One of my Leghorn hens laid this this morning. She's been a consistent one-a-day layer for a couple months now with no issues. 6 months old.
Edited by WhittHavenFarm - 10/8/15 at 7:02am
Roosters don't penetrate, so it's not likely to be caused by him. Do you have any drakes? Male ducks do penetrate, and chickens are not designed for that kind of breeding. Drakes can seriously harm female chickens.