If fed in moderation meat is fine,i wouldnt suggest feeding your grey meat on a daily / weekly basis,just as an occasional treat.Remember a little bit goes a long way on the portion side,one small piece of meat is more than sufficient for a grey.Many of our members here do feed their greys a chicken leg with little meat on it,they love to gnaw on the bone & will often eat the marrow which is good for them.Always supervise your bird when it has a bone