Ask the Expert — April/May 2018

Ask the Expert — April/May 2018

Wrinkled Eggs

I’ve attached a picture of two eggs that I gathered, two days in a row with very large ridges in them. What makes them do this? They were very rough and I imagine painful coming out. Three or four days before I got these I got one each day that was a little like them, it got worse each day until these two came. Is there a lack of something? Too much of something? Please advise.

— Bonnie Hutchins, Oklahoma


Hi Bonnie,

Eggs like this are most likely because of a viral disease – infectious bronchitis. Bronchitis usually causes some respiratory symptoms, but it also affects the oviduct. Albumen quality is also often affected, causing watery whites in the eggs. Hens will likely recover from the respiratory problems fairly quickly. Egg quality may take up to two months to fully recover.

This virus generally only affects chickens, though it is thought that other birds might carry it. It is spread by respiratory secretions and feces and can be carried on clothing and equipment, or contaminated feed or water. Infected birds can shed virus for up to 20 weeks, though the first week or so after infection is the worst.

If this is the cause, there isn’t really anything you can do for the hens, other than to keep them warm and well-fed to prevent other secondary infections. There are vaccines available for commercial use, but they generally aren’t available for small flocks. These are usually given to day-old chicks. They would not be useful for the hens that were already exposed.

Of course, this is not a firm diagnosis. You would need to contact an avian veterinarian or your state veterinary diagnostic lab for a diagnosis.


Extra Shell Membrane

I found this while gathering eggs. My chickens have just started laying again after molting and the eggs are so large I cannot close the egg carton! This find is the size of half of one of these eggs.

I enjoy Backyard Poultry very much, especially Poultry Talk. I have been reading Backyard Poultry since before I had chickens!

— Alice Claxton, Georgia


Hi Alice,

This appears to be an extra shell membrane over a previously formed egg. It was probably an egg that was nearly complete in the shell gland, and then reversed direction and was pushed back up into the isthmus of the oviduct. The membranes are formed in the isthmus, so when this egg arrived there, a new membrane formed over it. It must have passed back through the shell gland fairly quickly, or another shell would have been added.

Of course, the bigger question is why this might have happened, and that isn’t explained so easily! There are muscular contractions that force the egg through the oviduct, and these contractions must have reversed direction for some reason. There could have been some temporary blockage, or possibly a physical trauma to the hen. It’s really difficult to know what might have happened.

As long as this doesn’t continue to happen, you shouldn’t worry too much. If it continues, you might want to think about having the hen checked (if you can tell which hen is laying them!).

About the very large eggs you mentioned…

Very large eggs can be due to the hen’s age. Older hens tend to lay larger eggs. Genetics certainly plays a part, too. Diet can also affect egg size. High levels of energy (calories), and/or high levels of the amino acid methionine, can both increase egg size a bit. Very large eggs can be difficult for the hen, and also often have thinner shells. Fitting them in a carton can also be difficult, so breakage can be greatly increased. They probably aren’t very feed-efficient either.

If these are concerns, you might check their diet and consider whether they may be getting too much feed. Most laying hens will eat about four ounces of feed each day, though heavier breeds will need slightly more. Once the hens are in production, protein levels around 15 to 17 percent are usually good.


Blue Green Guts

I recently gutted out a chicken that had a small amount of blue/green stuff on the outside of its intestines in one area. What might it be?

— Martin Baker

Hi Martin,
The best guess is that this was because of bile, from the gallbladder. The gallbladder is a sac tucked under the liver, and it stores bile. When the chicken eats, bile is then released into the intestine where it helps emulsify fats for better digestion. Especially if the chicken has had feed withheld (which is usually done for cleaner processing), the gallbladder can become fairly full. The bile is a brilliant green color and will stain tissues if it gets spilled on them. It can also produce a bitter taste if it gets on meat.

If it wasn’t bile, then it’s hard to know. There could have been some sort of infection. Some diseases can cause green diarrhea, but this should have been confined inside the intestines.

Hope this helps!


Strange Egg

Over the years, my hens have left some odd shaped or strange looking eggs in their boxes. This egg, apparently from one of the Ameraucanas, has got to be the strangest! It is heavy as a rock and has a chalky appearance. Perhaps the experts know the cause?

Strange Egg

This group of hens is three years old. They are on 18 percent layer pellet, scratch feed, oyster shell, and they free range. I also have peafowl, so the chickens clean up what the peafowl drop (they have high feeders near roosts). Anything they pick up would be higher protein as well as a premium grain mix.

— Debby Ullrich


Hi Debby,

Very interesting!   

It’s possible that this is a mass of egg yolks and shell material from eggs that weren’t passed out of the oviduct, for some reason. If these built up in the abdomen, or in the shell gland itself, it might turn out like this. It would be interesting to cut through it and see what the inside looks like. There may be layers of dried yolk, membrane, and shell. 

It’s hard to explain why this might have happened if indeed this is what happened. There might have been an infection or damage to the oviduct that interfered with proper muscular movement, or there might have been some blockage. Whatever it was, it may have cleared up, or the lump got big enough that it passed anyway.

Hope this helps!


Double Yolk Eggs

I have 10 Asian Blue chickens who started laying last week. When my other chickens started laying, the eggs started out small and got bigger as the chickens got more mature. These eggs are huge! I was really surprised. Also, every egg I have broken open are double yolks. My question is, will the chickens have a shorter laying life because they lay double? I was reading in my book that a chicken has in them every yolk they will ever lay. I cherish every time I get my Backyard Poultry magazine and look forward to your advice. Thank you!

— Linda Caldwell


Hi Linda,

Double yolk eggs are fun to get, and in some places, are considered quite a treat. It’s not at all unusual that you are getting double yolks from your new layers. As hens mature and enter their laying cycle, they often don’t have their cycle in sync. They may accidentally release two, or even three developed yolks at once. These go through the egg formation process at the same time and are encased in one shell. As your chickens get older, their cycles will even out, and you’ll probably not notice as many double yolk eggs.

You are correct, your hens are formed with all the undeveloped yolks they will ever have. These represent the maximum number of eggs your hen can lay throughout her lifetime. However, chickens are formed with thousands of undeveloped yolks. Simple math would say that if a hen is born with 4,000 undeveloped eggs and she lays 250 eggs a year, it would take her 16 years to use up all her eggs. Hens usually don’t run out of undeveloped yolks as they don’t keep up such robust production throughout their lives.

So, no worries about eventually running out of eggs. Even with some double yolk eggs and other oddities mixed in the bunch, your hens should be producing well into the future.

For now, enjoy your tasty double yolk treats. Yum!


If you have health-related poultry questions, use the chat feature, email, or send them to us at Backyard Poultry, Attn: Ask the Expert, P.O. Box 566, Medford, WI 54451. All submissions will be considered for print publication. Please include your name and hometown with your questions, which should be as detailed as possible. Pictures help us answer questions, so please include those too!

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