My Barred Rockhen is 2 1/2 years old. Today I found an egg from her that is strange looking. It is covered with gray sandy patches of calcification, clumps and bumps all over the egg. The shell is not a uniform brown color as it usually is-- it is a lighter tan, mottled with a darker tan. I am worried. She has been such a good hen. I read that this could signal a reproductive tract infection or avian respiratory diseases. What is your best guess? I read that it could be hereditary to some breeds (she hasn't laid any like this in the past, although a few with lesser calcifications on them). Or that it could be age-related in hens. But is 2 1/2 years old the right age for it to be age-related? Could it have something to do with approaching the autumnal equinox (lessened light)? In the past this girl was known to lay 2 eggs in a single day-- usually at the beginning of laying season in March. She hasn't done it for a long time. I'm wondering whether this might be what happened. She laid one and tried to lay a second and the second didn't fully form but put extra calcification on the first? I did think I found 2 eggs from her the other day, but I suspected I had forgotten to gather the previous day's egg from her. But now I wonder. I sure hope she's not sick. She's my oldest and favorite hen. What do you think? Her energy and appetite seem good. She has lost feathers near her tail but I thought it was from molting or perhaps from being mated by the rooster.