23% should be okay for babies and lactating females but it's a bit high for your other rats. You might want to feed it only to those first two groups and look for something else to feed your adults, feeders and non-lactating females. Too much protein over a long period of time tends to end up with horrible skin and coat protein sensitivity issues. Probably doesn't hurt them as feeders but it's nasty to look at and not really nice for the rats to live with as they scratch a lot. I'd avoid that happening.