Buffalo Field Campaign, which is working to stop the bison slaughter entirely, also notes that there are no cattle in West Yellowstone for most of the year, and therefore no risk of transmission. (From November to June, cattle are trucked out of the area and into milder temperatures.)
And when the bison - including calves - are herded toward the holding facilities, it may disrupt other wildlife, too. "During a typical hazing operation, the ... agencies ride noisy, smelly snowmobiles, fly helicopters, run horses, and ride ATVs throughout sensitive habitat important to numerous wildlife species," the Buffalo Field Campaign wrote. When they flee from the noise, many animals - elk, moose, swans - use up energy they can't afford to spend during a cold winter.
Finally, there's the matter of the cull itself, details of which have been kept notably under wraps. In fact, parts of the park - public land - will be closed to the public during the event.