Producers at the Manitoba Beef Producers annual meeting here earlier this month heard some good news about the province’s bovine tuberculosis eradication efforts.
“The hope remains quite high that this winter’s surveillance in elk, deer and domestic livestock will move us closer to achieving the overarching goal of the program — eradication of the disease and a rebuilding of the wild populations,” said Allan Preston, lead co-ordinator of the Riding Mountain TB eradication project.
Over the past 12 years, 11 cattle herds have tested positive for TB with the last case found in 2008. Two cases of whitetail deer have been found positive, as well as 22 elk with that last case being discovered last spring.
“The most recent positive was last spring. The mature cow elk was 11 years of age, and she was located deep in the central area of the RMNP,” Preston said. “However, it is not unexpected to find positive elk born prior to 2004. If we do find TB in younger animals born after 2004, it will be a red flag for us as that indicates that the disease is still percolating in the wild populations.”
TB is contagious and transferred through saliva and eating contaminated feed. It is generally found in bison, elk, deer, goats, cattle and can affect other species, including humans.
In 2000, a provincial task force was created to combat its spread and ensure surveillance. Members included the Canadian Food Inspection Agency (CFIA), Riding Mountain National Park (RMNP), Manitoba Agriculture, Food and Rural Initiative (MAFRI) and Manitoba Conservation.
“For us today in Manitoba the primary implication of TB is a trade barrier. We are the only jurisdiction in Canada that has restrictions on the export of breeding stock from Manitoba into the U.S. The rest of Canada doesn’t have that imposition put on it and it is our goal to have that removed,” said Preston.
Top priorities for the year include demonstrating freedom from disease in the domestic livestock herd in the Riding Mountain TB Eradication Area (RMEA), maintaining the TB-free status in that domestic herd, and reducing TB presence in wildlife that pose a risk to domestic livestock.
The initiative is also looking to minimize interactions between cervids (deer and elk) and livestock, especially herding on livestock feed, which can transmit disease.
The task force will also be looking to reduce surveillance in both the wild and the domestic herds to maintenance levels, and develop and maintain a sustainable elk and deer population in the ecosystem.
“The standing committee on agriculture recommended back in 2003 that the elk herd size in the park should be maintained at about 2,500 head. Currently we are sitting in about 1,500 head,” said Preston.
A number of surveillance procedures have been undertaken again this year, including, domestic livestock and elk surveillance, hunter-kill surveillance, First Nations hunter-kill samples, on-farm risk assessments as well as pressing forward with premise identification and linking to CCIA records.
Testing buffer areas
“One thing that we are doing differently this year is that we are not doing any testing in the core area, which is primarily the RMs of Grandview and Rossburn. Instead the surveillance is concentrated on herds scattered in the buffer area. Roughly 10 per cent of those herds are undergoing tests this year, which translates into 33 herds and 3,500 head,” said Preston.
To date, 29 herds have been tested and with all negative results. Preston anticipates the possibility of ceasing herd testing outside of the core area after this year.
The initiative plans to complete the surveillance of 150 head of mature elk cows in the core area.
“On the elk surveillance program side, a second round of mature cow testing may be required in 2019-20 to allow us to be convinced that the disease is indeed well under control,” said Preston.
The TB eradication project is also working to develop a new testing model in order to find better ways to collect and analyze data.
“The issues of data collection, the premise identification and linking the CCIA accounts cannot be overestimated. We have done a lot of work this year with databases and we have been able to track down slightly over 80 per cent of the animals that leave to slaughter,” said Preston. “We are striving to bump that number up even higher as the closer we get to 100 per cent the more likely it is that we can use slaughter surveillance as the only mechanism… as opposed to herd testing on the landscape.”
Field staff members are now working with RMEA producers to conduct on-farm risk assessments and assist in finalizing details of cattle identification and premise identification that will enable full use of slaughter TB surveillance information on cattle born in the RMEA.
Slaughter data is critical to reduce emphasis on live animal herd testing. Risk assessments will assist producers in identifying potential risks of their cattle interacting with elk and help implement the appropriate measures to mitigate those risks.
“Manitoba producers have really made great efforts to ensure that we have risk mitigation put in place and that is probably the single most important factor that has led to the reduction of cases of TB in domestic livestock,” said Preston.
The TB eradication initiative is looking to perform the last core area herd testing in 2015-16 and continue with elk cow testing and surveillance until 2022 with the ultimate goal of provincial eradication by 2024.