Egg production in a chicken flock fol–lows a typical curve. While the curve is similar for most breeds of chickens (Figure 1), the specific numbers can vary significantly, especially with regards to age at first egg, peak production rate, and egg weight. Egg production typi–cally begins when the pullets reach 18-22 weeks of age, depending on the breed and season. Egg production, as a percent of hens housed, rises sharply until it reaches its peak about six to eight weeks later. Peak production levels of 90 percent or greater are common with some of the egg-laying breeds (such as leghorns).