It would make an interesting experiment....I generally don't have anyone older than 2 years around. I boiled a bunch of pullet eggs last year though and I know I saw at least one side cell. I'm actually having an issue with my two breeders' eggs not developing even though they've been fertilized and I'm seriously terrified I might have egg quality issues. Hoping it's just because it's still chilly out, but still...
Feed them some super high nutrition for 2 weeks.... then test the eggs again.