My poly senegalus loves pig heart, i chose this over beef heart as pork is a less fatty meat, although the pork has alot more fat around the outside of the heart, the heart tissue itself and muscle has no fat in it, just trim it off the outside, the butcher i get my hearts from recommned pork as the leanest meat.. and lamb as the fattiest to avoid, beef is in between,.. i make a little incison into the flesh and cram the inside of a cut chunk of heart ( a square approx 1cm long ) with either pellet or flake food, for the extra vitamins the meat cannot provide on its own