To help with your production, ditch the food your using..
Kaytee is just a filler for pets, not good for breeders at all. Get your hands on a quality lab block and ust supplement the seeds in 1-2 times a week to mix up their diet.
You will notice your females will recover faster after litters
I only feed 1-2 blocks per bowl and the rest is Regal Rat + seeds. I've read plenty of reviews and from what I have found Regal rat is the best.