Shell/calcium issues- and now, shell-less eggs

In the past week, I have had 3 eggs break in the nest. Based on shell color, they were from at least 2, if not 3, different chickens.

Separately, I have a 2.5 year old barred rock who has laid 4 soft shell eggs from the roost at night over the past month. She typically lays 2-3 times a week, so this is roughly half the time for her.

They have a high quality layer pellet (Vermont Organics layer) and free choice oyster shell. I can't tell how much oyster shell they're eating, as they seem to like to play in it-I often find it spilled out on the ground. As far as treats, they eat a little cooked corn and rice in the morning so they can have their probiotics, a few leaves of kale, and maybe an apple core. This is split between 8 chickens. They typically free range for 2 hours a day.

What would you change for them? Should I consider some kind of liquid calcium in the water? Just wait it out?

Has there been any stress...predator attack, molting, new birds, housing changes, etc?

Doesn't sound like they lack in calcium...but there are other nutrients that are needed to allow that calcium to be used efficiently by the body. Don't remember what they are offhand, but maybe posting the nutritional levels of your feed might help someone more knowledgeable figure it out.

Thanks for the suggestions aart!

In terms of stress issues:
1. There was an attempted hawk attack about two weeks ago- but everyone was uninjured, just a little freaked out for a couple of days
2. I would say a few are doing a very light molt- but no one walking around naked
3. I did wonder if maybe this was weather-related? We've had some extreme temperature swings recently. It keeps swinging back and forth from being in the 60s overnight to be in the 30s. Doesn't want to seem to settle into something consistent.

Here is the feed analysis from VT Organics:
Organic Layer Pellets

• Maximum ADF 7%
• Minimum Selenium 0.4ppm
• Minimum Vitamin A 5KIU/lb
• Minimum Crude Protein 17%
• Minimum Crude Fat 4.25%
• Maximum Crude Fiber 6%
• Minimum Calcium3.45%
• Maximum Calcium4.45%
• Minimum Phosphorus 0.6%

Ingredients: Organic Corn, Organic Soybean Meal, Organic Whole Grain Barley, Calcium Carbonate, Organic Wheat Middlings, Organic Roasted Soybeans, Organic Alfalfa Meal, Organic Flaxseed Meal, DiCalcium Phosphate, Hydrated Sodium Calcium Aluminosilicate, Brewers Dried Yeast, Choline Chloride, Organic Soybean Oil, Niacin, Vitamin E Supplement, Manganous Oxide, Zinc Oxide, Sodium Selenite, Riboflavin, Calcium D-Pantothenate, Menadione Sodium Bisulfate Complex, Ferrous Sulfate, Copper Sulfate, Vitamin B12 Supplement, Calcium Iodate, Pyridoxine HCL, Thiamine Mononitrate, Vitamin D3 Supplement, Folic Acid, Vitamin A Acetate, Salt, Sodium Bicarbonate, Methionine – 99%

Feed free choice to laying hens from 16 weeks of age, or at onset of lay, to end of production. A scratch feed may be used with this product as needed to keep litter loose. If using scratch feed, only feed as much scratch as the hens can clean up in 20-30 minutes, once per day.

Any other opinions about supplementing with additional calcium or just waiting it out?

Stress from a predator attack can effect things for weeks.

Is their housing adequate, lots of room?
Do you free range they may be eating other things that dilute the nutrition of their chow.

Are the broken eggs thin shelled(if there's any shell left to find)?

Older hens can lay funky eggs....how old are the other hens laying the broken eggs?

Are any of your hens laying good shelled eggs?

Short days are here, slows things down for adult hens and may contribute to funky eggs.

I've read that a feeding back dried crushed chicken eggs shells mixed with the oyster can offer another form of calcium and can help.

Not sure why you're giving a probiotic, if it's because of some illness/treatment that could be a factor too.
I'm hesitant to add any supplements unless there is a rock solid reason.

Upping protein, and adding animal protein, is good when they are molting.

Sorry no definite answers, just some things to think about.

aart said:

Is their housing adequate, lots of room?

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8 girls in a large coop, I forget the measurements offhand but the roosting bar could accomodate at least 4-5 more chickens if they were lined up wing-to-wing (which obviously would NOT be adequate room). They have a large screened run, which is approximately 15 x 20.

aart said:

Do you free range they may be eating other things that dilute the nutrition of their chow.

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They do- generally they have at least 2 hours a day outside- about 30 min first thing in the morning while I'm doing chores, an hour mid-day, and another 30 minutes during evening chores.

aart said:

Are the broken eggs thin shelled(if there's any shell left to find)?

Older hens can lay funky eggs....how old are the other hens laying the broken eggs?

Are any of your hens laying good shelled eggs?

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I have 6 hens who are about 1.5 years old (I got them as day old chicks in May 2013). I have two who are about 2.5 years old (I got them in January 2013 but don't know exactly how old they were as they had been rehomed by a neighbor- my assumption is that they were spring 2012 chicks).

All the broken eggs in the box have had shells, which are thin. I have never seen a shell-less egg. Based on color, I think all the broken eggs have come from the 1.5 year old hens.

The rubber eggs definitely came from the 2.5 year old Barred Rock. When she lays her normal egg, it almost always has a little pinpoint "pimple" at the tip, which I have read actually means excess calcium? The rubber eggs generally split open and have had those crinkled up shells that sort of fold in on themselves. Except once, there was one that had a normal shell but had cracked when it hit the ground under the roost- almost like the hen was caught by surprise in the middle of the night?

Aside from these hiccups, their eggs generally have good shells. Some of the 1.5 year old Wyandottes will occasionally lay oblong shells with wrinkled tips. As a group, they are very consistent layers, on an average day, I get 6 out of 8 eggs.

aart said:

Not sure why you're giving a probiotic, if it's because of some illness/treatment that could be a factor too.
I'm hesitant to add any supplements unless there is a rock solid reason.

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About a year ago, I was seeing a lot diarrhea in the flock. I took a couple to an avian vet, who did a fecal test (no excess worms noted) and a physical exam. He said there was nothing out of the ordinary that he could find, but said a probiotic might help keep everyone on track. I've given it since then and aside from really hot days, have never had any concerns with widespread diarrhea.

Thanks, aart, for helping me brainstorm! Since I posted this, nothing out of the ordinary has happened, so maybe it's just circumstantial- hawk + weather swings

I would not force feed any extra calcium.

Free choice oyster shell should be sufficient, they know when the need more.

Do a search of fermenting feed.

LOTS of information. Easy to do.

Many benefits, and could help your issues.

So the barred rock had another egg from the roost today. I let them out to free range around 5pm, and she was looking uncomfortable. She was a bit hunched up and didn't stray very far with the others. I looked her over, and couldn't see anything in th vent (though she looked like she was straining to poop). I was pretty sure she would lay from the roost. Locked them up for bed around 6:30, and went back out about an hour later I check on her-sure enough, she had already let go of the egg, it was laying on the ground. This one may have been shell-less, though it was hard to tell because it was pretty splattered in the sand on the floor. I checked her vent again and didn't see any obvious pieces of shell, but didn't do a thorough internal investigation. Looks like I need to do some more research on this condition, though I think what I find will be saddening...

Separately, no more broken eggs in the nest since I first posted

I have a barred rock with similar issues I gave her antibiotics (Clavamox) and 1/4 of a 1000mg extra strength tums for calcium and that seemed to help her

Had another shell-less egg yesterday. I opened the coop first thing in the morning, and the BR was hesitant to come off the roost. I lifted her out and she was looking uncomfortable again- hunched up and relatively still, not eating breakfast at all (which is very unusual for her- she's always hungry!!). To anthropomorphize for a minute, she really looked like a person with abdominal cramps, all hunched over. I went out to check on her at lunch, and she was back to her rambunctious self, bouncing around with the others as usual. Sure enough, there was a shell-less egg in the nest. This is a little different from the last few times, when she's only laid them off the roost at night. I'm really not sure what to do for her, but I think I'll keep track of when it happens here so I can see if there are any patterns about when it happens. One thing to note, the day before yesterday, they got a lot more free-range time than usual because my husband and I were off from work and doing a lot of outdoor chores, which allowed the chickens to be outside since we were around to watch them. Could be that she ate a lot of bugs, plants, etc., but not as much of the layer pellet and that is throwing off the balance she needs to lay properly. Will be interesting to watch and see if these things are related.