not exactly true . I 1st. bought 6 laying hens . 5 were rir's and 1 black austrolorp .
5 days later we bought 30 baby chicks all 1 week old . rir's barred rock and austrolorps .
I did find out one thing that is very important , AS SOON as weather permits , MOVE the chicks OUT of cages into the run and coopos . I have never seen CHICKS grow so fast and HUGE like my BO's did ... they are 3.5 months old and they look like they are 5 months old . Plenty of excerise , sunlight , food , water sure helped them grow faster than any of the others that were caged for 3 months .
they were in a 6 x6 wired cage with plenty of room , plenty of ventilation . food and water and they were pecking each other like crazy . I even separated the black austrolorps from the rir's and a barred rocks , made no different to any of the breeds ... I think its by nature they do this . ONLY breed that did NOT peck each other were buff orpingtons . I had 15 in a 6x6 cage and never had a problem with pecking and now they are 3.5 months old and already loose in one of the coops and runs with other chickens and NO PROBLEMS not what so ever . In that coop and run , I have ONLY 1 rooster and there are 20 head on that side . WORKS great .
The larger COOP & RUN I have 2 roosters and about 65 - 75 head . BIG RED is the " ALPHA " and he controls the flock . Now that they are older , you will still see pecking and chasing now and then between the flock , but not near as much as when they were younger . Now ., its like a playful game kinda thing .
I am going to post a picture of the Buff Orpinstons about a month or so ago , they were only 2 months old ... EVEN bigger now .