Some hard shells, some weak - why?

[MIChickandGuinea]

I have 9 laying hens, all a year old this spring. They are mixed breeds - some easter-eggers, some ISA Browns, some black Marans, one white leghorn, and one light brahma. They all live together in a large, properly sheltered/ventilated coop, have plentiful outdoor covered run space, and get several hours of free range time (on a farm with many acres of fields and forests to explore). They are all fed 16% layer feed from TSC along with supplemental oyster shell left for them to consume if they wish. All appear healthy and active, and all are laying almost daily (we get 7-8 eggs daily, occasionally all 9). So why is there so much variability in the hardness of egg shells?

For example, our light brahma lays very distinctive pink eggs - she's the only one who lays her particular size/shape/color of eggs, so we always know which eggs are hers. Lately, some of her eggs are very weak-shelled, and those eggs are also speckled with white spots on the pink shell, and have a kind of chalky surface texture (much like the first few eggs from each pullet when they were just starting to lay for the first time). Other days, her shells are hard and solid pink and have the normal smooth, slightly shiny surface texture. The insides of the eggs still look normal - bright orangey-yellow yolk, clear, healthy-looking whites.

The easter-eggers and leghorn are much more consistent - their shells are almost always really hard and strong.

And the other ladies - we see occasional weak shells from the ISAs and Marans, but not as frequently as the brahma.

So ... what's the deal? Do we have a feed problem? Health problem?

 

[IamRainey]

My Plymouth Rock lays fragile, brittle eggs too despite the availability of crushed oyster shell and cleaned crushed egg shell . I'll be following your thread.

 

[ChickenCanoe]

Nutrition is very complicated with birds that are prolific layers and by extension, must build egg shells almost daily.
I really wouldn't do anything different just yet nutritionally unless you are feeding scratch/treats. If you are, I would stop that till things improve.
One thing you can try is to add an acidifier to the water or feed. It can help hens assimilate calcium. Perhaps 2 tablespoons of ACV in a gallon of water.
There must be a delicate balance of calcium, phosphorus and D3 in the diet.

Here's a list of possible causes I found on a Canadian government website.
The most common causes of weak shells eggs in your flock are:

• Old Hens – Shell strength declines steadily as hens get older. If you buy old hens from a commercial farm, they are already well past their prime for shell quality.
• Calcium Deficiency – To supply the calcium needed to make good shells, 10% of the feed must be supplied as limestone or oyster shell. For birds in floor pens, a hanging feeder of limestone or oyster shell can be used as the calcium source. When a layer diet is used as the sole source of calcium, restricted feed consumption due to crowding and other problems can also restrict calcium intake.
• Poor Calcium Sources – Insoluble granite grit and egg shells are poor sources.
• Excess Phosphorous – Too much phosphorous in the diet will decrease shell thickness. If you make your own feed, carefully weigh out the amount of mineral phosphorous.
• Early Production – Hens that begin egg production before you get them on a good layer diet can rapidly deplete their bone reserves of calcium.
• High Temperature – Temperature over 32°C stresses the hens and reduces shell strength.
• Vitamin D3 Deficiency – Hens need a commercial source of vitamin D3 in the feed. Deficiency is most visible in the winter months when the birds get less sunlight and make less vitamin D3 on their own.
• Infectious Bronchitis – This virus readily attacks the shell gland of unvaccinated birds.
• Excitable Hens – Hens that are excited may produce thin or poorly constructed shells.

 

[azygous]

Since your hens are just a year old and have only been laying for a few months, there really isn't anything to be concerned about at this time.

If your Brahma gets to the point of laying consistently thin shelled eggs or even shell-less eggs, then you can step in with a calcium citrate +D3 400mg supplement. Give one tablet a day until the eggs are hard again and just beginning to bear tiny calcium "pimples", then discontinue.

 

[LLO]

Since your hens are just a year old and have only been laying for a few months, there really isn't anything to be concerned about at this time.

If your Brahma gets to the point of laying consistently thin shelled eggs or even shell-less eggs, then you can step in with a calcium citrate +D3 400mg supplement. Give one tablet a day until the eggs are hard again and just beginning to bear tiny calcium "pimples", then discontinue.

I am going to try this - thank you! I have 9 layers of various breeds. One of two 14 month old barred rocks has been consistently laying only weak-shelled or shell-less eggs for many months. We have separated her now from the others because they have been finding her broken eggs that drop out of her on the roost and anywhere else. It is such a mess! We are at our wit's end. We will try this and see if it makes any difference. How long do you think it might take to see a difference (if this is the issue)?

 

[azygous]

It's strictly an individual thing. I've had shell quality improve with just one or two days on the calcium citrate. The worst case was a hen laying two eggs per cycle with very thin shells. She finally responded after nearly three weeks on the citrate. Since then, she's stuck to one egg per cycle with only sporadic instances of thin shells. Usually one or two days on calcium tablets will correct it.

 

[VirginiaFarmerGirl]

I have 9 laying hens, all a year old this spring. They are mixed breeds - some easter-eggers, some ISA Browns, some black Marans, one white leghorn, and one light brahma. They all live together in a large, properly sheltered/ventilated coop, have plentiful outdoor covered run space, and get several hours of free range time (on a farm with many acres of fields and forests to explore). They are all fed 16% layer feed from TSC along with supplemental oyster shell left for them to consume if they wish. All appear healthy and active, and all are laying almost daily (we get 7-8 eggs daily, occasionally all 9). So why is there so much variability in the hardness of egg shells?

For example, our light brahma lays very distinctive pink eggs - she's the only one who lays her particular size/shape/color of eggs, so we always know which eggs are hers. Lately, some of her eggs are very weak-shelled, and those eggs are also speckled with white spots on the pink shell, and have a kind of chalky surface texture (much like the first few eggs from each pullet when they were just starting to lay for the first time). Other days, her shells are hard and solid pink and have the normal smooth, slightly shiny surface texture. The insides of the eggs still look normal - bright orangey-yellow yolk, clear, healthy-looking whites.

The easter-eggers and leghorn are much more consistent - their shells are almost always really hard and strong.

And the other ladies - we see occasional weak shells from the ISAs and Marans, but not as frequently as the brahma.

So ... what's the deal? Do we have a feed problem? Health problem?

They may have a calcium deficiency. I had my hens laying eggs without shells and really weak shells. I did some reading and almost everyone said calcium deficiency. What I now do everyday has fixed the problem for me I take their egg shells and bake them till they are dry then I smash or grind them up and mix them in with the feed or some times I just give then the egg shells without baking or grinding them. And now when we throw eggs off our deck they bounce