Although double yolk eggs are not rare (about 1/500 eggs), they are still really exciting to find and they have been throughout history. Some used to believe it was good luck in general while others believed it was a sign of an upcoming marriage or death. Whatever you choose to believe, it is still fun to crack open a large egg to see a double yolk plop in your pan! Consumers of store bought factory eggs hardly see these since they are usually separated from the eggs to make egg products instead. It makes finding them in your own coop even more special!
Reproductive Mistake
Double yolk eggs are a reproductive mistake that happen for a couple different reasons. The reproductive error can be hereditary, or it can be attributed to the age of the chicken. Chickens with a hereditary reproductive error will lay double yolk eggs occasionally or often through their entire life. Others may only lay them when they first start to lay eggs or at the end of their laying cycle. A young pullet that is just beginning to lay may have more trouble than others with synchronizing her reproductive cycle. Some may release eggs too quickly causing more than one to be enveloped in albumen (egg white), membrane, and shell. Some reproductive systems will actually lose track of egg yolks causing another to drop and connect to the first. Most girls will find a rhythm and begin to lay single yolk eggs regularly. At the end of a hen’s laying cycle, she may begin to sputter again and lay odd eggs including double yolk eggs.
Eating Double Yolk Eggs
There is nothing wrong with eating a double yolk egg! Its twice the nutrition in one shell! Great if you have hungry boys running around the house…
Hatching Double Yolk Eggs
Unfortunately, double yolk eggs will not hatch. There have been success stories with help from science and lady luck, but the chances are slim. First, there is not enough room in the egg for both chicks to develop. They will push against each other, and likely smother each other inside the shell. It would be more likely for one to pass, and one to live. Secondly, there is not enough air in the shell’s pocket for both. Lastly, even if there was enough air, it would be highly unlikely that both were positioned inside the shell to face the air sack due to a lack of space.
Egg Records
By account, the record for the most yolks in one egg is nine! The record for the world’s largest egg, however, is listed in the Guinness Book of World Records with 5 yolks and 9 inches in diameter! The record for the world’s heaviest egg is a double yolk egg with two shells and weighing in at 1 pound.
Resources
Damerow, Gail. Storey’s Guide to Raising Chickens. Third. North Adams: Storey Publishing, 2010. 223-24. Print.
"Egg Food Safety Frequently Asked Questions." Egg Safety Center. N.p., 2010. Web. 1 Oct 2012. <http://www.eggsafety.org/consumers/consumer-faqs
"Egg Problems." Avian Web. N.p., n.d. Web. 1 Oct 2012. <http://www.avianweb.com/eggproblems.html>.
Theer, Pete. "Odd Eggs, Double Yolks, No Yolks, etc."PoultryHelp. N.p., 11 Feb 2011. Web. 1 Oct 2012. < http://www.poultryhelp.com/oddeggs.html>.
"What Causes Double Yolks?" Better Hens and Gardens. WordPress, 13 Apr 2011. Web. 1 Oct 2012.