I may be wrong on this one, but the calf you mention somewhat reminds me of a female Nile lechwe (Kobus megaceros); the shaggy neck suggests lechwe to me.
@SivatheriumGuy I wasn't entirely sure, since it was very far away. The Nile lechwes were also kinda far away from the gemsbok, but it could have been a female that was just far away from the others. I definitely see the lechwe neck though
