How to Use Eggshells to Make a Calcium Supplement for Chickens | Raising Chickens

Every time a chicken lays an egg, she loses calcium. Therefore, hens need a calcium supplement regularly to keep them (and their eggs) resilient! In this post, we will teach you how to use eggshells to make a calcium supplement for chickens for FREE.

banner that says how to use eggshells to make a free calcium supplement for chickens with a bowl of mashed eggshells and a blender in the background

Why do chickens need a calcium supplement?

Did you know that every time a hen makes and lays an egg, she loses calcium? Makes sense, right? But did you ever think about that?! Hens need a calcium supplement regularly to keep them (and their eggs) resilient! If chickens do not have enough calcium, their bones and bodies can weaken, and it also results in weaker eggshells. In fact, weaker eggshells will be the first sign that a chicken needs more calcium. A calcium deficiency can even lead to more health issues for chickens.

This is because an eggshell is made up 94% calcium carbonate. So, if a hen doesn’t receive enough calcium in her diet, her body will take calcium out of her own bones. This is very similar to how a pregnant or nursing mother’s body will pull nutrients from her body to support the baby or milk if the mother is not receiving adequate vitamins and nutrition.

Most chicken feeds have calcium added, but extra calcium is still recommended. If you free range your chickens and do not offer much feed, then your hens definitely need a calcium supplement. With good calcium support, you can even prolong the life and health of your hen’s egg-laying years.

How do you supplement calcium for chickens?

Well, you may have heard of offering oyster shells to chickens. If you walk the chicken care area of a store, you will find that oyster shells seems to be the most common way to add calcium to a chicken’s diet. You can feed oyster shell in its own container (most recommended way), on the ground, in a run, or you can even mix it into your choice of chicken feed. Whichever oyster shell you buy will have recommended instructions on the package.

There are other means of adding calcium into a chicken’s diet. If you research online, you can also find other supplements, and you can even find that feeding chickens certain scraps can also help add calcium into their diets. Another way some homesteaders add calcium to their chicken flock’s diet is by offering raw milk. It is debatable, but some believe that it is one of the most nutritious foods for people and animals alike. We are RAW milk advocates. For more info, check out this site.

BUT, I started raising chickens to SAVE money, have nutrient dense food I trust, and to become more sustainable. I wanted to lower our monthly cost of raising chickens so that it was even more affordable. So, I researched and discovered how to use eggshells to make a calcium supplement for chickens for FREE. And, it also resulted in a no waste option that help me reach my sustainability goals!

How to Use Eggshells to Make a Calcium Supplement for Chickens:

Preparing the eggshells to make the calcium supplement:

Save eggshells after cracking and using the eggs.
Rinse the eggshells to clean off any remaining whites or yolks.
Set aside on a counter, or in a fridge, until you have a bowl or two saved up.

picture of two hands with a cracked eggshell in the background is two raw eggs in a stainless steel bowl and an empty egg carton on a white granite countertop

two bowls full of cracked and cleaned eggshells sitting on a white granite countertop

How to make the calcium supplement:

1. Preheat oven to 225 degrees.

2. Put all the eggshells on a cookie sheet in a single layer.

cracked and cleaned eggshells in a single layer on two cookie sheets on top of a stove

3. Bake for 20 minutes. (See below for why and for a faster way!)

4. Let the eggshells cool.

5. Put a few eggshells in a medium sized bowl and mash the eggshells with a masher, or crush using a mortar and pestle.

6. Add more eggshells and mash or crush. Repeat until all the eggshells are mashed/crushed.

crushed eggshells in a bowl with a blender in the background on a white granite countertop

7. Next, put the crushed eggshells into a blender or food processor to grind them into a powder.

crushed eggshells in a glass bowl and a kids hand using a copper colored measuring cup to put crushed eggshells into a blender on top of a white granite countertop

8. Lastly, add the powder to a glass jar or preferred container to store, or feed immediately to chickens.

final eggshell powder calcium supplement in a glass mason jar

How do you feed the eggshell calcium supplement to chickens?

You can feed this eggshell powder calcium supplement to chickens the same way you feed oyster shells. The powder can be mixed into chicken feed, but it is typically recommended to offer calcium supplements to chickens in a separate feeder. This is because it is difficult to get the right ratio for calcium into feed at home, but also because chickens actually are very intelligent when it comes to eating what they need. Chickens can better regulate how much calcium they take in if you offer it in a separate container.

Why do you have to bake the shells before crushing and grinding?

The eggshells are rinsed in preparation for making the eggshell calcium supplement, but rinsing does not kill bacteria and pathogens. Therefore, baking the eggshells helps ensure that any remaining bacteria and pathogens are killed, making the eggshell powder safe for your chickens to consume. Also, the baking process helps the eggshells get brittle enough that they can crush/mash and grind easier.

One way to bake the eggshells is at 225 degrees for 20 minutes. But, if you want to do it faster, you can bake the eggshells at 350 degrees for only 10 minutes. Both ways are common and safe practice, but I choose the lower temperature for longer because I highly dislike the odor that fills my kitchen when I bake the eggshells at a higher temperature. I find that baking at the lower temperature has little to no odor. So, you can try both and choose what you are comfortable with.

Can people use this calcium supplement?

People can, and do, consume this eggshell powder as a calcium supplement when prepared safely according to the instructions. This is not medical advice, and consume at your own risk. We encourage you to research information as well as pros and cons before trying it. Also, you should learn how much calcium is estimated in how many eggshells to know if it is sufficient for your body.

Things to watch out for!

Do not give this eggshell powder calcium supplement to chicks or pullets! Any calcium supplement for chickens is only for egg-laying hens to support their bodies through the egg-laying process. If a calcium supplement is given to chicks, pullets, or even roosters, they can be overloaded with calcium and this can cause kidney and join problems. This is especially true if they are on a store-bought feed that already has proper amounts for chicks, pullets, and roosters.
If you see one of your hens becoming regularly lethargic, it could be many things, but it may be an overload of calcium. Chickens typically eat what they need, it is possible to offer it too much, and this is why it is really good to offer it in a separate container and not mixed into feed.
If you are offering your hens a calcium supplement, yet their eggshells are still weak, it could be a few things. It is possible that your hen does not have enough phosphorus in her diet to balance with the calcium. If the chicken is on a store-bought feed, that is not usually the problem. Free-ranged chickens may need some snacks of grains or seeds to help their phosphorus levels. Another possibility is that the chickens are not getting enough vitamin D. This is most likely to happen in cold, winter months where they may spend time inside their coops hiding from the cold. But, typically, chickens in the sunshine have adequate vitamin D levels to work with the calcium.
Make sure your chickens are getting enough protein. Again, store-bought feed takes care of a mostly balanced diet. However, free-ranged chickens have to fend for themselves finding food, like grass, weeds, and bugs. Bugs are protein! But, maybe they aren’t finding enough. If your chickens are losing feathers, or it is molting season, be sure to add protein-filled snacks, treats, or scraps. Some ideas are grubs, mealworms, scraps of cooked meats, and even cooked eggs.
Also, make sure your chickens are getting grit. Grit helps chickens digest their food properly. Free-ranged chickens can find natural grit like small pebbles, but it can’t hurt to still offer grit in a separate container. Chickens in a confined space definitely need to be offered grit.

Conclusion

Chickens need extra calcium when they are in their egg-laying years. This post has covered why they need extra calcium, how to feed them extra calcium, and much more. We hope that these instructions were simple and easy to understand, so that you now know how to use eggshells to make a calcium supplement for chickens for FREE! Happy feeding!!

Live abundantly, Friends!