Raising backyard chickens is an enjoyable and gratifying undertaking. Laying hens, bred for egg production, are plucky pets that reward your tender care with a steady supply of fresh and wholesome. Hens lay eggs during the day, most frequently in the morning. The timing of oviposition, or egg-laying, varies with a chicken's breed and how much light exposure she gets.
A hen's reproductive cycle is controlled by photoperiod, or light exposure. Hens require at least 14 hours of light per day to lay eggs. They produce eggs at a maximum rate with 16 hours of light exposure. Hens generally lay eggs within six hours of sunrise -- or six hours of artificial light exposure for hens kept indoors. Hens without exposure to artificial lighting in the hen house will stop laying eggs in late fall for about two months. They begin laying again as the days lengthen.
How an Egg Is Made
Oviposition, or egg-laying, starts with ovulation. A hen ovulates by releasing an ovum, or egg yolk, from her ovary. It slowly travels down the hen's long oviduct where the egg white, shell membrane and eggshell form around the yolk. She lays the egg by pushing it out her cloaca, the single opening for her reproductive, urinary and intestinal tracts. It takes about 26 hours from ovulation to oviposition.
Timing of Ovulation
Hens usually ovulate in the morning but can ovulate as late as 3 p.m. Ovulation occurs about an hour after laying an egg. If a hen lays an egg in the afternoon, she may delay ovulating again until the following day. That egg will be laid about 26 hours later. This is why hens regularly skip a day of egg-laying.
Timing of Laying
A laying hen can at most produce only one egg about every 28 hours. She won't ovulate or lay eggs in the dark, and egg production rates vary with length and timing of photoperiod. All these factors influence the time of day an egg is laid, so it varies with each egg. But it usually occurs in the morning or early afternoon.
A hen's breed influences when she will lay an egg. Brown-egg breeds tend to lay earlier in the day, while white- and tinted-egg breeds tend to lay later in the day. Broiler hens, bred for meat production, lay eggs less frequently than laying hens. Broiler hens may lay their eggs before dawn.
- NC State University: Keeping Garden Chickens in North Carolina
- University of Kentucky: Avian Female Reproduction System
- University of Nebraska Lincoln: Proper Light Management for Your Home Laying Flock
- British Poultry Science: Photoperiod and Oviposition Time in Broiler Breeders
- Scientia Agriculturae Bohemica: Time of Oviposition and Egg Composition
hen image by Bobi from Fotolia.com
Kimm Hunt has been writing professionally since 1990. She has written for businesses, government agencies and nonprofit organizations, and previously served as the editor of a weekly suburban Chicago newspaper. Hunt holds a B.S. in agriculture from the University of Illinois. She is also a professional dog trainer.