I can't answer your question, but I can tell you what our set-up is. 8 free choice feeders on 3200 acres on our first season. I don't think it's near enough and we plan to at least double the protein sites next year and possibly do the cotton seed thing.
The last group fed 8,000 to 10,000 pounds a month
and I assure you we'll never have the extra cash to do that. I myself will implement 2 timed trough feeders next year that will drop at different times after dark. It isn't ideal driving 6 hours once a month to fill feeders IMO.