Literally nobody! I have been to the cme a few times and if I remember correctly its not even a pit but more or less a gathering place for traders (few) to come to once a week and see if anybody wants to bite on a few butter contracts lol! Dairy is not the hottest thing at the merc from what im told!
Commercial users are willing to trade it at a price of their choosing. The dairy industry is an oligarchy, i.e. it's dominated by too few firms with too much pricing power. Leave it alone.