The Idaho State Department of Agriculture proposes to change a 2006 rule that says adult cattle must be vaccinated for brucellosis before they can be brought in from another state or country.
Vaccination of cattle would be allowed on arrival if the 2020 Legislature approves the revision.
Brucellosis is present in about 60% of elk and bison in Yellowstone National Park. The contagious bacterial disease can spread to cattle through direct contact with infected wildlife and cause cattle to abort pregnancies.
Idaho, because of its proximity to Yellowstone, requires female cattle intended for breeding or grazing to be vaccinated. The rule does not apply to animals headed directly to slaughter.
Deputy State Veterinarian Scott Leibsle said risk dropped substantially due to good risk mitigation and disease surveillance in that area, and reduction in exposure and direct contact with infected wildlife. Producers in a designated surveillance area around Yellowstone must conduct whole-herd testing.
“Currently we have no herds in Idaho infected with brucellosis. Thirteen years ago, that was not the case,” he said. “Now there are not as many unknowns as 2006.”
Back then, the state did not yet have a designated surveillance area — created in 2009 — “and did not want more cattle of unknown disease status, particularly from those states that were also dealing with herds infected with brucellosis,” Leibsle said.
Producers planning to import cattle from another state or country — to optimize herd genetics, for example — now must first send them to a state that allows adult vaccination of cattle that did not originate in that state, such as Oregon or Montana.
Leibsle said that in addition to allowing in-state vaccinations of adult cattle that weren’t born in the state, ISDA’s proposed rule change would reduce the test-eligible age from 18 months to 12. That matches Montana and Wyoming rules, and is in keeping with a recommendation USDA made following a 2018 audit of the Idaho program.
The age reduction effectively tightens surveillance.
“It does include more animals of breeding age in the sense that it prevents an animal from being missed, brucellosis being most commonly transmitted when cattle give birth,” Leibsle said. “We don’t want to miss her on her first calf.”
Long-term, the change figures to benefit disease surveillance and maintain good relations with trading-partner states, he said.
“I think the changes will be minimal to the industry. They enable greater flexibility, and also flexibility for the agency to accommodate some oversight that may have transpired,” said Milk Producers of Idaho Executive Director Marv Patten. “It’s a positive step for the bovine industry.”
If the 2020 Legislature approves the rule change, it would take effect on adjournment — typically in late March or early April, when cattle, elk and bison are calving.
“The reason we have regulations in place is to keep cattle separate and apart from wildlife during calving season,” Leibsle said. “If infected wildlife abort their pregnancy in close proximity to domestic cattle, it provides the greatest risk of transmission of the disease, causing cattle to subsequently abort their pregnancies.”