My grandfather was a rancher and when he knew that one of his cows was bloated, he punctured to let the gas escape. If he didn't, the cow died.
Last night one of the bison in Lamar Valley became bloated. We were told that while it's calf tried nursing, the other bison gathered around it until it was beyond protecting.
Until this year, one wolf pack specialized in attacking bison calves. Other than that the elk, not the bison, are the preferred prey.
However, the deceased bison provided feasts to grizzly bears, wolves, and ravens while also providing lots of photo opportunities for tourists (in between rain/hail/snow).