Thats true but for a 700 lbs animal, there is no explanation other than genetics. They get to 150 lbs just by drinking milk. If a person is way bigger than another person it does not mean they eat more protein. An ecto morph is just genetically smaller. Protein helps grom muscle after its torn down, and bulls laying down 10 hours a day digesting grass doesnt look like a workout to me. Protein is important we all know, but genetics are genetics and more powerful than anything.