Listen Lissa: My hen lays funny-looking eggs! September 6, 2013

A Listen Lissa reader writes in with a question about her hens’ funny-looking eggs:

I have a question about some funny-looking eggs. My chickens are a year old now, and have been laying for about seven months. Recently, I’ve noticed that two have had extra shell build-up on the outside of their eggs, sort of spotty. Should I be concerned?

Do  your “funny-looking eggs” look something like this one?

Funny-looking eggs with calcium build-up

The brown egg with the calcium deposits on the right side of this photo was laid by a Rhode Island Red hen

If they do, the short answer is this: there’s probably no reason to worry.

Younger hens and older hens sometimes have egg or shell irregularities that are really nothing to worry about. Funny-looking eggs sometimes happen. Young hens may take some time to get into the groove of laying, while older hens may have some issues when age means everything doesn’t run as smoothly.

That said, your hens are a year old, which is young, but really not so young that their systems haven’t worked out the kinks. They’re not old either. That means it would be a little more unusual for you to see funny-looking eggs from your flock regularly. (Occasional egg shell issues can occur because of stress, for example if a loud thunderstorm or a predator disturbed your hens.)

If it’s a regular occurrence though, take a look at their diet. We always recommend feeding a layer feed to hens (of course!), and offering oyster shell (as a calcium supplement) free choice. I’ve noticed that I see more calcium pimples on my eggs when I’ve replenished the oyster shell; my girls often seem to over-do it with the freshly-filled bowl! If you’ve just refilled your oyster shell, perhaps that’s what you’re seeing.

Another possibility is that some people choose to mix their oyster shell in with their feed. Is that something you do? If so, it isn’t the worst idea in the world, but it does mean your girls may accidentally get more calcium than they need. When they don’t need it, they will have to eat around it and actively avoid it. Excess can be excreted in the deposits and pimples on the shell. Remember, the oyster shell is meant to be a supplement, used by the girls just in case they need it. If you are mixing oyster shell into their feed, stop that for a while—offer it in a separate dish—and see if the problem doesn’t disappear.

It’s possible, too, to see more pimples or deposits when sunlight begins to wane and laying slows down. One of my girls has eggs with calcium pimples only between equinoxes (between September and March) because she lays fewer eggs then, but doesn’t change her diet significantly. In other words, she’s getting the same amount of calcium, but using it to produce fewer eggs.

You may see funny-looking eggs, too, if your hens have run out of water. As you can imagine, that’s bad for a number of reasons, but even being without water for a short time can temporarily stall an egg in your hens’ reproductive tract. If it gets stalled in the shell gland, extra calcium can be distributed on the shell.

Calcium metabolism in chickens is also affected by other nutrients like vitamin D and phosphorus. If you’re feeding a lot of treats—especially when you’re feeding oily treats like seeds—it’s possible for their nutrition can get a little out-of-whack. Cut down on treats to make sure they’re getting a proper nutritional balance. That may work. For instance, too much vitamin D can cause your hens to absorb too much calcium from their diet, which can then be deposited on egg shells, or even cause kidney or bone problems. This is why you should always offer treats in moderation.

Lastly, you may just have a hen whose shell gland doesn’t work perfectly. In other words, she may just be a hen who lays funny-looking eggs. That’s okay, too. Unless your girls showing other signs of illness (lethargy, a lack of appetite, changes in droppings, respiratory issues, etc.), it’s probably not a big deal. If you do notice something that makes you think they’re ill, contact a vet to get a firm diagnosis and treatment options.

Listen Lissa

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Do our readers have any additional advice? Please share in the comments!


George Castonguay September 6th, 2013

My feathery ones are about a year and a half old now and they will still lay loooong eggs on occasion and calcium pimples and warts occurs on the shell as well. I still eat them and have found no oddities inside. They get laying food and have extra oyster shell in a separate container if they feel the need. I’ll still even get a soft shell egg on occasion. Hens are interesting critters.

debbie September 8th, 2013

i have a rooster with my hens can i still eat the eggs

Lissa September 9th, 2013

Yes, of course. You can find the answer to most frequently asked questions like that in our Chicken Help pages.

Stevee Salazar September 10th, 2013

Are lettuce and fresh fruits considered treats??
My girls also have calcium deposits on thier eggs sometimes… honestly I tried offering them oyster shell seperate and no body touched it! So I didn’t want to waste it (I bought the big bag because I have a large flock) I mixed it into their Layer mix figuring that would help… this is the first time I’ve ever heard not to, whoops. I also bought a big bag of B.O.S.S. and mixed it in, because most are moulting right now and read about giving them a little extra protein. So I mixed in the black oil sunflower seeds. I wonder if it’s the veggies and fruit contributing to their bumby eggs as well? The calcium deposits are not anything new & the eggs still taste delicious!!
In the feed store they sell something called a “complete” layer mix with mostly layer pellets, some cracked corn and oyster shell mixed in… is that a good option?

Lissa September 13th, 2013

Yes, anything other than their nutritionally balanced feed is a treat. The idea of offering calcium supplements (like oyster shell) separately–in other words, offering it free choice–IS exactly that: it’s a choice. They don’t have to touch it when they don’t need it. Remember, oyster shell doesn’t go bad or get stale like feed does, so if you have a big bag, you can just use it as needed and it may last many years if your birds don’t need it. Any commercial layer mix should be fine. You may find your flock does better on one brand than another, or that they prefer one to another, and that’s okay. There can differences in the amount of protein, etc., but any commercial layer mix should be properly nutritionally balanced.

Debbie January 4th, 2015

i have hens with frothy diarrhea. I have 12 hens in a 10×10 fenced area with a 6×10 coop. Vinegar in water, diatomaceous earth sprinkled in dirt. Oyster shell crushed, use commercial pelleted feed supplemented with greens and bread, leftovers in moderation. One hen died. Help! What can I do and what is causing this?

Lissa January 4th, 2015

Frothy diarrhea can indicate a number of conditions, from coccidiosis and worms to worse, depending on other symptoms. Please have your chickens evaluated by a vet who can give you a firm diagnosis and treatment options.

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