Why are bones a food source anyway? I can see some sort of recipe where you’d boil them to make a weak soup stock, but even my pitbull can’t exactly ‘eat’ bones. Doesn’t stop him from trying, but all he’s doing is slowly gnawing them down to powder.
Edit: Playing a character that cooks her food before she eats it has shown me that yes, you can indeed make broth from bones.
But why not ‘tainted bones’ that can be used to make things that require bone, but not safely eaten; zombies already drop nonstandard flesh, why not nonstandard bones?