It's recommended to bleed the animal while the heart is still beating so that it forces more blood out of the carcass. That's just a hygienic thing that keeps the meat fresh longer and was pretty important back in the day before refrigeration and some folks claim it changes the flavor of the meat if the blood is kept in the tissues.
I can't say I've ever eaten an animal that didn't have a good bleed out, so I cannot attest to any flavor differences that may occur when there is no proper bleed out.
I can't say I've ever eaten an animal that didn't have a good bleed out, so I cannot attest to any flavor differences that may occur when there is no proper bleed out.