I have 12 hens of several brown-egg breeds, all about one year old that started laying last fall. Most of them laid all winter. In the past two weeks the pigment of most of the shells has become noticeably lighter. I can't think of any obvious stress/fear factors or visible illness like bronchitis. They have a good "watchdog" rooster and two livestock guardian dogs that they seem very comfortable with (the dogs make their rounds but have never been seen to chase or pester them). The chickens are out foraging daily, which makes their yolks wonderfully yellow, but some of the shells are cream colored or very light brown. The hens seem happy, though some appear to be molting. Any thoughts?
