For lack of a better set-up and to keep my sole buck from getting too lonely, I've had him share a fence line with my does. But they'll be kidding soon and it's time to get him his own digs. Since I plan to retain a doe or two (if I get one) from these kiddings, I'm shopping for a buckling - to give my herd sire a buddy and for new genetics... but assuming I buy a young buckling, how old does he need to be before he and my buck could share a pen. My buck is pretty docile. I even ran him with my does for awhile in the winter because they have a nicer, warmer house.