One of my girls (began laying this fall) has been laying eggs with lots of calcium deposits. Poor thing! I thought it was just a phase but she's been doing this for weeks now. They free range all day long and rarely touch their feed. They have oyster shell available but they haven't touched it. I give them black sunflower seeds (a handful split between four birds) once or twice a day to get them into the coup for when I let the dogs out to use the restroom. They aren't locked up but 15 minutes. So I'm not sure how to fix "too much calcium" when she's basically eating her natural diet?
It could be that the hen has a defective shell gland, if it's an ongoing issue. Short term causes are usually incorrect feeding and/or disturbances during the calcification process. https://www.backyardchickens.com/a/common-egg-quality-problems
If it is common across your flock, it is a flock problem. If it is only one hen, it is a one hen problem. Since it is only one and is consistent, it has something to do with that individual hen. Maybe how she processes the calcium she eats or maybe something to do with the shell gland. Why do you say “poor thing”? How bad is it? It’s not all that uncommon. What makes you think she is hurting? As for a natural diet, chickens that forage can get calcium from a lot of sources, certain plants they eat, hard-shelled bugs, and if you are in limestone country even the pebbles they use as grit. How much calcium they get depends on what plants, bugs and rocks they eat. Obviously yours are in a calcium-rich area. I don’t have an idea of how to fix that when it is something individual to one hen if it even needs to be fixed. Just don’t hatch any of her eggs to pass that trait on to future chickens.
She seems okay. I say "poor thing" because I wouldn't want to pass an egg like that. When she first began laying, she didn't have the calcium deposits. I haven't changed their diet but we did go from fall to winter. I wonder if available foods in the winter have more calcium? It's just her. No other birds have calcium deposits. I just wanted to make sure there wasn't something I could do. If it's a faulty shell gland then I'll just let her be and hope she never has complications from it.
