Making use of the odd bits

When I look at a bag of dog food, cat food, etc. I see all the off bits of stuff, almost the same stuff as in organic fertilizer these days. Just about every bit of protein ends up cycled into the yard, but I like to cycle it as heavy as possible before it ends up there.

Take the ground hogs, occasional bird, et cetra that the dog and cat catch: I feel like there should be a way to throw it in a boiling soup vat for 24 hours then grind the whole mess up with some leftover bread and serve it portioned out to the animals or something.

We also have guests weekly. We feed them chicken. Although my family doesn't leave much but some shell of calcium, some guests leave quite a bit. I pick what I can of the bones and let the animals have it, but why can't I turn that into dog food?

I know if you boil chicken bones enough they disintegrate. I'm not sure what whole groundhog or bird would be like. I really don't want to spend a long time processing them. I tried once on a groundhog and didn't get far. The dog also tried eating raw meat and vomited. I can't imagine boiling a whole hairy groundhog would smell good. Maybe I could roast it instead?

We are getting quail soon and we also have fish. Quail means I will be adding more feathers and random body parts to the system. A way to grind them into a meal for dog food, cat food, fish food, or quail food would be nicer.

I've heard people just letting the flies getting the road kill and serving the flies to the birds, but we are in close proximity to the bird house and I don't want to feel like barfing all day.  Thanks!

I suggest a pressure cooker.
If possible,  gather animal feed in the freezer til you have enough got for a batch, then pressure cook it for an hour,  plus.
Bone will fall apart.
Collegen  will melt.

We're raw feeding the dog.  So we save heads, necks, non-GI organs, feet, etc for him.  If I part out a chicken he gets the back.  As long as it's raw, chicken bones are fine for dogs.  We'll be saving the organs we won't eat including tripe from the lambs when I slaughter them for dog food too.  

I have 3 solar cookers, so there is almost always one available, and I cook leached acorns most every day for my chickens.  Into this same pot goes any trapped rodents (I catch a ground squirrel every few days through the summer...they are quite the pest here, roadkill squirrels also if they are pretty fresh, dead mice out of mousetraps, the occasional bird trapped in the nets on the fruit trees and grapes.  After a day in the cooker, all of them are so soft they can be flung whole to the chickens, who happily tear them apart and the whole thing basically vanishes, fur and all!  It's a much quicker, cleaner, and easier method of recycling these sorts of things than just about anything else.  Another way is to use black soldier flies, which will thrive even on the vilest imaginable things (rotten roadkill and humanure, among other things!) and bring off a yield of poultry or fish food.