A Plan for Johne's Control
Implementing small management changes improves animal health, increases profitability for Cass County beef farm.
Adopting simple management changes helped Cass County beef producer Gail Peterson significantly reduce the level of Johne's disease in his 250-head Angus operation. Peterson, who farms with his wife, two of his sons and his mother, credits participating in the Johne's Disease Control Demonstration Project with dispelling some common myths about the disease and determining how to decrease the disease's incidence in their herd within a relatively short period of time.
The Johne's Disease Control Demonstration Project was a near decade-long research project conducted by Michigan State University (MSU) researchers and MSU Extension specialists that evaluated Johne's disease control strategies in an effort to identify which management practices are the most effective at controlling the spread of the disease.
Johne's disease, a contagious and untreatable disease caused by the bacteria Mycobacterium paratuberculosis, or MAP, typically occurs in calves, but animals generally don't express clinical signs of the disease until later in life.
Because calves in cow-calf operations are managed differently than they are in traditional dairy operations in that they typically remain with their mothers until weaning, the calving area is the most critical area to focus on in an effective Johne's disease control program.
"I thought you only had to test the younger animals and not the entire herd," Peterson admitted. "By working with the MSU team, we were able to put new management practices in place to slow the transmission of the disease in our herd."
Peterson first suspected their herd had a problem with Johne's in 2004 when fresh heifers were developing severe cases of diarrhea and losing weight shortly after calving. Because calves are raised until they're ready for market, the weight loss had a direct effect on the farm's profitability. The Petersons joined the MSU research project in 2005, at which time they conducted a whole-herd test to identify which animals tested positive for the disease.
Animals that tested positive were separated from the rest of the herd to minimize the potential of transmitting the disease to younger cattle. They were also monitored more closely for weight loss and sold before they lost too much weight.
Whole-herd test results indicated that almost all of the positive cows were from the younger generations, which supported what the Petersons had been seeing: They first noticed clinical signs of the disease in their younger cows after calving. Densely stocking the calving area and housing weaned heifers with cull cows during the fall and early winter likely led to the rapid transmission of the disease.
"The biggest thing we did was to remove young calves from the larger group of cows getting ready to calve," Peterson explained. "We have also divided the calving area so we have more, smaller lots so they are not as concentrated."
The stocking density of the calving area was reduced significantly and new cow-calf pairs were moved to transition pastures as soon as possible. The Petersons also stopped housing weaned heifers with cull cows. Any animals that test positive for Johne's are not bred back to calve again and are eventually culled.
Since 2005, the number of test-positive animals in the herd has declined from 7.2% to 2.2%.
"We have seen a lot of positive things just by making a number of small changes," Peterson said. "We hope to get to a point where we can become a test-negative herd and are able to sell quality Johne's-negative seedstock. I believe that will give us an advantage when we go to sell cattle."
The Michigan Johne's Disease Control Demonstration Project was a partnership between the MSU College of Veterinary Medicine and Diagnostic Center for Population and Animal Health, MSU Extension, the Michigan Department of Agriculture and Rural Development and the U.S. Department of Agriculture in collaboration with nine Michigan veterinary clinics. Findings from the Michigan farms involved in the study were pooled with data collected from 17 other states as part of the larger, multistate project, the National Johne's Disease Control Demonstration Project.
For additional information on the Michigan Johne's Disease Control Demonstration Project, visit http://cvm.msu.edu/johnes.
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