Dogs should ONLY be given raw bones, not cooked bones. This is because the cooked bones produce chips that damage the digestion system causing intestinal bleeding.
In the diet it is very noticeable how the way of pooping for dogs changes. Toby has always given good color, good smell and good firmness except when he has a stomach problem, which is as common as a human.
The advantage of calcium in the diet is for puppies that are constantly growing and along with breastfeeding their mother, they need to meet their demand for calcium. That is why sometimes small raw bones or eggshells are added to give a little calcium that is needed. The intention of giving them big bones is to maintain the health of their jaws.