The Montana Department of Livestock (MDOL) has adopted changes to rules affecting brucellosis vaccination requirements and the boundary of its brucellosis designated surveillance area (DSA).

According to MDOL, the newly adopted brucellosis vaccination rule (ARM 32.3.433) mandates that eligible animals in 10 Montana counties must be vaccinated against brucellosis. The change requires that all sexually intact female cattle and domesticated bison 12 months of age or older in Beaverhead, Big Horn, Broadwater, Carbon, Gallatin, Jefferson, Madison, Park, Stillwater and Sweet Grass counties must be brucellosis vaccinates. Prior to this rule-making, only cattle and domesticated bison in Gallatin, Madison, Park and Beaverhead counties were required to be vaccinated.

This rule includes cattle that enter any of these counties for seasonal grazing, MDOL added.

Beyond the addition of new counties, the rule also moves away from Dec. 1 as the cutoff date for completion of vaccination and no longer specifies that animals be calf-hood vaccinates, MDOL said, noting that this gives producers more options for the management of replacement heifers and allows animals to be vaccinated as adults.

“Vaccination in a broader area than Montana’s DSA provides some protection from sudden changes to the distribution of infected wildlife on the landscape,” Eric Liska, MDOL brucellosis program veterinarian, said. “Vaccination has been shown to minimize the spread of the disease if it is introduced into a livestock herd.”

Producers who have not vaccinated their replacement females in the past should contact their local veterinarian to schedule replacement heifer vaccinations and discuss options for unvaccinated adult females in the herd, MDOL said.

Additionally, changes to ARM 32.3.433 adjusts the DSA boundary in a portion of Beaverhead County. Cattle and domestic bison that utilize this area will be subject to all brucellosis DSA regulations. DSA regulations include brucellosis testing prior to change of ownership and movement as well as vaccination and identification requirements.

The DSA boundary has expanded three times since 2009, MDOL said, explaining that each expansion was made in response to findings of brucellosis in elk that required the inclusion of additional cattle and domesticated bison in the surveillance program. Undetected disease spread outside of Montana’s DSA could jeopardize Montana’s federal brucellosis class free status, MDOL said, noting that in 2008, a loss of brucellosis class free status was estimated to have cost Montana’s producers up to $11.5 million annually.

According to MDOL, DSA regulations and producer compliance have allowed for early disease detection when a periodic transmission from wildlife to livestock does occur. This success promotes trading partner confidence in the disease-free status of Montana’s livestock.

The mission of MDOL is to control and eradicate animal diseases, prevent the transmission of animal diseases to humans and protect the livestock industry from theft and predatory animals. For more information, visit www.liv.mt.gov.