Egg Shell Layer Calcium

One of the main staples of our diet is eggs from the chickens on our farm. In addition to food in the form of eggs and meat, the chickens provide an odd relaxing sensation with their soft sounds of clucking and scratching. We enjoy every aspect of having them… well almost every aspect as evidenced by the sign on our front door that reads “Check Your Shoe For Chicken Poo”. Then there’s the screeching “egg song” 16 times a day and the rooster’s crowing at 0400 even on days when you don’t have to get up, the fencing needed around my flower and garden beds, and… ok, wait a minute, why do we have them again?

Anyway, even though they free-range all day, sometimes it’s necessary to supplement a couple of our girls with calcium. We have two that seem to just be prone to brittle and rough egg shells and sometimes lay what looks like a rubber egg.  People have different names for them, but they are shell-less, with only a membrane.  They look like this:

Gross, right? It’s even grosser to grab one of these out of the nesting box, not realizing it isn’t a normal one.  As far as the hens that lay the shell-less and brittle shelled eggs, I don’t know if it’s their breed or their history before they came to us or if they just don’t forage like the others, but we try to make sure they always have access to a calcium supplement because, for us, with one exception, insufficient calcium has always been the problem. Layer calcium can be purchased at the feed store but we prefer to make our own from the shells of eggs that have already been laid. It’s really an easy process with the only drawback being that you have to have an accumulated stash of used shells hanging around somewhere in your kitchen. Egg shells are comprised mostly of calcium anyway, so it makes sense to use them instead of paying for something we already had but threw away.


To make your own layer calcium, simply collect a dozen or so egg shells.  We keep a colander to put egg shells in so that they can dry out as we collect them.  I have toasted them in the oven and over the woodstove in the past to make sure they are completely dry, but I really don’t think it’s necessary and it seems like the hens prefer them un-toasted anyway.  A dozen egg shells will produce about 1/4 cup of calcium powder.

Break Them Up:

You can break them into smaller pieces any way you choose, but we put them in a gallon Ziploc bag and I let my 6 year old bash them with a wooden pestle… because what 6 year old boy doesn’t love to smash stuff!


To grind them up, you can use a mortar and pestle or you can use a seed/coffee mill.  I prefer the later, and even though that’s not “the old way”, I’m pretty sure Ma Ingle wouldn’t have turned her nose up at the chance to use one if she had the opportunity.  Grind the shells well so that you have almost a fine powder when you’re done.


Either mix the powder in with your regular chicken feed, or place it by itself in a free-choice container near their food bin.

There are many causes of shell problems with eggs (shell-less, eggs with rough surfaces, brittle or thin shelled eggs, etc.) and additional calcium may help remedy at least a few of these problems.  Even if you’re not experiencing issues, you can still offer your girls a calcium supplement in free-choice fashion and they will only partake of it if they need it.  It can’t hurt and it’s easy to make.  Some people say that you shouldn’t feed shells to hens because it will give them a “taste” for eggs and they will begin to peck their own once they lay them.  I can’t say I’ve noticed an increase in hens that peck because I’ve fed them back their own shells.  I think it’s quite the opposite.  If you have a hen that’s pecking her own eggs, it’s either because she’s prone to do this and would have developed the habit with or without being fed egg shell calcium, or that she is exhibiting signs that she NEEDS a calcium supplement.  To them, insufficient calcium affects not only the quality of the eggs they lay, but also the quality of their health, so egg pecking could be looked at as a means of self-preservation.

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