Chickens eat basic grain and produce egg pallets.
Barley and wheat can be fed to chickens directly, no processing or mixing required.
Chickens seem to really breed out of control once you reach certain level of them, or maybe it was my initial purchase of them not sure. At first I bought 4 chickens and 1 rooster, then addition to chickens I got 1 sheep of each four brands, now chickens only have two brands / types, a "chicken" and a "rooster". So again don't know if it was my initial purchase of "chicken 4" so that 4 is now multiplied over and over again, or are chickens just configured to breed so much more, really dont know yet. Anyways point being, when I was still at 32 sheeps in one sheep barn, I already had THREE (3) chicken coops with hundreds of chickens, you could say chickens will breed out of control