Many hens need extra calcium when they reach egg-laying age and people might have suggested that you should give them eggshells, which are rich in calcium. But can chickens eat eggshells? For many people, the suggestion sounds weird or even wrong. After all, chicks grow inside eggshells.

Even if it may sound a little odd, your chickens can eat eggshells and they are an excellent way of ensuring your laying hens get the calcium they need. Your chickens will also get many other important nutrients from eggshells. To learn more about feeding chickens eggshells, keep reading the article.

Why Give Eggshells to Your Laying Hens

Why Give Eggshells to Your Laying Hens

When most chicken keepers decide to give their hens eggshells, it is usually to add more calcium to their diet. While calcium is important for all chickens, your chicks, roosters, and pullets will not need extra. Laying hens, on the other hand, may need an extra portion because they need it not just for their wellbeing, but to produce eggs, too.

In chickens of all ages, calcium supports healthy bones and supports the functioning of the nervous and digestive systems. For laying hens, calcium has an important role in egg production and making the process of passing the egg through its cloaca.

Calcium helps to control muscle spasms that can occur when the hen is laying an egg and it helps to control the hen’s heart rate. Calcium is also essential for the proper formation of eggshells. In hens with a calcium deficiency, eggs will come out with soft shells. Calcium is also needed for the proper functioning of a hen’s reproductive system.

If a laying hen has a severe lack of calcium, its body will pull calcium from the bone, which will weaken its skeletal structure. To protect itself, the hen will reduce the number of eggs it lays or stop completely.

Other Nutrients Chickens Get From Eggshells

The main nutritional value in eggshells comes from the calcium carbonate they are composed of. However, eggshells also contain other minerals, including phosphorus, magnesium, and fluoride. Magnesium is used to regulate the hens’ metabolism and enzyme activity, and phosphorus and fluoride are both used to strengthen bones.

While your chickens will get many useful nutrients from eggshells, it needs to be remembered that eggshells are supplements, not the main feed. You should always give your chickens balanced food with all the nutrients and vitamins they need.

Which Chickens Need Extra Calcium

If you are feeding your egg-laying hens with layer feed, they will not need a calcium supplement every day and some will not need it at all. You should only give extra calcium to those hens that need it, for example, if you notice they are laying soft-shelled eggs. Give them 1/8th to 1/4 cup of eggshells in a week and see how they get on.

You should not give extra calcium to chicks, pullets, or your roosters. Since they do not need the extra calcium for egg production they can get enough calcium from their regular feed. When your pullets start laying eggs, you will want to up their calcium intake.

What Can Too Much Calcium Do

What Can Too Much Calcium Do

If hens get too much calcium, one of the consequences can be that the eggshell is too thick. This can be a serious problem if you want to hatch eggs but the shell is too thick for the chicks to break through them.

In chickens that are not ready to start egg laying, too much calcium can lead to them producing eggs too soon, which can cause them to become egg-bound or lead to a prolapsed vent.

In laying hens, excess calcium can also reduce the fertilization rate, meaning the eggs will remain unfertilized even after the hen has mated with a rooster. In all chickens, too high calcium consumption can lead to difficulties breathing, organ calcification, kidney problems, and in the worst cases, even death.

Calcium and Phosphorus

The ratio of calcium to phosphorus in your chickens’ diet is very important for their overall health as well as for egg production. While lack of calcium is a more common cause for soft eggshells, it can also be because of phosphorus deficiency.

If your chickens do not have enough phosphorus, then supplementing their diet with calcium could make the problem worse. To avoid this, offer your flock a phosphorus supplement next to their calcium supplement. Defluorinated rock phosphate is an easy way to add phosphorus to the diet.

Separate Portions or Mixing Eggshells With Regular Feed?

Some people mix the eggshells with the regular layer feed they give their hens. While this may be a good way to get your chickens to eat the eggshells, it is not recommended. Why? Because they will not all need the extra supplement of calcium and you run the risk of calcium toxicity in some chickens.

A better way to do it is to offer your chickens free choice. Many chicken keepers have observed that somehow the chickens know themselves when they need extra calcium. Place the crushed eggshells in a separate container so those chickens who want it can access it together with their regular feed.

Will Give Chickens Eggshells Encourage Them to Eat Their Eggs

Will Give Chickens Eggshells Encourage Them to Eat Their Eggs?

Many people are hesitant about giving their chickens eggshells because they fear it will encourage egg eating. In most cases, feeding your chickens eggshells will not lead to them eating their eggs.

Often, the opposite can happen. When the chicken is calcium deficient, it may start to eat its eggs to replenish the calcium. Giving calcium-deficient chickens eggshells can therefore prevent them from eating their eggs.

However, you should always crush the eggs into small pieces so the chickens will not recognize them as eggs. If they connect their eggs with the supplement you are giving them, it can sometimes lead them to mistakenly eat their eggs.

Preparing the Eggshells

Start by collecting eggshells in a bucket or container. You can crush them to fit in more shells and rinse them using warm water to clean off any dirt. Some people allow the eggshells to air dry, others like to speed up the process by drying them in the oven.

If you would like to dry them in the oven, heat your oven to 225°F (105°C). Cover a baking tray with a baking sheet and spread the eggshells evenly. The shells will need 16-30 minutes in the oven. When they come out of the oven, they will be brittle and break down more easily.

Once the eggshells have been air or oven dried, you need to crush them into small, chicken-bite-size pieces. You can either use a mortar and pestle or place the shells in a thick bag and crush them with a rolling pin. Some people like to use a blender but you need to be careful not to end up with egg powder.

This video shows one chicken keeper preparing eggshells.

Things to Remember When Feeding Chickens Eggshells

When you have the eggshells ready, there are some things you need to remember and some things you should avoid,  such as mixing the shells with regular feed. It is better to give your chickens the option. Remember to crush the eggshells so small that there is no resemblance to an egg to avoid the chickens starting to eat their eggs.

Do not offer the eggshell supplement to chickens that are not laying eggs yet or your roosters as this may cause health issues in them. You should only give your chickens eggs from your flock. Eggs from another flock or a store could carry diseases or parasites.

Other Sources of Calcium for Chickens

In addition to crushed eggshells, there are other foods you can give your chickens to supplement their diet with calcium. Many chicken growers like to give their flock crushed oyster shells which contain a range of vitamins and minerals that are essential for chickens. You can find oyster shells in shops that sell chicken feed or online.

Crushed limestone is another great source of calcium. It also provides chickens with some grit they need to digest their food. However, limestone residue can build up inside chicken’s beaks so when you are giving them limestone chick, check their beaks regularly and remove any buildup.

You can also give chickens dairy products such as milk or yogurt but ensure they are low-fat options to prevent weight gain. Vegetable scraps can also provide a source of extra calcium for chickens. The best sources are leafy greens, including cucumber or broccoli leaves and kale, turnip, and squash greens as well as cabbage.


Feeding your chickens eggshells is not only acceptable but can also provide them with an extra helping of calcium. When feeding your chickens eggshells, remember that not all your chickens need it and that too much calcium can be a health risk.

Hopefully, the article has covered all your questions on the topic of whether chickens can eat eggshells. If there is anything else you would like to ask, write your questions in the comments section.

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