Those double yolk eggs are from older laying hens that have gone through their first cycle of laying, have gone through a fallow period, & are into their second laying cycle. These eggs tend to be larger but fewer & if you're lucky, you have double yolk eggs too.
"Aggie, Aggie, Aggie, Fight, Fight, Fight"
Sorry, proud Aggie here (Agricultural Sciences, UBC)
Any other Aggies on the board?
Anthony