Thomas Lamprogiorgos
Songster
I think that minorca black breed lays by far the hardest shells...
My aunt and mother share the same opinion with you.I haven't had every breed so no idea.
Of the breeds I've had its easily the BCMs that lay the hardest shells.
Inbreeding maybe.I did not know that breed affects egg shell strength! I have mixed bantams and their egg shells are always very thin and very light colour. Thinner than the shop bought eggs. I feed only layer pellets. Could this mean they are not getting enough calcium?