I have Nubians, too. The cattle panels and other woven wire fences previously mentioned work well for me. However, horned animals may get their heads stuck in fencing depending on spacing of wires. Our goats do not have horns so it is not a problem for us, but we've had a few wethers with horns...
Most of our browns, as well as the Holderreads buffs we had a few years ago, begin developing Dewlaps by 5-6 months old. It may be a difference in lines.
I have them as a hobby but try to breed them to meet standards. It is the only breed/variety that I have. I would like to find s good unrelated rooster.
Thanks for the comments!