Incubation - Practical Aspects

Question 1

how is fertility determined ?

Answer 1

• incubation test
• fails to differentiate very early embryonic death from infertility
• usual way of determining fertility in industry
  microscopic test during early incubation

Question 2

what is percent hatchability

Answer 2

• % of total set eggs
• hatched/ eggs available
• does indicate a reason for low hatchebility

Question 3

how do you find the of fertile eggs

Answer 3

fertilized + hatched / total eggs
- removing the ones that have died

Question 4

what are common patters in embryonic mortality

Answer 4

• usually 1-7 is early death
  or 21-28 embryonic death

Question 5

What are some expected hatchability numbers

Answer 5

• egg production - 88-90%
• broiler breeders - 82-85%
• turkeys 75-80%
• these can vary with each strain, season and bird strain

Question 6

when should you candle an egg

Answer 6

5-10 days

Question 7

what are the different eggs classifications

Answer 7

• clear - infertile or early embryonic mortality (0-3 days)
• blood ring - dead embryo
• live embryo

Question 8

what are common hatch problems

Answer 8

• hatch removal - break out eggs that havent hatched
• examine chicks - those that will not thrive in the hatchery cant go to farm

Question 9

what are some causes of fertility issues

Answer 9

• fertility ( nutrition, body weight (over under rate), male to female ratio ( males in large amounts will fight over females), diseases, external parasites and artificial insemination problem

Question 10

what are some causes of embryonic mortality

Answer 10

• egg handling and storage
• improper setter and hatcher settings
• disease
• breeder age
• genetic factors (inbreeding)

Question 11

what is the % of mortality

Answer 11

• infertility 42%
• early embryonic mortality 28%
• mid term mortality 6%
• late mortality and pips 24%

Question 12

what is the Amnion

Answer 12

• low level protection
• clear fluid surrounding embryo

Question 13

what is the yolk sac

Answer 13

• membrane enveloping the yolk
• nutrient uptake - primary nutrient
• primary source of energy during last third of incubation
• drawn into body cavity prior to hatch
  early nutrient supply for newly hatched bird 72 hours

Question 14

what is the allantoic membrane

Answer 14

• development initiated on third day and complete by the 12 day
• completely envelopes the embryo and highly vascular
• function - respiration, excretory and digestive

Question 15

what is chorion

Answer 15

• fuses with inner shell membrane and allantoic membrane
• chorioallantoic membrane - gas exchange, excretion and digestion