Fertilized Egg – How Does a Chicken Egg Become a Fertilized Chicken Egg?

A chicken egg becomes a fertilized egg through the mating of a rooster and a hen.

Here’s what happens:

Mating: When a rooster mates with a hen, he transfers sperm into the hen’s reproductive tract. This sperm contains genetic material from the rooster. Once the egg is formed then hatched by the hen it is a fertilized egg and will be able to develop into a chicken.

Egg Formation: Hens have a specialized reproductive system. They produce eggs regularly, with or without the presence of a rooster. The egg begins to form in the hen’s ovary.

Fertilization: If a rooster has successfully mated with the hen (we jokingly call this ‘done the do’ on our farm), the sperm from the rooster will meet the egg in the hen’s oviduct. Fertilization takes place when the sperm cell from the rooster combines with the egg cell inside the oviduct. This creates a fertilized egg.

Egg Development: Once fertilized, the egg continues its journey through the oviduct. During this time, the fertilized egg develops into an embryo, and various layers such as the shell membranes, egg white (albumen), and shell are added.

Laying: The fully developed fertilized egg is laid by the hen. At this point, it can be collected and incubated if someone wants to hatch the egg and raise chicks. If you decide to do this, you should take an egg that is laid after the first week towards the beginning of the season and also not the eggs towards the end of the season. The reason for this is so that the hen especially if she is a fist time layer has time to develop and lay a normal sized egg. The first eggs of the season and from a pullet (a young hen) can be small and not the best to use for creating chickens.

It’s important to understand that not all eggs laid by your hens will be fertilized. In the absence of a rooster or if a rooster is infertile (meaning it cannot fertilize an egg), hens will lay unfertilized eggs, which are what you usually find in your local grocery store.

Can I Eat a Fertilized Egg? Is it safe to eat it?

It is perfectly fine to eat a fertilized egg as long as it has not been sitting under a chicken for more than a few days. If you do happen to collect an egg that has been fertilized and has been under the hen for more than a few days, you may see veins or blood when you crack that egg open.

It is not dangerous to eat a fertilized egg like that, but most people prefer not to eat a fertilized egg. It may have begun to develop a fetus and you may see a larger blob which is the beginning phase of a baby chicken.

Note: there are countries who prefer to eat fertilized eggs. When I used to sell eggs at the local Farmers Market and Sunday Rotary Market in our town, I had requests from customers as to whether I had any fertilized eggs to sell for eating? The customers said they wanted the eggs to be one to three days before hatching. At first, I thought they were joking but on further research I found it was a real thing. That’s another topic for another post.

Can a Chicken Egg become fertilized after it is laid?

No, the egg needs to be fertilized before it is laid.

No, once a chicken egg is laid, it cannot be fertilized. As discussed above the fertilization of a chicken egg occurs within the hen’s reproductive tract before the egg is laid. After the egg is laid, it begins to cool down, and the process of development stops unless it is incubated under a chicken or incubated which requires specific temperature and humidity.

However, scientists have developed a way to fertilize chicken eggs outside the hen’s body through a process called artificial insemination.

This method is commonly used in poultry breeding to control and optimize genetic traits and improve the quality of chicken populations. Here’s how it works:

Collection: Mature roosters are trained to ejaculate into a collection container. This semen contains sperm. Imagine that, training a rooster to ejaculate into a container – Okay, maybe not.

Semen Processing: The collected semen is then processed to remove any impurities or non-sperm components.

Insemination: Hens are inseminated with the processed semen. This is typically done by inserting a small amount of semen into the hen’s reproductive tract using a specialized syringe.

Fertilization: The sperm from the collected semen fertilizes the eggs within the hen’s reproductive tract, just as it would in a natural mating. Yes, all this happens inside the hen.

AI (Artificial insemination not Artificial intelligence) 😉 allows for controlled breeding, genetic selection, and the creation of specific traits in the offspring. It is commonly practiced in commercial poultry production to improve the quality and productivity of chicken breeds.

Can I Leave a Rooster in with My Chickens and still collect and eat the eggs?

Yes, as discussed above you can do this, however, don’t leave it too long.

A little bit of information about eggs – just in case you needed to know this…

Eggs are a great source of complete food, as much as for humans, as for the chickens who use the goodness of what’s in the egg to develop and grow. If you boil an egg and eat it, you will find that it is easily digestible and jammed packed with vitamins and minerals.

It is a versatile and complete food source. It contains: 11% minerals, 11% fat, 12% protein and the rest are water around 65%. To be precise the egg contains: Energy, proteins, carbohydrates, cholesterol and fats. Vitamin A, B1, B2, B5, B11, B12, C, D, E, and Biotin. Minerals: Calcium, Iodine, Iron, Magnesium, phosphorous, Potassium, Selenium, Sodium, and Zinc

How do I Know Which Hen is Laying the Eggs?

With a bit of practice, you will always know which Hen is laying eggs. There are signs you can look for:

• A fluffy butt
• A deep (voice) – NO, a deep red cone
• A fluffed-up appearance (but not so fluffy that she has become broody – that’s a whole lot fluffier and called, Clucky. And, Clucky produces no eggs as she is ready to sit and brood.

How Big Will My Chickens Egg be when it is laid?

Depending on the size and age of your chicken they usually lay their eggs in proportion to their size. Bantam chickens lay smaller eggs and standard size chickens lay larger eggs. A pullet (a young hen) will often start with a smaller egg then progress to laying a larger size egg. For example: an Isa Brown pullet may start by laying an egg as small as 42-, 45- or 48-gram egg up to 55, 60 gram or larger eggs later in the season.

I Collected an Egg from My Chicken but It Has Two Yolks? Is It Still Okay to Eat this Egg?

This happens from time to time and yes, an egg with two yolks or even three yolks is perfectly fine to eat. It is usually quite a surprise to see. If the double yolk egg were fertilized it would produce twins. This rarely happens because the two chickens in the one egg is very crowded. In all my years of breeding chickens I have only ever seen twins come out once and the twins didn’t survive for very long sadly.

How Can I Make My Chicken Lay More Eggs?

The key to great egg production is a:

• Healthy
• Happy
• Hen.

If you provide your chickens with fresh clean water and a high (at least 18%) protein quality feed all day every day, and enough light throughout the day you will be sure to be collecting an egg a day from each hen.