oluble Versus Insoluble Grit
There are two different types of grit sold in the feed store and it's important to buy the right type. In this article we've been discussing the insoluble type (not digested and of no nutritional value). Insoluble grit is composed of small stones, generally granite.
The other type of grit is soluble (digestible) and is often made of flaked oyster shells. Soluble grit is a calcium supplement and helps your chicken's build strong egg shells. It dissolves during digestion and will not work to break up larger food particles. If your chicken's have a diet that requires grit, the soluble kind isn't the right type to use to assist digestion.