Today’s commercial turkey is selected to efficiently produce meat at the lowest possible cost. "It is an excellent converter of feed to breast meat, but the result of this improvement is a loss of the bird’s ability to successfully mate and produce fertile eggs without intervention. This means that turkeys marketed as 'heritage' must be the result of naturally mating pairs of both grandparent and parent stock." The definition of heritage turkey will help you understand what you're getting when you shell out the extra dough at Thanksgiving for your bird.