What is the difference between insoluble and soluble grit?

Insoluble grit, usually flint or granite, physically grinds food in the gizzard and does not dissolve, needing regular topping up. Soluble grit, usually crushed oyster shell, dissolves and mainly provides calcium, which matters particularly for hens actively laying eggs.

Do all chickens need grit, or just laying hens?

All chickens need insoluble grit for digestion, since none of them have teeth to grind food otherwise. Soluble grit's main benefit is the calcium it provides for eggshell production, so it matters most for hens that are actively laying.

Should grit be mixed into chicken feed?

No — grit works best offered free-choice in its own separate container rather than mixed into pellets or grain, so birds can take exactly as much as they need rather than a fixed amount with every feed.

How do I know if my chickens need more grit?

Undigested whole grain appearing in droppings, or a hen eating normally but losing condition, can both suggest inadequate grit intake. Making sure grit is freely available and checking whether things improve is a reasonable first step, but ongoing problems are worth investigating further.

Chicken grit

Chicken grit is small, hard particles that sit in a chicken's gizzard and grind up food, doing the job teeth would do in another animal. Without adequate grit, even a good-quality pellet or grain diet is not broken down and absorbed as effectively, which makes grit a genuine nutritional necessity rather than an optional extra.

The two types, and why they are different

Insoluble grit, usually flint or granite, does the actual grinding work in the gizzard and does not dissolve, needing to be topped up regularly as it wears down and passes through. Soluble grit, usually crushed oyster shell or limestone, dissolves in the digestive system and is primarily a calcium source rather than a grinding aid, particularly important for laying hens producing eggshells.

Confusing the two, or offering only one when a flock needs both, is a common mistake — insoluble grit is needed by all chickens for digestion, while soluble grit's calcium benefit matters most for actively laying birds specifically.

How much and how to offer it

Grit should be offered free-choice in its own separate container rather than mixed into feed, so birds can take as much or as little as they need rather than getting a fixed amount with every mouthful of pellets. There is no need to measure exact quantities — chickens self-regulate their grit intake when it is available.

Birds kept entirely on soft ground with no access to natural grit sources need it provided more reliably than free-ranging birds who may pick some up naturally, though even free-range birds generally benefit from a supplementary supply being available.

Signs grit might be missing

Undigested whole grain visible in droppings, or a hen that seems to be eating well but losing condition, can both point to inadequate grit intake, since digestion is not working as efficiently as it should. Adding grit and observing whether droppings normalise over the following days is a reasonable first step, though persistent problems are worth investigating further.

It is worth checking the grit container itself before assuming a flock's diet is at fault — grit left out in the open can become damp and cake together in wet weather, effectively making it unavailable even though the container still looks full. Refreshing it after heavy rain, and choosing a hopper with some kind of cover where the run is exposed, keeps it usable rather than solving the same problem repeatedly without noticing why it keeps recurring.

What we stock

Everything below is in stock with us, priced with delivery worked out, and packed and posted by hand in the UK.

Feathers & Beaky Chicken Treat

A chicken treat for the flock, fed after layers pellets rather than instead

£14.05

Browse all of Birds →

Common questions

What is the difference between insoluble and soluble grit?: Insoluble grit, usually flint or granite, physically grinds food in the gizzard and does not dissolve, needing regular topping up. Soluble grit, usually crushed oyster shell, dissolves and mainly provides calcium, which matters particularly for hens actively laying eggs.
Do all chickens need grit, or just laying hens?: All chickens need insoluble grit for digestion, since none of them have teeth to grind food otherwise. Soluble grit's main benefit is the calcium it provides for eggshell production, so it matters most for hens that are actively laying.
Should grit be mixed into chicken feed?: No — grit works best offered free-choice in its own separate container rather than mixed into pellets or grain, so birds can take exactly as much as they need rather than a fixed amount with every feed.
How do I know if my chickens need more grit?: Undigested whole grain appearing in droppings, or a hen eating normally but losing condition, can both suggest inadequate grit intake. Making sure grit is freely available and checking whether things improve is a reasonable first step, but ongoing problems are worth investigating further.

Written by Matt Garnett, who runs Giddy Pets and is a lifelong pet owner — not a vet. This is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your animal. How we write these guides.