Roosters have different calls for predators depending on if it is a hawk or a dog or fox- these calls are very easy to distinguish. I’m so used to the calls now when the rooster makes an “aerial predator call” to warn his hens I look up automatically and there is always a hawk, and when he makes the “dog alert” call I look low for the fox or dog. He makes no such call for vultures or the little red-shouldered hawk that is not a threat, no call for my dog, only strange ones. The rooster also makes distinctive sounds depending on what he finds to eat, be it bread or a snake. If it’s something normal like corn a few of the hens will lazily come to him but if he sounds really excited about a lizard or snake they all come running.
Like someone else said, sounds like the cow is low on a mineral; could be salt or calcium, especially if the cow has given birth recently.
One of my clients had a donkey and a goat on their property. She told me one day that the donkey actually opened the gate to the goats stall and let it out into the pasture where it killed the goat and tossed it into a ditch. Animals are weird.