Could you perhaps pass along some training tips? I know I have at least 3 roos in my group. I would love to keep one, but I don't want an aggressive one. Any tips to help him stay "nice" would be greatly appreciated.
The objective is to condition a male chick early on to control his aggressive impulses. It's based on his accepting you, his human flock leader, as dominant. So whenever he displays any aggressive behavior, pecking you, for example, you need to get him in a confining hold and keep him in it until he relaxes, indicating submission. It's also a good idea to pick him up frequently and handle him in this proprietary manner so he understands you are the one in control, not him.
This training requires vigilance and consistency. But it's well worth it because it makes discipline during the hormonal stage much easier and shorter.
You need to pay very close attention as he nears four or five months. This is when you can expect him to test you. When he pecks you or does that little sideways dance, or flares his neck feathers, etc, either pick him up and confine him under your arm or pin him to the ground, his head immobilized until he submits.
After age four months, the rules, no sudden movements, and
Never. Turn. Your. Back. On. Him. are most crucial. This applies to anyone, spouse, son, daughter, who happens to be in the cockerel's vicinity. If anyone encounters the cockerel in his/her path, walk right over him, never veering to avoid him. He must be made to realize that he has to get out of your way. He needs to respect you.
Many people have been unwittingly responsible for a young cockerel getting started on a pattern of aggression by being careless in his presence. Depending on the cockerel's temperament, even a small sudden move near a hen, or being near him and performing a task with your back turned to him, can trigger a sudden sense of fear and alarm in him that will cause him to attack you.
The period between onset of hormones around age four months and the abatement of those hormones around age one year are very crucial months and you need to be on your guard constantly if you intend to keep this guy and have him turn into a well-disciplined and trustworthy rooster. After that, it's relatively smooth sailing.