I once buried the leftover bones from bone broth making into my garden. I had attempted at making my own bone meal but failed because the pork bones were just too tough and strong. I never find out what happened to the buried bones, but I never saw them again despite digging up the area for planting after a couple of months later. So, I guess they’ve composted.
Bone meal is the dried and ground powder form of animal bones. It contains a good amount of phosphorus and calcium and is a wonderful fertilizer for the plants.