What's on this egg?

I have one chicken that lays eggs that always have this rough coating on the eggs. It's non uniform and doesn't cover the whole egg. I can scrape or wash it off, which I do.

I used to get two of these every day, but now I only get one and whoever the 2nd chicken was who was laying them has moved on to laying regular eggs. Oddly, too, they used to be very dark brown, almost as brown as a marans but are getting lighter. They also were jumbo egg. Whoever was the 2nd chicken laying them now lays smaller and lighter eggs because all the rest of the eggs are smaller and lighter in color. We have 7 chickens and I often get 7 eggs. So I used to get 2 of these jumbo dark eggs with the coating, but now I only get 1 and it's lighter in color but still jumbo and with the coating.

This photo is blurry but you can see the coating. It's whitish in color.

I haven't a clue what the coating on the egg is. However lighter eggs tend to go with heavy laying. The more often a hen lays, the lighter (relatively) her eggs will be.

mine have that also. only its speckles or polkadots not splotches like that...wonder what it is?

I asked at backyardchickens and I think it's calcium. I guess it means the chickens are getting a lot of calcium. Someone else posted a pic of an egg with calcium on it and the pattern is different so I guess how it appears on the egg varies from chicken to chicken. But now I know it's not a horrible thing. It will probably vary over time depending on what they eat when they're free ranging.

very interesting bc I do NOT give mine oyster shell or any type of extra calcium. my Buff Orp eggs look like you threw cream paint at them & EE eggs look like someone took a pen & put dots on the eggs.

I don't give mine any extra calcium type stuff either. Here's a link to some possible causes:

http://www.thepoultrysite.com/publications/1/egg-quality-handbook/17/sandpaper-or-rough-shells

This message was edited Jan 23, 2010 10:44 AM

"Sandpaper shells" ? Oooh, poor hen!