We practise our own ways of breeding rats, not the "only" way so I'm not saying ours is best...it's just what we do. We rest each female after her pups are weaned at 4 weeks of age. That rest is dependent on the size of the litter she ended up raising. It's always a week minimum but days are added to that to reflect the physical stress of raising a big litter compared to a much smaller litter. Basically our rule of thumb is....

7 or under: a week off

8 - 15: two weeks off

15+: one extra day for every pup over 15

Basically one day of rest for every pup raised as long as that rest is never more than at least a week. Since the vast majority of our females tend to birth 10 plus (most are around 15 per litter) the normal resting period is two weeks.

We also buddy breed all our females so at least 2, if not 3 females, go into the breeding tub with whichever male is up for rotation or best suits those females genetically. This allows us to have similar age litters going in case we need to foster some pups or have an unexpected maternal loss.

We currently have 4 males in full rotation, 1 male that is pretty much semi-retired and 1 male that is only allowed to breed with very select females due to his genetics so he's pretty much got a part-time job LOL.

It does mean that we have a lot of females to manage at different stages....in for breeding, awaiting birthing, nursing litters, resting after weaning, etc. I can get complicated LOL. I do believe strongly that resting them well between litters serves a few purposes. It allows the female to fully regain her strength and a strong mother makes for bigger, stronger litters and healthier birthings. It avoids immediate re-impregnating so a female will not both be nursing a litter and developing a new group in her body at the same time. It seems, for us anyway, to extend the viable breeding life of our females by about 2 to 3 months (which is pretty decent really). Also once they are finished breeding they are not all worn out and used up but remain a healthy, albeit older rat that still has a job in our busy colony (they babysit the weanlings, keep the resting rats company, etc.) They are also still healthy enough to be considered a good, large feeder rat or even be adopted out as pets.