The Chickens’ One Day Egg Cycle

The chicken’s egg cycle takes 24-26 hours with most of that time making the shell out of calcium which protects the yolk from bacteria (P. Biggs). Female chickens, like humans, are born with a lifetime supply of “ova” in their ovaries. As an “ovum” (yolk) enters the reproductive tract, strands of white protein spin around the yolk creating the egg white or “albumen” as more membranes are added forming the egg shape. The next 20 hours are devoted to shell formation: like humans who need calcium for strong bones, hens need high calcium levels to make strong shells. They get calcium from food and supplements as well as crushed oyster shells which are always accessible to them (C. Boeckmann).

The egg enters the cloaca pointy end down so laying will be easy. The final clear “cuticle” covers the shell which seals the 6,000-8,000 pores of the egg shell from bacteria. Finally, the egg turns so the rounded end will have a soft landing in the nest. Hens need 12-16 hours of light every day to lay eggs, and farmers can keep lights on “fooling the hens” to increase laying, but this technique can shorten the life of laying hens. Hens lay eggs in a 8-12 day cycle, then take a day off before starting a new cycle. First year hens will lay 250 eggs, 2nd year 80%, 3rd year 70%, 4th year 60%, and after 5-8 years no more eggs. Chickens live 3-7 years, but if protected 10-12 years. Old hens are great bug catchers, contribute rich manure, are good broodies, and finally a great dinner (Almanac).