The document summarizes the process of egg formation. It begins with the ovary containing follicles with ova. When the pullet reaches sexual maturity, hormones trigger yolk development over 10 days. Mature ova are released through ovulation into the oviduct. The oviduct is composed of 5 parts where different layers like albumen and shell are added over 2-3 hours. The completed egg is held in the uterus for 18-20 hours before being laid through the vagina.

1. Formation of the Egg
WAQAR UL HASSAN
2011-ag-2155
University of Agriculture Faisalabad

2. Formation of the Egg
Egg consists of reproductive cell
Cell is located on surface of yolk
Cell are surrounded by albumen, shell
membranes, shell and cuticle

3. OVARY
 Ovary is a quiet mass of small follicles containing ova
 Some ova are large to be visually seen
 Full-size yolks necessary for egg production

4. Formation of yolk
 Yolk is not true reproductive cell
 Yolk is a source of food material
 When the pullet reaches sexual maturity a sequence of
hormonal changes occur
 The FSH produced by anterior pituitary gland

5.  Active ovary begins to generate hormones
 That are estrogen, progesterone and testosterone
 The first yolk to begin maturing does so as major amount of the
yolk material
 A day or two later, the second yolk begins to develop and so on,
until at the time the first egg is laid

6.  About 10 days are required for an individual yolk to
mature
 The color present in the yolk is due to xanthophylls
 Egg yolk is composed mainly of fats and proteins

7. Ovulation
 At maturity the ova are released a process known as
ovulation
 Each ovum hangs on the ovary to enter the oviduct by a
process known as ovulation
 Each ovum hangs on the ovary by a narrow stalk

8.  When the ovum is mature the hormone progesterone produced
by the ovary
 That cause the release of the luteinizing hormone (LH) from
anterior pituitary
 The time necessary grow an egg to transverse the oviduct
varies with individuals
 Most hens lay successive eggs with time intervals of 23 to26
hours

9. Defective Egg Shells
 When the normal interval of about 23 to 26 hours between
ovulations is broken
 More eggs are produced with defective shell
 From 5 to 7% of the eggs produced have some form of the
defective shell
 Yolk size affects egg size

10.  The size of the completed egg is more closely associated
with yolk size

11. Oviduct
 Oviduct is a long tube
 In which yolk passes and remaining proteins of egg are
secreted

12. Parts of oviduct
 Oviduct have 5 major parts
1. Infundibulum
2. Magnum
3. Ishmus
4. Uterus
5. Vagina

13. 1. Infundibulum
 The funnel shaped upper portion of the oviduct is the
infundibulum
 Length is approximately 3.5 inches (9 cm)

14. 2. Magnum
 The magnum is the albumen secreting portion of the
oviduct
 Length is about 13 inches (33 cm) long in average laying
hen
 It takes 2 to 3 hours for the developing egg to pass
through the magnum

15. 3. Isthmus
 The developing egg is forced into the isthmus
 Length is 4 inches (10 cm)
 It remains for 75 minutes
 Here the inner and outer shell membranes are formed

16. 4. Uterus (shell gland)
 Uterus is formed 4.0 to 4.7 inches (10 to 12 cm) long in the
laying hens
 Developing egg normally remains in the uterus from 18 to 20
hours
 Much longer then other section of the oviduct

17. 5. Vagina
 The final section of the oviduct is the vagina
 Length is 4.7 inches (12cm) in a bird during egg
production
 Normally, the egg is held in the vagina for only a few
minutes
 Vagina has no role in egg formation

18. Thanks