One of the most common questions asked by new chicken owners is, what's the difference between grit and shell? Do I need to feed my baby chicks grit? Do baby chicks need supplemental oyster shell?
The difference between grit and shell is that grit is just fine gravel. This has been milled such that it's the right size for your chickens to use in their gizzards. Chickens don't have teeth to chew their food - it all goes into a pouch called the gizzard. Chickens swallow small pebbles and bits of rock, which stay in the gizzard. These help grind up the food inside the gizzard, so that it can be digested farther along the road.