Brucellosis shows up in bison at Ruby Valley ranch

For the first time, a Madison County livestock herd has tested positive for brucellosis.

The positive test was made public Nov. 16 and occurred in a bull bison owned by Ted Turner at his Snowcrest Ranch in the upper Ruby Valley.

The test means the ranch is under quarantine until its herd has three clean tests, said ranch manager Russ Miller.

The state imposed quarantine means animals shipped off the ranch must go to slaughter and not be sold or used to stock other ranchers, Miller said.

No other animals on the ranch tested positive for the disease, he said. The ranch runs nearly 1,700 head of bison.

Brucellosis is a bacteria that can cause females to abort their calves. In Montana, the disease exists in wild bison and elk herds, but was originally a livestock disease.

Montana had a brucellosis-free status until September 2008. The disease has cropped up in cow herds in counties around Yellowstone National Park starting back in 2007.

The Snowcrest Ranch is located in Montana’s Brucellosis Designated Surveillance Area. This DSA includes portions of counties surrounding Yellowstone National Park. Livestock producers that run bison and cattle in the DSA must have herd health plans to monitor for the disease. These plans include regular testing and vaccinations.

Brucellosis can be spread from animal to animal by contact with an aborted calf or afterbirth from a female elk, cow or bison that has the disease.

It is likely that elk passed the disease on to Turner’s bison, Miller said.

One of the difficulties in protecting livestock from the disease is the ever-present elk that share the same rangeland with local livestock, he said.

“I’m not sure, with that continued exposure that all ranchers are going to have to public wildlife, whether or not a person is ever going to get out from under quarantine or stay out forever,” Miller said.

Last winter Montana Fish, Wildlife and Parks captured and tested 100 elk in the upper Ruby Valley. Twelve of those elk tested positive for exposure to brucellosis. Of those 12, four carried vaginal implants into calving season, said Neil Anderson, FWP biologist conducting the study.

Of the four cow elk with implants, none experienced abortions, which would have been a sure sign the animals were not only exposed to, but also infected with brucellosis, Anderson said.

He is going to be conducting more capture and study operations with elk in the Sage Creek area of Montana elk hunting district 325, which is west of last winter’s capture site.

The general idea is to continue to study elk to try and understand how far brucellosis has spread in elk and how the animals react to infections and spread the disease, Anderson said.

He recognizes the situation is difficult for both wildlife managers and livestock producers.

“Once you get something like that established in the wildlife population, eradicating it or eliminating it or managing it becomes difficult,” Anderson said. “I think everybody recognizes that this is not an easy issue to solve, biologically or socially.”

Rick Sandru is a Ruby Valley rancher who runs cattle in the upper Ruby Valley. His herd doesn’t neighbor the Snowcrest Ranch. If it did, he would be required to test his animals now to ensure they’re brucellosis free.

The positive test wasn’t really a surprise, given the level of infection in the elk population, Sandru said.

“It could just as easily turned up in any of our cow herds,” he said. “I don’t think it’s a surprise to anyone that we’re going to have an occasional positive … It’s not a surprise, but you sure hate to see it.”

The main thing this positive test proved is the system in place for testing and addressing the disease in a herd works, he said. That’s important to all local producers because selling animals at market must continue to be a priority.

“The important thing here is that we keep a healthy product out there for sale,” he said. “We need to have protocol in place that ensures we’re going to sell clean cattle.”

Ruby Valley rancher Neil Barnosky did have cattle neighboring the Snowcrest Ranch. His herd must all be tested for brucellosis. He’s already pregnancy tested about 500 head, which is a normal process for ranchers this time of year. Those animals must be run through the chutes
again, along with the rest of his herd.

“We’re testing everything now,” he said.

The state pays for the brucellosis testing and $2 a head to Barnosky to help offset his manpower costs associated with the process.

Like Sandru and Miller, Barnosky is concerned about brucellosis in the elk.

“The biggest thing seems to me is that the state of Montana is going to somehow have to deal with their infection rate in their elk herd,” he said. “I don’t think the whole burden of this should be on the producers as far making sure the disease is contained.”

One of the weak links in protecting livestock from brucellosis now is not having a highly effective vaccine.

The livestock vaccine protects animals from the symptoms of brucellosis, namely the abortions, Anderson said.

And maybe developing a better vaccine is the place to focus efforts, Miller said.

“I would say we all need to be working, whether it’s beef producers or bison producers, we all need to be working on a better vaccine,” he said.

No Comments.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>