What determines egg size???

[srd5757]

We adopted a couple chickens a few months ago. Our Buff Orpington is now about 9 months old. She's been laying since we got her, about a medium sized egg. Yesterday she laid an egg literally twice the size of what she normally lays, then today back to the normal size...
Just wondering why this would be, and if there is something I can do to keep getting a bigger egg!
TIA

 

[sourland]

Age, condition, breed, diet all affect egg size. My guess is that yesterday's egg is a 'double yolker' resulting from a glitch in the assembly line. Sometimes it just happens.

 

[srd5757]

Thanks! Yep, cracked it open yesterday and sure enough, double yolker. I was kinda disappointed, was hoping for really big eggs always! Oh, well.

 

[Coop de Grille]

I got another double yolker today from my Buff Orp too, second one in three days. It would be great to get them on a regular basis lol.