If those calcium needs aren't met, hens can suffer from osteoporosis, fractures, and mobility issues. Fortunately, with the right husbandry practices, you can keep your flock strong, active, and free from preventable bone diseases.

The Hidden Strain of Egg Laying

Each time a hen lays an egg, her body uses roughly 2 grams of calcium, mostly to form the shell. This calcium comes from her diet and her skeletal system—especially a type of bone called medullary bone, which acts as a reservoir.

In commercial settings, hens confined to cages often suffer from “cage layer osteoporosis,” a condition where bones become porous, weak, and prone to breakage. But even backyard birds can develop bone issues if their nutritional intake and exercise levels are inadequate.

Key Nutrients for Strong Bones

Calcium

This is the most obvious and essential nutrient. Laying hens need about 4 grams of calcium per day, primarily for shell formation and bone health. Offer free-choice crushed oyster shell or limestone in a separate dish in addition to their feed.

Vitamin D3

Vitamin D3 enables hens to absorb calcium from their digestive tracts. Without it, even a calcium-rich diet is useless. Most quality layer feeds include D3, but hens also benefit from sunlight exposure for natural synthesis.

Phosphorus

Phosphorus works with calcium to form strong bones. The correct calcium-to-phosphorus ratio is critical—about 2:1. Too much calcium without phosphorus can actually weaken bones over time.

Magnesium

Magnesium supports bone density and plays a role in calcium absorption. It’s typically present in balanced poultry feeds but can also be found in leafy greens like kale and spinach.

Nutrition by Life Stage

• Pullets (young hens): Before they start laying, their bones are still developing. Feeding a starter or grower feed with proper phosphorus and vitamin D3 is essential. Avoid supplementing calcium too early—it can damage the kidneys.

• Laying hens: Once they start producing eggs, switch to a layer feed (16–18% protein, 3.5–4% calcium) and offer oyster shell separately.

• Senior hens: As they age, hens may lay less frequently but are still at risk of bone loss. Continue offering calcium and make sure they maintain a healthy body weight.

Encouraging Natural Movement

Exercise helps build and maintain bone strength. Chickens that roam, perch, scratch, and fly short distances develop denser, more resilient skeletons.

To promote movement:

• Offer multi-level perches that encourage flying and climbing.

• Provide outdoor access or secure runs so hens can forage.

• Scatter treats or scratch grains to stimulate natural behaviors.

Avoid keeping hens in spaces where they can’t stretch or move freely. Sedentary birds lose bone mass quickly.

Recognizing Signs of Bone Issues

Pay attention to symptoms like:

• Limping or reluctance to walk

• Difficulty standing or perching

• Droopy wings or hunched posture

• Decrease in egg production or soft-shelled eggs

If you notice any of these, isolate the bird, provide supportive care, and consult a veterinarian. Often, improving calcium intake and reducing egg laying with light management can help.

Special Consideration: Avoid Overbreeding

Excessive egg laying—common in commercial hybrids like ISA Browns or White Leghorns—places extreme demands on the skeletal system. Backyard chicken keepers may wish to choose heritage or dual-purpose breeds, which lay fewer eggs but maintain better long-term health.

Conclusion

Maintaining skeletal health in backyard hens is about more than just giving them calcium—it’s about providing balanced nutrition, safe space to move, and attentive daily care. By understanding how your hens’ bones work and what they need to stay strong, you’ll ensure a healthier, happier, and longer life for each member of your flock.