I stopped giving treats to the gals I was worried about this new of my pullets laying soft eggs.... But was told it was more likely because she had just started laying last month. But being paranoid I figured why tempt the Fates....Hmmm maybe they're getting the wrong sort of food? You could call your chicken vet and check. Certainly something is not right for so many of your hens to have passed from fatty liver. Are the neighbours giving them bits of bread maybe?