I imagine it would have something to do with going into winter. Perhaps the chicks need to be chunkier in order to survive the cold.
Excellent deduction there, would make perfect sense, get a little fat on them bones to insulate them.
My understanding is that mature hens lay fewer but larger eggs after their first molt.
Ive heard that, Ive also heard that the egg size may increase every year after molt. I had a few that did not really molt bad at all this year, you barely knew, and they did not stop laying during the process, yet it seems all 3 of my current layers...well...2.5 one is hit or miss, are laying much bigger eggs since we had the cooler weather roll in.
another interesting thing that I am sure should not have anything to do with it but they all been free ranging for weeks now, and I have not been feeding them much at all in the way of processed food, they get one narrow bowl around noon. I feel this way they get their bugs and stuffs from the yard and 'round out' whatever they need from the food I give them. I find they are not as ravenous as they are first thing in the morning gorging themselves at the food dish either. and more like 'top off'. yet eggs are perfectly healthy and firm.
Maybe processed food for them, we love to 'think' it's super great with all these vitamins bla bla, but it's really crap kind of, you know, like the processed $41t WE eat every day is in the long run, not really super healthy for us either, not even canned veggies and stuff that is supposed to be good for you, because of all the salts and chemicals and garbage in it.
I've cooked (to make the process work better) and analyzed the bigger and smaller eggs with my XRF, and can't see anything really different in them, although, I am restricted to a resolution of only down to about 3 to 5 ppm on some stuff, when I don't know, I may need to be looking for PPB on some things???
Interesting, looking forward to seeing any other inputs on this thread.
Aaron