Buck is 11 months, very healthy and happy, it's been winter so I know it's not heat sterility. The 2 does I'm not sure of their ages, but I suspect their getting old. 1 doe has been bred 3 times to the buck to no avail, the other doe had a successful litter (8 kits) from him once, but her second breeding to him didn't take. I've watched all the breedings, he falls off at least 3 times per session, he's not "missing" and I make sure they don't piss it out. So my question is who's the one who's a dud?