I used to coyote hunt on a cattle farm that was literally covered up with them. One winter an old bull died, and I figured I'd kill a pile of coyotes hunting over the carcass. Nothing touched it.............not buzzards, nor possums, nor coyotes. It just lay there and dried up to a pile of skin and bones. You could see where the coyotes did drag off a few bones eventually, but I thought maybe the hide was so tough that nothing to tear their way through it in order to get to the meat.
I've seen the same thing on several other cattle farms I've hunted, including my own. They just don't seem to go after the older animals like they do a smaller one. There are several deer hit my cars every year out on the highway next to my driveway, as it's a major deer crossing there. I'll always drag the deer off the road, and put them in a back field with the idea to hunt over them. I've found that they don't last over a couple of days, until there's nothing left. I guess venison tastes better than beef.
My curiosity is killing me... to test your theory did you ever try to go over and cut the dead cow open so there was access to at least the internal organs? It seems those are the first things they take on deer and elk... once accessed, they might hang around for a free meal...
I did not cut any open, really never crossed my mind to do so. I would have thought that they could have gone in through the rectum and opened the animal up there. To be specific.......I lost a large cow to grass tetany a few years ago. That's a condition that occurs in early spring when the grass begins to green up, and cows consume too much of it, and it can kill them. The solution is to feed a high magnesium mineral, with the magnesium preventing the poisoning from happening. Anyway, I drug her off to a remote area of the farm, in a place where I've killed many coyotes over the years. She lay there and nothing touched her for months. I'd see coyote tracks passing right by the carcass, yet they never attempted to eat of off it. That cow died with no drugs in her system, so that was not the reason for nothing eating it. I just thought maybe that the hide was too tough to chew on.
