Why are you so sure you have a pair? I'm sorry if you already clarified this, but I missed the earlier conversation so I am just curious. I have found from the many hogs I have seen that sexing visually is pretty easy. The males have a much longer distance vent to tail tip than the females, even very young. When they are young, you won't have some of the other "signs" like the dip after the cloaca in the female, but the tail length is pretty obvious. Where did you get yours?