How a Chicken Makes an Egg and Why Some Eggs are Unusual

| 6/6/2012 1:15:21 PM

Tags: Chicken Eggs, Odd Eggs, Strange Eggs, Egg Color, Large Egg, Striped Egg, Spotted Egg, Speckled Egg, Blood Spot, Flat Egg, Rough Shell Egg, Wrinkled Egg, Hen Reproductive System, Hen Oviduct, , Kathy Shea Mormino,

As a backyard chicken-keeper, it is not uncommon to find irregular eggs. Do not worry unnecessarily about the occasional strange-looking egg; take a picture of it, discuss it at the water cooler next day and get a good chuckle out of it. They happen, and the vast majority of the time they do not indicate any cause for concern.

Before we get to all the pretty, funky and bizarre egg pictures, it’s important to understand how a hen’s reproductive system is supposed to work when firing on all cylinders.

How a Hen Makes Eggs Odd Eggs Array on Hydrangea

Here's the deal with a hen's reproductive system: a female chick's ovary contains all of the ova it will ever have when it's hatched. The ovary begins to convert ova to egg yolks when she is mature. With the right lighting conditions exists, hormones stimulate ova to develop into yolks. Yolks are released from the ovary into the oviduct when they reach the right size and travel down the oviduct to acquire their whites, membranes, color (if any) and shell. An egg requires approximately 25 hours to complete the addition of the
egg white, the shell membranes, and the shell. Soon after an egg is laid, the process starts again.

A hen's reproductive system consists of an ovary and oviduct (a long tube with several parts that have different jobs).1
   How a Hen Makes Eggs Odd Eggs Reproductive System Anatomical Drawing 

The following is an actual hen's reproductive tract.1 I have labeled the functions that occur at different junctures along the way. If fertilization is to occur, it happens in the infundibulum, which is the area immediately to the right of the ovary (the black line is running through it in this photo). The infundibulum is a muscle that essentially engulfs the ovum (yolk) when it is released. The sperm waits in the infundibulum and has a narrow, 15-18 minute window of opportunity in which to fertilze the ova there.

michel tom
6/14/2012 1:38:14 AM

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kathy mormino
6/13/2012 11:39:37 AM

I agree completely, Sara! My pleasure.

kathy mormino
6/13/2012 11:39:13 AM

Thanks Pam. :)

kathy mormino
6/11/2012 3:12:42 AM

Donna, congratulations, your name has been drawn as the winner of a Happy Hen Treats prize package! Please email me with your mailing address:

kathy mormino
6/11/2012 3:10:48 AM

I got my first chickens in July and first eggs in December but there's always the issue of decreased daylight and its impact on egg-laying. You may want to read a little more about it to see if supplemental lighting is something you want to do or not.

kathy mormino
6/11/2012 3:04:44 AM

My pleasure, thank you!

kathy mormino
6/11/2012 3:04:17 AM

I'm sure they do, Alex. It's pretty good incentive to get to work. LOL Good luck!

kathy mormino
6/11/2012 3:03:32 AM

Thank you Britny. :)

kathy mormino
6/11/2012 3:03:21 AM

Thanks Janet and good luck!

kathy mormino
6/11/2012 3:03:06 AM

Thanks for stopping by tonight Charity!

charity mccurdy
6/11/2012 2:18:02 AM

Yay! Ive seen this page before but didnt know this was where to comment! Lots of great info, Ive learned a LOT here!! Thanks! Charity

britny garcia
6/11/2012 1:57:47 AM

Great always! :) Thanks for the info!

janet christian
6/11/2012 1:55:45 AM

this is a very good article -- i would love to win the treats

alex turpen
6/11/2012 1:36:53 AM

My chickens haven't started laying yet, but I can't wait!! They absolutely love themselves some meal worms.

suburban stone age/rebecca simpson
6/11/2012 1:32:29 AM

Loved the article, will re-post! Thanks for the tips!

kathy mormino
6/11/2012 12:58:21 AM

They'll get there before you know it! Thank you. :)

kathy mormino
6/11/2012 12:58:00 AM

Thank you Mary. It certainly doesn't cover all the freakish egg possibilities, but it does cover the most common. I hope your peeps enjoy it too. :)

kathy mormino
6/11/2012 12:57:00 AM

Thank you Lisa!

kathy mormino
6/11/2012 12:56:51 AM

My pleasure, Sharon. Thank you for stopping by to read it!

sharon lee-bense
6/10/2012 6:37:37 PM

This is so interesting. Thank you for posting!

lisa a
6/10/2012 12:51:44 PM

This is such an amazing blog, so informative and fun!!! thank you!

mary stewart
6/10/2012 8:38:21 AM

This is the perfect, perfect post for all those egg questions...and the photos sure make it easier to understand. I will for sure be passing this post on to my peeps.

kathy mormino
6/10/2012 4:56:00 AM

My pleasure Diane, thanks for stopping in to read it!

kathy mormino
6/10/2012 4:55:38 AM

Thank you Karen, I appreciate that.

kathy mormino
6/10/2012 4:55:20 AM

Thank you Patty!

kathy mormino
6/10/2012 4:55:11 AM

Thanks Cheri! Me too. ☺

kathy mormino
6/10/2012 4:54:55 AM

Thanks! It'll be in a nest box before you know it!

amy capobianco geraldi
6/10/2012 2:38:43 AM

We got them in april, they are 6 weeks old, I am assuming the eggs are coming in november,lol. We can't wait for them! We are enjoying our little ladies so much!

6/10/2012 2:28:07 AM

I cannot WAIT until mine start laying....I just gotta hang in there...LOVE THE INFO!!!

cheri kaelin
6/10/2012 12:35:47 AM

Love the egg info!!! Love Grit...... Cheri @ Angel Hill Farm

kathy mormino
6/9/2012 10:45:52 PM

Thank you Marilyn!

kathy mormino
6/9/2012 10:45:40 PM

Hi Alex! Thank you. ☺

kathy mormino
6/9/2012 10:45:27 PM

Kimberley, did you just call me cheep? LOL! Thanks for stopping over to read my blog post on Grit Magazine's website!

kathy mormino
6/9/2012 10:44:44 PM

Did you just get them this month, Amy? Collecting your first egg is very exciting but the truth is, it never gets old!

kathy mormino
6/9/2012 10:44:00 PM

Thank you Dolly and you're in!

kathy mormino
6/9/2012 10:43:48 PM

Good for you, Linda! Be sure to share pictures on Facebook with us when they do!

kathy mormino
6/9/2012 10:43:27 PM

Hi Karen and thank you for stopping by to read along today!

kathy mormino
6/9/2012 10:43:11 PM

Thanks Dolly, you got it!

kathy mormino
6/9/2012 10:43:01 PM

Flavia, did they tell you that? :o

kathy mormino
6/9/2012 10:42:47 PM

Kara, I've never had an egg within an egg either. Crazy, isn't it?

kathy mormino
6/9/2012 10:42:19 PM

Thanks Alison and you're entered!

kathy mormino
6/9/2012 10:42:01 PM

You bet Michele, thank you!

kathy mormino
6/9/2012 10:41:47 PM

My pleasure, Shantel!

kathy mormino
6/9/2012 10:41:33 PM

You'll always remember your first egg, Felicia. Keep that camera handy!

kathy mormino
6/9/2012 10:41:09 PM

Welcome to chicken-keeping Susan. It's a BLAST!

kathy mormino
6/9/2012 10:40:55 PM

Funny, Sandy. I hope it helps to shed some light on a few things for them! :)

kathy mormino
6/9/2012 10:40:25 PM

I'm sure they do, Deborah. What's not to love about Happy Hen Treats? :)

kathy mormino
6/9/2012 10:40:00 PM

Good luck Alicia!

kathy mormino
6/9/2012 10:39:48 PM

Thank you Buffy! Will do. Good luck!

kathy mormino
6/9/2012 10:38:54 PM

My pleasure, Leslie. Thank you!

kathy mormino
6/9/2012 10:38:28 PM

Thanks so much, Elizabeth. I appreciate that. :) Great tip on preserving "windys." ;)

kathy mormino
6/9/2012 10:37:36 PM

Thank you Renee!

patty watkins-myers
6/9/2012 10:37:18 PM

Interesting reading.

karen collins warren
6/9/2012 8:48:36 PM

Very informative and interesting article!

kathy mormino
6/9/2012 7:05:14 PM

Thanks Stacy! If you ever get twin embryos, let me know!

kathy mormino
6/9/2012 7:04:27 PM

Thanks so much, Debbie! It's nice to have you joining me in my chicken adventures!

kathy mormino
6/9/2012 7:03:40 PM

You jinxed her!

diane genco
6/9/2012 7:03:32 PM

Excellent Article, very informative and great photos. Thanks for sharing..

kathy mormino
6/9/2012 7:03:12 PM

So eggciting, Robin! Did you take a picture?

robin mcdowell
6/9/2012 5:17:35 PM

I got a double yolker today !!

michele chlebik
6/9/2012 5:05:07 PM

I had a hen that consistently laid a double-yolk, until i bragged about it. No more doubles.

debbie ellerd
6/9/2012 4:13:53 PM

I loved reading all about how an egg is formed and all the other articles you posted. This is my second year to have my four hens and I am loving them so much. I sell the extra eggs to purchase feed for them and my customer's love the fresh eggs. I follow you on facebook and also your blog and would love to have those treats for my hens.....they are so spoiled!!!! Thanks for the

pam baum
6/9/2012 4:12:59 PM

Thanks for this article! I had no idea what an actual production line egg laying is...fascinating.

stacy wagers
6/9/2012 4:09:52 PM

What a great post this has answered many of my chicken" I wonder " question about Eggs..I've always wondered if a double yoke egg could actually develop two chicks!! Amazing and very informative..:>

renee drossel
6/9/2012 4:02:32 PM

Great article, thanks ! We've had a few of these odd eggs so far... I always refer back to your site when I have a question ! Please enter me in the treat giveaway ! Thanks !

elizabeth white
6/9/2012 3:42:26 PM

Great info, Chicken Chick, as always you have done your homework, making sure to share accurate information. That's just one of the many reasons I am a one of your fans!!...I have several "windy's" ("windy" my granny's name for the yolk-less eggs) that I have collected from my hens over the years...I wash them, which removes the bloom, and just lay them up in a sunny window to let them "dry up"...then add them to my enter my name in the giveaway. Thanks!!!

leslie johns
6/9/2012 3:42:07 PM

Thank you for such a wealth of information! And I love the pictures of the eggs...this makes me excited for my girls to get old enough to lay! :)

sara sweatman
6/9/2012 3:21:53 PM

I love the beauty and variety of eggs. I think the biggest joy of having chickens is having a variety of eggs. Thank you for the useful information!

buffy smith
6/9/2012 3:01:16 PM

Great article! Thanks for putting it all together-so educational! Please enter me in the Happy Hen (chicken crack) giveaway! :-)

alicia n tony parker
6/9/2012 2:58:46 PM

Would love to win some Happy hen treats for our ladies :)

deborah ciesla
6/9/2012 2:57:46 PM

We wanna win our hennies some Happy hen treats please! They literally eat them out of our hands!

sandy abell
6/9/2012 2:57:05 PM

I have to show some of my friends this blog because they don't understand how you get a chick out of an egg and all that fertility stuff! Lol! Thanks: )

susan wheeler
6/9/2012 2:56:35 PM

It's an anatomy lesson and science all rolled into one! Great info for newbies like me!

felicia johnson
6/9/2012 2:52:37 PM

I can't wait for my first egg. So exciting.

shantel scardina
6/9/2012 2:48:32 PM

I can’t wait to get our first egg! So much to learn, thanks for the article!

michelle craft
6/9/2012 2:48:12 PM

Thanks for all the information! Very informative!

alison patrick
6/9/2012 2:46:44 PM

Always love reading your blog...would love to be entered to win some girls (and boys) LOVE them....its been a while since I've gotten any so some of the "newbies" will get a first taste of heaven lol

kara erickson
6/9/2012 2:45:12 PM

I've had just about all of these, except the egg within an egg. I think it's interesting how different all the eggs can be!

flavia mcqueen
6/9/2012 2:44:23 PM

very interesting and my hens feel like they need some treats, so please enter us in the giveaway !

dolly sarrio
6/9/2012 2:43:50 PM

Love all of the information in this article. Please enter me in your giveaway. I thank you!

karen pinsonat
6/9/2012 2:43:13 PM

Great article, very informative!

linda mcdonald
6/9/2012 2:41:03 PM

Thanks for this info, new to raising chickens so will be some good info when my hens do start to lay, which should be soon!

dolly sarrio
6/9/2012 2:40:22 PM

Love this informational post. Please enter me in your giveaway also and thanks!

amy capobianco geraldi
6/9/2012 2:36:04 PM

My chickens will be laying eggs in November, this was very informative!

kimberley carville
6/9/2012 2:34:24 PM

I recently had a really long egg with a double yolk, and because my chickens are young we get funky eggs all the time. Thanks, you cheep

alex summersell
6/9/2012 3:26:07 AM

Hi Chicken Chick. Very informative.

kathy mormino
6/9/2012 2:51:41 AM

Thanks Makenna, great timing! :)

kathy mormino
6/9/2012 2:51:17 AM

Thank you Marilyn!

kathy mormino
6/9/2012 2:51:06 AM

Be sure to take a photo of it, Julia! And if you're feeling ambitious, blow it out so you can save it forever (the shell anyway!). DIY instructions are on my blog here:

julia moncus
6/9/2012 2:01:15 AM

Great post! I can't wait to get my first egg!

marilyn alexander
6/9/2012 1:46:07 AM

I loved this posting..

makenna vanegas
6/9/2012 1:43:09 AM

Great blog post Kathy. Good information-especially because I just got my first fart egg today from one of my new layers! Now I am not the worried about it.

kathy mormino
6/8/2012 1:58:13 AM

Thanks so much, Robin!

kathy mormino
6/8/2012 1:57:58 AM

Thank you, Melissa. ☺

kathy mormino
6/8/2012 1:57:31 AM

Thank you Amanda!

kathy mormino
6/8/2012 1:57:18 AM

Thank you, Marie! Happy to share. :)

kathy mormino
6/8/2012 1:56:54 AM

Thank you, Audrey. The good news is, you don't have to remember everything, you can always refer back to my blog posts to refresh your recollection. Keep your camera handy for that first egg!

kathy mormino
6/8/2012 1:55:44 AM

Knowing just a fraction of the things that can go wrong in the process of making an egg, I find it remarkable that 'normal' eggs are produced with such regularity.

kathy mormino
6/8/2012 1:54:48 AM

Thank you Gavin! It's so nice to have one of my long-time BYC peeps along for the chicken-keeping journey with me. :)

kathy mormino
6/8/2012 1:54:11 AM

Thanks Holly! Give my best to Cheep-Cheep! ;)

kathy mormino
6/8/2012 1:53:53 AM

Bernadette, you DID?! I hope you took a photo of it! That particular weird egg totally fascinates me. I've never had one.

kathy mormino
6/8/2012 1:53:06 AM

Stick with me, Pupp, I'll bring you up to speed with your lovely wife. ;)

kathy mormino
6/8/2012 1:52:39 AM

Thank you, Donna!

donna nagirny
6/8/2012 1:25:56 AM

This was such an information piece--I will stop worrying about those occasional egg 'oddities' I can't explain. Your photography is amazing--very clear to follow along with your explanations and insight. Thank you SO much.

pupp naish
6/8/2012 1:00:07 AM

Very informative. We have chickens (lots of them) and my wife knows a lot. I just pick up the information here and there. Picked up a lot today :)

bernadette kuhail
6/8/2012 12:59:18 AM

Very interesting, I actually had an egg within an egg a few months ago, it was the weirdest thing ever! Thanks for the info!

holly olejnik
6/8/2012 12:58:39 AM

Awesome page! A lot of great information!

gavin dyer
6/8/2012 12:38:40 AM

Love all your posts, both here and on fb...... Gavin.

shellie werich
6/7/2012 8:27:58 PM

It's always good to be reminded of the possibilities our girls leave for us to find .. And to know why these oddities probably happened.

audrey siebert
6/7/2012 7:44:59 PM

I think I learn something new every time I read your blogs/post/articles! Thank you for taking time to share your chicken knowledge with us! I hope I retain everything I've learned when my ladies start laying eggs in the next month or 2!!

marie james
6/7/2012 4:38:01 PM

Fascinating article! I have studied a lot about hens and eggs but I sure learned some new things here. You have some great photos too! Thanks :)

kathy mormino
6/7/2012 3:56:35 PM

Thank you, Heather. :)

kathy mormino
6/7/2012 3:56:08 PM

Thanks Christine!

kathy mormino
6/7/2012 3:55:42 PM

Thanks Elisha! Nice to have you following along!

kathy mormino
6/7/2012 3:55:06 PM

My pleasure Esther. Keep your camera handy because it won't be long before yours are laying too!

amanda yelverton
6/7/2012 3:17:50 PM

Your blog is always so informative. I have really enjoyed reading this post!

melissa bayness
6/7/2012 3:15:47 PM

thanks for the post! so informative and interesting, and thanks to grit for sharing your blog! Melissa~

robin mcdowell
6/7/2012 3:03:22 PM

I love your blog! So informative . Thanks you!

esther widgren
6/7/2012 2:30:41 PM

Now I know what to expect when my chickies start laying! Thanks for a great overview :-)

elisha hutchinson
6/7/2012 1:46:52 PM

Great information... thank you so very much! Love your blog too.... always enjoy learning more about my chickens :) Thanks!!!!!!!!

christine layne
6/7/2012 1:43:09 PM

Thank you for posting this article! Very informative and it's always great when there are pictures to go along with descriptions, makes identification so much easier!

heather paladino
6/7/2012 1:37:36 PM

Thank you Kathy! I love your blog. What a wonderful article. I love how you described the whole egg process, the beautiful pictures, and the illustrated pictures. I'm going to share it with all of my friends. Have a blessed day.

kathy mormino
6/7/2012 1:06:52 PM

Congratulations on your new baby chicks Nicole!

kathy mormino
6/7/2012 1:06:26 PM

That's great to hear, Nikki. Thanks for following my blog, it's nice to have you along for the adventures!

kathy mormino
6/7/2012 1:05:39 PM

Thank you Joann!

joann mcgregor
6/7/2012 12:28:45 PM

love the pics, you always have some great info, love it "Got Eggs!!!" have a wonderful day.

nikki ashley
6/7/2012 12:21:20 PM

I had turned to this article when our hen had put out a pimpled egg. Super informative and I made sure to bookmark it so I can keep coming back whenever I have a question!

nicole shelley
6/7/2012 12:18:13 PM

Very informative. My pet hen, Penny, just hatched out four chicks this week. I, as well as they are learning something new everyday. Thanks for this post on the egg cycle.

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