This is sort of unrelated, but my father in law is a professional orchid grower. And he raves about a product called "Hoof and Horn" that seems to be made of African Antelope hoofs and horns. He loved it, because it took longer to break down than standard hoof and horn meal.
He said it was imported by a company in California, but that he hadn't seen it on the market for several years.
Anyone heard of this stuff, or know if it's still produced/imported? Thanks, John
You can email me personally if you have any source of it.