There hasn't been much demand for caprids in recent decades, besides takin (and I think that has even tempered somewhat in the past few years). It seems that zoos in this part of the world have trended towards flashy, new exhibits for popular flagship species, and hoofstock have not fared too well with that development. African hoofstock have done reasonably well because of open savanna-type exhibits, but caprids, deer, and Asian hoofstock have backslid tremendously. While supply is decent because caprids are prolific breeders, the demand is so low that the few zoos breeding them (ex. Los Angeles) are having to send them away to safari parks and rural zoos to keep from going over capacity.