Do Chickens Need Oyster Shells? (A Simple Look at if Hens & Other Chickens Require Oyster Shell)

Should I Give My Chickens Oyster Shells?

Oyster shells (Amazon) are only needed for egg-laying hens who need extra calcium in their diet.

High-quality commercial laying feed has a fast-release source of calcium in the form of limestone. However, egg-laying hens tend to need more slow-released calcium than what high-quality commercial laying feed gives them.

Why do they need so much calcium?

Because hens use a lot of calcium to produce eggs.

When an egg-laying hen’s diet is deficient in calcium, she might lay eggs with thin shells or no shells at all.

Also, if a hen doesn’t get enough calcium, this can lead to the calcium from her bones leaching out in order to create eggshells. That may lead to bones that are fragile, deformed, or broken.

Being deficient in calcium might also cause behavior problems like egg-eating since the hens are so desperate for calcium.

If a calcium deficiency becomes a problem, a supplemental source of calcium should be provided, such as crushed oyster shells (Amazon).

Oyster shell is a soluble grit. This is because the calcium from the oyster shell dissolves in the hens’ stomach and is used in making eggshells and strong bones.

You should only start offering your flock some oyster shells if you have hens that are currently laying eggs or they have reached 18 weeks old. Baby chicks, older non-laying hens, and roosters do not need any oyster shells added to their diet.

In fact, if chickens aren’t deficient in calcium, they will instinctively refuse to eat oyster shells for their own safety. Too much calcium can cause kidney damage, egg binding, bone abnormalities, metabolic issues, and more.

How Often Do You Give Oyster Shells to Chickens?

Too much calcium can be harmful to a chicken’s health. So the best way to feed oyster shells to chickens is to serve it in a feeder that’s separate from the chicken feed.

I repeat. Do not mix oyster shells in with the chicken feed!

A layer that needs extra calcium will eat the oyster shell while the other chickens will just ignore it.

Do Chickens Need Oyster Shells and Grit?

A lot of people think that grit (Amazon) and oyster shells are the same things, but they’re not.

It’s essential that chickens have access to grit if they eat anything other than commercial feed, including bugs, grass, and other small animals.

Grit is a coarse material, such as tiny stones and rocks, that helps chickens grind down food in their gizzards. Grit is crucial for chickens to digest their food properly.

On the other hand, crushed oyster shells won’t help chickens in breaking down food. It’s only used as a calcium supplement.

For more information on grit, check out my post: Do Chickens Need Grit?

Can I Give My Chickens Egg Shells Instead of Oyster Shells?

Clean, air-dried, and crushed egg shells are a good source of calcium for chickens. But hens typically require more than just eggshells as a calcium source.

So if you want to cut down on costs, you can mix eggshells in with your oyster shells.

Just make sure the eggshells are crushed enough that they don’t look like eggs anymore. You don’t want to train your hens to start pecking at the eggs you want to eat!

Conclusion: Are Oyster Shells Good for Chickens?

Yes, oyster shells are good for egg-laying hens that need extra calcium to lay eggs with strong eggshells.

However, too much of a good thing can be bad. This is why it’s crucial that you only give your laying-hens oyster shells free choice (in a bowl or feeder separate from their chicken feed).

If a chicken doesn’t need extra calcium in its diet, it won’t eat oyster shells.

For roosters and non-laying hens, the high level of calcium in oyster shells can cause health problems such as impaired liver function. Chicks are especially vulnerable to the dangers of oyster shell consumption since their bodies are not yet able to process the calcium properly.