The system of naming animals in agriculture relies on precise terminology to indicate a creature’s stage of development, sex, and reproductive status. This nomenclature is particularly detailed within poultry farming, where differentiating birds by age is economically significant for producers and hobbyists. Using distinct names for different life stages allows farmers and breeders to communicate clearly about maturity, track nutritional needs, and manage flock dynamics.
The Specific Name for a Young Female
The name given to a young female chicken is a pullet, a term used from the time she is a chick until she reaches reproductive maturity. Generally, a chicken is considered a pullet if she is under one year of age and has not yet begun laying eggs. In commercial and backyard settings, this designation typically applies to the period between 4 to 17 weeks of age, often referred to as the “teenage stage” of a chicken’s life.
The pullet phase is a time of rapid growth where the bird transforms from a downy chick to a fully feathered, adolescent chicken. During this time, the young female develops the skeletal and muscular structure necessary to support future egg production. This phase requires a specific starter-grower feed, notably lower in calcium than a layer feed, to ensure proper bone development before egg formation begins.
The Transition from Young to Mature
A pullet officially transitions to a hen when she begins laying her first eggs, making the onset of egg production the primary biological marker for maturity. This physical change usually occurs when the bird is between 18 and 25 weeks old, though this varies based on breed and environmental factors. The shift from a pullet to a hen is driven by hormonal changes, similar to puberty in other animals.
The increased production of estrogen triggers physiological preparations for laying, including the development of medullary bone. This woven bone acts as a temporary internal calcium reservoir, allowing the hen to access the calcium required to form eggshells without depleting her structural bones. Externally, physical signs of this transition become visible, such as the comb and wattles growing larger, becoming fully red, and feeling warm. The pubic bones, which are narrow and tight in a pullet, will also begin to separate to allow for the passage of an egg.
The timing of this maturation is also influenced by the photoperiod, or the duration of daylight hours. Increasing daylight stimulates the hormonal pathways that activate egg formation, which is why chickens naturally begin or increase their laying cycle in the spring and summer. Once the female has started laying eggs consistently, she is referred to as a hen, regardless of the one-year age mark.
Distinguishing Young Female and Male Chickens
To complete the nomenclature for young poultry, the male counterpart to a pullet is called a cockerel. A cockerel is a male chicken that is also under one year of age and has not yet reached full reproductive maturity.
Distinguishing a pullet from a cockerel visually becomes possible around 5 to 7 weeks of age as secondary sexual characteristics begin to develop. Cockerels often show earlier and more pronounced growth of their comb and wattles compared to the smaller facial features of pullets. The young male progresses to become a rooster, or cock, once he reaches one year of age and is fully mature.