It’s no secret I love talking to people about all things chickens. People who are really interested in these feathered friends always ask me about Happy or Roxanne, if I have the fluffy chickens (Silkies), and how many are in my flock. But I also got some questions that surprised me.
I’m a firm believer that there are no bad questions. After, “How do you keep your chickens warm in the winter?” I usually get, “Do you need to have a rooster for your hens to lay eggs?” One time, I even got, “Do hens nurse their chicks?” Haha! I got a good laugh out of that one, but again, there were no dumb questions, so I simply answered that no, they didn’t! But heres some answers to the questions you might have on roosters and eggs.
Chicken eggs that you buy in grocery stores are unfertilized. This means they do not contain an embryo and cannot hatch into a chick. The hens that laid those eggs did not mate with a rooster.
How Fertilization Happens
For an egg to become fertilized a rooster needs to mate with a hen. During mating the rooster deposits sperm inside the hen’s reproductive tract. The sperm can then fertilize an egg as it’s being formed inside the hen.
Fertilization occurs high up in the hen’s oviduct, before the egg is fully formed. When the yolk is released from the ovary, it gets picked up by the infundibulum area of the oviduct. If sperm are present there, one sperm can penetrate and fertilize the germinal disc on the yolk.
The germinal disc is a small white spot on the yolk that contains the female’s genetic material. In a fertilized egg, it contains both the male and female DNA. As the fertilized egg travels down the oviduct cell division begins and the embryo starts developing.
Unfertilized Eggs Have No Rooster Involvement
In commercial egg production, hens are kept in large barns or cages together, without any roosters present. This prevents fertilization from happening.
Since the goal is to produce eggs for human consumption, not hatch chicks, roosters are not necessary. Their mating activity would be disruptive and add no benefit in the egg laying facilities.
When you crack open a store-bought egg, the small white spot on the yolk is solid and doesn’t have a bullseye shape. This means the egg hasn’t been fertilized and only has the hen’s DNA in it. There is no rooster involvement at all.
Why Stores Don’t Sell Fertilized Eggs
There are a few key reasons why commercially produced eggs are unfertilized:
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No embryonic development – Fertilized eggs would eventually start growing into chicks if incubated. Unfertilized eggs cannot develop so they have a longer shelf life.
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Food safety – A developing embryo may increase bacterial growth like salmonella in the egg. Unfertilized eggs have lower food safety risks.
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Consumer preference – Most people prefer to eat unfertilized eggs. The idea of consuming developing eggs may be unsettling.
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Efficiency – Having roosters mixed with hens would disrupt operations. Collecting fertilized eggs also takes more labor.
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Cost – Keeping roosters and hatching chicks would be more expensive with no added value. Customers only want the eggs.
It makes the most sense for big egg producers to sell eggs that haven’t been fertilized. The eggs stay fresh longer, are safer, and meet customer needs. Plus, not dealing with roosters streamlines the process.
How to Tell If an Egg is Fertilized
It’s pretty simple to tell if an egg has been fertilized by cutting it open and looking at the germinal disc on the yolk.
Here are some visible signs that an egg is fertilized:
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The germinal disc appears larger and irregularly shaped, like a bullseye pattern.
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You may see a network of veins radiating outward.
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A few hours after being laid, you can see a dark spot where the egg is growing.
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After 3-4 days of incubation a small heartbeat is visible in the dark spot.
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By day 7 a dark eye spot forms indicating the head of the developing chick embryo.
In contrast, an unfertilized egg will have a small, round germinal disc that looks solid white, with no bullseye or veins. Nothing changes or develops even when incubated for days.
Can You Buy Fertilized Eggs?
While unfertilized eggs are the norm at supermarkets, you can sometimes find fertilized eggs to purchase:
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From local small farms – Some small backyard chicken owners sell extra fertilized eggs. Look for listings at farmer’s markets.
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Specialty suppliers – There are a few hatcheries and websites that ship fertilized eggs for incubation.
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Ethnic food stores – Some Asian, Indian, and Middle Eastern markets sell fertilized duck or chicken eggs considered delicacies.
However, fertilized eggs must be handled carefully to prevent embryo development. They have shorter shelf lives of only 7-10 days when refrigerated before use.
Fertility in Home Chicken Flocks
When you raise backyard chickens, you’ll get a mix of fertilized and unfertilized eggs depending on your flock makeup. Here are some scenarios:
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Hens alone = All eggs unfertilized
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Hens + 1 Rooster = Majority of eggs fertilized
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Hens + Multiple Roosters = All eggs fertilized
The rooster to hen ratio impacts fertility rates, but typically one active rooster can fertilize the eggs of 8-10 hens successfully.
To prevent unwanted broodiness and chick hatching, adding fake plastic eggs to nests can help. Or simply collect eggs often so they don’t sit in nests and get incubated.
Even with a rooster present, some hens may occasionally lay an unfertilized egg now and then. But most backyard eggs with a rooster will be fertilized if left to develop in the nest.
In Summary
The key takeaways are:
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Commercially produced eggs are unfertilized and contain no embryo.
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No roosters are kept in commercial flocks, preventing fertilization.
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Unfertilized eggs have longer shelf life and lower safety risks.
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Fertilized eggs can be found from small farms, ethnic markets, or specialty suppliers.
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Backyard eggs may be fertilized if a rooster lives with the hens.
So next time you crack open an egg, look for that little white spot on the yolk. An even, rounded shape means it’s unfertilized and came from a hen without a rooster!
How Do Roosters Fertilize Eggs?
When a rooster and a hen engage in mating behavior, the rooster transfers sperm to the hen through a process called “cloacal contact. ” This occurs when their cloacas, the common opening for reproductive and digestive tracts, make contact, allowing for the transfer of sperm from the male to the female.
Once inside the hen, the sperm can remain viable for several weeks, ready to fertilize any eggs the hen lays during that time. If an egg has been fertilized, the embryo begins to develop within it.
Its worth noting that the eggs we typically consume are not fertilized (from the grocery store or your coop as long as you dont have a rooster). However, its also perfectly safe to eat a fertilized egg, as long as theyre fresh and havent been incubated. In fact, fertilized eggs look and taste just like unfertilized ones (see the comparison below).
Do Chickens Need a Rooster to Lay Eggs?
My very first time hatching eggs was 4 years ago. I got these fertilized eggs from Alabama Silkies.
I get this question a few times a year. The answer is no! You don’t need a rooster for a hen to lay an egg. Hens will lay one egg every 24 hours all on their own. However, if you want to hatch out chicks, you do need a rooster.
To produce an egg, chickens need an average of 12-16 hours of light, adequate calcium and a good diet. The whole process of forming an egg inside a hen is absolutely incredible!.
How do chicken eggs get fertilized? *More Than You Ever Wanted To Know*
FAQ
Are the chicken eggs we eat fertilized?
No, the chicken eggs you typically buy at the grocery store are not fertilized. They are laid by hens without the presence of a rooster. Hens can lay eggs with or without mating with a rooster.
Why do chickens lay eggs unfertilized?
As part of their natural reproductive cycle, chickens lay eggs that haven’t been fertilized. They don’t need a rooster (male chicken) to start this process. Biologically, the amount of sunlight a hen is exposed to is what makes her lay an egg, not the presence of a rooster.
Can a chicken lay eggs without mating?
Yes, a hen can lay eggs without mating with a rooster. Hens will lay eggs throughout their laying cycle regardless of whether they are near a rooster.
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).