Hmm, when you say cold, how cold is it? It's been cold here too but only down to the teens and only for short periods. My cockerel is 7 1/2 months old and 100% fertility; we sold his dad last month because "his" fertility was low, only about 40% and besides, not half as nice as his son has turned out. We just hatched 13/14 eggs this past weekend, and the 14th died at halfway through hatch, not sure why.
Course, this morning I thought DH might want cockerel for dinner - crowing at 3:30 am and not stopping till dawn was a big annoyance.
I don't think there is such a thing as a "quiet" crow, is there?