I have a huge problem with soft shells in my laying chickens. My ducks have bulletproof, hard and thick shells. They eat the same feed, a layer pellet. Though a friend once told me she loves the thin chicken shells because they are so easy to crack, I do not love them because they are fragile and they don’t last very long in the fridge.
I find that eggs don’t really “rot” when refrigerated (unlike if you find an old one that’s been sitting out in open air, pee-ew!). But they do start to dry out. When this happens, it compromises the aesthetic quality of the egg from a cooking standpoint. The strength and integrity of the yolk and its separation from the white starts to decline. If you try to fry eggs over easy (which is our favorite way to eat them), the yolks break really easy in an aged egg. And even cracking them into a bowl for scrambling or baking, the yolk just kind of splooges out in a runny mess, and it just looks bad.
They cook up fine. And in fact, older dried out eggs make better hard boiled eggs, the peel neater. Too-fresh eggs make that miserable mess when peeling, where bits of the white leave with the shell, which is so frustrating if you’re trying to make pretty deviled eggs.
So I find that about two weeks in the fridge is the limit or my chicken eggs before they just look unsightly. We eat the older ones, and I use them in our dog food, but I only sell them when they are fresher. The duck eggs by comparison- boy, they last a long time. Even after a month in the fridge, I can see no decline in quality. I haven’t managed yet to keep any long enough to where I thought they were starting to look poorly, I’m guessing it would be three months or more.
So, what to do to fix this soft shell problem in my hens? The universal advice is to offer oyster shells free choice, which I have been doing for over a year with no improvement. I also experimented with all purpose poultry feed, and also a high protein feed meant for growing turkeys. The layer pellet feed they are on is, in theory, optimized for egg production. But my suspicion is that they eat so much “other stuff” being free ranged, that they are being pushed into some kind of dietary imbalance. (Who knew that abandoning confinement feeding practices and trying to be more natural would actually be bad for them. ) We do have weird soils here, and they eat a lot of grass.
So here I am, contemplating mineral imbalances in my chickens just as in my sheep. I haven’t found a lot of scientific advice on this, other than that we know that the calcium : phosphorous ratio can screw up either calcium or phosphorous absorption. Ironically it sounds like they can actually get soft shell problems from eating too much calcium (thus creating a phosphorous deficiency) as well as not enough. It’s interesting, considering that for ruminants, there is a ton of advice available on mineral supplementation. But it must be that animals that eat only a single grass source are much more vulnerable to imbalances; whereas omnivore poultry have less of a problem with this, so it’s not nearly as studied.
So the next thing I’m going to try is offering them the Cattlemen’s mineral supplement. Since it’s specifically designed to compensate for weaknesses in our local soil, maybe it’ll help. I’m sure tired of eggs cracking just from the slightest jostling, or even just a chicken stepping on them in the nest box!