I had to log in just to tell you... good one man... I actually laughed out loud... Tired... f’n canucks...
Could be lot's of things like someone playing a joke and basically staging it and intentionally putting the tire on the cow. Tire is obviously wore out and appears to be of Ag or forestry origin. Could be as simple as they left the wore out tire laying in the pasture and cows doing the brilliant stuff cows do decided to crawl through it and ended up stuck half way.
First...that ain't no cow. Like most sorta-males he saw a hole and tried to fill it. And like most of these events it never quite works out the way we intended.......
They use old tires for feeders. My guess is the cow was bored, started playing with the tire and ended up there. I grew up on a dairy farm, have seen cows end up in some weird ass predicaments.