Grit & Oyster Shell

Give your chickens the nutrients they can’t find on their own. Grit helps birds grind food for better digestion, while oyster shell provides calcium for strong, healthy eggshells. Offer both separately so hens can take what they need when they need it. Simple, natural, and essential for every flock.

Essential supplements for digestion and strong eggshells

Grit and oyster shell are fundamental to chicken health but often overlooked. Grit helps chickens grind food in their gizzards since they have no teeth. Oyster shell provides the calcium laying hens need for strong eggshells. Offer both separately so birds can self-regulate their intake based on individual needs.

Why grit and oyster shell matter

Grit aids digestion: Chickens need hard particles in their gizzards to grind down whole grains and fibrous foods
Prevents soft eggs: Oyster shell provides soluble calcium that laying hens convert directly into eggshells
Self-regulation works: Hens instinctively consume the right amount when supplements are available separately
Essential for confined flocks: Free-ranging birds find natural grit and calcium sources, confined birds cannot

Popular choices

Mixed grit – combination of insoluble flint grit (for digestion) and soluble oyster shell (for calcium)

Oyster shell – pure calcium supplement specifically for laying hens to support strong eggshell production

Tip: Offer grit and oyster shell in separate containers using feed stations. This allows laying hens to take calcium as needed whilst other birds access grit without excess calcium.

Complete your chicken setup

To keep your flock healthy and productive, explore:

Cartoon chicken eating grit with a playful gizzard illustration showing how grit helps digestion.

Even pellet-fed birds benefit from grit for optimal digestion

Why do chickens need grit if they eat pellets?

Pellets are designed to be easy to digest. But most chickens eat more than just pellets.

What else chickens eat:

Kitchen scraps and tough greens
Grass and weeds from the run
Whole grains or scratch mixes
Insects and worms

All these need grinding. The gizzard uses grit to pulverise tough materials into digestible particles.

Two types of grit:

Flint grit (insoluble): Hard stones that stay in the gizzard permanently. They grind food, wear down, and pass through. Chickens replace them by eating more as needed.

Oyster shell (soluble): Softer, calcium-rich pieces that dissolve in digestive acids. These don't grind food. They're absorbed for eggshell production instead.

Free-range birds find natural grit like small stones and sand. Confined birds need supplementary grit.

How to tell if grit is working: Firm droppings indicate good digestion. Undigested grains in droppings suggest inadequate grinding.

Keep grit available year-round in a dedicated station. Chickens self-regulate perfectly.

Cartoon hen choosing between a mixed grit bowl and separate flint grit and oyster shell containers

Both approaches work but separate feeding gives more control

Should I offer mixed grit or separate oyster shell?

Mixed grit combines both. One product provides flint grit for digestion plus oyster shell for calcium. Simple and convenient.

Benefits of mixed grit:

One bag instead of two
Single feeding station
Hens pick what they need
Perfect for small flocks of layers

Separate feeding gives precision. Different containers let you control exactly what's available to different birds.

Benefits of separate feeding:

Control calcium access for chicks, roosters, non-layers
Monitor consumption accurately
Better for mixed-age or mixed-species flocks

Who needs what:

All chickens need grit: Everyone who eats anything other than pellets.

Only laying hens need extra calcium: Active layers producing eggs daily. Too much calcium harms chicks, roosters, and retired layers.

The practical choice: Small flock of all laying hens? Mixed grit works brilliantly. Mixed ages or roosters present? Separate feeding is safer.

Both systems work. Choose based on your flock composition.

Cartoon hen inspecting eggs with different shell strengths and a friendly oyster shell character nearby.

Eggshell quality tells you everything about calcium status

How do I know if my hens need more calcium?

Strong shells need lots of calcium. A hen deposits about 2 grams into each egg. She must get this from diet or her own bones.

Signs of calcium deficiency:

Soft-shelled eggs (rubbery, flexible shells)
Thin shells that break easily
Rough, pimpled texture
Shell-less eggs (just membrane)
Reduced laying

Why deficiency happens:

Layer feed alone may not provide enough for heavy layers
High production strains need more calcium
Heat stress reduces feed consumption
Older hens absorb calcium less efficiently

Prevention is straightforward. Offer oyster shell freely in a separate container. Hens eat what they need. Some days they eat loads, other days they ignore it. This is normal.

Layer feed plus oyster shell covers most needs. Some keepers also offer crushed eggshells (baked and crushed to prevent egg eating).

Check shells weekly. Strong, smooth shells indicate good calcium status. Soft or thin shells mean increase oyster shell availability immediately.

Calcium deficiency is easy to fix. Just make it available.

Cartoon mother hen with chicks beside different grit sizes for chicks, growers, and adults.

Particle size matters for safe and effective digestion

What grit should I give to chicks versus adult chickens?

Chicks need smaller particles. Their tiny gizzards cannot handle adult-sized grit.

Chick grit (0-8 weeks): Fine particles about the size of coarse sand. Essential once chicks eat anything other than starter crumbs.

Grower grit (8-16 weeks): Medium particles for growing pullets.

Adult grit (16+ weeks): Standard mixed grit or flint grit for fully grown birds.

When chicks need grit:

Eating treats like grass or vegetables
Free-ranging and pecking at insects
Offered scratch or whole grains

Don't offer oyster shell to chicks. Excess calcium damages developing kidneys. Start oyster shell at point of lay (around 18-22 weeks).

Mixed-age flocks: Offer adult grit freely but keep oyster shell where chicks cannot easily access it.

Signs of inadequate grit in chicks:

Undigested food in droppings
Crop that doesn't empty overnight
Lethargy or hunched posture

Keep appropriate sizes on hand for your flock's age range. Grit is cheap insurance.

Proven Results in Backyard Runs

Soft eggs solved immediately

"Three days of oyster shell and eggshells hardened right up. Wish I'd known sooner."

Hens know what they need

"They ignore the grit station for days, then suddenly eat loads. Trust their instincts."

Essential for confined birds

"No free-ranging here. Grit station is vital. Digestion improved noticeably."

Mixed grit is so convenient

"One bag, both supplements. Hens pick what they need. Simple solution."

Your Grit & Oyster Shell Questions Answered

Yes. Chickens have no teeth and use grit in their gizzards to grind food. Without it, they cannot properly digest whole grains, seeds, or fibrous materials.

Grit (insoluble) stays in the gizzard to grind food. Oyster shell (soluble) dissolves to provide calcium for eggshell production. They serve completely different purposes.

Free-ranging birds often find natural grit sources like small stones. However, offering supplementary grit ensures adequate supply, particularly in areas with soft soil.

Laying hens need substantial calcium to produce strong eggshells daily. Layer feed contains some calcium, but oyster shell allows hens to self-regulate additional intake as needed.

No. Offer it separately so laying hens can take what they need whilst non-layers (chicks, roosters, retired hens) avoid excess calcium, which can harm kidneys.

Consumption varies. Chickens eating whole grains need more than those on pellets. Offer it freely and let birds self-regulate their intake.

Soft-shelled or shell-less eggs, thin shells that break easily, reduced laying, and in severe cases, egg binding or weak bones.

Crushed eggshells provide calcium but may encourage egg eating. Oyster shell is safer and provides calcium in optimal particle size for digestion.

Chicks eating anything other than commercial chick crumbs need grit from a few days old. Offer chick-sized grit (finer particles) initially.

Use separate feed stations or containers. Position away from main feeders. Keep dry and check weekly to top up as needed.