P.S.
Just some things to remember:
1.) You can't put a new adult rat in an established colony without a fight going on... that includes a rat that has grown up with the colony, moved out for some time, then put back in. Therefore, when you need a male to breed with the breeder female, you will need the male to grow up in the colony without it being separated at all. Otherwise, you will need to have to start a new colony from virgin stock.
2.) A breeder is past its prime at about 18 months old. You will notice a drop in litter-size around this time. So, you might want to start a new colony a few months ahead of time.