Mineral grit serves as a time-release source of minerals, most notably calcium carbonate (which laying hens need to produce strong eggshells), and therefore is commonly called Calcium grit
Grit refers to a finely ground, hard substance that is given to chickens. There are two types of poultry grit: oyster shell grit and flint grit. Oyster shell grit is a type of calcium that helps make eggshells stronger. Insoluble grit, also known as flint grit, helps chickens with digestion.