And say the processing costs a modest 20 cents a pound. That amounts to $4500.00. Who pays that bill?
It usually ends up being taken care of in one of two ways:
1. The hunter pays a reduced rate for processing - essentially the base 'cost' for the work. Or, one of the various meat donation charities will cover the cost (at a reduced rate, of course).
Or, more commonly-
2. The processor just eats the cost. Many of them simply do the work and donate the packaging materials, because they want to help people when there's plenty of "extra" meat laying around. Others do it because they can claim it as a charitable donation. Some people do it for both reasons.
One of the game and livestock processors near me just had a post on his website in December showing that he handled 135 big game animals, 17 livestock (cows, sheep, pigs, etc), and almost 2,000 birds last year - all part of one of the various types of "Hunters for the Hungry" programs. All together, he "lost" just under $30,000 by donating the time and materials, because he doesn't take shortcuts (like saw-cutting big game) like some other processors do for donated animals.
He maintains one rule about donations:
If there's room in my cooler, bring it in and fill out the paperwork.
He can't stop people from killing animals they have no intention of eating. He can, however, donate a little time and material to make sure that meat gets put to good use.