Every time that an animal eats a plant or another animal, the conversion of food biomass into the consumer’s biomass involves an efficiency of much less than 100%: typically about 10%. That is, it takes around 10,000 pounds of corn to grow a 1,000 pound cow. If instead you want to grow 1,000 pound of carnivore, you have to feed it 10,000 pounds of herbivore grown on 100,000 pounds of corn.
— Guns, Germs, and Steel by Jared Diamond
