By offal are you talking about the organs or the other remains? Offal, the liver, kidney, brain, etc can be turned into many interesting foods. Head cheese is just one option.
As for the inedibles...
Pelts can be tanned. If you don't want to do it, lay a sheet of wax paper on the flesh side and roll it up. put it in a plastic bag and freeze it. There are bush craft and survival groups that will be happy to take it off your hands.
Bones can be left out for insects to clean off. Don't put them straight into the compost since they will take a super long time to break down. Do this with your chicken, pork, and beef bones from the kitchen as well. When winter comes round burn the lot in the fireplace/stove. Add that calcium rich ash to your compost. Having broken the bone down by fire the micronutrient becomes available for your garden.
Ears make good dog treats, I understand. And feet are traditionally used for charms, if you lay any stock in that idea.