1. Incubation Temperature
• Maintain the temperature in the 99-102° F.
temperature range (100-101° F., if possible).
Place the thermometer to measure the
temperature at a level at or slightly above where
the center of the egg will be.
• Overheating the embryo is much more
damaging than is under heating it; overheating
speeds up embryo development, lowers the
percentage of hatchability, and causes abnormal
embryos.

2. Incubation Temperature
• Although a short cooling period may not be
harmful, longer periods of low temperatures
will reduce the rate of embryo development.
Excessively low temperatures will kill the
embryos.
• Avoid temperatures outside the 97-103° F.
range. If the temperature remains beyond
either extreme for several days, hatchability
may be severely reduced.

3. Humidity
• The moisture level in the incubator should be about
50 to 55 percent relative humidity, with an increase to
about 65 percent for the last 3 days of incubation.
• Moisture is provided by a pan of water under the egg
tray. The water surface should be at least half as large
as the surface of the egg tray. Add warm water to the
pan as necessary.
• If more humidity is needed, increase the size of the
pan or add a wet sponge. Humidity adjustment can
also be made by increasing or decreasing ventilation.

4. Ventilation
• Ventilation is crucial because the embryo is a living
organism which exchanges oxygen and carbon dioxide
through the shell during the incubation process. The
amount of air exchange needed increases as the embryo
develops.
• The vents, which are located above and below the
eggs, should be opened gradually until they are fully open
the final three days of incubation. Ventilation rates that
are too low prevent normal moisture evaporation and
cause large weak chicks or death.
• High ventilation rates remove too much moisture and can
cause the shell to stick to the chick, making hatching
difficult.

5. Humidity
• Humidity is also important because of the egg’s
porosity. Keeping adequate humidity in the incubator
will help insure that no more moisture than necessary
is lost by the developing embryo.
• Humidity should be adequate for the first 18 days of
incubation if the water pan is kept full and covers an
area greater than half the floor of the incubator.
• During the last three days of incubation, adding a
large sponge inside the incubator should increase the
surface area of water and give the necessary boost to
humidity.

6. Humidity
• Low humidity can cause the shell to stick to
chicks, rough navels, small chicks, short down,
and/or death.
• High humidity can cause an unabsorbed yolk
sac, resulting in the chicks being smeared with
yolk.
• The relative humidity inside the incubator
should be between 50 percent and 55 percent
during the first 18 days and between 60 percent
and 65 percent during the remainder of the
incubation period.

7. Incubators
• If you use the incubator for the first time it is
recommended that you operate the
incubator with a small quantity of
inexpensive eggs to be assured of your
operating procedure and the performance of
the incubator, before attempting to hatch
large quantities of eggs or expensive eggs.

8. Incubators
• An incubator or brooder is designed to bring
normal room temperature to the desired
temperature. Room temperature of 60
degrees F. or below will reduce the
temperature in the incubator. Room
temperature changes of 10 degrees or more
will change the temperature in the incubator.
The change is more pronounced below a
temperature of 70 degrees F.

9. Setting eggs
• Temperature may not be set to the correct
temperature from factory. Check against
thermometer supplied. Allow 2 hours to
stabilize the temperature before setting eggs.
Ensure that the bulb is adjusted just clear of
the top of the eggs.
• Fine adjustments can be made the control to
increase or decrease the temperature.

10. Temperature
• The Thermometer will always be sitting on the
wire floor of the incubator. In a still air
incubator, the closer you get to the top of the
incubator, the higher the actual temperature.
• We have worked out scientifically the proper
thermometer reading for different size eggs,
when on their side on the floor and when they
are in the automatic turner. When setting eggs
of different sizes, you will have to use an
average half way between temperature in the
chart below.

11. Recommended Incubation
temperatures
& Incubation period
Hens:
39.2°C 102.5°F
Pheasant : 39.5°C 103°F
Quail:
39.2°C 102.5°F
Ducks:
39°C 102°F
 Geese :
39°C 102°F
21 days
24 days
17 days
28 days
28-32 days

12. Moisture
• Moisture in an incubator prevents excessive
drying out of the natural moisture in the egg. It
is impossible to give any set rule for supplying
moisture. If the incubator is operated in a damp
cellar or in a room with considerable natural
moisture, then it may not be necessary to supply
artificial moisture. If operating in a dry climate
or in dry room, moisture will be needed. The
important thing to watch is the air space in the
egg. When testing eggs for fertility, note the size
of the air space. If the air space is too
large, provide moisture.

13. Moisture
• Moisture in the incubator is controlled by
putting water in the small inner trough of the
bottom. The small trough by itself will increase
the humidity to take care of most climates. If
you live in an extremely dry climate you may
need moisture in the larger outer trough instead
of the small trough. During time of hatching, you
need higher humidity that is usually provided
from moisture of hatched chicks drying off.
Check and fill water trough twice a week.

14. Moisture
• Important: In the winter time, three days
before time to hatch, put water in both
troughs of bottom to compensate for extra
dryness of air.
• Special Notice: Spray duck and goose eggs
thoroughly with water twice each week, and
spray at least three times a week during the
last ten days.

15. Plastic Vent Plugs
• The front vent plug (just below label) is used
to regulate humidity and the back vent plug
(by electric cord) is used when there is
excessive humidity, as follows:
• When incubator is over 75 percent of
capacity, remove the front vent plug one
week before hatch date.
• The day that chicks start to hatch, remove the
back vent plug.

16. Plastic Vent Plugs
• If incubator is over 90 percent of capacity and
contains large chicks, it may be necessary to
prop one side of the incubator top up about
1/8 inch to get chicks dry. Leave side propped
up just long enough for most of moisture to
clear on windows, but no longer than one
hour at a time.

17. Plastic Vent Plugs
• When incubator is from 25 to 75 percent of
capacity, remove the front vent plug the day
chicks start to hatch.
• When there is moisture condensed on the
windows, remove front vent plug.
• Be sure to replace vent plugs before next
setting of eggs.

18. Plastic Vent Plugs
• If vent plug should be lost, close the vent
hole with scotch tape.
• Chicks may be removed 24 hours after they
start to hatch. Extremely wet chicks should
be left in incubator to dry.