Egg production is a remarkable thing. A pullet (young female chicken) begins laying eggs at 18 to 20 weeks of age. She reaches peak production at about 35 weeks, with a production rate greater than 90 percent (that’s 9 eggs in 10 days for a
single hen or 9 eggs from 10 birds daily). This period of peak production lasts about 10 weeks, after which her egg production slowly begins to decline.
A high-producing hen’s annual egg production is more than 10 times her body weight. The average commercial Single Comb White Leghorn hen lays about 265 eggs per year, with backyard breeds laying fewer. In most cases, the more exotic the breed, the poorer the egg production.
Hens stop laying eggs for a variety of reasons. External and internal stimuli affect hormone levels, which change the condition of the ovary and oviduct, the organs responsible for egg production. The result of these changes is the reduction or cessation of egg production. The most common stimuli that affect egg production are decreasing day length, disease, broodiness, poor nutrition and stress. However, even under ideal conditions, every hen’s egg production eventually slows down and stops.
Decreasing day length causes hens to molt and cease egg production, a process that may take several months. Molting is a natural process that allows the hen to replace old, worn feathers and rejuvenate her oviduct, the organ that “makes” eggs. Natural molting is a seasonal process and usually occurs in the fall. But in domestic birds it can occur at any time, especially if the hen is exposed to stress.
Broodiness is the natural tendency for a hen to sit on her eggs to hatch chicks. Most hens eventually go broody, some breeds more than others. When a hen becomes broody, hormonal changes result in the stoppage of laying eggs. To reduce broodiness, collect eggs daily from nests and hiding places. If a hen shows a desire to stay on the nest for extended periods, remove her from access to the nest for several days. After a period of time, the broody behavior will cease and she will return to egg production.
Eventually, all hens cease egg production. Normally, chickens will produce well until they are 2 to 3 years old, and then egg production declines.
Egg production is a hen’s reproductive activity. It is not a requirement for hens to thrive. When a hen experiences stress, even so minimal as to go unnoticed, she may respond by ceasing egg production. Moving, handling, overheating, fright, and lack of food or water are stresses that can be detrimental to egg production. Protection from the elements and predators, clean and well- maintained facilities, adequate ventilation, constant availability of feed and water, etc. will reduce stress and help maintain high egg production. Maintaining a healthy, well-managed flock will result in high producing hens and many high-quality eggs for the family or for sale.
Source: Why Did My Chickens Stop Laying? Oregon State University Extension publication PNW 565, Jan. 2003