Regarding the question what happened to the hoofstock after the zoo closed, rumours went around that a lot of them had TBC and were most likely put down - again no source or proof for that, but I would not be surprised...
I too had heard that the zoo was riddled with TB. There is quite a professionally produced website somewhere that lists where some of the animals went to after the zoo's closure.
I visited the former site about three years ago and was surprised to see that, considering the robustness of some the structures, there is absolutely nothing left at all except the house.