2b – Hatchery Management

Question 1

Where is the site of fertilization?

Answer 1

• Infundibulum

Question 2

What is oviposition?

Answer 2

• Expulsion of egg from oviduct to external environment
• *expulse eggs in morning, mate in afternoon before egg shell is formed and then the egg develops through the night

Question 3

How many cells are in the ovary of a day old chick?

Answer 3

• 30,000 to 60,000 ova (cells)=high potential to lay eggs!
• *left ovary regresses
• Right ovary=functional

Question 4

What are the two ways to determine fertility? (before incubation)

Answer 4

• Macroscopic
• Microscopic
• *use light from bottom=lighter ones=not fertile

Question 5

Macroscopic examination of fertility before incubation

Answer 5

• Open egg and look at white germinal disc
• “if blends in=fading away=not fertile”
  o Proteins are degrading

Question 6

How is fertility determined at the hatchery?

Answer 6

• Incubation test
  o Fails to differentiate between early embryonic death from infertility
  o Usually how it is done!
• Microscopic test during early incubation (research)

Question 7

2 ways to determine percent hatchability

Answer 7

• % hatchability of TOTAL egg set
• % hatchability of fertile eggs

Question 8

% hatchability of TOTAL egg set

Answer 8

• Does NOT indicate the reason for low hatchability
• *usual term used in industry

Question 9

When do you see peaks in embryonic mortality?

Answer 9

• Day 5
• Day 26: lots of energy need to peak out of egg OR malpositions

Question 10

What is the expected hatchability?

Answer 10

• Slightly different between egg production, broiler and turkeys
• ~75-90%
  o Lower in broilers as they are selected for MEAT production not hatchability
• *numbers vary with season, strain of bird, etc.

Question 11

What are the 3 ways to classify eggs by candling eggs? (light to the eggs)

Answer 11

1. Clear: infertile or early embryonic mortality (0-3 days)
   a. Open egg to determine which one
2. Dead embryo/blood ring
3. Live embryo

Question 12

What do you do with hatch removal?

Answer 12

• Break out eggs that have not hatched
  o Define if mid OR late embryonic mortality

Question 13

What are the tops causes of low hatchability?

Answer 13

• Fertility (42%)
• Embryonic mortality
  o Highest in early then decreases as go into late
• Common incubation problems

Question 14

What are the causes that lead to fertility causing low hatchability?

Answer 14

• Nutrition
• Male to female ratio
• Disease
• External parasites
• AI problem

Question 15

What are the causes that lead to embryonic mortality causing low hatchability?

Answer 15

• Egg handling and storage
• Improper setter and hatcher settings
• Disease
• Breeder age
• Nutrition
• Genetic factors