They are sex link hens, and they eat Purina flock raiser. It is only one that is doing that the other 10 have normal eggsIn my case it was just a result of me switching from All Flock feed to Purina Lay Pellet too fast after we sold off the ducks and geese. It didn’t bother me too much because the eggs still edible, it’s just a different color. What breed of chicken? We have copper Marans, cucku Marans, Wyandotte’s and some orpingtons.
You're positive it's from the same bird?