Well, I was wondering about the shell quality with my flock of 26 free rangers. The also get fed 18% layer ration.
I was getting really thin shells and wrinkled shells as well. I treated an apparent mite infestation and have cleaned the coop weekly.
Well talk about stress, I also discovered there was a skunk under my coop which has a partial wood and partial dirt floor.
Guess it stressed the chickens out too.
Being somewhat easy digging in soft sandy soil, there also appeared to be a skunk under the cabin. Well in our small town, I could not find a trap to borrow or purchase so next trip out I got a dual pack of traps.
12 skunks later ( 2 families including 10 kits!)I couldn't believe it!
My egg quality improved 100% in just over a week after the skunks are gone! Coincidence?