He's got away with not bring ringed today, nothing has dropped - I can feel balls but they are not properly in his scrotum. I left my Roughs entire as they went to the butchers by Oct so I'm not sure if I'm trying to do him too early? Or is it another Shetland thing? 
I've had a few of ours (commercial sheep) where I've had to wait an extra day or two this year, not sure why. Usually we get no more than a handful in about 400-ish lambs, this year it's been a much more noticeable number where I haven't been able to ring them on the second day. 36 - 48 hours is my preferred timing - usually they've dropped, the lamb is fed and strong, but it's still early enough that there's only a very short period of discomfort. A day or two later, they always seem to feel it a bit more, and for a few minutes more.
I think I've heard a few on here talking about being a struggle to ring some of the smaller primitives within the statutory week, as their little testicles are too small and slip through the ring!
