I kept 2 brothers and all was well, free ranging with 12 hens, then one day at age 8 months old they decided to fight to their death. Bloody combs, faces torn up and they just wouldn't quit. I rehomed the aggressor and immediately I had "calm" around the flock. Hens were no longer hiding in the Coop,coming out to free range again and this rooster I kept is so gentle on the hens. I rarely see him breed a hen. But, have 100% fertility on my eggs right now. He is 1 year old now and never has shown a bit of aggression to me or the hens.