Feeding Your Chickens Eggshells the Right Way (With Photos)

Our hens are some of the hardest-working animals on the homestead. They have to lay eggs day in and day out, for years, and you can tell it takes a lot out of them even if they don’t have to hatch and raise their chicks.

And no matter what breed they are, all hens have something in common: they need calcium and a whole lot of it – that’s because eggshells are composed almost entirely of calcium. If we let our girls run low, they can start to suffer from devastating health issues.

Soft eggs or even those with partially formed shells can cause egg binding and death in short order. We don’t want that to happen!

Luckily, it’s easy to keep our girls topped off with calcium by feeding them eggshells. It’s natural, safe, and super easy. Keep reading, and I’ll tell you everything you need to know.

Won’t Feeding Chickens Eggshells Entice Them to Eat Their Own Eggs?

Let’s address the elephant in the room. You are right to be nervous about your birds eating eggshells and then developing a taste for them: normally, they will!

Once chickens learn that their eggs taste pretty good, even if it’s just the shells, they will start to readily eat the eggs that they lay as a convenient source of calories, protein, and calcium. This behavior has proven for centuries to be very difficult to break once it starts.

Worse, it is a sort of social contagion, and chickens that see hens eating eggs will start to eat them themselves! Pretty soon, the whole flock will be doing it.

But we are going to process the eggshells by baking them and then crushing them. Together, that changes the flavor, odor, and texture enough that your birds won’t associate the crushed shells with actual eggs. Works like a charm!

Oyster Shells vs. Eggshells

You might also be wondering why you would go through the trouble and potential risk of cannibalism by feeding eggshells back to your flock versus going with other calcium-rich supplements like oyster shells.

The short answer is that you don’t have to; oyster shells work well enough and have a pretty good track record. But I can tell you from long experience that most chickens will eat eggshells far more readily, and they are easier to digest.

Lots of oyster shell brands on the market are too big to be appetizing to chickens, and if you’re going to spend time processing something you paid good money for, that seems like a bit of a waste to me.

You can, though, “cut” your prepared eggshells with flaked oyster shells to make it go a little bit farther if you want to.

Never Mix Eggshells in with Other Foods

One more thing before we get down to business, and this is really important: don’t make the mistake of mixing the eggshells in with chicken feed or anything else.

I can understand that you might want to encourage your chickens to eat it more readily, or you want to disguise the flavor and texture of the eggshells even more, but this is a huge and potentially harmful mistake.

Chickens have a highly developed sense of what minerals they need, and calcium is probably foremost among them. If you set out the crushed eggshells where they can eat them free choice, they will eat them when they need them and ignore them when they don’t.

However, if you mix it in with their food, they won’t know how much calcium they are getting, and that can lead to poisoning and substantial kidney harm. This is especially problematic for baby chicks and roosters—birds that don’t need nearly as much calcium as laying hens.

Keep the eggshells separate from their other foods always!

What You’ll Need

Chances are very good you’ve got everything you need for this procedure in your kitchen right now. Gather and prepare all of the following, and we will get started.

Eggshells: just eggshells. When you are using eggs in your own kitchen or for any other purpose, remember to collect the shells. You can also ask neighbors, friends, and family to keep theirs for you.

Food Storage Container with Lid: you’ll want to process a larger batch of eggshells at a time, so to make things easy on yourself, keep your collected shells in something like a tupperware in the refrigerator. This will keep odor to a minimum.

Oven: we will bake our eggshells both to sterilize them and also to change their texture and odor. This is critical for the health and safety of our birds, and to prevent the onset of egg cannibalism as discussed above.

Baking Sheet: baking a large batch of eggshells is easiest on a big baking sheet, but if you don’t have that, you can use a large cast iron skillet, baking dish, or anything else that’s convenient. It really doesn’t matter as long as it’s oven-safe and big enough.

Rolling Pin: I prefer to crush the baked eggshells using a rolling pin. It’s quick, quiet, and gives me a little more control over getting the finished texture just right.

Ziploc Bag, Large: a large zipper or any other food storage bag works great for holding the eggshells while you crush them with the rolling pin. It keeps the small pieces together and prevents a big mess on your counter. The little bits tend to fly everywhere otherwise!

Coffee Grinder or Food Processor (optional): if you want to speed things up or just don’t want to mess around with a rolling pin and baggie, you can dump the eggshells into an old coffee grinder or into your food processor to mulch them really quick.

Glass Jar with Lid: for storing your finished, baked eggshells. They will last for quite a while once they are processed, and then you’ll have them on hand when your chickens need them.

Oyster Shells (optional): as mentioned, if you want, you can cut the finished eggshells with oyster shells. This helps the eggshells go a little bit farther, and the texture and flavor of will encourage the chickens to eat the oyster shells, too…

Step-by-Step Instructions

The following instructions will walk you through this simple process step by step.

Step 1: Collect eggshells, store in fridge. Remember to keep any eggshells that you crack open when you are cooking. Drop them into your container and then keep them in the refrigerator so they don’t get stinky.

Note that you do not have to wash eggshells prior to storing them. You can if you want to, but it’s not necessary.

Step 2: Preheat oven. Once you’ve collected enough eggshells to make a worthwhile batch, turn your oven on and preheat to 300° F (150° C).

Step 3: Lay out eggshells on baking sheet. Dump your collected eggshells out onto your baking sheet in a rough single layer.

They don’t have to be spaced out perfectly, but they will turn out better if they all have a little bit of room to breathe. If you have too many eggshells, simply bake them in two batches.

Step 4: Bake eggshells at 300° F / 150° C. Pop the baking sheet in the oven and set your timer for 5 to 10 minutes. If you have a smaller batch, 5 minutes will be sufficient. Bigger batches should be baked for 10 minutes.

Step 5: Remove eggshells, let cool. Carefully remove the baking sheet from the oven and set it aside until the eggshells cool down so they can be safely handled.

Step 6: Place eggshells in large Ziploc bag. Dump the eggshells into your large Ziploc baggie, working in batches. You don’t want the bag packed full to bursting, and it helps for them to have some room to move around during the following step.

If you are using a food processor or coffee grinder, place the eggshells inside now.

Step 7: Crush eggshells. Remove as much air as you can from the bag and then seal it up tightly. Lay it flat on your countertop and roll back and forth over it with your rolling pin, making sure to press down with even pressure and roll across the entirety of the bag.

If using an appliance, skip this step.

Step 8: Process to correct size. Chickens have a definite size preference for eggshells. The ideal size is somewhere between a grain of rice and a flake of oatmeal. Make a few passes with the rolling pin and then check it. Repeat until most of the shells are a roughly uniform size.

With a food processor or coffee grinder, pulse the eggshells until they are the right consistency.

Step 9: Dump shells into jar. Once processed, you can dump the shells out directly into your clean, glass jar for storage.

Step 10: Repeat. If you have any remaining that haven’t been processed, repeat the previous steps until the whole batch is done.

Step 11: Store. If you aren’t feeding your crushed eggshells to your flock right away, put the lid on the jar tightly and then store it in the refrigerator. They will keep for a very long time!

Step 12: Done! And you’re all finished. Your birds are ready to enjoy a great, natural, and tasty source of calcium.

Serving Eggshells to Your Flock

This is super simple. All you need to do is pour out the eggshells into a separate feeder, dish, or other container.

You don’t want to scatter them on the ground because they will quickly get lost and wasted, and you want your girls to know what they are and where they are. That way, they can eat them when they feel like they need them.

Give them a small quantity at first to see how they react and how much they eat, then refill as needed. Keep the surplus inside an airtight glass jar in your refrigerator as described above.

If desired, you can mix in the crushed or flaked oyster shell when serving the eggshells. A good ratio is two to one eggshells to oyster, or you can go one to one.