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Eggshell Variations

Chicken health, Facts & Tips

Something I often get asked about is eggshells. Why my egg shells soft? Why are they lumpy? There can be many variations of a chicken egg!


Why Do Eggshells Vary?


1. Age of the Hen

  • Older Hens: As hens age, particularly those in the final stage of their laying phase, their eggs tend to get larger while the efficiency of shell mineralisation decreases, leading to more fragile shells. As hens age, their bodies become less efficient at depositing calcium onto the eggshell, primarily due to decreased absorption and metabolic changes. It’s important to monitor the calcium sources in their diet closely, perhaps incorporating higher levels of easily absorbed calcium as they age.
  • Juvenile Hens: Young hens, or pullets, who have just begun laying, might produce eggs with thinner shells due to an immature shell-forming process. Pullets just starting to lay are still adjusting hormonally, which can result in irregular eggshells. Offering a balanced starter feed specifically formulated for laying hens can help stabilise shell quality over time.

2. Hen Welfare

  • High stress levels can adversely affect numerous metabolic processes, including those involved in eggshell formation. Low welfare standards might result in weaker shells and other problems like egg retention or blood-stained eggs.
  • Stress can come from various sources: predator threats, pecking order conflicts, or inadequate living conditions. Ensuring a peaceful, safe, and spacious environment can significantly reduce stress. Regular observations and gentle handling can also help to calm nervous birds and promote a stress-free atmosphere.

3. Nutrition

  • The quality of eggshells heavily depends on the hen’s diet, specifically the levels of amino acids and minerals like calcium. Inadequate nutrition can lead to weak, thin-shelled eggs.
  • Beyond calcium, other nutrients like phosphorus, vitamin D3, and magnesium are crucial for proper shell formation. A deficiency in any of these can lead to shell abnormalities. Supplements and a diversified diet can help meet these nutritional needs. Frequent reviews of dietary intake and adjustments based on eggshell quality observations are recommended.


Here are some of the more common egg shell variants and their meanings:


1. Bloody Eggs
More often than not, bloody eggs arise from pullets in early lay, or a hen coming back on the lay after winter. They can be more prominent in overweight hens, or from poor coop hygiene. Bloody eggs are generally not something to worry about, but you can double check their vent to make sure there is no prolapse if concerned.

Persistent bloody eggs could indicate more than just minor issues; they might suggest vascular inflammation or high blood pressure within the hen. Regular veterinary check-ups can help diagnose and manage these conditions effectively.

2. Shell-less Eggs

Sometimes, you may find an egg with no shell whatsoever. They are protected only by a squishy membrane. Almost like a stress ball! Again, this may just be from a young pullet, or hen coming back on the lay. But, if you are finding this happens more often, you may have a nutritional deficiency on your hands. I would recommend a broad nutritional supplement such as one (or more) or our products in the Natural Blend Range – Calci-protein specifically targets chooks laying soft or shelless eggs, Anitone Supplement, or Livamol. Please also make sure you have calcium either in the form of crushed egg shells , or shell grit  or calci-protein blend available at all times. We also have our calci-pack available to make this easy.

Continual occurrence of shell-less eggs could be a symptom of serious nutritional deficiencies or hormonal imbalances. It might be beneficial to consult with a poultry nutritionist to tailor a diet that supports optimal egg production.

3. Wrinkled Eggs

These look like older skin. The have thinly creased and wrinkled surfaces. This can be due to stress or overcrowding. Check there is no reason for you chooks to be stressed and make sure you have adequate space for the number of chickens you own. Each chook needs 1m2 at a bare minimum.

If the white of an egg (or the Albumen as it is correctly known) is watery, it is harder for a shell to be formed correctly around the egg, and quite simply, this can cause an egg shell to be wrinkled or to have ripples on it.
Otherwise you could have an older hen with a defective shell gland, or a bronchial disease. Infectious bronchitis would show itself in other ways also, such as coughing, sneezing and low appetite.

If environmental and health-related causes are ruled out, genetic factors could also play a role in producing wrinkled eggs. Some breeds are predisposed to certain shell abnormalities, and understanding these genetic factors can aid in breeding decisions.

4. Lumpy Eggs

This presents as small lumpy, pimply type calcifications on the eggs. 

If there is debris of any kind in the oviduct as the shell is being formed, calcium can be released to enclose that debris. 

That will result in rough patches or bumps on the shell. More common in older hens, they can also be the result of improper nutrition.

The deposits can normally be brushed off with your fingernail, although sometimes the shell will come away with them. 

An egg with rough patches or bumps is okay to eat. 

Ensuring the coop is clean and free of debris can reduce instances of lumpy eggs. Regular cleaning and maintenance of the nesting areas help prevent debris from entering the oviduct.


5. Oddly Shaped Eggs

Sometimes an egg is cracked in the shell gland pouch and then repaired before lay. Aren’t our chooks clever? This can be due to stress, overcrowding, or bird age.

Monitoring the hen’s environment for potential stressors like sudden noises or interruptions can minimise the occurrence of oddly shaped eggs. Creating a calm and routine environment can help maintain regular egg shapes.

6. White Calcium Deposits

These eggs have white, irregularly shaped spots deposited on the shell. This could be due to disturbances during calcification, a defective shell gland, or excess calcium in the diet. I recommend giving the chooks calcium in a separate dish – with a calci-pack. Chickens are actually very clever; they know just how much calcium they need and will eat it, when they need it. However if you don’t separate it, and instead add calcium to their feed then they could end up eating too much of it.

Adjusting the timing and method of calcium supplementation can help manage the occurrence of these deposits. For instance, providing calcium at the end of the day when hens are most likely to ingest it for overnight shell formation can be beneficial.

7. Thinly Shelled Eggs

Thinly shelled eggs are usually a sign of calcium deficiency. If you already have a calcium products available for your chooks, you may need to look at a full nutritional supplement as above in the ‘shell-less egg’ section. Calci-protein specifically targets chooks laying soft or shelless eggs. I would also look at reasons for stress, such as heat, cold or recent additions to your flock.

Besides dietary calcium, exposure to natural sunlight or supplementary lighting can help boost vitamin D3 levels, essential for calcium absorption and effective shell formation.

8. Lash Egg

Lash eggs may look like eggs, but they’re really a buildup of puss. These masses are caused by salpingitis, an inflammation of the chicken’s oviduct caused by an infection. If your chicken lays one of these masses, it’s a red flag. They may be suffering from a virus or bacterial infection. Lash eggs can be caused by various bacteria including E. coli, Salmonella, and more.

A lash egg is the expulsion of some of this infection material and, because it travels through the bird’s oviduct, comes out in the general shape of an egg. But it’s not an egg.

A lash egg is not necessarily a death sentence. While a chicken can die from this infection, it can also fight it off and go on to live a long life, though it may be less productive or stop producing eggs entirely.

Coliform salpingitis can be treated with antibiotics, however, when a lash egg is found, it’s often difficult to tell which chicken in a flock produced it. If you do know which hen laid the lash egg, it is recommended to get to a Vet for some antibiotics.

Many chicken owners who find lash eggs simply wait to see if the afflicted chicken can fight off the illness on their own — which is sometimes possible if the bird has a strong immune system. I recommend using a natural immunity booster such as Spice Blend.

In addition, cleaning the coop and nesting boxes, supplying the flock with fresh food and water, and reducing stress can have a positive impact on the chicken’s overall health and may help it recover.

9. Egg inside an egg

The fancy name for an egg inside an egg is counter-peristalsis contraction, but in everyday terms, they’re eggs that somehow found themselves inside another egg.

It’s not common, but it does happen. 

It occurs when a hen releases a second egg into the oviduct before the first egg has completed the laying process. This causes the first egg to reverse in the oviduct, which is then added to the second egg.

The two then have a second albumen and shell form encasing both eggs.

This rare phenomenon, while often not preventable, highlights the complexity of a hen’s reproductive system. While occasional occurrences are normal, frequent instances should be discussed with a veterinarian.


Additional Considerations:


  • Routine Health Check-ups
    Regular veterinary visits for your flock can preemptively address health issues before they manifest in egg production. This includes vaccinations, parasite control, and general health assessments, which can prevent diseases that indirectly affect eggshell quality.
  • Environmental Enrichment
    Chickens benefit from an environment that stimulates their natural behaviours, such as pecking, scratching, and foraging. Adding enrichment elements such as dust baths, perches, and varied terrain can enhance their physical and mental health, reducing stress and its negative impact on egg production.
  • Water Quality and Availability
    Ensure that chickens always have access to clean, fresh water. Water intake is crucial not only for hydration but also for maintaining the metabolic processes involved in egg production. Poor water quality or limited access can directly affect the health of your flock and the quality of their eggs.
  • Lighting
    The amount of light, especially for flocks raised indoors, significantly affects laying cycles. Providing consistent, natural light or supplementing with artificial light can help regulate and enhance egg production. The goal is typically around 14-16 hours of light per day to mimic optimal natural conditions.
  • Community Engagement
    Connecting with local poultry clubs, online forums, or agricultural extensions can provide additional support and knowledge. These communities often share insights and experiences that could be particularly beneficial in troubleshooting unusual egg issues and improving general poultry care practices.
  • Record Keeping
    Maintaining records on the health, productivity, and behavioural patterns of your chickens can help identify trends or issues early. Detailed records can aid in adjusting care practices more precisely and effectively over time.
  • Sustainability Practices
    Implementing sustainable practices such as composting chicken waste, using solar-powered coop lights, and growing feed supplements like herbs and greens on-site can contribute to the overall health of your environment and your flock.

By broadening the scope of care and management, you not only address the symptoms, like varied eggshell conditions, but also enhance the overall welfare and productivity of your chickens. This holistic approach ensures that both the chickens and their eggs are of the highest quality, reflecting a well-managed, healthy poultry environment.

Sometimes, if you have exhausted all these options, you find you just have a slight genetic anomaly in the chicken. Everyones different.

  • Learn why your chickens may have no shells are eating their own shells here *
  • Learn how to feed your eggshells back to your chickens here *

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