Did you know chicken reproduction isn’t the same as other barnyard animals or even other birds?
Yep, your fine feathered beauties have a unique way of going about procreation.
We’ve raised backyard chickens for many years and the most asked questions about chickens always revolve around reproduction. It’s one of those mysterious and curious things that people are just dying to know!
Let’s take a look at the 4-1-1 of chicken reproduction from the mating to the chick.
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How Do Chickens Mate?
Anatomy of Mating
Fun fact: The surprising anatomy of a hen is that she has two ovaries, but only the left one is functional.
Chicken mating is a pretty funny sight to behold. They mate in much the same way that most animals mate, the male mounts the female, jerks around a little bit, ejaculates, then jumps back off.
It’s pretty simple in its action, and isn’t anything special at first sight, but what does make chicken mating unique is the way that the rooster shows affection for his favorite female chicken before he does the deed.
The mating dance
Roosters put on a display to attract hens called the mating dance. A ready rooster will spread out his wings and move jerkily back and forth in front of her to get the hen’s attention. If she’s interested, she’ll squat down and spread her wings to prepare for him to hop on.
When chickens mate, the rooster jumps on top of the hen, using his talons to grip her back, and often biting her back neck feathers as well. The rooster will touch his cloaca to hers in a few swift movements, then jump back off. The whole mating process takes under a minute.
Hens and roosters do not have external genitalia but instead use an orifice called the cloaca to mate. When the cloaca touch together, sperm is transferred into the hen referred to as a “cloacal kiss.”
The cloaca or vent is also where waste excretes. To protect the egg from touching any feces, the hen’s uterus turns inside out beyond the cloaca (vent) when laying occurs. That way, the egg is not contaminated by excretions.
Roosters tend to choose favorite hens out of the whole flock of chickens that they mate with more often. These hens may have feather loss on their back from the constant action.Sometimes aggressive roosters will also pull out the feathers on the hens neck while they mate.
You can avoid these issues two ways.
First, make sure that you have enough hens for the number of roosters you have. In our experience, you should only have one rooster for every ten hens, and really you may even want to spread that ratio out even further.
Another thing you can do to ensure healthy hens is to buy or make some chicken saddles. Chicken keepers use chicken saddles to protect the hens, the saddle goes around their wings and over their back to prevent the rooster from digging his talons into her.
You can also try to separate the hurt hens from the rooster until their feathers have recovered.
We found that having roosters in smaller bantam breeds helped a lot with damage to the hens during mating. These little roosters were lightweight and didn’t hurt our old hens or smaller hens.
The downside to this choice was that our bantam roosters were rarely ever able to successfully mate with the hens because of their smaller size. We found a lot of unfertilized eggs in the nesting boxes.
For us, this wasn’t a big deal, we kept the roosters around for flock protection, not for a breeding program, but if that’s a big deal to you, definitely keep in mind that bantam breeds may have a hard time mating with standard breeds.
Fertilization
Fun Fact: A rooster’s sperm is viable for between two to four weeks! Amazing, right?
The ovum (yolk) starts as one cell and enters the oviduct, which is a 25-27 inch winding tube. The first section in that tube is the infundibulum, and once the ovum enters it, this is where fertilization takes place.
The yolk stays in this section for 15-17 minutes.
The Formation of the Egg
The magnum section of the oviduct is thirteen inches long, and the yolk takes three hours to travel through as the thick albumen or egg white forms around it.
Then on to the third section, called the isthmus, which is just four inches long. Just as its name implies, it is a restricting section that forms the inner and outer shell membranes. This whole process takes seventy-five minutes.
Next up is the shell gland, which is another four to five inches in length. The shell forms around the egg in this section, taking up to twenty hours to complete the transformation. This is where the eggshell color is formed through a pigment.
The egg then moves on to the uterus. Here it enters small end first then turns to the large end coming out first. The muscle of this area helps to push the egg out by extending itself with the egg and turning inside out to expel it.
Who knew that finding eggs in the egg box was the end result of such a complicated system?
Do Hens need a Rooster to lay eggs?
When we first started talking about raising chickens, an ‘experienced’ chicken keeper acquaintance of ours told us we absolutely had to get a rooster if we wanted to have fresh eggs. This is an odd belief that’s simply not true.
Just the same as with humans, cats, dogs, and most other critters, the female chicken will go through the menstrual process whether or not there’s a male chicken around. Humans go through this process once a month, chickens go through this process once a day.
The rooster isn’t needed for the process of an egg forming and being laid, they are only needed to fertilize the eggs and make them viable to become baby chicks.
Mating is not a requirement for egg-laying.
Light is the stimulus for a hen’s egg production, not romance. Hens are programmed to lay eggs when light is plentiful, spring time and summer.
However, if you desire a fertile egg to hatch the rooster is a must.
How can you tell if an egg is fertilized?
There are a couple of ways to tell if an egg is fertilized.
Cracking
If you know you don’t intend to incubate the egg and just want to check if your rooster is doing his job, you can easily check to see if an egg is fertilized by opening it up.
If the egg is fertilized but hasn’t been incubated, you will find a white bullseye on your egg yolk, which is two rings of white, one inside the other.
Candling
Candling is the best way to “see” into the egg without cracking it. This is a great way to check for fertilization and developing embryos on eggs that have been incubating either in an incubator or under a broody hen. You obviously wouldn’t want to crack those eggs open because you would kill the developing chick inside.
Instead you candle the egg, which is really easy to do!
To candle a chicken egg, shine a super bright flashlight through the egg while in a very dark room. Depending on how long the egg has been incubating you may see different things inside.
If you see a group of blood vessels, what looks like an eye or even an outline or shadow of the chick’s body, then you have a fertilized and developing egg.
If all you see is a yolk floating around inside the egg, it’s not been fertilized, or if it was, it did not make it to the point of developing a chick.
Brooding or Incubation?
Now that you know your eggs are fertile you may be wondering whether you should allow your broody hen to take over or try incubation.
There are several factors to consider, and you can read more about that: Hatching Eggs: Broody Hen orIncubator Which is Best?
But for this article, we will look at just a couple of factors: time and money.
A broody hen can save you both by taking on the job herself. There is no need for the expense of an incubator or continual turning and checking.
Many people find this the best choice because often a mother hen will do a better job of incubating fertile eggs than an incubator will.
However, the awe and wonder of hatching chicks and becoming a chickie mommy have its appeal. We absolutely loved hatching chicks in our incubator over the years.
It’s great fun for the whole family to watch the whole process of a chick hatching and then raising those babies by hand makes for friendly chickens who are securely bonded to their keeper.
We hope this article has cleared up all your burning questions about chicken reproduction. It’s a fascinating topic!
These are just a few of the basics of chicken reproduction. If you would like to learn more check out Penn State’s article: Avian Reproductive System.