. Bolton said the multiple-state demonstration herd project involves producers in evaluating management practices for controlling Johne's. He is working with part of Michigan's demonstration herd to study early detection of the disease in calves.
The Dairy 2007 study, which the USDA recently released, includes information about the prevalence of Johne's disease and implementation of management practices. The information sheet "Johne's Disease on U.S. Dairies, 1991–2007" provides relevant data from Dairy 2007 and similar studies in 1991, 1996, and 2002.
The report indicates that producers have become more familiar with Johne's, probably as a result of educational efforts. Participation in Johne's disease certification or control programs has increased, with almost a third of operations reporting participation in such a program during 2007.
The full report is available at http://www.aphis.usda.gov/animal_health/nahms/index.shtml by clicking on National Animal Health Monitoring System, then looking under "New Publications."