2. Incubation
Incubation refers to the process by which birds hatch their eggs,
and to the development of the embryo within the egg.
The most vital factor of incubation is the constant temperature
required for its development over a specific period.
The average incubation period for chickens is 21 days
3. Types
There are two types of incubation
Natural incubation
Artificial incubation
4. Natural incubation
Incubation under a broody hen is the ideal way to hatch a small number
of eggs. A hen can successfully hatch 12-15 eggs depending on her size
5. Artificial incubation
Use of a machine which warms, turns, humidifies bird eggs to incubate
and eventually hatch them.
7. Temperature
Temperature is the most critical environmental concern during
incubation
During setter phase temperature required is 98.5-100.5⁰F( 37.2-38.3⁰C)
During Hatcher phase temperature required is 98-99⁰F (37-37.5⁰C)
8. Cont…
When incubation temperature deviate from the optimum level,
hatchability will decline And the incidence of the malformed chicks will
increase
Too high temperature results in excessive late embryonic mortality
Low setter temperature result in show embryo growth, late and uneven
hatching, and high percentage of unhatched eggs.
9. Temperature requirement of different
species
Species Temperature (°C)
Setter phase Hatcher phase
Chicken 37.2-38.3 37-37.5
Turkey 37.5 37.0 O
Geese 37.7 37.5
Duck 37.5 37.2
Japanese quail 37.5 37.1
Pheasant 37.5 37.1
Ostrich 36.1 – 36.7 36.0 - 36.7
10. Humidity
Humidity is also important because the rate at which eggs lose water by
evaporation depends on the ambient relative humidity
The relative humidity of air with in incubator should be about 60%
During the last 3days the relative humidity should be nearer 65-70%
11. Cont…
Too much moisture in incubator prevents normal evaporation and
results in a decreased hatch, chick with a large yolk and a sluggish chick,
which is difficult to save
Too little moisture result in excessive evaporation, causing chicks to
stick to the shell, remain in the pipped shells, and sometimes hatch
crippled
13. Humidity Requirement of
different species
Species Humidity (%)
Setter phase Hatcher phase
Chicken 55 65
Turkey 55 75
Goose 50-55 75
Duck 55 65
Japanese quail 60 70
Pheasant 65 90
Ostrich 20 – 40 60 – 70
14. Ventilation/ air
Proper ventilation is important for successful incubation
Insufficient ventilation may result in embryo or chick death
During the hatching period additional ventilation must be supplied to reduce
the carbon dioxide in the incubator
Each process is speeded up approximately 100 times between the first and
21st day of incubation
15. Ventilation
Since 1,000 eggs require 143 ft3 of fresh air per day (oxygen in the air at
21%) on the 18th day of incubation
As the embryo grows it needs a larger supply of fresh air
The movement of gases through the pores of the shell and the shell
membranes is important because the developing embryo must receive
a constant supply of oxygen and must eliminate carbon dioxide and
moisture.
16. Oxygen in the Air
oxygen content of the air in the setter and Hatcher remains at about
21%, but there may be some variation in the hatcher where large
amounts of carbon dioxide are produced by the newly hatched chicks
Hatchability will drop about 5% for each 1% that the oxygen content of
the air drops below 21%.
17. Gaseous exchange during incubation
Day of incubation
Absorption of oxygen
(ft3)
Expulsion of carbon dioxide
(ft3)
1 0.50 0.29
5 1.17 0.58
10 3.79 1.92
15 22.70 11.50
18 30.00 15.40
21 45.40 23.00
18. Turning
The turning process allows the embryo to revolve and slide in the inner
white, yolk does not adhere to the shell membrane and provides access
to additional nutrients for embryonic development.
If turning is not occur in the incubator Deforming of the inner
membrane started and eventually the yolk will touch the shell
membrane
19. Cont…
If it happens embryo uppermost the embryo will stuck the shell and die
For this reason turning is essential for the survival of healthy chick
For good hatchability, eggs should be turned to a position at least 45
from vertical, then reversed in the opposite direction to a similar
position
Egg turning should be undertaken 6-8 times per day
20. Cont…
Eggs should not be turned in a complete circle, as this has a tendency to
rupture the allantois sac with resultant embryonic mortality.
Eggs should not be turned in either large or small incubators during the
hatching period.
21. References
http://www.avianweb.com/images/products/brinsea/incubation.pdf
Joseph M. Mauldin, Extension Poultry Scientist at the University of
Georgia explains the exchange of oxygen, carbon dioxide and moisture
in the egg during incubation in the Spetember 2003 issue of the
University's Poultry Tips
Handbook of poultry production (A Brief Encyclopedia)
Commercial chicken meat and egg production 5th edition
