Antlers, whether they be Elk, Deer, Moose, etc, can be used for ferrules, but generally only the tips of the antlers. The base and most of the branching material is too porous and not strong enough. And even not all tips are dense enough, you have to inspect them individually. That said, once a suitably dense tip is identified, it can be sealed with cyanoacrylate or thin epoxy.
HTH
Gary