Reproductive Anatomy of Broiler Breeders

Question 1

What are the levels of hormonal control of egg laying?

Answer 1

1. Hypothalamus
2. Anterior pituitary
3. Ovary

Question 2

What parts of the bird contribute to forming the yolk, albumen and shell of the egg?

Answer 2

Yolk - liver
Albumen - oviduct
Shell - skeletal system (calcium) and oviduct (shell gland)

Question 3

Describe ovulation.

Answer 3

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”.

Question 4

How many hours of the day is a chicken in the Open Period for LH Release

Answer 4

6-8 hours a day in which LH is released and the chicken can ovulate

Question 5

What is oviposition and when does it take place?

Answer 5

The process of laying an egg about 24-28 hours after ovulation. It occurs in sequences.

Question 6

Describe a bird’s laying sequence

Answer 6

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.

Question 7

When does a chicken’s prime sequence usually occur?

Answer 7

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.

Question 8

What is lag?

Answer 8

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.

Question 9

What might a long lag time indicate?

Answer 9

Chicken has slow rates of follicular maturation and shorter sequences of laying.

Question 10

What is EODES?

Answer 10

Erratic Oviposition Defective Egg Syndrome often due to feeding a broiler breeder ad libitum

Question 11

What might cause a bird to develop EODES?

Answer 11

Random ovulation
Random oviposition
Excessive large follicle development

Question 12

What are the symptoms of EODES?

Answer 12

High incidence of double yolked eggs
High incidence of multiple eggs/day
Shell defects
High incidence of follicular atresia (degeneration)

Question 13

Why do broiler breeder farmers feed restrict?

Answer 13

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

Question 14

What may be the cause of a flock that doesn’t have enough follicles after peak production?

Answer 14

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

Question 15

What may cause excessive follicles leading to poor shell quality eggs and double-yolked eggs in a flock?

Answer 15

Birds fed aggressively coming into egg production

Possible light stimulation problems

Question 16

Describe how a late maturing and early maturing bird will be fed (unintentionally) during rearing and laying?

Answer 16

Late maturing - underfed during rearing (didn’t grow fast enough) and overfed during laying (doesn’t need as much feed as it can’t yet lay)
Early maturing - overfed during rearing (grew way too fast) underfed during laying (needs more nutrients to maintain size and amount of follicles)

Question 17

When is it most important to feed the exact ideal amount to a bird and why?

Answer 17

During the prelay and pre peak periods
Prelay = 20-26 weeks, pre peak = 26-34 weeks
Farmers need to encourage ovary growth during this time, but don’t want excessive growth of follicles.

Question 18

What are the three most important things to keep small in order to create the best flock uniformity (from most important to lesser importance)?

Answer 18

Most important: Breeder chick BW
Then: Mature Pullet BW
Then: Breeder Sexual Maturity
(Think of the inverted triangle, the smaller the bottom is, the smaller the top will be)

Question 19

What are some consequences to allocating nutrients?

Answer 19

Since there are major gains in body weight prior to sexual maturity, the immature pullets will grow body mass while the mature pullets will begin to develop sexually when on allocated nutrient feed.