While I see what you mean in relation to species like, say, Black footed cats, it makes little practical sense for this to occur. It is generally favourable to have the institutions breeding a certain species closer together to facilitate the coordination of the breeding efforts. Having different populations across continents often leads to isolated gene-pools and decreases the genetic viability of the individual populations massively. In spite of this, a concerted effort involving a large import to several zoos in another continent can of course work, as has happened with the Coquerel’s sifaka.