Q. How many eggs does a chicken lay in its lifetime?

A. A laying hen’s lifetime productivity depends on many factors, including breed, feed, environment and life span, but rough estimates for the first two or three years of laying, when a hen is most highly productive, suggest figures in the high hundreds.

One authoritative survey, issued regularly by the Department of Agriculture based on commercial operations, puts the most recent United States figure at 276 eggs a year.

Poultry hens on small farms in Australia can be expected to yield four to five eggs a week, or 200 a year, by one estimate, while Canadian battery hens are estimated by the Canadian branch of the Humane Society International to lay eggs on seven out of eight days, for a total of about 320 a year.

Commercial flocks are often culled when hens stop laying or taper off sharply. This may be as soon as the end of the first year.