We have a flock of 50 meat chicks that we will butcher in about four weeks. We plan on keeping parts for the dogs, an I was thinking the backs, necks, and hearts, as well as what ever else is left over that we won't eat. what other parts are good for them to have? My husband will want the livers. (I hate those, but he loves them). He mentioned the heads and feet also. Are those parts OK for the dogs?