How Does a Chicken Get Pregnant?

Chickens are amazing creatures that provide us with nutritious eggs and meat. However, the process of how a chicken gets pregnant and lays eggs is a mystery to many. In this article, I’ll explain in simple terms how chicken reproduction works.

Overview of Chicken Reproduction

For a chicken to get pregnant and lay fertilized eggs, mating with a rooster is required. Hens are able to lay eggs without a rooster, but the eggs won’t be fertile. Here’s a quick rundown of how it works:

• Hens start producing eggs around 18-20 weeks old They don’t need a rooster to lay eggs.

• A rooster mating with a hen fertilizes the egg inside her, Now the egg has potential to become a chick,

• It takes 24-26 hours for an egg to form inside the hen after mating occurs.

• A fertilized egg forms a chick embryo after about 3 days if incubated

• Chicks hatch after 21 days of incubation.

Now let’s get into the details…

How Mating Occurs

In order for fertilization to occur, a rooster needs to mate with a hen. Here’s how it happens:

• The rooster will grab the hen’s comb with his beak and position her.

• He lifts his tail and lowers his back to align his vent (cloaca opening) with the hen’s.

• The cloaca is the single opening chickens use for urination, defecation, and reproduction.

• The rooster contracts his cloaca to force his semen into the hen’s vent.

• The sperm then travels up the oviduct to the infundibulum where fertilization happens.

Egg Formation

24-26 hours after a hen is mated, an egg starts forming inside her oviduct. Here are the key steps:

• Infundibulum: This is where fertilization happens. The sperm meets the ovum and a zygote is formed which will become the embryo.

• Magnum: Over the next 3 hours, albumen (egg white) is formed around the zygote.

• Isthmus: The egg next moves to the isthmus where the inner and outer shell membranes are added.

• Uterus: In the uterus, the egg spends 20 hours developing a hard calcium carbonate shell.

• Vagina: Pigments and bloom are added to the shell in the vagina.

• Cloaca: Muscle contractions move the egg from the vagina into the cloaca prior to laying.

The whole egg formation process takes around 24-26 hours total. Amazingly, hens ovulate almost daily, allowing them to lay an egg nearly every day.

Incubation and Hatching

If a rooster has fertilized the eggs, chick embryos will develop under proper incubation:

• At 3 days, distinct red blood cells appear.

• By day 5, eye sockets form.

• By day 8, the legs and wings are visible.

• Around day 13 the chick’s gender becomes apparent.

• Days 15-21 the chick turns and gets into position for hatching.

• On day 21, the fully developed chick uses its egg tooth to pip through the shell and breathe air.

• Over 12-24 hours it fully emerges from the shell!

Eggs need consistent 99.5°F temperature and humidity levels around 50-65% in order to hatch after 21 days.

Benefits of Having a Rooster

While hens don’t need a rooster to lay eggs, having one does offer benefits:

• Fertilized eggs allow you to hatch chicks and grow your flock.

• Roosters will mate with hens repeatedly to ensure fertilization.

• Roosters provide protection and alert hens to food sources.

However, they can be aggressive and noisy, so weigh the pros and cons of having a rooster. Some communities prohibit keeping roosters due to noise.