Guide to Calcium for Chickens-What They Need

You may be surprised to learn that every egg laid by your hens has a shell that contains almost 95% calcium carbonate. The production of hard eggs requires the chicken to consume approximately 20 times more calcium than the bird has in her bones. As a responsible keeper, it’s your duty to ensure that your chickens are getting sufficient calcium in their diets.

Many people believe that their hens can get all the calcium that they need purely from their diet. But calcium supplements for chickens have been used by farmers for generations. Adding calcium to the hen’s diet will improve the hardness and quality of the shells. This brief guide should help you to implement this new regimen.

Is Calcium for Chickens Necessary?

Chicken Laying an egg

When it comes to evaluating calcium for chickens, it’s important to recognize that this is an essential nutrient for all poultry. Chickens need to develop and support healthy bones like many lifeforms. But they need sufficient calcium to produce an egg with a hard shell too. Well-developed hard eggshells help you to avoid flaws that make the egg thin and prone to breaking. If the eggs produced by your hens break frequently, you should consider adding calcium supplements to their diet.

Why Are My Hens Laying Soft Eggs?

If the hens eggshell gland cannot produce a viable shell then you may get an egg that has a soft shell instead. This is a common anomaly found in poultry that are deficient in calcium. A soft-shelled egg is an egg that doesn’t really have an outer shell. In fact, these inferior eggs typically have membranes as the outer surface. Although this thin membrane may have a certain integrity, the egg it surrounds is simply a bag of fluid.

What is the Cause of a Shell Less Egg?

If your hens are laying shell less eggs, the cause is not a calcium deficiency and there are other factors to consider. The three main causes include: illness, stress and a lack of sufficient nutrients in the hen’s diet. This is also a common phenomenon when older hens lay an egg and it’s not unusual to find a shell less egg from time to time.

When Should I Add Calcium Supplements?

If your hens are healthy, but you are noticing an increased frequency of shell quality problems, it’s probably time to consider adding calcium to their diet. Calcium for chickens is an ideal supplement for a healthy feed program. When eggs are malformed, thin shelled, and have thin spots, it’s a sign that the shell quality is poor.

But, if you’re concerned about bumps, lumps, and deposits of calcium on the shells, this will not be solved with calcium supplementation. A bird that’s molting or has molted once is old enough to receive calcium supplements. If you have poor quality shells from hens that have not molted yet, you will need to investigate other causes.

What is a Suitable Calcium Supplement for Chickens?

Many people feed their chickens used crushed egg shells, this is a viable method, but it can be a time-consuming approach. Others swear by the use of crushed oyster shells that are very rich in calcium and readily available.

If you want to add calcium to the diet of your flock, it’s pretty easy to get started. Chickens are savvy about their diet and if you try to mix the calcium supplement, it can be hard to get the mix right for them. If they don’t want to eat the calcium, they will pick it out and all your efforts are wasted. For this reason, it’s a better idea to place the calcium in a dedicated feeder. When the chickens want some calcium they will help themselves.

How Much Calcium Does a Chicken Require?

Calcium Chicken feed

When a hen is 18 weeks or older it’s considered to be an adult and the daily intake of calcium should be 4-5g. But, there are other essential elements required to produce a hard shell, including manganese, magnesium, phosphorus, vitamin D3, and zinc. This is why it’s important to use a good quality commercial layer feed because these ingredients and limestone flour are already added.

As you begin to feed your chickens additional grains, kitchen scraps and free range feeding then the concentration of these essential elements can be diluted. This is especially true if these new feed sources don’t contain sufficient trace elements to make up the difference. The most critical balance is the ratio of phosphorus and calcium. Extra calcium must be accompanied by extra phosphorus or the shells can degrade in quality.

The first reaction of many people when they see a poor-quality shell is to force extra calcium on their flock. They mix the calcium into a mixed feed with no added phosphorus and this can make the problem far worse. Extra calcium should never be fed to a chicken under 18 weeks of age and they should not be fed layer feed either.

What are the Consequences of Excessive Calcium?

If too much calcium is fed to a hen, it will be excreted in the form of calcium phosphate. This in turn will lead to a phosphorus deficiency, this lack of balance in the calcium to phosphorus ratio can be recognized by the following signs:

  1. A reduction in healthy egg production.
  2. A reduction in the consumption of feed.
  3. The egg shell surface may be “pimply”.
  4. Excessive calcium deposits creating rough ended shells.
  5. The production of shell less or soft-shelled eggs.

Is Milk Suitable to Boost Calcium?

The short answer is no. Although chickens are not lactose intolerant, they are prone to diarrhea. The diet of your flock can be supported with a little milk, buttermilk, whey, and cottage cheese. But, this should be the occasional treat because it’s easy to overdo it.


In Conclusion

Hopefully, we showed that it’s easy to add calcium for chickens to improve the eggshell quality. Don’t add the calcium to the regular grain because mixing it to their liking is not possible. In fact, the flock is likely to pick out the shells to find more grain which wastes your efforts. Place the calcium supplements for chickens in a separate dedicated feeder and they will take what they need.