Horizontally-enhanced hens lay enormous eggs ?
This may be an eggs-aggeration. 
Those eggs are real. Not laid of course, but processed into that loaf form.
That’s right. They’re actually laid by loaf-chickens.
Loaf-chicken are related to boneless chickens, right?
(Far Side boneless chicken ranch flashback)
Whence, following several months of mental abuse, comes mocked chicken loaf.
Now that’s a yardbird.
Cite?