Calcium: The Unsung Hero of Hen Health
We all know chickens lay eggs, but many don’t realize just how essential calcium is for those eggs — and for the overall health of your flock. Beyond eggshell production, calcium plays a vital role in a hen’s well-being. Unfortunately, modern, highly productive hens are more prone to calcium deficiency because they need so much calcium to keep producing those eggs.
That’s why understanding and addressing calcium needs in chickens is so important. This article will be your comprehensive guide. We’ll explore calcium’s role in egg production, how to spot the symptoms of calcium deficiency, how to use supplementation strategies, and what to consider for different life stages.
Why is calcium so important for chickens?
Calcium is essential for a hen’s health for a number of reasons, but it’s especially critical for laying hens.
Laying hens and egg production
Eggshells are almost pure calcium carbonate — about 90% calcium, in fact. Each egg contains about 2.2 grams of calcium.
That means a laying hen needs a lot of calcium to produce the strong, sturdy eggshells you expect. If a hen lays an egg every other day, she has to gather enough calcium to make a strong, sturdy eggshell roughly every 48 hours.
Beyond eggshells: Calcium’s other vital roles
Calcium is also important for other functions in chickens, including:
- Muscle function
- Nerve function
- Blood clotting
It’s also critical for bone health, helping chickens maintain strong bones.
The science behind calcium utilization
If your hens aren’t getting enough calcium, they’ll start laying thin-shelled or even shell-less eggs. Here’s a bit about why calcium is so important.
The formation of eggshells
Did you know that it takes a hen about 20 hours to form a shell around an egg? During that time, she’s drawing calcium from her diet, and if her diet isn’t sufficient, she’ll draw it from her bones, especially the medullary bone (the bone that stores calcium). In fact, hens can draw up to 10% of the total calcium in their skeleton to make eggshells, and 30% to 40% of the calcium in an eggshell can come directly from the hen’s bones.
Calcium and its twin nutrients: phosphorus and vitamin D3
Calcium doesn’t work alone. In order for a hen to absorb calcium, she needs to have sufficient amounts of phosphorus and vitamin D3 in her system. Vitamin D3 helps the hen absorb calcium through her intestine. So, to make sure your hens are utilizing the calcium they’re getting, make sure they’re also getting plenty of phosphorus and vitamin D.
How to Spot Calcium Deficiencies
How can you tell if your chickens aren’t getting enough calcium in their diets? Here are some signs to watch for:
Early Signs of Calcium Deficiency in Laying Hens
- Thin or soft eggshells
- Reduced egg production
- Shell-less eggs
Symptoms of Severe Calcium Deficiency in Chickens
- Bone weakness and fractures
- Skeletal problems, such as rickets or osteoporosis
- Hypocalcemia, a dangerous condition that can lead to death
Calcium Deficiency in Chicks
Chicks who don’t get enough calcium can develop rickets, a disease that affects bone development.
Low blood calcium can also lead to increased pecking among growing pullets, possibly because they’re trying to get calcium from each other.
Do All Laying Hens Have a Calcium Deficiency?
Fortunately, not every hen will have a calcium deficiency. However, it’s a pretty common occurrence, especially in high-production breeds.
Factors like age, diet, laying rate, season, weather, disease, and digestive health can affect the amount of calcium a hen needs. So, even if you’re feeding your chickens a diet that should be adequate, they could still develop a deficiency if other factors are at play.
How to Supplement Calcium
If your hens are laying soft-shelled or shell-less eggs, it’s time to add some supplemental calcium to their diet. Here are some of the best ways to do it:
Common Sources of Supplemental Calcium
- Crushed oyster shells. Many chicken keepers swear by crushed oyster shells as the ideal calcium supplement.
- Shell grit. Shell grit is another good option.
- Seashells. If you live near the ocean, you could gather your own seashells.
Whatever you choose, make sure the calcium is in large particles, as this helps the chickens absorb it better. Experts recommend that 65-70% of the calcium in a laying hen’s diet should be in this form.
What about phosphorus and vitamin D supplements?
If your hens don’t get a lot of sunlight, it’s a good idea to add vitamin D3 to their diet, as this vitamin helps them absorb calcium. Also, make sure the calcium-phosphorus ratio in their feed is balanced. Consult with a poultry expert or veterinarian to determine the right balance for your flock.
How to meet your flock’s calcium needs
Here are some tips for making sure your chickens get enough calcium:
Dietary considerations
- Feed chickens a complete layer feed. These feeds typically have plenty of calcium, phosphorus, and vitamin D, which are all essential for egg production and overall health. Layer feeds contain about three times the calcium that non-laying chickens require.
- Provide unlimited access to a large-particle calcium source. Shell grit, oyster shell, or even crushed eggshells can help your hens get all the calcium they need.
- Limit treats to less than 10% of your flock’s diet. Too many treats can throw off the nutritional balance of their feed.
- Avoid forages high in oxalic acid. Certain greens, like spinach and chard, contain oxalic acid, which can interfere with calcium absorption.
Special tips for summer
- Remember that heat stress can trigger calcium deficiency. When chickens are too hot, they may eat less, which means they’re not getting enough calcium.
- Provide electrolytes in the water during warm weather. Electrolytes can help chickens stay hydrated and maintain proper calcium levels.
- Make sure your hens are kept cool. Provide shade, plenty of fresh water, and consider using fans or misters to keep them comfortable.
Planning for bone weakness in older laying hens
As hens age, their bones can become weaker, making them more prone to fractures.
- Make sure your roosts are safe. Design roosts that are low to the ground and easy for older hens to access.
What about chicks? How much calcium do they need?
Chicks aren’t just small chickens. They have very different nutritional needs than adult laying hens. Baby chicks, for example, need much more protein in their diets.
It’s important to avoid feeding chicks and pullets “layer feed” until they are close to laying age (around 16-18 weeks old). Pullets, in particular, need different amounts of calcium at different stages of development.
Here are the recommended calcium percentages for pullets at different ages:
- Starter: 0.970%
- Development: 0.95%
- Pre-laying: 0.860%
- Laying: 2.200% – 4.508%
Can chickens get too much calcium?
Yes, although it’s not very common. Excess calcium can create problems like shell deposits in young hens or hypercalcemia (too much calcium in the blood).
Too much calcium can also damage a chicken’s kidneys and cause other health problems.
The best thing to do is watch your chickens for signs of calcium deficiency or calcium excess. If you see anything unusual, talk to your vet. They can diagnose the problem and help you adjust your chickens’ diet to get them back on track.
The Bottom Line
Calcium is essential for the health of your laying hens and for producing eggs with strong shells. If your flock isn’t getting enough calcium, you may notice symptoms like thin-shelled eggs, reduced egg production, and even skeletal problems in your birds.
To ensure your hens get the right amount of calcium, you can supplement their diet with oyster shells or limestone. But remember to consider the age of your birds, their breed, and their environment when deciding how much calcium to provide.
A balanced approach to calcium supplementation will help keep your hens healthy and laying strong.