My roosters and hens both "shut down" reproductive behavior after extreme stress. The older the bird or the more stressful the event, the worse it seems to be.
This is generally accompanied by cessation of mounting in the boys, shrunken combs, "hen" vocalizations instead of their deeper clucking, less or no tidbitting (food sharing seems to stop altogether sometimes, as in they will drive hens away or even be bullied away by them during normal meals. Forget about sharing treats too) dancing, or crowing.
Hens get the shrunken combs and stop laying, but this is far less dramatic of a change and easier to miss.
If he's not suffering from infection or another injury, he's likely to rebound in a couple of weeks to a month, but that's just a guess based on my own limited experience.
