Oooh, I really like the tail swish! It gives the cow so much character.
I think that when the cow bends to take a bite out of the grass (or drink water) the legs shouldn't really move. Maybe just bend the neck and head? The legs look like they're crossing and she's going to trip. Or maybe try just spreading the front legs and not the back?
I've never seen a cow get down on the ground before, but the way you animated it, I believe that that's how they do it! Great work!