The Making of an Egg, Why Calcium is Important to Hens

If you own chickens, you know there is nothing so wonderful or delicious as fresh eggs. Every day we go out and feed the hens and in return they give us those glorious eggs. But how much do you know about how an egg is made? Do you know why calcium is so important to your hens? Do you know how to supplement their calcium intake? Fear not, I have all the answers for you, right here, right now!

First off the egg….. It takes about 25 hours for a hen to “make” an egg. But how does she do it? Once the yolk leaves the ovary it enters an area called the magnum. For the next few hours the membrane is added to the yolk before it travels to the isthmus where the white is added. Once the egg gets to the uterus it spends the next approximately 21 hours getting the shell put on. And what is that shell made of? Calcium!!! Yeah, it is kinda of important to the whole egg process.


If you raise your own hens, you will undoubtedly get some “funky” eggs from time to time. The egg making process is a complicated one and sometimes things do go amiss…. eggs with no yolks, double yolks, an egg in an egg, extra bumps on the shells, etc. But one thing you can help with are the calcium issues, like thin shells or rubber eggs.

A “normal egg,” An odd shaped eggs with pigment issues,
and a thin shell egg that was so thin the yolk was lost

Making eggs takes a lot out of hen and can actually leach calcium from her bones, so supplementing their calcium is important for good health and great egg shells. But how do you do this? Well, in extreme causes you could use a liquid calcium supplement, but it is better to be preventative from the start. There are two great ways to supplement your hens calcium and that is by either using store bought oyster shells or feeding back your eggs shells to your girls.

Now some folks think that feeding your hens back their own eggs will make them “egg eaters” but we have never had an issue. For many years, farmers have done this to keep cost down, while providing an needed supplement. And why buy something you can make for free. Why throw those eggs shells out when your done!?!? What a waste of a great sources of calcium. Simply wash your shells after you use them and let them dry. Next place them in a zip lock bag and grab your rolling pin. Do not turn the shells to dust, just break them down into bite size pieces.

Store bought or homemade, your girls should have continuous access to their calcium supplement. Do not mix it in with their food. Keep in mind, too much calcium is not good for your pullets (female chickens who have yet to start laying) and can damage their kidneys, so do not mix in food that is shared by a variety of ages. Simply provide a container of oyster or shells near their feeding area and they will eat as much or as little as they need. It is amazing how they “know” what they need.

So now that you know how an egg is made, why they need calcium and how to provided it, take a moment to enjoy one of our Goldie’s “misfired” eggs….. *bong bong*




**Homestead Tips on Tuesday is a weekly series where we help you learn skills, tips, and trick to help you on your journey of homesteading. Many places post list of things you should/could do as far as homesteading skill, but I feel lists are at times overwhelming and can make people give up before they even start. So every Tuesday I share one thing for you to try or consider. I hope you join us every Tuesday and I would love to hear about your adventures with each weeks topic.**

22 thoughts on “The Making of an Egg, Why Calcium is Important to Hens

  1. Great post! I need to learn as much as possible as I am new to chicken keeping. Just a couple of questions, do they make feeds with extra calcium and do you need to feed your hens extra calcium?

    1. You provide them access to the extra calcium by offering the oyster or your own crushed shell. Surprisingly, they know what they need and will take what they want! Each type of feed varies on what is in it, and since too much calcium can harm other non laying birds, the amount in the feeds may not be up to what a layer needs, thus the little extra offering on the side

  2. Thank you f9or this educative post! Thanks for coming and linking up at The Weekend Social. All posts get pinned on our pinterest board! Please be sure to come back next week starting Thursdays at 9PM EST on culinaryflavors.gr! I hope to see you there!

  3. Thank you so much for linking up to Teach Me Tuesday last week. You are very much appreciated. Hope to see you again this week!! http://3glol.net/2014/07/28/teach-tuesday-14/

    Have a great week!!!

  4. I wish I read this earlier. I just crushed up a bunch of eggshells to feed back to my flock today. Using a rolling pin would have been so much easier. Thank you for sharing at Green Thumb Thursday.

  5. Hi Mindie – We have been having shell problems. This may help. Thanks so much for sharing with the Let's Get Real party.

  6. Well I didn't think much about eggs until your post Mindie. Thanks for another informative post and sharing with us at Over the Moon.

    1. Sorry LOL I know most people go through life without giving them a second thought but they are amazing to me.

  7. I'm still hoping to have chickens one day, so thanks for the education! And Goldie's egg!!

  8. This is fascinating. I know nothing about hens and eggs – but found this very informative.

    Now if I could just get out of living in a city suburbs and move to a farmhouse in the country….

    1. Check to see if you local ordinance allows poultry! Many places do these days 🙂

  9. What a great article. 🙂

    Thanks for joining Cooking and Crafting with J & J!

  10. One day, I hope to have the opportunity to raise chickens, so this is fascinating stuff. I especially enjoyed the video. Thank you for not bursting the egg on camera.

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