You need to breed chickens into a domesticated strain. The chickens you start with are wild.
Keep breeding them - you should be able to get two sets of chicks before the first grow up. Cull the prior generation so they don't get mixed up. Eventually, instead of the yellowish wild chickens, you'll get white ones. Also, the Waila tooltip will stop saying they're from "Improving Minecraft" and just say "Minecraft". Those chickens will lay eggs.
Ah!! thanks!!..