Soft, Thin or Missing Egg Shells

Soft or missing egg shells (sometimes called shell-less eggs) are quite common in older birds, especially high production hybrids / good layers, especially as they come into or out of lay for the season. A ‘soft shelled egg’ is one that has a membrane but no shell.

This short clip shows you the difference between a thin egg-shell and a soft egg without a shell, just the membrane:

Back garden chicken-keepers are often concerned when they find a soft-shelled egg so this article aims to provide information about the causes of these strange eggs.

Some causes of soft-shelled eggs

Here are some of the reasons chickens lay shell-less or thin shelled eggs. I don’t think this list covers every situation but should cover the majority of cases.

1. In good layers

Good layers are the usual candidates for soft / shell-less eggs. For example hybrid hens have been selectively bred to lay hundreds of eggs (it’s not uncommon for the commercial ‘brown hens’ we see to lay 320 or more in a year) and I believe they are just producing eggs faster than they can shell them. The normal ‘shelling process’ usually takes around 24 hours and I have had hens produce a perfect egg followed by a shell-less egg in less than 12 hours.

In pullets (female chickens under a year old), sometimes an egg stays in the shell gland for too long and is often covered in excess calcium (see calcium coated shells), then the egg that follows doesn’t spend long enough in the shell gland. Again, the two eggs are laid closely together on the same day.

Having kept hybrids alongside pure breeds for many years, I’ve seen far more instances of shell-less eggs with the hybrids. Maybe we’ve pushed mother nature to the limit in our quest for more eggs?

2. Hot days

Thin egg shells or shell-less eggs can occur more frequently on hot days. This is associated with a lower food intake and shell thickness / shell will return to normal when the temperature drops again and your chicken’s food intake returns to normal. There have been some mentions of this in commercial farming where they see lower intakes of food on hot days and lower shell quality.

3. Insufficient shell-forming material

Oystershell-GritThis is the most obvious, but I have only listed it as number 3 because most of us these days are feeding our birds with a modern balanced feed and our hens have some access to free range and grit. Poor shells however can occur if hens aren’t supplied with sufficient shell forming material (mainly calcium). Chickens get calcium from soluble grit often called Oyster shell grit (shown right) and this should be supplied either on its own or as ‘mixed grit’ which includes flint grit for digestion too.

Another big source of calcium in a hens diet comes from their food. If you look at the ingredients on the back of layers pellets, you will see there is far more calcium than other feeds such as growers pellets. Fresh greens also provide hens with a source of calcium.

4. Old age

Some birds can lay more soft egg shells as they age. Again, this is particularly true of hybrid breeds that have been optimised to give as many eggs as possible during their first year such as the Bovan Goldline often found on commercial farms. Once these birds reach 4 or 5 years old, you may find they start to lay eggs with soft shells. If you are keeping ex-batts then our section of Rehoming Ex-Battery Hens has a number of articles, specifically for ex-battery hens and their needs.

5. Insufficient protein in the diet

Chickens need the correct level of protein in their diet as well as minerals and various other vitamins. Vitamin D3 (Cholecalciferol) for example is used for the metabolism of calcium and phosphorus so that they are able to form egg shells as well as strong bones. Vitamin D is found in Cod Liver Oil but they shouldn’t normally need this if they are fed the correct formulated layers feed, are free range and have sunshine on their backs.

6. Overweight hens

Chickens that are over weight can stop producing eggs altogether or produce lower quality eggs, sometimes with missing shells. Take a look at the breast of your birds, when the feathers are parted, you should see the skin is thin (almost like tracing paper) where the breast bone protrudes forward. If there is a thick skin, or you can’t see the breast bone clearly, the chances are your birds are carrying too much fat.

Caution: Mixed Corn and kitchen scraps
Mixed corn or ‘scratch’ as it’s sometimes called is made up mainly of wheat with a little cracked maize (yellow in colour). Wheat typically contains 10% protein which isn’t a sufficient amount for a laying hen. Maize is very fattening and hens carrying fat internally are more prone to laying problems such as prolapse and lay more shell-less eggs.

Keep corn as a treat only. A handful per day per bird is sufficient.

You can check to see that you are feeding your chickens correctly on this page: Feeding Chickens. I only give my hens an extra handful of mixed corn on cold winter days – they can use the extra fat to keep warm.

Feeding household / kitchen scraps is technically no longer allowed by DEFRA but if you feed ‘allotment scraps’ (where scraps have not gone into the house / kitchen), they can be a bit of a mixed bag of what a hen needs in her diet. Whilst this is a way to save on feed costs, as a general rule, scraps shouldn’t exceed 25% of a hen’s diet. Allotment scraps should ideally be boiled and then mixed with layers mash to make a crumbly mixture so the hen is getting  a more balanced diet from the layers feed but since you’re not allowed to even pass through the kitchen with these scraps, it makes boiling them tricky!

The best way to ensure a hen is getting the correct diet is to use a balanced layers feed and then supplement this with greens and some free range for a hen to top up with other things she needs during the peak months of egg production.

If hens can be allowed to free range on grass or rough ground then this is much better than any vitamin drink or supplement. They will be able to pick up a lot of the extra grit, vitamins and minerals they need and be a lot less prone to health problems as well as soft-shelled eggs.

Soft Shell Less Egg

A soft, shell-less egg, laid by one of my hybrid hens.

Other reasons for soft-shelled eggs

If the above doesn’t seem to be the cause in your case or soft-shelled eggs are being laid regularly, then there could be a number of other reasons:

  • Inflamation of the oviduct (and there isn’t anything that can be done about this as far as I know).
  • Calcium absorption problems (if the diet is correct and oyster shell grit is provided ad-lib then there is sufficient calcium available but it cannot be absorbed correctly by the hen).
  • Stress. The problem usually goes away once the cause of stress is removed. Keep an eye out for bullying / feather picking, especially if it is occurring around the nest boxes and you are finding the soft-shelled eggs outside of the nest boxes. Apple Cider Vinegar is good to help hens with stress.

Soft shelled eggs laid once in a while are nothing to worry about. Hens that are at the start of their laying period, or have come to the end of it, often lay a soft-shelled egg.

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Tim Daniels

Tim is the founder of the poultrykeeper website and lives in Herefordshire, UK. He keeps Cream Legbar chickens, Silver Sebright bantams and hybrid layers for eggs, Abacot Ranger ducks, Brecon Buff geese and some quail.
  • Louise

    Thanks Tim this is really helpful. One of my girls laid an egg two days ago that looked really hard and white plus a soft egg same day and it could be the first was over calcified. Yesterday she sat all day and didn’t lay so I’m worried about her, but I think she overproduced the day before. I’m waiting this morning to see an egg, but I am reassured by your helpful article, thanks.

  • Shelby Goatz

    I have a new layer that is laying eggs that has absolutely no shell-not even the soft shell. Should i worry, or keep an eye on her for a bit first?

    • I wouldn’t worry if it’s an egg or two, keep an eye on her.

      If it continues, then there could be a problem.

      • Shelby Goatz

        Thanks! I wouldn’t have even known if i hadn’t actually seen her “lay” this oddity yesterday.

  • I would give them a bit of time. When they are coming into lay, or finishing a laying cycle, it’s not unusual to get a few soft eggs.

    This can be especially true if they have been taken off layers pellets and put onto layers before they are fully mature.

    There’s more information on point of lay and feeding in this post:

  • One thought – It’s common for hybrids (especially Goldline like they use commercially) to get thin / brittle shells around this age. Sadly, commercially, they are spent hens. You don’t say what sort of hen she is but this would explain the poor quality shells at this age if she is a hybrid layer.

    With the moulting, it’s most likely that she is over preening herself or the others are taking the feathers. This can be a bad habit, or it can be because of lice / mites or other irritation.

    The moult can take a couple of months but they lose feathers and they regrow again. With feather picking, they will usually eat small feathers around the chest area – they are high in protein and were even used in cheaper feeds before animal products were banned after the BSE outbreak.

    It could be something more serious but I’d start off considering the basic things, I’ve even seen hens with a mysterious bald patch that were simply leaving through a rough piece of fence to get to some tasty greens and catching their feathers on the fence, wearing them down.

  • ISA Browns are basically a hen developed for commercial egg production. At 2.5 years old can start to have poor quality shells and egg whites. They are genetically selected to produce a lot of eggs in the first year and a half and after that, it doesn’t matter commercially, they would normally be replaced.

    With the bare chested hen, I would wait to see if the feathers are replaced when they moult this winter. There is something happening – and I still suspect it could be her or her flock doing this. You probably won’t see her doing it, it could be for example when she’s roosting close to the others.

    When I’ve seen it happen, they can be seemingly preening quite innocently and then eating the odd feather that drops out. They pick up the bad habit and the next thing they casually pluck a feather out and eat it.

    The way to really break the habit would be to use some ‘bumper bits’ from Omlet:

    First let me say, these shouldn’t be used when hens are bored in a run and are feather picking – you need to fix the boredom problem before fixing the bad habit. But in this case, to break the habit of the hen that’s doing the feather pecking, you could use them.

    Basically they clip onto the beak and stop it closing all the way. A hen can still eat and drink but they can’t pull feathers out….

  • It’s good she’s laying and not having difficulty passing the eggs. Prolapse is horrible and rarely puts itself right.

    I would ensure there is grit and she gets a good diet and see if things settle down after a while.

    Soft eggs are relatively common – especially at the beginning and end of an egg laying cycle and at this time of year, she could easily be ready to stop laying and start to moult.

  • So long as she’s passing the eggs and there’s nothing trapped or broken inside, then as far as I know, you can only monitor her to see if the problem continues at this stage.

    It could be as simple as her coming to the end of a laying cycle and she will stop laying for the winter, then start again as normal in the spring.

    If she gets any worse, then I would consider taking her to the vet (they may do an X-Ray) so that they can see if there’s something going on inside.

  • Raebirth

    Thank you for this very informative article. I have been searching for answers regarding soft shelled eggs from one of my six hens… specifically over three eggs in one night, all pecked clean and removed from the nesting boxes when I let them out this morning. There were five normal eggs so I believe it’s just one hen that’s having a little meltdown in her egg factory. One egg yesterday was porous and pale (they’re all red sex-link hybrids), but the shell was still hard, if brittle. They are fed layer pellets and have free access to shell, grit, and about 300 sq. ft. of rotating pasture.

    I have a sneaking suspicion that it’s a stress response to something. I usually shutter them up super tight at night but it’s been unusually hot and humid so I left the louvers on the coop open (the coop is inside a reinforced run, as predator proof as I can possibly make it.

    What concerns me is the sheer volume of soft eggs in such a short amount of time. Three in one night seems very excessive from one hen, and I’ve not found others with the same issue of quantity that I’ve having. I’ll keep an eye out for changes, but if this hyper production of duds continues, should I start a quarantine to figure out who it is, and schedule a vet visit? I’m worried for my girls.

  • Hens will supplement their diet when free ranging. I assume you see them foraging throughout the day doing this? They instinctively know what they need and if they can get it naturally then they will 🙂

  • Nicky Langlands

    are soft shelled eggs safe to eat ?…my wife is afraid of bacteria in the eggs…we are new to keeping chickens and our birds have just started laying …. the first few eggs were good but most are soft shelled now

    • I would eat mine – providing they are fresh and intact and there’s no soiling in the nest box.

  • They normally lay more of these ‘rubber eggs’ as they get older but also towards the end of the laying cycle. I’ve not heard of an increase when hens get sick. Normally they stop laying when ill.

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