We have been grinding our own feed for our girls as they grow. They are now at a laying age and I am wondering what I need to change. I have access to: whole oats, ground oats, ground corn, and distillers pellets (20% protein). I can buy other grains and grind them if I need to. I have free choice oyster shells available to the girls. What and how much do I need to be feeding my hens that should be laying any day now? Thank you for your help.