[blacksmythe]

Horses are very much domesticated. It was probably very difficult, requiring many generations of breeding.

By comparison, zebras are very hard to work with.

http://theconversation.com/why-zebra-refused-to-be-saddled-w... "In many ways, zebra appear very like horses (or ponies, given their size). Yet underlying differences in behaviour have meant that while horses and donkeys have been successfully domesticated, the zebra remains predominantly wild... Horses were initially kept as a food animal."