My hen's egg shells have rough patches, and sometimes little hard pimples on the shell. Should I be concerned?
If your chicken is young, sometimes rough shells occur for a while until her egg-laying cycle has settled. Older chickens may also lay eggs with rough or pimpled shells. In the winter, sometimes a chicken may be getting excess calcium as laying slows down and they are less able to graze; this excess is distributed over the shell, sometimes in "pimples" or rough patches. You may try increasing high-protein treats like sunflower seeds. (Lots of corn or scratch usually has low protein, and will cause your hens to reduce their laying.) Presuming you have oyster shell free choice, any hens that need more calcium can get it.
Sometimes, rough shells will be caused by water shortages, which may happen in the winter if the water freezes. When that happens, the egg sort of "stalls" in the reproductive tract for a while, getting excess calcium distributed to its shell. The same thing can happen if your chickens are scared by an intruder or even a very loud storm! Chickens can go "off" laying due to a disturbance, and when they resume their first eggs, may be misshapen, missing a shell or have a very rough shell. This is usually an occasional thing, although older hens are more prone to it. It is not usually a cause for concern.
If you believe your hen is ill, however, we recommend you get her to a vet for a check-up.