16-20 weeks. I'd go more towards the 16 though. I processed 2 roosters at 21 weeks and unless it was in the crock pot, it was tough. (I did 1 in the crock pot - nice and tender, the 1 I baked was tough)
Well, you were all wrong. My "rooster" started laying on Friday. Got a second egg out her today. I had decide to wait for it to crow before eating it; good thing I did. She doesn't know how close she was to the soup pot.