ditto here...
I also keep my males with their respective harems at all times. Cause otherwise mice can fight when reintroduced, sometimes with nasty results! Though my webster line don't cannibalize their first litters, I've noticed another line I have a box of, one of the females must have eaten her whole litter. But she's never touched the other female's litters she shares the cage with. We'll see how she does in the future. It's nice to have mice with some color in the colony, though they haven't measured up when pitted against my webster line albinos! Best of luck with future litters. And in the future, keep track of litter size, and do note how the babies are raised up, ect. And when you discover an excellent mother or two over time, hold back a whole litter, or as I do, keep only males in one litter, and females in another litter, that way the mother can put more into a smaller litter size, to help increase the size of the future breeders. It's just something I do, with the intention of developing a better group of mice. Plus, I always start out a cage of mice with more females than I intend to keep over the long run. If I want 1.4, I start out with 1.6 and I watch how things develop. If they all get producing just fine, all about the same time, I leave em be if I can. Sometimes a female dies in birthing a litter, or gets sick somehow, so it's nice to have that extra female in the cage. Otherwise you get a whole cage with only two or three females when it can easily hold double that many. Otherwise, if I notice there is a female that is smaller than the rest when the others start to produce, she's out, fed off to the snakes. This is where having all white mice can come in handy sometimes, then I'm not letting color or cute markings play the part in how I keep back breeders! But like I said, I do have a couple color mice around. That being said, I'm very careful to keep my white line pure. I cross the white line into the color line all the time. So colored mice throw albinos, but those albinos always hit the feeder bin. And I never pull babies back from the feeder bin, cause I don't know their background. I had it happen in the past where I did that, and the male, though albino in looks, carried the brindle gene and the babies in that cage were colored despite having albino parents! That sure was an odd mystery, but apparently the albino brindle was a different type of albino being expressed versus the Webster line albino. Wow, this was a long winded response! whoops!
Russell