Chicken Life Cycle – Stages, Facts and FAQs

The life cycle of a chicken comprises 5 stages- Egg fertilization, Egg embryo, Chick, Pullet, and Adult. A chicken’s life cycle lasts around 21 days, beginning with the hen laying a fertilized egg and ending with the chick hatching. Chickens are the members of the free flocking birds that are widely used for their eggs and meat and they have four stages in their life cycle.

Generally, the chicken lives between three to five years but some breeds can live even longer. In this article, we will read detailed information on the life cycle of chicken, and its various stages like egg fertilization, embryo development, chick stage, pullet stage, and adult stage.

Life Cycle of Chicken

The complete life cycle of the chicken has 5 stages:

• Stage 1 – Egg fertilization
• Stage 2 – Egg embryo
• Stage 3 – Chick
• Stage 4- Pullet (teenager)
• Stage 5 – Adult

Stage 1 – Egg Fertilization

This is the first stage in the life cycle of the chicken where the egg is fertilized and the rooster courts with the hen. The criteria for choosing the best rooster are appearance, attentiveness, and food-finding. All these criteria will depict the health of the rooster and the food-finding ability will tell if the rooster is a good flock leader or not.

The mating is a brief process and the fertilization process takes place in the infundibulum– a part of the reproductive tract that follows the ovary. The sperm fertilizes the egg and remains for 15 minutes only. If the sperm does not fertilize, then the egg will remain sterile. The egg is encased in a protective shell and it contains all the nutrients that are required for the developing embryo.

Stage 2 – Embryo

The hens lay eggs and incubate them for 21 days by sitting on them. which is known as brooding. The embryo develops into a chick inside the eggs and comes out through hatching. The following data gives a detailed insight into day by day growth of the embryo:

Day 1	Development of the germinal disk begins
Day 2	Blood circulation starts and the tissues start to develop
Day 3	Heartbeat starts and blood vessels become visible
Day 4	Amniotic sac develops
Day 5	Eyes become visible and elbows start to develop
Day 6	Voluntary movement starts and the development of the beak begins
Day 7	Comb starts to grow
Day 8	Feather follicles start to appear and ear canals open
Day 9	Claws develop and the embryo starts to look like a bird
Day 10	Egg claws and teeth are formed
Day 11	Tail feathers start to grow
Day 12	Feathers start to appear
Day 13	The leg scales are formed with a light covering of feathers over their body
Day 14	The head of the embryo turns to the piping position
Day 15	The chick will consume the white of the egg
Day 16	The body is completely covered with feathers
Day 17	The egg white is completely absorbed and the head is between their legs
Day 18	The embryo is completely grown with the yolk sac still outside the body and the head under the right wing.
Day 19	The yolk sac moves inside the body and the embryo occupies all the space except the air cell.
Day 20	The yolk sac is absorbed and the umbilicus gets closed. The embryo starts to breathe the air and becomes a chick. It is at this time the piping starts
Day 21	The hatching of the egg takes place and it is accomplished within 18 hours.

Stage 3 – Chick

Once the chick is hatched it is dry and fluffed up then it can be safely transferred into the brooder area. Once the chick is inside the brooder it will be introduced to water and feed that is placed under the light on the brooder plat. The food must have vitamins, minerals, and protein that is necessary for sustained growth over several weeks.

In the initial stage, the development and growth of the chick is at a high rate. Some breeds grow at a faster rate, for example cornish cross birds grow at a fast rate at 8 weeks and weigh about 8-10lbs. The chicks are first covered with a fine down coat and they will start losing that coat at 6-8 days of age; this first moulting process will be finished by the 4th week. The second molting process starts around 7-12 weeks and at this point, the feathers will start to differentiate between male and female birds.

Brooding

The special care and attention that is given to the chicks immediately after hatching is called brooding. This is done to ensure the health and survival of the chicks. There are two types of brooding:

• Natural
• Artificial

Natural Brooding

When the female hen (a broody hen) sits on the eggs till it hatches it is called natural brooding. The mother hen provides warmth, food, and water for the chicks. This is the simple way and it can brood only a few eggs at a time and is usually used in small farms. The advantage of natural brooding is that is has a higher hatch rate compared to electronic incubators.

Artificial Brooding

Artificial equipment is used instead of broody chicken in farms where large number of chicks are raised by maintaining optimum temperature. It has various advantages like:

• The chicks can be raised in any season
• A large number of chicks can be raised at the same time
• Temperature and sanitary conditions can be controlled
• Proper feeding with a good amount of nutrients can be provided

Hoover brooders and infrared brooders are two types of artificial brooders.Ventilation, temperature, humidity, and space are the basic requirements of artificial brooders.

Stage 4 – Pullet

After 4 weeks of hatching, the chick becomes a pullet (female) or cockerel (male) and this stage lasts for 12 weeks. It is considered as the teenage stage, where the bird looks gawky and artless. Once the birds are about 2/3 size of the adult, they are introduced to the adult birds and the young birds will know their place and will start challenging the adult birds. An female pullet can lay eggs but those eggs are very small in size.

Stage 5 – Adult Stage

Once the pullet or cockerel reaches maturity, they become a hen or a rooster respectively. The hens starts laying eggs after twenty weeks of hatching. The first laid eggs are usually small and infrequent, and it needs time and a good feed to lay a good amount of eggs frequently. The feed of birds should have less protein and high amounts of calcium and other nutrients in order to get healthy and strong egg shells.

The average lifespan of a chicken is from 3 to 8 years if they are well protected from diseases like coccidiosis (caused by parasites and bacteria) and Marek’s disease. These diseases can be prevented by vaccines and the chickens can live for much longer.

Conclusion: Chicken Life Cycle

The lifespan of chicken is usually between 3 to 8 years and there are about 5 stages in its life cycle; egg fertilization, embryo, chick, pullet and adult. After the development of the embryo, the eggs are hatched either by natural brooding or artificial brooding methods. Before their owner kills them for their meat, they can be used as egg warmers for two to three years. The adult male roosters are used in cock fighting and other sports. The lifespan of the birds can be increased if they are protected from prey and disease. This will improve their egg productivity also.

FAQs – Chicken Life Cycle

What is the Age Cycle of the Chicken?

The life cycle of some chickens is short and some of them have a long life. The life cycle of the chicken has an egg, embryo, chick, pullet and adult. On an average the bird lives for 3 to 8 years.

How Long does a Chicken take to Grow?

The chicken usually takes 5 to 6 months to reach maturity and full size, this can vary among different breeds. It is at this time the hens are fully feathered and start to lay eggs. The size of the egg will change as they grow older.

How Long is a Chicken Cycle?

The life cycle of the chick is about 21 days where the mother hen incubates for 21 days and turns them 50 times in a day. The internal temperature should be maintained at 99.5℉ for the egg to hatch.

At what Age do Chickens stop Laying Eggs?

Most of the flock birds lay eggs for 3 to 4 years, the level of egg production, egg size and shell quality starts to decrease over the years.

How many Eggs does the Chicken lay in a Day?

The hen can lay one egg per day, it takes 24 to 26 hours to produce an egg. It can vary depending on certain factors like its age, breed and overall health.