I make bone broth quite regularly. I use it to make soups or as a stock. Recently I have started to use my blender to make the bones into a dog food. The dogs love it. Just make sure you only use chicken bones (I don’t think lamb or beef bones will soften enough to blend) and also make sure you sieve it afterwards to make sure there are no sharp bits left. Add a bit of water or leave a bit of the stock in to blend them into a thick liquid. It will then set semi solid in the fridge.