Reproductive Anatomy of Broiler Breeders Flashcards
What are the levels of hormonal control of egg laying?
- Hypothalamus
- Anterior pituitary
- Ovary
What parts of the bird contribute to forming the yolk, albumen and shell of the egg?
Yolk - liver
Albumen - oviduct
Shell - skeletal system (calcium) and oviduct (shell gland)
Describe ovulation.
An increase in progesterone from the mature follicle (F1) sends positive feedback to the hypothalamus to to the Anterior pituitary to produce more LH. This triggers further growth of the follicles and release of the F1 follicle out of the ovary during the “Open period for LH release”.
How many hours of the day is a chicken in the Open Period for LH Release
6-8 hours a day in which LH is released and the chicken can ovulate
What is oviposition and when does it take place?
The process of laying an egg about 24-28 hours after ovulation. It occurs in sequences.
Describe a bird’s laying sequence
A period of 1 or more days of consecutive egg laying. Each egg will lay slightly later each day. Each sequence is separated by a break period of 40-44 hours.
When does a chicken’s prime sequence usually occur?
The longest laying sequence of a hen occurs about the time of peak production. In egg-type hens its about 60 days and in broiler breeders it is about 20 days.
What is lag?
The difference in hours of the day that a chicken laid her eggs during a laying sequence. Ex. if at 9 am on day 1 and 11 am on day 2, it wold be a 2 hour lag.
What might a long lag time indicate?
Chicken has slow rates of follicular maturation and shorter sequences of laying.
What is EODES?
Erratic Oviposition Defective Egg Syndrome often due to feeding a broiler breeder ad libitum
What might cause a bird to develop EODES?
Random ovulation
Random oviposition
Excessive large follicle development
What are the symptoms of EODES?
High incidence of double yolked eggs
High incidence of multiple eggs/day
Shell defects
High incidence of follicular atresia (degeneration)
Why do broiler breeder farmers feed restrict?
Prevent excessive follicle development
Better the chances of getting good eggs
Create the best balance for the right amount of follicles and right size of follicles
What may be the cause of a flock that doesn’t have enough follicles after peak production?
Inadequate light stimulation
Birds are underweight (not as able to produce)
High incidence of atresia (degeneration of follicles)
Normal decline in follicle number with age
What may cause excessive follicles leading to poor shell quality eggs and double-yolked eggs in a flock?
Birds fed aggressively coming into egg production
Possible light stimulation problems