Yesterday we needed to cull our BR rooster due to him severely injuring one of our hens. They are all around 4 months old. He had been mating nicely with his #1 favorite. He decided to go after one of our Orps. She resisted and he fiercely chased her for two days. She didn't even want to go into the coop at night. He got her outside and ripped a huge hole in her neck (she was twisting and trying to get away) causing a good bit of bleeding. Needless to say I brought her in and have been treating her. Previously when the young hens didn't want to mate he stopped. Something snapped in him to pursue her and he was enraged. His #1 hen cried all day for him. It was pathetic. Even at night she didn't seem to know where to sleep. I feel so horrible for her but we had to cull for their safety and health. (Yes, we did try to rehome him).