Why is the same egg always smashed?

[jamiebelle1207]

Here is what is happening. A month ago we brought home 3 mature hens (first-time chicken owners): a white leghorn, a red sex link, and a buff orpington. The leghorn laid an egg every day for six days and then I found a smashed egg in the litter, out of the nest box. She then didn't lay at all for like 2 weeks. She is laying about every other day for the past week, but every time, the egg is pulverized. The other two lay brown eggs just about every day and these are fine. I feed them laying pellets (about 2 cups between the four of them….I also have a six-month-old pullet not yet laying at all) and oyster shell daily, and they also free range and get random kitchen scraps. The brown egg layers' eggs are fine.

What could be happening? It also tends to take her hours to lay her egg, she's in and out of the coop like she can't decide what to do. I always seem to miss the actual laying and when I go out there, there are one or two perfect brown eggs next to a smashed up white one. The other day she was covered in orange goo, like she rolled in her own smashed egg. lol

 

[Ol Grey Mare]

There are a few different things that *could* be going on - the fun part is figuring out which one(s) it is.
When you find the smashed egg, have you examined the shell pieces to compare their thickness/strength to that of a piece of shell from one of the other eggs (next time you crack/use one of the other eggs hold onto a piece of the shell)? If so, how does it compare to the shells of the other eggs?
I would be keen to catch her "in the act" (I know you said you keep missing it) because it may be that she is doing something that is causing the breakage vs. a case of weak/thin shell (or a combo of the two issues) - and knowing what that is will help in knowing how to address it (ie the use of a "roll away" nest box, etc).

 

[jamiebelle1207]

She finally laid a good egg today! I think she knew it was my birthday. Lol