Absolutely nothing has changed in their care or feeding. They look fine when cracked and taste fine scrambled. Haven't tried frying yet. I wouldn't think the eggs would change as early as 4 years, would they? All seem to be very healthy.
I have 26 chickens of various breeds. 2-4 years old. Within the past few weeks we have some eggs with mushy yolks when boiled. Everything looks fine, even the yolk looks fine,looks like any normal yolk, it is just mushy. I have found previous discussions about egg whites doing something similar...