If your hens give you more cracked eggs than whole ones, it's time to give them a calcium boost.
Inside the nest boxes, four brown eggs wait to be collected. Three of the four are nestled in wood shavings, the fourth looks like a wet mass; the egg’s insides are visible along with a flimsy film of shell. Laying an egg or two with a flimsy shell might occur as days get shorter in the fall and winter and young layers reach peak production. However, if you continue to see thin-shelled eggs, you need to examine the variables affecting a hen’s health.
Understand Shell Structure
An eggshell’s main ingredients are calcium carbonate, magnesium carbonate and calcium phosphate, as well as soluble and insoluble proteins. Ninety-five percent of the eggshell is calcium carbonate—the same sturdy substance that makes up coral, limestone and seashells.
It takes 2 grams of calcium carbonate for a backyard hen to form each egg. To come up with the necessary calcium each day, the hen borrows it directly from its own bones. Leg, wing and rib bones contribute the calcium without impacting its health.
An eggshell has an inner and outer membrane, a mammillary layer, a spongy layer and a cuticle layer that is finished with calcium carbonate, says Joe Regenstein, professor of food science at Cornell University.
"The porous nature of the egg allows for gas transport between the interior and exterior of the egg,” he says.
The eggshell can release carbon dioxide build-up inside while absorbing atmospheric air into the interior. At hatching, the air cell inside the egg is 15 percent of the egg’s volume, providing the first air the chick will breathe.
Regenstein explains that if the hen isn’t laying a structurally sound eggshell, its hormones, physiology and nutrition might not be working efficiently to support the egg-development process. If a hen isn’t consuming enough calcium in its for eggshell production, it may need more nutritional support.