SBGA - Egg

Fertilisation and Egg Development

Stay Behind, Get Ahead

Female Reproductive System - Birds

• Ovary, oviduct and cloaca are the functional parts of the female bird reproductive system

• 1 functioning ovary (cluster)

• Ovum formation is collection of lipid particles from blood which form the yolk

Multiple Select

Which part of the reproductive system in birds secretes the albumen (the white)?

• Infundibulum

• Magnum

• Cloaca

Multiple Select

Which part of the reproductive system adds the shell membrane?

• Cloaca

• Magnum

• Isthmus

Multiple Select

Where is the egg and waste products passed?

• Infundibulum

• Cloaca

• Uterus

Stages of Egg production:-

• Step 1- Takes place in the Infundibulum, the yolk is received from the ovary and is fertilised by the sperm.

• Step 2- takes place in the Magnum, the albumen is deposited and layered around the yolk.

• Step 3- Takes place in the Isthmus, here both the inner and outer shell membranes are added.

• Step 4- Takes place in the Uterus, Here water is added, which makes the outer white thinned, shell material is added which is made of calcium carbonate; some pigment are added to the shell

• Step 5- The egg is then laid out the Cloaca

Fertilisation

• Process begins with copulation, male places sperm into the oviduct of the female by depositing sperm from the papillae to the wall of the females cloaca

• Sperm can linger for up to three weeks!

• Sperm fertilises the yolk in the infundibulum, egg is formed over 25 hours

Multiple Choice

Shell- calcium carbonate, function is ____________________. Semi permeable, allows for gas exchange

• protect organs

• protecting developing chick

• provides nutrients

Multiple Choice

Yolk- Yellow part of the egg. ___________________ as embryo grows and develops

• Provides food and nutrients

• Protects developing chick

• Provides protection from pain and suffering

Multiple Choice

What forms a sac to protect the embryo and holds amniotic fluid as a shock absorber?

• Amnion

• Yolk Sac

• Chorion

Multiple Choice

What holds the yolk in the egg white?

• Chalaza

• Chorion

• Allantois

Embryo Development

• Female chicken can lay up to 200-300 eggs a year

• Normally lay an egg every 24 hours

• Incubation and moulting can prevent eggs from being laid

• Incubation is the period in which the embryo is developing inside the egg

Factors Effecting Egg Production

• Availability of light

• Temperature

• Food availability, diet and health

• Breed

• Husbandry factors

• Moulting

• Age

Multiple Choice

Incubation - in commercial systems, what temperature are the eggs kept in order to incubate them?

• 33^oC - 35^oC

• 35^oC - 37^oC

• 37^oC - 39^oC

Incubation

• Underheating or overheating eggs can lead to abnormal embryos

• Humidity is 60% for the first 18 days and 70% for the last 3 days to stop the egg drying out

• Ventilation is important as oxygen enters through the shell. This is increased gradually as the egg begins to hatch

• Eggs are turned about 3 times a day to stop the developing embryo sticking to the inside of the shell