Hello, welcome to this blog on the topic: process of egg formation in poultry farming and structure of a fertile egg.
Table Of Contents
- Process of egg formation in poultry.
- Structure of a fertile egg.
- Revision Questions.
Process of Egg Formation in Poultry
The process of egg formation is controlled by hormones. The egg is formed partly in the ovary and partly in the oviduct.
OVARY: The yolk is secreted by the ovary and enclosed in a follicle. The yolk increases in size by accumulating yolk materials carried from different parts of the body by blood stream. The germinal disc is attached to the top of the Yolk. The follicle bursts to release the yolk.
INFUNDIBULUM: The yolk released by the ovary is taking up by the INFUNDIBULUM, the internal terminal part of the oviduct. Fertilization of the egg occurs in the this part of the oviduct, before the other components are added. However, complete formation of the egg is dependent of whether the egg is fertilized or not. The egg spent 15 minutes in the INFUNDIBULUM before it moves to the Magnum.
MAGNUM: In the Magnum, the egg stays for three hours and part of the albumen is secreted on the yolk. Chalaza is also formed in this region. The egg now moves to the isthmus.
Isthmus: The egg stays here for 19 to 20 hours where the shell is formed from calcium carbonate secreted by glands of the uterus. Mineral solutions are also added to the egg after which it moves to the vagina.
Virgina: The eggs stays here for a very short time before it is laid through the cloaca of vent. It takes almost 26 hours for a complete egg to be formed and laid.
Structure of a Fertile Egg
Shape: The egg is oval or oblong in shape. It is either brown or white in color. The differences in color are due to differences in breeds.
Shell: The hard shell covers the egg externally. It is rich in calcium carbonate and its protects the egg.
Membrane: Immediately after the outer shell are outer and inner membranes. Both membranes give protection to the egg.
Airspace: The airspace is loaded on one of the pointed ends of the egg. It is found in between the outer and inner membranes. The airspace is very important for respiration of the embryo.
Albumen: This is also called the egg white. It accounts for over 50% of the total body weight of the egg. It is rich in protein.
Yolk: This is located at the center of the egg. It is a yellowish jelly like mass. It is rich in proteins, mineral salts, vitamins and other food substances. It supplies the embryo nutrients.
Embryo: This is also called germinal disc. This is located at the center of the yolk as a dark spot. The germinal disc is only found in fertile eggs. It develops to form the chick during incubation period.
Chalaza: Chalaza extends to both side of the yolk. It is a piece of thick protoplasm. It holds the yolk and the embryo in place within the albumen.
Revision Questions
- What are the process of egg formation in poultry?
- State And explain the following structure of a fertile egg. Shape, shell, yolk, membrane, embryo.
- Briefly explain the functions of the following, ovary, infundibulum, Magnum, isthmus, uterus, vigina.