A chicken’s ability to lay eggs depends entirely on its sex and current physiological state. Egg production is a complex biological process tied to specific reproductive anatomy and hormonal signals. While the female chicken (hen) is the only one equipped for the job, even she can temporarily or permanently cease production due to age, environmental cues, or underlying health issues. A significant number of chickens do not produce eggs, either because of their biology or external circumstances.
The Biological Difference Between Laying and Non-Laying Chickens
The most fundamental reason a chicken does not lay eggs is that it is a male, known as a rooster. Roosters lack the specialized reproductive organs required to form an egg, which is exclusively a function of the female anatomy. Female chickens, or hens, possess a single functional ovary, typically the left one, which is responsible for releasing the ova, or yolks.
The yolk then travels down the oviduct, a long, coiled tube where the albumen (egg white), shell membranes, and hard shell are progressively added over about 25 hours. Since the male reproductive system is designed only for producing sperm, a rooster is biologically incapable of egg production. Roosters represent the largest population of chickens that do not lay.
Natural Cycles That Halt Egg Production
Even a healthy, mature hen will stop laying eggs when her body prioritizes other biological functions or responds to natural environmental changes. One common temporary halt is molting, the annual process of shedding old feathers and growing new ones, which typically occurs in the fall. Feather regrowth demands a high amount of protein and energy, which the hen’s body diverts away from the reproductive tract. This hormonal shift causes the reproductive organs to regress and rejuvenate.
Egg production is strongly influenced by photoperiod, or the length of daylight hours. Chickens require approximately 14 to 16 hours of light per day to maintain optimal production. When daylight hours fall below 12 hours, the pineal gland stops producing the hormones that stimulate the ovary. This signals the hen to slow down or stop laying in preparation for winter.
A hen’s age is another irreversible factor that leads to a natural decline in egg production. Hens generally reach their peak production around 30 weeks of age, after which their output decreases each subsequent year. While a chicken may live for many years, most hens significantly slow down after two or three years and may stop laying entirely between six and eight years of age. This reduction is caused by a decreased rate of ovulation and the natural slowing of reproductive processes as the hen ages.
External Stressors and Health Issues That Stop Laying
A hen may also stop laying due to external factors that disrupt her body’s ability to allocate the necessary resources for egg formation. Poor nutrition is a frequent cause, as egg production is metabolically expensive and requires a constant supply of specific nutrients. A deficiency in calcium is particularly detrimental, as this mineral is the primary component of the eggshell. Insufficient calcium causes the hen to cease laying completely to protect her bone health.
Similarly, inadequate protein in the diet can halt production because protein is needed for both the egg white and the structural material for new feathers. A hen’s body will prioritize its own survival, diverting limited resources away from reproduction. Even a temporary lack of fresh water can quickly cause a hen to stop laying, as water is the single largest component of an egg and is involved in every metabolic process.
Environmental stress can trigger a physiological response that shuts down egg production as a survival mechanism. Extreme temperatures, such as heat stress, cause the hen to divert energy into cooling her body, leading to decreased feed consumption and a drop in egg output. Sudden, disruptive changes—such as new flock members, predators, or excessive noise—elevate stress hormones. This stress response signals danger, causing the reproductive tract to regress and the hen to stop laying.
Finally, illness or a heavy burden of parasites will divert the hen’s energy from laying eggs to fighting the ailment. Both internal parasites, like worms, and external parasites, such as mites and lice, cause stress and can lead to anemia and nutrient malabsorption. When a hen’s immune system is compromised, the high-energy function of egg production is temporarily suspended until her health is restored.