The day has come. Our hens are now 23 weeks old and when I went to usher one of the Wyandottes out of the coop to get some pictures of her - I found it! There, in the actual nesting box was a cute little bluish green egg. It is pretty tiny, about half the size of a store bought large egg. I cannot explain how exciting it was to see it there, in the nesting box, so perfect! It is perfectly smooth. Judging by the color, we know it is from one of our Easter Eggers, as they are the only breed we have that lay green/blue eggs.
How do chickens make eggs anyway?
Chickens, on average, drop an egg per day and will continue laying until they have "enough" eggs. At this point they will sit on the eggs to keep them warm, the embryos will develop and the eggs (if fertilized) will hatch at the same time - even though they were originally laid on different days. Since we take away their eggs, they feel the do not have enough and keep laying - about one per day. Sometimes, hens will lay more but the natural cycle is a 24 hour period. But where do the eggs come from?
It's All in the Eyes
As I said before, the cycle is a 24 hour period - or "per day". Chickens, just like us, are aware that a day has passed because of the environmental changes. When your chickens eyes takes in the morning light, its photo-receptors signal to a gland near the eyes that starts the cycle. There is a term for this 24 hours cycle, that is seen in other animals and plants - it is called a "circadium rhythm" with circa meaning "around" and dium meaning "day".
The gland is called the pineal gland, located in the epithalamus, and it produces melatonin. Melatonin regulates our sleep cycle and is directly cued by darkness. The daylight (or artificial light) cues the start of the cycle and the drop of the egg cell - or ovum.
Egg Cell to Egg Shell
The egg cell begins as one single cell, the ovum or yolk. The uterus fills with albumen to protect the yolk and provide extra nutrition to the developing egg. It is what we know as "egg whites" and is mostly water and about 10% proteins. When fertilized, the baby chick will develop and live off the yolk inside the egg. The yolk will also transfer antibodies from the mother hen to the baby chicks. The ovum, yolk and albumen are enclosed in a membrane that forms along the wall of the uterus. Salt and calcium form a hard shell around this.
Egg Shape
As the shell forms it takes on the shape of the hens uterus. The narrow end faces down.
30 Second Delivery
When the egg is ready and fully formed the hens uterus contracts and the "laying" process begins. While the egg was developing it was travelling from the ovary through the oviduct -"Fallopian tube"- down to the cloaca. The cloaca is an opening that is used for reproduction, urinating and defecating. Hens have one cloaca - or "vent" for feces and eggs to pass through (chicken urine is a white paste that comes out around the stool). The egg is pushed out of the vent with the muscle contractions. The process of laying an egg is pretty quick. It takes longer to fry an egg!
The Clean Truth
It sounds pretty dirty - they are pooping an egg out of the same hole they defecate from! The truth though, is that eggs are basically sterile when they come out. They are very clean! If you notice dirty eggs, it could be that they are getting dirty from the hens walking over them, them rolling through the coop, or it might be a health concern. The egg does leave the chicken through the vent, and so do the feces, but they pass through different tubes. As the egg travels through the last part of the oviduct, the oviduct protrudes out with the egg, past the vent. The oviduct membranes can be seen encasing the egg while it is passing through the vent. With the contractions, it is pushed out of the oviduct and released. The pressure of the delivery pushes the large intestine closed, keeping any feces blocked off while the egg passes through the vent! Shortly after the egg is laid, the oviduct retracts.
Egg Production Comparison
Orpingtons: 100-200 eggs/year - medium to large brown eggs - lay during winter - very broody - start laying late
Easter Eggers: 250 eggs/ year - blue/green eggs - exceptional layers - our first eggs!
Leghorns: 180-250 eggs/year - large white - best egg to feed ratio
Wyandottes: 100-200 eggs/year - tinted/brown - great mothers - dense feathers around the vent make it harder to breed
If you want to see more breeds compared I found this awesome chart:
Chicken Breed Comparison Chart
Nesting Box
So far our nesting boxes haven't been used for much of anything. Everytime I put nesting materials in there, they have kicked it all out in search for food. They don't seem to understand what It is for. Or atleast that is what I thought. I was ecstatic to find our first egg and shocked to see it in the unused nesting box!
As you can see, there is no nesting material left in there and they still decided it was the best place to lay! They have an outdoor run attached to their chicken tractor where they could have nested in the grass, but somehow they knew the nesting box was for nesting!
Nesting Box Basics
-One nesting box per 4 hens
- Location: A dark and safe area that is undisturbed, off the floor for cleanliness. We put our boxes on the opposite side of the roost so that they would roost and poop far away from the nesting box.
-Size: Big enough to fit your chickens but still small enough that they are snug and safe feeling.
- Materials: Try different bedding. You want a lot of nice bedding in there because as you can see, they will easily pull it all out. If they don't seem to like what you have in there - try something different. Straw, shavings, paper bedding.
Get your Hens in the Nesting Boxes
-Decoy: Put ceramic eggs in the nesting box to make them think "not enough eggs there!"
-Confine them: Keep them confined to the area with the nesting boxes when you know they are going to lay (early morning).
Fun Egg Facts
- Double yolks happen when the ovulation cycle happens too quickly, this is common with young pullets who haven't developed a synced rhythm.
- No yolk happens when reproductive particles move into the oviduct and stimulate the production of an egg. People call these "wing eggs" or "cock eggs"
- Eggs are viable for up to two weeks after they are laid. Once the hen decides she has enough eggs and gets broody, she will boost the development of the embryo and the chicks will develop at the same age
- Chickens only develop one ovary and one Fallopian tube
- If hens don't leave the nest after laying, that egg will develop before she gets a chance to lay more
- It takes baby chicks 21 days to develop inside the egg to the point of hatching
- The Unites States is one of the only countries that refrigerates chicken eggs
- Egg shells are covered in a natural protective layer that fights bacteria and keeps contamination out, when US egg production facilitites clean the eggs they remove the protective layer and expose the thousands of pores in the shell - which means anything that goes on your egg goes into your egg!
Have more fun facts or thoughts to share? Please comment below! We would love to see your first egg pictures and hear your first egg stories!
