When we got our chickens we were using a soy-free feed. The egg yolks were huge! I thought it was the chicken breed. Got another breed laying, thought we lucked out again with a breed that made large yolks (I love yolks). Then my husband accidentally bought a feed with soy, and the eggs got smaller and the yolks smaller. Switched to a different soy free feed and everything is big again. Anyone else experience this?