Egg eating is a habit that is easier to prevent than to stop. It usually starts as a result of accidental egg breakage. A curious hen pecks at a broken egg—perhaps trying to satisfy a calcium or vitamin D deficiency or typical chicken curiosity—and develops a taste for it. Chickens being imitators, others follow suit and quickly learn egg breaking and egg eating from one another.
You can take action to help head off the habit of egg eating among your flock. Control measures to prevent egg eating include reducing stress and providing proper nutrition.
To reduce stress, use the following strategies:
Provide proper nutrition in the following ways:
If egg eating is occurring in your flock, you can take steps to try to stop it. First, however, ensure that your birds are the egg eaters. Snakes, skunks, rats, weasels, and other predators could be the culprits instead. To determine whether your flock members are responsible for the egg eating, examine your hens. Egg-eating hens usually have dried yolk on their beaks and the sides of their heads. If you do catch an egg eater, it is best to cull it from the flock. Otherwise, other hens will imitate the behavior.
The following tricks might work to break an egg-eater:
If all else fails, consider beak trimming. Identify egg-eating hens by looking for the presence of egg yolk on the beak or head. When you have identified an egg eater, trim 1/4 to 1/2 inch off the upper beak, making it difficult for the hen to break the shell of an egg. CAUTION: Only trained and monitored personnel should perform beak trimming, using proper equipment and procedures. Using beak trimming on an entire flock in high production can reduce feed consumption and egg production.
Prevention of Egg Eating, Phillip Clauer, Virginia Tech.