Describe briefly the processses of egg formation in poultry.

Answer Details

Process of egg formation in poultry

Egg formation takes place in the reproductive tract of the hen and takes about 24 to 26 hours to complete one egg.

1. Ovary: The yolk (ovum) develops and is stored in follicles on the ovary. When a yolk is mature it is released (ovulation).
2. Infundibulum (funnel): The released yolk is picked up by the funnel-shaped infundibulum. Fertilization by sperm, if the hen has mated, takes place here.
3. Magnum: As the yolk moves down, the thick albumen (egg white) is secreted and added around it.
4. Isthmus: The two shell membranes (inner and outer) are formed around the albumen here.
5. Uterus (shell gland): Water and mineral salts are added to the albumen (plumping), and calcium carbonate is deposited to form the hard shell. Shell colour or pigment is also added at this stage.
6. Vagina and cloaca: The completed egg passes into the vagina and is finally laid through the vent (oviposition), usually with the broad end first.