When a hen gets to be about a year to a year and a half old, the mineral reserves in her bones and body start to get depleted, regardless of how nutritionally perfect her diet is. In order to rejuvenate the hen, it is necessary to temporarily stop egg production. This stage of rest from egg production is called molting.
Chickens, as most birds, are stimulated to lay eggs by increasing amounts of light and day length, which initiates their reproductive season in the spring. In order to make egg production stop, the usual practice is to shorten the day length and the availability of light to be comparable to a short winter day when most birds do not lay eggs. The diet is also changed to fit the "off-production" period.
During a molt, the flight feathers are shed and grow back. Molting is a natural process that would occur in a flock of hens at some point in their production cycle. After a hen stops producing eggs, she will be fed a rejuvenating diet. The lights are then increased to simulate the lengthening days of spring, and the hen starts producing eggs again. In this second cycle of egg production, eggs are larger and the shell quality is better. Molting is a practice mostly used by farmers who have a significant market for Extra Large eggs. Since Eggland's Best Eggs are usually available in the Large size, the majority of Eggland's Best Eggs are not produced from molted hens.