I noticed early on in breeding that the little roos who started to crow soonest, as early as 2 months, turned out to be more aggressive. They tended to crow frequently and repeatedly during the day and acted over-sexed, harassing the hens and other roos. So over time I selected for roos who developed more slowly, using ones who started crowing later, around 4 months or longer and that seemed more calm. I think that led to pullets who also developed more slowly. Especially in my Silvers, the pullets didn't start laying until 8 or 9 months, even with several months wasted on supplemental lighting over the winter.
This past year some new sprig developed in my slow-maturing strain of Silvers. A few young roos started crowing at 2.5-3 months. And this September I had 2 pullets begin laying at 5 months. I plan to use some of these earlier maturing birds as primary breeders next year. Some of the earliest-to-crow roos are just too aggressive for me. They can't seem to get along, always picking fights with other roos and mercilessly chasing down hens. I just can't bring myself to use them.
It feels like walking a knife edge between early maturation and excessive aggression to breed a spring pullet who starts laying in the fall. I'm hoping by using the early-laying hens and roos maturing slightly earlier than average that I can achieve my goal.