I think the females deserve a bit of time to rest and recoup after litters, especially the larger litters. If one is production breeding rats then of course there's a difference in how you manage them but for most of us breeding in smaller colonies for smaller snake collections, it's quite possible to allow the females a decent rest after the strain of breeding, pregnancy, delivery, nursing and raising an active litter.

Sure I have to keep extra females around so I can cycle this way. Generally we work with 6 females per male. 2 in with him breeding, 2 currently nursing his offspring, 2 resting (or thereabouts...it's never that exact). We have three breeder male rats that cover our group of female rats this way.

I have three females currently in our colony that have been with us the longest. They've been bred and rested as even though they are all either 2 years old or older they are in prime condition and do not even appear to be "older" rats. They still have their place in the colony. They keep resting females company, act as companions to females being raised as future breeders and take turns "babysitting" the recently weaned rats in the grower bins (I've noticed this cuts way down on any scrapping that goes on in there when new weanlings are introduced).