Mix up some Cracked corn, Oats, Flaxseed, and if you have any dried Peppermint, (you can also use the peppermint tea, as long as its only peppermint in the ingredients).
you only need 1 or 2 tea bags or 1 to 2 tablespoons, to about 5 to 6 lb of the mix.
the peppermint, increases appetite, and sooth there tummy's if any thing is upsetting their tummy's.
3 lbs corn
2 lbs oats
1/2 lb flax
I would give about 1/4 of a cup to each Chick a day Plus there regular feed
probably give it before they go to bed, so there not using up energy from the food during the day, and they will have full tummy's before going in for the night
Maybe some else will have better idea to