Humans adapt and eat what is most abundant. In India however the oxen was the most valuable animal. For centuries it was the de facto tractor. When the monsoons came many starving Indians ate their tractors. No tractor, no crops. So, it became forbidden to eat your tractor, no matter how hungry you got. Adaptation, planning, food cultivation and storage lead to population growth. A billion plus people is the result. On the other hand when cattle eat inedible grass and turn it into protein, more people eat. Along with the price of vegetables growing down, because of a balanced diet.
