I generally offer mine food a day or two after laying eggs. I give them a nice clean tub and a day or two to recuperate then feed a smaller then usual rat. Once I see that they can handle that OK they go back on their weekly feeding. They usually jump right on the food voraciously as soon as I offer it and they keep eating well too. I've had a few mousers now that I've been able to switch to rats after they laid their first eggs.