I also have a d'uccle roo, he is about 10 months old now, and very calm and mature. He has always been very sweet and his personality hasn't changed at all. He went through his hormonal stage at about 4 or 5 months old, but was never ever aggressive, the only way I could tell he was hormonal was he would occasionally try to mate my arm when I held it out for him to fly up on, lol. His hormones seemed to even out by 6 or 7 months old. He still lets me carry him, handle him in any way anytime, jumps on my lap or shoulder, follows me around. People say he's more like a puppy than a chicken, lol. AND he is a wonderful roo to his 12 hens. When we introduced them to him they were only 9 weeks old and he was 7 months old. I was worried he might try to mate and harass them but he treated them like babies from the start, teaching, feeding, and protecting them. The first time he tried mating was just before we got our first egg, when the hen was ready and squatted for him, and he was gentle with her. He's a perfect gentleman and a wonderful protector to his girls, as well as being gentle to humans. Sorry for going on and on, but this little d'uccle roo is the love of my life and I can't help myself!
Anyway, back to your your question, I personally think by about 4 months old, you'll have a pretty good idea of a roo's personality, but I wouldn't say it's 'set' until after the wacky hormonal stage passes, around 6-8 months old. And even then, sometimes nasty roos can be 'reformed' if you're willing to work with them. I don't have any experience with silkies, but I bet your d'uccle's sweet personality won't change as long as you keep handling him and spend lots of time with him. I have read that d'uccle roos are known to be less aggressive than other breeds. Can you guess which roo I think you should keep?
