i hear that depending on a hen's diet her eggs come out different say if she lacks calcium the shell of the egg is poor and if a free range hen eats wild grass and insects the yolk is more rich in vitamins that is either good for human food or for hatching.
ABSOLUTELY TRUE!!! Compare a store bought egg produced by a hen in an over crowed hatchery/facility to an egg from a chicken that is free ranged, farm raised.
I fed mine some cilantro the other day and I swear I tasted a hint of it in an egg a couple days later. I will try a few other strong flavored herbs and see what flavors come through in the eggs, plus the chickens will enjoy the experiment