Organs from game ruminants are fine - check with your local fish and wildlife rep to see what diseases or parasites game carries in your area. There's a prion infection similar to mad cow that deer can get, but it's very localized and the fish and wildlife people are highly aware of where it is. In other areas, feeding raw liver might be problematic due to a parasite, but again your game warden will know of the risk.
Becca Shouse
Maggie and Zhi (queen bees), Ben, Gus, Cord, Rocky, Ted (BCs), Lu and Tully (Maremma flock guardians)
Irena Farm, Semora, NC
