Who Knew? Chickens Need Two Kinds of Stone

by Peppy Hen Products | July 9, 2025

Think of calcium like Alice in Wonderland – chickens need just enough calcium, not too much and not too little. Most laying hens don’t get enough calcium from their feed alone–and that’s on purpose because over-feeding calcium is detrimental. But insufficient calcium puts a big demand on a hen’s system, especially if she’s laying regularly, and can lead to soft, small eggs, weak bones, and poor health. The good news is that adding extra calcium (free choice) to your hen’s diet is super easy.

Why Calcium Matters

With eggshells containing around two grams of calcium, laying hens need 4 to 5 grams of dietary calcium per day. Low blood calcium at night means calcium is borrowed from their bones. Slow-release calcium works best. If you’re starting from scratch, growing pullets require almost three grams a day. All told this ranges from 1.5 to four pounds each year. POULTRY NOTE: Broilers and turkeys have similar requirements.

Oyster Shell and Coral Calcium

Offering hens a free-choice calcium supplement is simple and effective. Don’t blend it with feed. If provided calcium through free choice, chickens will only take whatever amount of extra calcium they need. Oyster shells and coral are a popular choice, but hens can be picky, and many will refuse this option. Plus, the depletion of limited marine resources isn’t the best choice. If returned to the ocean, oyster shells restore reefs, breakwaters, and estuaries.

Peppy-Shell™ Travertine Calcium from Utah

Here’s where the choice gets easy. In central Utah is a large deposit of travertine from ancient hot springs (the very same kind of stone used to make travertine tile, pavers, and dimension stone). Turns out that this travertine is outstanding as a calcium source for chickens – they love it! Like oyster shells, it’s high in aragonite minerals that release slowly during digestion, plus it’s coarse. This ensures that your hens have high blood calcium at night when they need it most. Just offer Peppy-Shell™ free choice in a separate feeder. It’s that simple. You’ll be amazed what a big difference just a few pounds of extra calcium per year will make! And best yet, you won’t be depleting ocean resources.

Chickens Don’t Have Teeth

Most chicken owners don’t appreciate the importance of insoluble gritstone and gizzard development (exercise!). Chickens “chew” their feed in their gizzards. Unlike calcium, insoluble grit is not absorbed. If it’s large enough, gritstone gets stuck in the gizzard where it works like teeth. Grit-fed poultry gizzards are as much as 50% larger! Poultry science calls the gizzard the “central modulator” of poultry digestion. Did you know that food only stays in the gizzard for 30 to 60 minutes? Gritstone dramatically slows down the entire digestive process. The longer the better. Proper grit and gizzard development typically results in significant production increases (20% or more on the same feed).

Size Matters

Most gritstone sold in feed stores is too small to do much good. Gritstone has to be larger than the gizzard outlet, otherwise it passes through the body and is wasted. For layers, gritstone needs to be around 5mm in size but the best size can vary over time and breed. Chickens are smart. If provided a variety of sizes free-choice, they’ll take exactly what they need.

Chicken Chompers™ Insoluble Gritstone

A great pairing with Peppy-Shell™ is Chicken Chompers™ Insoluble Gritstone. Chickens love it! It may look large compared to other brands but you can trust the poultry science behind it. Chickens will eat the correct size and amount they need. Just make it available free-choice in a separate feeder (do not mix with feed or calcium).

Stone For Chickens: Final Thoughts

Providing calcium for chickens is a must to raise happy, healthy and efficient layers. The question is, how do you want to provide that calcium? Pairing a slow-release option like Peppy-Shell™ with an insoluble gritstone like Chicken Chompers™ provides laying hens with the tools they need to stay healthy and provide lots of strong-shelled and yummy backyard eggs. Who knew two different kinds of stone could make such a difference in your flock’s health and productivity? Try it and see for yourself.