I have a tiny OEGB roo and two hens. One of the hens is broody right now and I'd like to set a few eggs under her. Unfortunately, ever since my large hens started laying, my banty eggs haven't been fertile. My little roo has been too busy trying to mate the big girls unsuccessfully, due to his small size. So, now I don't have any fertile eggs. If I put him in a small cage with my other banty hen, how long will it take before her eggs are again fertilized?