Hens don’t need a rooster to lay eggs, but they do need one to lay eggs that have been fertilized. Chickens are different from mammals in a lot of ways when it comes to their anatomy and therefore their reproductive system. Let’s talk about how eggs are fertilized by chickens.
When roosters mate with hens, they transfer their sperm through cloacal contact and not by penetration. The first fertile egg is laid between 36-48 hours after mating. A chicken lays an egg on the day it mates, but an egg laid three days later is fertile.
A lot of people who have chickens in their yards want to know if roosters are needed for hens to lay eggs. The short answer is no, hens will lay eggs whether there is a rooster or not. However, roosters are needed to fertilize the eggs so that chicks can hatch. So how does a rooster fertilize a hen’s eggs? Let’s take a closer look.
Understanding Chicken Reproduction
Chickens reproduce through internal fertilization Here are the key steps
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The rooster mates with the hen by mounting her and making cloacal contact. The cloaca is the common opening for the digestive, urinary and reproductive tracts in chickens.
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During mating, the rooster’s cloaca delivers sperm into the hen’s cloaca.
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The sperm then travels up the oviduct and is stored inside the hen’s reproductive tract.
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As yolks are released into the oviduct, they may become fertilized by the stored sperm. This typically happens within 15 minutes of ovulation.
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The yolk moves down the oviduct while the egg white, membranes, and shell form around it.
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Around 24 hours after fertilization occurs, the fully formed egg is laid by the hen.
When Fertilization Happens
Fertilization can only happen when mating occurs. Hens are open to roosters when they are ready to lay eggs, which usually starts between 18 and 20 weeks of age.
From then on, hens will mate with roosters and release many eggs over their lifetime. Each time mating happens, the rooster’s sperm can fertilize eggs for up to 2-3 weeks afterwards.
So as long as the rooster remains with the flock and mates regularly, the eggs have a chance of being fertilized when the hen ovulates.
Signs Of A Fertilized Egg
How can you tell if an egg is fertilized? Here are two ways:
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Candling – In a dark room, hold the egg near a bright light source. Fertilized eggs will show a spiderweb of veins and a distinct embryo spot.
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Opening the egg—Cut the egg open and look at the yolk. A bullseye pattern on the yolk indicates fertilization.
If fertilized eggs are incubated for 21 days, embryos will develop and hatch into chicks. So the presence of a rooster allows hens to produce chicks!
Rooster Behavior With Hens
In addition to fertilizing eggs, roosters display other mating behaviors:
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Roosters establish a pecking order and mate with females accordingly. Dominant roosters mate more often than lower ranked males.
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Roosters mate numerous times per day. They can fertilize over a dozen hens in a large flock.
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Young roosters under 1 year old may have lower fertility rates. Male fertility improves with age.
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Roosters guard and herd their hens, keeping a lookout for threats. They provide protection to the flock.
What Mating Looks Like
Before a rooster mates with a hen he will prance around her and cluck. When he mounts the hen, he bends his tail down and the hen will lift her tail up. The cloaca vents will press together and the rooster injects his sperm.
What is The Cloaca?
A hen has just one opening where both feces and eggs exit the body. This is also where sperm enters. The rooster’s cloaca passes feces and transfers sperm to the hen.
Chickens don’t urinate! They don’t have bladders or urethras, liquids exit with their poop through the cloaca. There is much less liquid urine in their coop, so it stays dry much better than if they were peeing on their bedding all day. Their liquid feces are able to dry quickly.
When the hen and rooster touch, sperm enter the oviduct and are stored in glands that can hold more than 500,000 sperm. Sperm can stay alive in the storage glands for up to 3 weeks fertilizing eggs. An egg is fertilized about 24 hours before it’s laid.
How eggs are fertilized by chickens is more similar to mammals than you might think. Considering the fertilizing happens inside of their body even though the growing happens outside of their body!.
How do roosters fertilize eggs?
FAQ
How does a rooster fertilize the chicken?
Before a rooster mates with a hen he will prance around her and cluck. When he mounts the hen, he bends his tail down and the hen will lift her tail up. The cloaca vents will press together and the rooster injects his sperm.
How does a rooster mate with a hen?
There is a short contact between the rooster and hen’s cloacas, which is often called a “cloacal kiss.” The rooster and hen’s cloacas are the openings for their reproductive and digestive tracts, and they touch briefly to transfer sperm.
How do farmers know if a chicken egg is fertilized?
Farmers can determine if a chicken egg is fertilized through candling or by cracking the egg open and observing the yolk. Candling involves shining a bright light through the egg in a dark room to see if there are signs of development, such as blood vessels or a dark spot (the embryo).
How many times a day does a rooster mate?