Roosters require calcium as well. Just at a lower level then hens in lay. If you completely remove calcium, you will within a few days see health issues and ultimately death.No ,
Who says they don't need protein
They need protein for their good glossy feather growth
Protein helps their feathers come out early without much itching
Roosters can't eat calcium
Because calcium makes their kidneys works.hard
But in very lil quantity like 0.3mg is fine occasionally very rarely