I try to save and eat the heart and liver from all my animals. but livers from rutting bucks and bulls is often inedible. Ketosis from hormone fuelled bucks and bulls that are running around eating little and metabolizing body fat will make the liver full of nasty tasting stuff. that's why so many people don't like liver. Livers from fawns and does and early season bucks and very late season bulls is good.
Paté is wonderful, I make it from deer, duck, goose, elk, and sometimes pork and preserve it in small jars done up in a pressure cooker. Keeps for a couple years with no refrigeration. Wonderful on toast with mayo and a pickle.
Parts not good for humans are pretty much all good dog food, but I would cook it first to destroy parasites, especially risky are hydatid cysts in lungs of elk and moose. Hydatid tapeworms are not infective to people who eat game meat, but they are to canines. Dogs with hydatid tapeworms don't get very sick, but will pass the tapeworm eggs that WILL infect people and cause hydatid cysts in human lungs and livers and sometimes brain. I am a professional animal nutritionist if that matters.