Grit for chicken comes in two varieties. The calcium in oystershell grit is used to fortify the egg shells, and flint grit is used for grinding down food.
You may also want to read about the best chicken feed.
The best grit for chicken
1. The insoluble grit or flint
Apparently, teeth in chickens are extremely rare, so these birds rely on a powerful muscular organ called a gizzard to help them chew and digest their food. Chicken flint grit Grit is a substance that chickens collect while foraging and store in the gizzard in order to grind their food. While this isn’t necessary if your chickens are truly free range, these days few of us have the room or the safety from predators to let them forage on their own.
You can find flint (or insoluble grit) at any decent pet or farm store for very little money; the container you put it in, however, will set you back a bit more if you want it to last.
Buy insoluble grit here.
2. Granulated oyster shells or water-soluble grit
Chickens need to get a certain amount of calcium in their diet so that their egg shells can develop properly. The majority of an egg’s shell is composed of the mineral calcium. Oystershell grit isn’t strictly necessary anymore because formulated feeds (offered as layers mash or layers pellets) contain enough calcium, but it’s cheap and simple to mix in with the flint grit that they need above, so it’s a good idea to provide some, just in case.
Since high production hybrid hens can lay a staggering number of eggs per year on a relatively small amount of feed (a term used in the commercial poultry industry: “conversion ratio”), they are more likely to require supplemental calcium in order to lay the required number of eggs of adequate quality.
If you can’t find oyster shell grit in a store near you, baked and crushed egg shells will work just as well because calcium is the main component of both. Dry them out and crisp them up in the oven for 10 minutes before adding them to your grit hopper.
Buy the best granulated oyster shells here.