Off color / rough shells on eggs - PIC included

[BoerneChickens]

Cadbury, my SC Marans, has been laying for about two months now. She normally lays 6 and sometimes even 7 days of the week - rarely skipping a day. This week she has only laid twice in the last four days - once yesterday and once two days before that. The egg from four days ago is her normal dark brown glossy egg. The egg yesterday was not normal - the shell color was much lighter and the egg felt rough and had an odd dark spot on one end that was even more rough than the rest of the egg. Here is a picture:

My other girls all lay green eggs or are bantams that haven't started laying yet and do not go into the same nest box - so I know the egg is Cadbury's.

She seems to feel fine and is running around and eating and being her usual chickeny self - but I am worried that maybe something is wrong that is causing the egg shell to be off. They have oyster shell available free choice all the time and I feed Coyote Creek organic layer feed. They have clean fresh water every day and our temperatures have cooled off (but even our month of 100 degree days she laid nearly every day). Is there anything I need to keep an eye on?

Any ideas on what causes the odd shell color and rough egg? Have others had this happen? This is my first time with chickens so I am still learning what is or isn't normal when it comes to egg laying.

 

[gritsar]

You'll find some good information here about the differences in eggs you'll get. Most all are normal occurences, including sandpaper shells, off-color eggs and the occasional shell-less egg:


http://www.thepoultrysite.com/ourbooks/1/egg-quality-handbook/

 

[BoerneChickens]

Quote:
Thank you!!

 

[BoerneChickens]

Reading it is says stress can cause it and to minimize disturbances around the coop. I have been building an addition on the side of my coop - I guess maybe that is what coudl cause her to slow down laying this week and lay this weird egg. Thanks for the link - that is a useful one for sure!