Feeding Chickens Eggshells, Crushed Oyster Shell & Grit

Crushed Oyster Shell Chicken GritIt often comes as a surprise to new keepers of hens that their birds need to have their feed supplemented by things that appear quite inedible to us such as crushed oyster shell and grit.

Calcium Sources

Like us, chickens require calcium to form strong bones but laying hens require far more calcium for their size than us because eggshells are mainly – 97% – calcium carbonate. One of the symptoms if calcium deficiency is soft-shelled or thin-shelled eggs. Laying hens need 3 times the calcium of non-laying hens.

Many commercial feeds produced for laying hens will incorporate calcium rich mineral limestone flour to cover this need for high amounts of calcium to produce those eggs. Even so the hens, especially breeds that lay the most eggs, can need additional calcium.

Often backgarden hens kept primarily as pets will be need more calcium as their diet has more treats from their well-meaning owners than is good for them, stopping them from having enough of the formula food.

Crushed Oyster Shell

Crushed oyster shell given ad-lib will ensure the hens have enough raw materials to make the eggshells. It’s quite cheap and they don’t need much, so well worth providing a small bowl with the shell available to the hens.

Should You Feed Hens Eggshells?

A traditional and still quite a common practice is to use eggshells as a substitute for oyster shell or calcium rich mineral limestone flour.

It is important that the eggshells are roasted until dark and crisp and then crushed up or your hens may get a taste for eggs and start eating their own eggs.

Since crushed oyster shell or limestone flour is very cheap to buy, it hardly seems worth the effort and risk of using eggshells which can be used on the compost heap with less fuss processing instead.

Why You Should Feed Chickens Grit

Hens do not have teeth, hence “as rare as hen’s teeth” so they use the grit in an organ called the gizzard to crush and break up the grains and other feed they consume instead of chewing like we do.

When free-ranging they will pick up and swallow small stones for their gizzard but, like crushed oyster shell, suitable grit can be purchased very cheaply and put in a small bowl for the hens to pick at whenever they feel the need.

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