I thought I would mention this because I had a great dominant roo whom was killed by 2 other roos.They were jealous he got all the ladies. I wanted his babies and pulled 3 eggs out of fridge and put them in an incubator to get "his" offspring.3 hatched but only one was his. I didn't know at the time I could have just collected fresh ones for up to 3 weeks from the other hens, but I would have had to separate the other roos from the hens for a bit. Also I borrowed a roo once, since I didn't have one. I found out it only took one day for the eggs to be fertile. I hope this has been helpful.