I have a breeder pen of sort... when I want eggs from a mating, I put them in for a month and collect the last week or two of eggs or till I get how ever many I want. When collecting pure breds, I don't let them free range... else they all go out with everyone else.
I have two separate breeds for this coming Spring...two separate units in my henhouse...I will alternate with free range in the evenings every other day....they both each have their own runs from the coop....