At what age do roosters start loosing their potency? I have a roo that is about 3 and then a young roo that is not quite 1. These guys along with a barred banty cochin are with about 35 hens. I just incubated a bunch of my eggs and was suprised at how many didnt develope. Is my roo getting to old or are they slowing down since it is getting colder out. I have a couple more roos that I am going to keep but my main roo chased the others so much I just figured he was doing his job but now I am not so sure. Thanks Jenn.