I have made a lot of ground turkey and sausage and the way I do it is to just skin the turkey or rooster and not bother with the feathers or skin at all. Ground skin does not sound very appetizing to me, but that's me. I debone it all and make chicken stock out of the bones by simmering them in a large pot with fresh onions, garlic,carrots salt and pepper. The meat I find grinds best, it I cut it into 1inch to 1 1/2 inch wide strips and put them in a single layer inside a plastic bag, on a sheet pan in the freezer for about 10 - 20 minutes, to firm them up. Do not freeze them, or the refrozen meat will be a bit mushy when thawed. You can add seasoning for sausage before putting it into the freezer and let it absorb into the meat for a few hours or overnight, in the frige, tossing it in the bag a few times to get the seasoning well distributed. I often add a beef chuck roast (cut into the same size strips to ground burgers or sausage and grind them together, beef and poultry burgers or sausage and the fat on the roast makes the lean chicken or turkey taste better, I think. I do not use the fat from chickens or turkey. I know some people who render it and use it for frying. If I am going to use the ground burger or sausage within 3 months, I use regular zippered plastic freezer bags. If I make a lot, as most sausage seasoning spice blends call for making 25# at a time, I vacuum package in seal-a-meal type bags. I hope this helps, but hens will be falling off the bone tender if cooked in a crock pot/slow cooker for 8 hours. When making chicken stock, only bring it to a simmer, not a boil. Simmer the bones until the meat falls off and reduce the stock to a concentrate to put into smaller freezer containers for recipes calling for chicken stock, which is most recipes these days. Restaurants seldom use water in recipes, it's mostly chicken stock!