How To Prepare Eggshells For Chickens To Eat

I constantly found myself having to buy more and more oyster shells for the chickens calcium supplement. But when I realized eggshells were a great substitute, I started preparing that instead for free!

What some people in my close circle don’t understand is that we didn’t choose homesteading to make life harder on us. Rather, it’s a choice we made because we wanted to become more self-sufficient.

When we first purchased our chickens, I really struggled with being more self-reliant with having them. Am I really being more self-reliant if I’m constantly buying feed from the store monthly and also supplementing with grits and oyster shells.

What Are Oyster Shells?

Oyster shells are just oyster shells that are ground up. I really wish I liked the taste of them, otherwise I, myself, would eat them weekly. They’re one of the most nutrient dense foods out there! The same applies for chickens. When chickens become of laying age, they need to start supplementing with calcium for not only a healthy bird, but for a healthy egg as well. Oyster shells are a great source of calcium, but as I’ll touch upon, there are other free options you can use.

Why Feed Chickens Oyster Shells?

One word… calcium. Chickens need calcium for many reasons:

It helps create a hard-shell for the eggs.
It prevents bone damage to the chickens.
It strengthens blood vessels.

How Do You Know Your Chickens Need More Calcium?

Soft Eggshells: If they’re soft and squishy, it’s definitely time to supplement with added calcium. Eggs are only hard when there is proper calcium in a chickens diet.
Bone Damage: Hens will firstly send the calcium to their eggs and the remainder to their bones. If they’re not getting enough, then their bones will suffer. They can have osteoporosis, broken bones, or have problems standing.
Behavior Issues: Calcium deficiencies can lead to poor behavior. If there is a chicken in your flock acting meaner than normal or pecking others, it could be a calcium deficiency.
A Decrease or Stop of Egg Production: Obviously there are times when your chickens aren’t laying. Factors that prevent them from laying are age and lack of sunlight. A lack of calcium could also cause a decrease or stop in production.
Lameness: Chickens who suffer from stiff legs might actually have a bone problem due to a calcium deficiency.

When Do You Start Feeding Oyster Shells (Extra Calcium) to Chickens?

Oyster shells are only used for chickens that are of laying age. Usually around 18 weeks (at the earliest) should you start supplementing. This is because your chickens will start laying in the near future.

Chicks, pullets that aren’t laying, older chickens who have stopped laying, or roosters DO NOT need the added calcium.

How Often Do You Feed Chickens Oyster Shells (Calcium)?

There are actually complications to feeding chickens too much oyster shells. If you’ve given them too much, they could experience some side effects: kidney failure, inability to absorb calcium, metabolic problems, egg binding, joint issues, leg abnormalities.

Simply make it free choice for them and they’ll be in tune with what they need. Put it in a separate bowl from their regular feed. It’s especially important when your hens are broody or molting. Or you could offer it once a week to them, just don’t add to their food.

How To Make Your Own Oyster Shell Feed

In the name of self-reliance, I didn’t plan on sharing how to make oyster shell feed, but if you do happen to live in the right area then you wouldn’t have to make any replacements.

If you have access to a lot of free oyster shells, then try this!

Wash shells and spread on a baking sheet.
Bake at 250 degrees Fahrenheit for 10 minutes.
Once baked, place in a double or triple-lined bag and smash the shells with a hammer. For a powdery consistency, put them in a food processor after.

Eggshells are a Great Alternative to Oyster Shells

Feeding your chickens ground-up eggshells is a great way to get them the calcium they need. I really like this method because I don’t have to constantly head to the store to spend our hard-earned money on something we could otherwise get for free here.

We already have an abundance of eggs, why not put those eggshells to good use! Plus, I prefer using the eggshells for a calcium supplement because they take FOREVER to decompose in my compost pile.

There is one thing to consider… If you’re using eggshells to boost calcium, but you notice they’re lacking calcium, the eggshell powder might not be that high in calcium.

A few of your table scraps can also suffice to start getting their calcium going (yay for free!):

spinach
kale
yogurt
broccoli
milk
rhubarb
cabbage
salmon
summer squash

Lastly, just note that the calcium releases slower when using eggshells as compared to oyster shells.

How To Prepare Eggshells for Chickens to Eat

Preparing eggshells is a very easy process. My recommendation is to use only eggshells that your flock has produced and that you can account for because you know their health.

Rinse your eggshells and get any debris off.
Dry out your eggs. There are two methods that you could do depending on your lifestyle.
- First, you could simply add your eggshells from the day onto a plate or bowl and let it dry overnight.
- Second, you could do a big batch of eggshells and bake them. If you bake them, you could set the oven anywhere from 200-400 degrees Fahrenheit. I like to add them to the oven if I’m already baking something else. Bake until they’re dry. Could be 5-10 minutes depending on what temperature you set it too. Don’t overthink it!
Once your eggshells are dried out simply mash them up. Chickens won’t be able to eat them if they’re in powdered form. I think the confusion with feeding chickens’ eggshells is that it promotes them eating their own eggs. As long as you mash it up, they won’t be able to correlate that the eggshell pieces are eggs. But I’ve also heard chicken owners just give them the cracked eggshells without mashing them with no issue. Experiment and see what works for you.
- Ways you could crush the dried eggshells: potato masher, mortar and pestle, food processor, or blender or hand crush them.

How To Prepare Eggshells for Chickens the Easy Way (My Version)

The above process is all well and good, but I don’t like the extra step of doing dishes after baking the eggshells.

Rinse your eggshells
Place in a bowl and let them air dry. I leave my bowl out on the counter. Aesthetically it doesn’t bother me. I think the different colors of the eggshells are pretty. It usually takes a day for them to dry.
Once they’re dry, mash them up by hand and feed to the chickens when you’re ready.

Bonus: Other Uses For Crushed Eggshells

Anytime I can use something I already have around the house; I love being able to use it! Here are some other things you could use the crushed eggshells for:

Feed to your chickens
Process it into a finer powder and use as a calcium supplement for yourself
Toss them in the compost pile (not my preference because it takes longer to decompose, but it won’t hurt anything)
Use the egg shells to start seedlings
Give your tomatoes a calcium boost.