Quote Originally Posted by chromeitout View Post
I understand the "check them" thing, but what I'm talking about is keeping track of the individuals that continually have low numbers and should be replaced by new females, due to age or whatever. There is no way that I could remember on looks alone of a particular female that she is a poor producer in a rotating community. I totally understand how the moving around part works, but the question about records is regarding efficiency.

Edit: Also, if there are no records kept in this type of setup you could very possibly have females in the breeding colony taking up space that never get pregnant at all and you wouldn"t know it. You would just check her, see that she wasn't pregnant and put her back in there until next week when you would do the same thing again.
Thats is true, and can happen to where rats may not be getting pregnant. Never thought about it though.