U test will save bovines, money

Geoffrey Ziezulewicz

University researchers hope a new diagnostic test will help protect Minnesota’s cattle population from a type of chronic wasting disease.

Johne’s disease, a chronic wasting condition that affects hoofed mammals, costs the dairy industry millions of dollars each year. But a new diagnostic test developed at the College of Veterinary Medicine might make it easier for the industry to manage the disease.

The test is cheaper and faster than previous tests, said Scott Wells, a University clinical and population sciences professor.

Identifying the disease early is important in preventing its spread, he said. Once farmers know a cow has the disease, it can be removed from the herd to prevent more cows from becoming infected.

The disease originates when young cows ingest bacteria in cattle feces, but Wells said symptoms do not appear for years.

Infected cattle remain active and continue eating as the bacteria make their way to the intestine and begin interfering with nutrient absorption. Animals lose weight, experience diarrhea and eventually die.

The main money loss is in milk production, Wells said. He said conservative estimates state that Johne’s disease costs the dairy industry $200 million each year.

In Minnesota, the dairy industry accounts for 54,000 jobs, and generates $2.4 billion in annual revenue for the state.

Wells said about 25 percent of Minnesota dairy herds are affected by the disease.

The U.S. Department of Agriculture recently approved the college’s test.

The old test, which involves bovine fecal samples, requires months to return results. The new one can deliver results in days.

“It’s not terribly difficult to diagnose the cows as ill, but by that time they are shedding in huge numbers and infecting everybody else,” Wells said. “We need to get ahead of it.”

For those in the industry, a quicker diagnosis means they might not lose as many animals to the disease.

Some farmers with infected herds lose about $200 per cow, he said.

Wells said the industry is just beginning to fully understand the disease, but he said its gradual nature keeps it out of the public eye.

“It’s not really on the public radar,” he said. “Foot and mouth disease is incredibly contagious and infectious, and it appears as an outbreak. This is a very slow disease that takes three to five years to show symptoms.”

The University’s test is quicker because it uses DNA to identify the disease’s bacteria, said Carrie Wees, one of the scientists who helped develop the test.

Jim Collins, director of the veterinary college’s diagnostic laboratory, said the test will save the dairy industry money. Currently, the test is available almost exclusively through the Minnesota Board of Animal Health.

The test will cost $15 per animal – $10 less than the old diagnostic test.

“If you multiply that over thousands of animals, it gets to be a big savings for the industry,” Collins said.

Collins said Johne’s disease has not been found to be a health risk to humans and that cooking meat kills the bacteria.

The next step is to hone the technique to speed up results and further drive costs down.

Collins said once the test is perfected, it could be commercially licensed to a private company.

“This is version 1.0 of the test,” he said. “We hope to get version 1.1 out in the next six months or so.”