He's seen a few sunrises. Definately mature, but in apparently great condition. Nice shine to his feathers and a clear bright eye - he'll get the job done for you.
I don't know if they become infertile but I've heard when they get older they become less fertile. I don't know if thats true or not. either way he sure is pretty and those are some massive spurs!
If the large spurs become a problem they can be trimmed or removed. Look for info on BYC or other Internet sources for instructions. He's a pretty fella. Mature roosters are a thing of beauty!