[theBCnut]

Bones have very little phos, but meat is the main source of phos. That’s why you have to have the right amount of bone for the amount of meat. Most bonemeal is considered to be contaminated, but I’m really not sure if it is more contaminated than other beef bones. The longer the animal lives before becoming food, the more likely it is to pick up heavy metals in its bones, and most sources of bone meal are cattle, which are at least 1 1/2 years old.