In terms of efficiency I hear good things about rabbits. Pigs are also good, or so I hear. Pigs can also handle disposal of other... waste...

Water buffalo, because mozarella is 🔥

Pigs are your best bet with all that corn - they convert feed to meat super efficiently and will happily eat whatever corn you've got plus kitchen scraps and forage if you rotate them on pasture (check out some good rotational systems at gearscouts.com if your interested in portable power for electric fencing).

I was really perplexed by that first sentence in the title before I saw what sub this was