I worked on the boneing tables as a young man and turned into a pretty fair meat cutter but don’t know crap about live cattle nor pastures.
I heard Allan Savoy from South Africa give a talk on cattle behaviour and he claimed he could make cows eat rocks if he could pack them tight enough and keep them moving in a large herd. He thought a large herd was in excess of 8000 animals.
No answer to your question I know LJ just thought that was interesting.