Soft Shelled, Misshapen Shelled, or Eggs With No Shells

“One of our three chickens has started laying eggs without a shell. They’re in the sac and rather jelly like! I thought it was just a blip, but we’re still finding them after 4 days, so would be glad to find out what’s happening. Is it likely to be dietary?

They get mash morning and evening and a few handfuls of corn in the afternoon and have access to grit and water. They also get greens such as spinach, lettuce, carrot peelings and left over veg. most days. We give them a scatter of dried mealworms as a treat. We’ve had them since April and they are all good layers, we get three eggs a day. They are moulting a little, but it hasn’t made any difference to the laying so far, unless this is the cause of the odd eggs. Any help welcomed please!” ~ Michelle Perrott

Michelle, we get questions like yours often so I’m glad you wrote.

It sounds like your chickens are getting a great diet and that you take very good care of them. I can only assume that their calcium intake is too low.

The shell is the last step in the egg’s formation, save only the protective coating called the bloom. It is made up mostly of calcium carbonate, in fact 97% of the egg’s shell is calcium carbonate.

One more quick statistic before your eyes start to glaze over and you begin to fall asleep; calcium carbonate is 40% calcium.

The point is that laying hens need a lot of calcium. In fact the shell gland must contain on average, 2.5g of elemental calcium to produce each egg shell.

This calcium is taken in through the hen’s diet.

Calcium is delivered to the shell gland via the blood stream, the intestine and from reserves stored in the medullary bone.

A side note here; we’ve talked recently about the pros and cons of allowing your hens a natural time of rest annually by not providing artificial light to lengthen their daylight hours in the fall / winter. When a hen slows down or even temporarily stops producing eggs during her annual molt, the calcium reserves have an opportunity to be replenished.

If you are going to keep your hen for only a few seasons and then send her to the stew pot, these reserves are not as important. However, a hen that does not have a reserve of calcium will have brittle bones.

So the question is, “How do I get all that calcium into my chicken?”

My preference for providing calcium is through a free choice offering of crushed oyster shell. Oyster shell is not terribly expensive and because of it‘s size, it remains in the gizzard, slowly breaking down and providing a constant supply of calcium to the blood stream.

Limestone is another choice for calcium supplementation.

If fact, in areas where limestone is prevalent, limestone is much more commonly used than any other supplement. Limestone is more quickly digested and therefore 50 to 60 % retention of calcium can be expected. This is important because you’ll need to provide more limestone to get sufficient calcium retention.

Some people prefer to supplement with egg shells. Wash the shells and let them thoroughly dry or spread them on a cookie sheet and place in an oven at a low temperature until they are very dry and brittle. Crush the shells and offer them to your flock in a separate free choice container.

My nature causes me to be a little skeptical about using egg shells because of the law of diminishing returns but I have no statistics to back that up.

Because chickens know what they are lacking dietarily, you can offer any of the above supplements in a free choice container. Your chickens will eat them as needed – isn’t that neat?

Michelle, I realize that your hens are older but for those of you who have hens that are just starting to lay, odd shelled eggs are common. It will take some time for your girls to get the hang of laying. Prior to point of lay their calcium requirements are lower. As they mature, be sure to provide a commercial feed formulated for laying hens or to provide additional calcium in their rations. Always provide a calcium supplement for strong bones, egg shells and for feather replacement.

So if you are having problems with soft shelled, misshapen shelled or no shelled eggs, your first course of action would be to provide more calcium.

Keep in mind that it may take 4 to 5 days to start seeing the results.

If soft shells or misshapen ones are a regular problem in mature hens and additional calcium has not rectified the problem, consult a veterinarian.

There are a few diseases and infections that could be present and need to be addressed. Take comfort though as there would most likely be other symptoms present if this were the case.

I hope this has been informative.