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3 Benefits of Oyster Shell for Chickens

Oyster shell for chickens is crucial! So if you’ve been curious as to whether or not you should be feeding your chickens oyster shells this post will explain all of the benefits!

Chickens pecking at the ground

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For as long as I can remember, I have fed my chickens oyster shells. My grandpa who I consider an expert on raising chickens always emphasized to me how important it was and I have personally seen the benefits.

But if you’re new to raising chickens or maybe even a long-time chicken owner, you may still be wondering why your chickens need oyster shells.

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Why Do Chickens Need Oyster Shell?

Adding oyster shells to your hens’ diet is extremely important. There are other things you need to feed your chickens such as layer feed for egg production and fresh herbs for extra health benefits.

But providing oyster shells for your hens to eat will ensure optimal hen health for egg production by providing them with a good supply of calcium.

Below I’ll go over the three most important benefits. 

1.) Oyster Shell Produces Strong Eggshells

Nobody wants an egg that breaks in the nesting box or that simply falls apart when you handle it.

So to ensure that your hen is able to lay eggs with strong shells, she needs a diet high in calcium.

Eggshells are about 95% calcium, so it’s no wonder why laying hens need a calcium supplement.

2.) It Helps Hens Stay Strong and Healthy 

When laying hens do not receive enough calcium their body begins taking it from their bones. This can then lead to weak and brittle-boned chickens.

3.) Helps With Continued Egg Production

If you’ve noticed that your hens are not laying there are a few reasons why, such as she may be molting, she may be too young still or getting too old, or she needs additional calcium.

Signs of calcium deficiency in hens include,

  1. Eggs with thin shells.
  2. Eggs with soft shells.
  3. Eggs with no shell.
  4. Slow egg production.
  5. Broken eggs.
Broken eggshells in nesting box.

Guide to Feeding Oyster Shell

First off, only laying hens need additional calcium, roosters do not.

In fact, excess calcium can be harmful to chickens that don’t use up the extra calcium to produce eggs.

So let’s start with when to start feeding it.

When to Start Feeding Oyster Shell

When your hens are approaching laying time which is anywhere from 18-22 weeks of age. Or as soon as you notice that they’ve started laying.

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How Much Oyster Shell for Chickens

The simple answer to this question is as much as they need.

Layer feed has a good amount of calcium in it and for some chickens that will give them plenty. But for others, they’ll need extra.

So the best thing to do is give them free choice. Put the oyster shell in its own separate dish or feeder and always keep it available. Chickens will never overeat on it, their bodies instinctively know when they need additional calcium and so they’ll only eat it as needed.

You should be able to find flaked oyster shell at your local feed store, but if not, they even sell oyster shell on Amazon.

Additional Ways to Provide Calcium

You may have heard about other chicken owners feeding their own eggshells back to their hens. There are both negative and positives about doing so.

One negative belief is that hens will then try to eat their own eggs.

A positive is that you’re being resourceful and still providing a good source of calcium.

For many years eggshells have been fed back to their hens to eat and so I don’t see it as a problem. I believe that practices that have been around for a long time tend to be pretty smart.

However, if you decide to feed the eggs shells back to your hens then just make sure that you first wash off the yolk, dry them out, and crush them up.

Don’t just throw an egg on the ground and let them eat it. Once they start to enjoy the taste of the eggs they’ll want to eat their own.

I’ve had quite a few egg-eating hens over the years so trust me on that one…

Here is also a list of some great calcium-rich foods that you can feed,

  1. Broccoli
  2. Brussels Sprouts
  3. Butternut Squash
  4. Chard
  5. Collards
  6. Dandelion Greens
  7. Green Beans
  8. Kale
  9. Mustard Greens
  10. Okra
  11. Parsley
  12. Podded Peas
  13. Spinach

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Additional Supplements to a Chicken’s Diet

Grit is another important part of a chicken’s diet. And this one is not only for hens but for all backyard chickens.

Grit and oyster shells are two completely separate things and each serves its own purpose.

Oyster shell is specifically for laying hens to provide them with the extra calcium needed.

Poultry grit helps the chicken’s digestive tract by putting its food into a usable form.

Chickens don’t have teeth so the grit is what helps to break down their food. After a chicken eats the grit it settles in its gizzard and stays there to grind food.

You can learn more about feeding grit here.

In summary, as long as you’re providing your chickens with oyster shell, grit, and a good quality layer feed, you’ll have a healthy flock of chickens and wonderful fresh eggs with strong shells.

Learn more in my YouTube video below!

Why Your Laying Hens Need Oyster Shell

Want to learn more about the best laying hens? Be sure to head to this post here, The Best Chickens for Eggs.

Or even the best chicken breeds for beginners? There are some breeds that I’ll always keep in my flock so be sure to learn about them in this post here, 5 Best Chicken Breeds for Beginners.

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A white chicken

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  1. Thank you! Oyster shells can work wonders so if you are not yet feeding them to your hens you should try it out 🙂

  2. Please help. My hens are 18 weeks old. They don’t free run. I’ve always fed them the crushed layer feed and haven’t switched to pellets yet. I just introduced them to oyster shell but they don’t take any interest. They’re not laying yet and I also couldn’t find the shell in crushed form. Does it take like a week for them to eat it or is it because it’s not crushed?

    1. Hi Melody 🙂 Hens don’t need that extra calcium until they have started laying. And being that you said they are only 18 weeks old I’m assuming they are not laying yet or maybe barley have started. They will instinctively know when they need the extra nutrients, so don’t worry that they aren’t eating it. Right now with them being so young the layer feed is providing them with all the nutrients they need. Hope this helps! Let me know if I can help out more 🙂

  3. I wonder if I can use freshwater clam shell as a diy substitute for oyster. I live next to a river with a thriving clam population and see plenty of shells littered on the bottom of the river. A simple mortar/pestle to pulverize them would be easy enough to create.

  4. My grandmother always washed her eggshells, crushed them and then browned in the oven. I assume to fool the chickens that they weren’t eating something that was readily available to them. Ha! But she never had egg eaters as far as I know.

    Getting 4 baby chics and 2 pekin ducklings tomorrow. Soooo excited. :).

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