OK, here's a weird one (but I hope also a fun one). My girlfriend and I have noticed that the pastured eggs we get are thicker, or more viscous: when you put the eggs in a pan, the whites of one egg don't just run into the whites of another egg, but each one keeps its shape, separate from the others. Now, she told me that it is definitely the case that older eggs get runnier, including the yolk (and this is something you can take into account for cooking, so that you might use eggs of different ages for different purposes). But will the diet of the chickens affect the thickness of the eggs also? If we get eggs from a farm are they thicker just because they are fresher? Or does a properly-fed chicken produce thicker eggs (so that a pastured egg will be thicker than a non-pastured egg when both have been out of the hen for the same period of time)?
Has anyone out there noticed similar things? Do you have some data that could help answer the question one way or other?
If diet does affect thickness, are there any thoughts on the science behind it?
A weird question, I know, but I just can't deny my curiosity.