Graduation to the chicken coop

My chickens are finally outside, and growing at a fast rate.
One thing I find amazing is the discrepancy of size when it comes to the roosters I bought.
They are HUGE. I don't have access to my camera at the time of this posting, so I'll post the pics later.
They are at least twice the size of my hens, and still growing.
I'm guessing that they have been genetically modified to be this way..... Well... It surely worked.
There have been scuffles between the two roosters I bought and the bantam Rooster we have from last year (he just wandered onto our farm, and we have no idea where he came from). He seems to want to establish dominance over the birds from this batch. I guess everything will work itself out.