A hen requires about 24 to 26 hours to produce an egg. After the egg is laid, the hen starts all over again about 30 minutes later. The hen’s reproductive system consists of the ovary, the organ where the yolk develops, and the oviduct where the egg is completed. The ovary is attached to the hen’s back, about halfway between the neck and the tail. The oviduct, a tube-like organ about 26 inches long, is loosely attached to the backbone between the ovary and the tail. Most female animals have two functioning ovaries, but the hen uses only one, the left. The right ovary and oviduct remain dormant.