Hi Erik,
The reason horses are used to " cultivate" the anti venom is that the horse cells are compatible with human blood cells, if the cells are not compatible outr bodies will reject the anti venom. Guys with long hair, thick glasses and long white coats worked this out, I prefer not to argue with them, because I will definately loose the argument. The info I have given is for RSA, I don't know if other countries follow different processes.