Double yolk eggs

About 20% of the eggs laid by our hens are extra large – and they mostly have double yolks. Double yolk eggs are single eggs that happen to have two yolks in them. They often occur with pullets when a hen releases one yolk soon after another, and both are in the same egg. But older hens can also produce double yolkers.   Chicks are born with about 4,000 ovum (the yolks), and they don’t produce any extra during their lives. So, the total amount of eggs a hen can lay is set from the start. Some producers use extra lighting to get hens to lay more eggs – but that doesn’t increase the total volume – it simply brings forward the rate of lay, causing each hen to age more rapidly.