Grit is bits of rock and small stones that a chicken will consume. These small rocks will travel down the esophagus and remain in the gizzard to aid in grinding their food. Grit is needed when chickens have access to grass and table scraps. You can purchase grit at the feed store or create your own. Grit is an important part of poultry diets, as it enables the chicken to absorb the utmost amount of nutrients.
WHAT is chicken grit?
Chickens do not have any teeth, therefore it is the job of the gizzard, along with insoluble pieces of small rocks, to breakdown and crush the food, so nutrients can be absorbed. The need for grit is amplified if birds are eating fresh greens and whole grains.
Chickens will choose to increase the amount of grit and the size of grit they eat depending on their diet. In a study posted on the National Library of Medicine, poultry eating fresh greens and grain appeared to choose grit that was larger and rougher, and consume a greater quantity1.
The main purpose of chicken grit is to aid in digestion.
The chicken digestive system begins with the beak. Chickens swallow their food whole. Food moves to the crop, which is a temporary storage container. Food can remain in the crop for up to 12 hours.
The digestive process continues to the proventriculous which softens the food with digestive enzymes.
Next is the gizzard, the muscular stomach. The gizzard contracts and grinds the food with the help of firm keratinized coilin tissue, combined with solid rock grit.
The small intestine absorbs nutrients, and waste is eliminated through the vent. Observe food moving through the chicken digestive tract in this well-done animated video.
WHY: The importance of grit for chickens
Without grit, chickens are known to consume 20% more feed to meet their nutritional needs.
It is likely that chickens also choose to ingest grit as treatment and prevention for parasites.
Grit prevents digestive issues such as gastrointestinal impactions, which is “a blockage that keeps food and liquid from passing through the chicken’s system2.” These obstructions can be deadly.
Grit is especially important for free-range chickens that have access to tall grass3.
Although insoluble grit does not directly provide mineral benefits, it indirectly increases their ability to absorb the essential minerals they need in their diet, such as calcium, phosphorous, sodium, potassium, manganese, chlorine, and sulfur4.
Forms of grit, what is grit made of?
Insoluble grit:
- granite
- pegmatite rock (quartz, feldspar, albite, haematite5)
- flint grit made of flint stones
- small pebbles
- sand- for young chickens, it is not recommended for adult chickens as the particles are too small to offer any value and will be expelled through the vent
- coarse soil
- gravel
Soluble grit:
Despite what the name entails, this is not grit. This is a supplement to prevent calcium deficiency.
Some may refer to these soluble options as supplemental grit, but they must be paired with insoluble grit. Soluble grit dissolves quickly and does not benefit grinding the food.
To ensure your feathered friends are getting adequate calcium, provide a container of free-choice calcium carbonate along with their chicken feed.
Ground-up oyster shells (and all calcium supplements) are reserve for adult birds only! Chicks and hens that are not laying do not need that much calcium. It can cause health issues such as seizures, gout of the intestines, and salt deposits building up on their innards6.
- limestone- a calcium supplement
- oyster shell supplements- a good source of calcium
- Egg shells- crush the egg shells to deter your flock from eating their fresh eggs. You can dry egg shells in the oven before hand to make them shelf stable.
*Remember, these are not effective grit substitutes! Rather, they provide extra calcium to a balanced diet. This dietary supplement is a great way to ensure your laying hens produce strong egg shells.
Commercial layer pellets will contain limestone or calcium, but this is not true grit. Store bought feed is formulated in a way that chickens don’t need grit; it softens quickly enough to be mashed by the gizzard alone.
Chickens raised solely on store bought feed will not experience dire effects if you eliminate grit.
Size of grit
You can get grit in many sizes, but the smallest three will be suitable for chickens. These sizes are often simply label by numbers. One being the smallest. Check out this document to see different size comparisons.
- #1, chick grit, used for young chickens and ducks. 1/16″- 3/16″ sized pebbles
- #2, chicken grit, used for mature chickens, ducks, and young turkeys, 3/16″, 5/16″ sized pebbles
- #3 used for mature turkeys, young ostriches
How much grit do they need?
Laying hens will consume 1/6 pound to 1/3 pound of grit per month7.
Broiler meat chickens will even benefit from grit! 10 grams of granite grit per month has increased feed efficiency and conversion rates, as it enables optimal nutrient absorption8.
Free range chickens can often scavenge and find their own sources of grit, but it is a good idea to offer free choice grit as well.
How to feed it to them
Chickens can sometimes mistaken grit for feed. You can sprinkle it on their feed for the first couple of days, and then offer in a free choice hopper or small bowl. It doesn’t need to be fancy.
WHERE to buy it:
- Local Feed Store- Tractor Supply, Peavey Mart
- Amazon
Make your own grit
Natural grit such as creek sand, gravel, or any coarse soil from your property, will be perfect for your backyard chickens. Grit is very inexpensive, but if you don’t have to pay for rocks… then don’t.
Choose gravel from a clean location- away from potential contaminates from vehicles. You can strain the largest of the rocks out to avoid them piling up in your coop area. Rinse the pebbles if you deem necessary. Allow your flock free access and keep it topped up to ensure they get enough grit.
WHO needs chicken grit and WHEN?
Baby chicks do not need grit in the first few days of their life; chick crumble will be sufficient. After a few days, you can offer your chicks fine grit or sand along with their feed, although it’s not completely necessary. For added entertainment and nutrition, you could simply pull up a dandelion and leave the soil covered roots for the young birds to peck at.
Chickens should have grit for the entirety of their life.
Fun Fact!
Other animals, such as crocodiles, ducks, and seals, have been known to consume small rocks9. No one really knows why!
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Check out these articles
- Takasaki R, Kobayashi Y. Effects of diet and gizzard muscularity on grit use in domestic chickens. PeerJ. 2020 Nov 12;8:e10277. doi: 10.7717/peerj.10277. PMID: 33240626; PMCID: PMC7666813.>National Library of Medicine ↩︎
- Gastrointestinal Obstructions> Poultry DVM ↩︎
- Huang AS, Carvallo FR, Pitesky ME, Stoute S. Gastrointestinal impactions in backyard poultry. J Vet Diagn Invest. 2019 May;31(3):368-370. doi: 10.1177/1040638719843966. Epub 2019 Apr 11. PMID: 30973086; PMCID: PMC6838716.>National Library of Medicine ↩︎
- Merck Manual Veterinary Manual>Nutritional Requirements of Poultry>Doug Korver PhD University of Alberta ↩︎
- Martín-Ramos P, Carrión-Prieto P, Sánchez-Báscones M, Ruiz-Potosme NM, Martín-Gil J. On the composition of gastroliths from broiler breeders. J Anim Physiol Anim Nutr (Berl). 2018 Feb;102(1):e504-e508. doi: 10.1111/jpn.12775. Epub 2017 Oct 6. PMID: 28983972.>National Library of Medicine ↩︎
- Merck Manual Veterinary Manual> Poisons in Poultry> Calcium and Vitamin D Poisoning in Poultry>Carmen Jerry, DVM, PhD, DACVP, DACPV, University of California, Davis ↩︎
- American Pastured Poultry Producers Association> Comprehensive Guide to Feeding Grit to Pasture-raised Chickens, Turkeys, and Poultry>By Nathan Boggs ↩︎
- Idachaba CU, Abeke FO, Olugbemi TS, Ademu LA. Influence of granite-grit on nutrient digestibility and haematological parameters of broiler chickens fed rice offal based diets. Pak J Biol Sci. 2013 Oct 1;16(19):1061-4. doi: 10.3923/pjbs.2013.1061.1064. PMID: 24502172.>National Library of Medicine ↩︎
- Gastroliths> Matt Wedel> ucmp.berkeley.edu ↩︎
Excellent guide to chicken grit. Thank you!
Very informative! Thankfully we have tons of rocks, gravel, and coarse dirt that our free range chickens have access to, and we don’t have to get anything extra.
Free range chickens are great and so resourceful !
I never thought to make my own grit. Thanks for sharing!
This is so helpful! Thank you for sharing!