If you read the tag of ingredients on your feed bag you see that virtually all chicken feed, chick Starter, Grower, Raiser, etc all have calcium. Sure, all chickens need some calcium for good health.
But Layer feed has almost double the calcium of other feeds. This is to provide the egg layers with the extra calcium they need to make egg shells. Non laying chickens, whether roosters, chicks or adolescents do not need that extra boost of calcium that is found in Layer feed. It is potentially harmful to their kidney and other systems.
If you provide a calcium supplement, such as crushed oyster shells in a side feeding bowl, only the laying hens will normally mess with it, as only their bodies are graving it.