Also, if no meat is saved, why aren't slaughtered animals killed by sticking them through the heart or lungs? Just a thought.
My guess would be because sticking them through the heart or lungs may not kill the animal instantly, which with cows could become very dangerous.
My first deer (and only) was hit in the neck. It was drived to me along with two other does, and my second shot (buckshot) hit one of them in the neck. She dropped right away, but still sprawled around and tried to get up. I quickly ran up and finished her with a slug through the heart, which in turn took off a large portion of meat on the shoulder..
If I could choose a shot it would be behind the shoulder, but that day my pellet just happened to connect with neck.