A SMALL DISPLAY
L. W. Kalch
Associate Extension Poultryman
Florida Agricultural Extension Service
Institute of Food and Agricultural Sciences
University of Florida, Gainesville
CONSTRUCTION AND OPERATION OF A
SMALL DISPLAY INCUBATOR
The incubation and hatching of eggs can be a very interesting and educational project for both young
4-H Club members, science students and others have found observation of the development of the
chick to be a highly educational and interesting experience.
This leaflet describes the basic requirements for the construction and operation of a small incubator.
The incubator described in this leaflet will have a materials cost of $20 to $25. Some students may
wish to design and experiment with their own incubators. Less expensive incubators can be constructed.
He ti, i a ind control
unit contact Hyoulr
county a$ent or Depart-
iment of Poultry Science,
I'1niirrnsitf of Florida,
G(uimc.rille, for infornm-
(ti in 1;n,' sources of hc'at
uit ornd thcr (. lon1cftefr.
Plywood-%" x 2' x 4', AA Exterior.
Glass-1 piece 3/16" x 15" x 17" (front of incubator).
1 piece 3/16" x 12" x 17" (top of incubator).
1%" hardware cloth-12" x 16" (bottom of egg tray).
Nails-1 lb cement coated box nails.
Metal trim or molding-72" (holds glass in place).
Sheet aluminum or tin-2 discs, each 1" diameter (covers
for ventilation holes).
Paint--3 oz. can of enamel in color of your choice.
White shellac-3 oz. can.
Paint brush--" wide.
Pan-approximately 6" wide, 8" long and 2" deep.
Heating and control unit.
From the 2' x 4' piece i k" AAS ,'t
Drill onei" vtilatio
tor. Position one hole in thefSt
and the other hole in the t r'
This provides cros ventilation. ..
Sirc thwo ieceubut I with, exs iti
will oneI 1 1 h. wi 'hdi thiroughilyaftr
flit' In ..i,,r t h I ti .'ti h r (in.lu igt
Fertile Eggsoe he
A theply of fhetile inzz (un. ti twu iloin) may be
ibtin]ne. frnm hatchcr'ie. ,r fion ;iny |Ipultry l1ock where
ro..stc.rs art be.ng kept w.th the hvnm. Eggs purchased
Iroi ft d .ti ret. ai not ftpril.o iian thi ref,.rt will not
Hutrhinlg .'. shouluhlI in.cubatii a --iotn a- pwi.-.sible
altir they are laid. They can, hot. t.i, be .hitortl up to
rvnll days with gvLd ia rsnlts thg n held at a temperature
tf 'i to i6-F and a relative humidity of 70 to 75 percent.
Temperature of Incubator
This type incubator is a "still air" incubatui, which
requires an operating ttnlpelature of 10'' to 10.' F at
the top of the eggs. It is necessary that the temperature
be kept as close to 102-103-F as possible-thus the need
for an accurate thermometer and a reliable heating and
Each incubator is different. Through experience the
operator will be able to determine the best operating con-
ditions for his particular incubator. For example, if the
first hatch of chicks comes off at 20 days instead of the
normal 21 days, the incubator was too warm and the
operating temperature should be lowered about one de-
gree F for the next hatch. If the chicks are requiring
more than 21 days to hatch, the incubator is too cool and
the temperature should be raised about one degree F.
(Normally chicks pip the shell on the 19th day, emerge
from the shell on the 20th day, and are dry and fluffed
out and ready to be removed from the incubator on the
Do not place the incubator in drafts or direct sunlight
or allow it to be subjected to other conditions that might
cause fluctuations in temperature.
To prevent the eggs frbm drying out too rapidly, mois-
ture must be added to the air. This can be done by filling
the small pan with water to a depth of one inch and placing
it under the egg tray.
Figure 2 shows the comparative size of the air cell
in an egg on the seventh, fourteenth and eighteenth days
of incubation. If the air cell is too slow in enlarging, too
much moisture is present. On the other hand, if the air
cell is too large, more moisture is needed. Size of the
air cell can be determined by candling (placing the egg
before a strong light).
It may be necessary to sprinkle the eggs lightly with
warm water at the time of hatching to prevent the chicks
from sticking to the shell. This is done when the first
Turning the Eggs
It is necessary to turn the eggs from the second to the
eighteenth day. After th'e eighteenth day the eggs can
remain in one position.
Turning prevents the developing embryo from sticking
to the shell. It is desirable to turn (roll) the eggs to the
opposite side an odd number of times each day. Three
times daily is a minimum (morning, noon and night). By
turning the eggs an odd number of times, the eggs will
not rest all night in the same position as the previous
Mark each egg with a pencil as an aid in determining
that all eggs have been rolled at each turning.
Figure 2.-Size of air cell on the seventh, fourteenth and
eighteenth days of incubation.
The small holes (% inch in diameter) located on the
sides of the incubator will supply sufficient ventilation.
Adjust ventilation by opening or closing metal discs over
Thoroughly wash the egg tray and interior of the in-
cubator (except heating unit) after each hatch.
The operation of a small incubator presents an ex-
cellent opportunity to develop projects of your own design
in the fields of embryology, physiology, anatomy, nutri-
tion, breeding and genetics.
Outlines for some projects can be obtained from your
county agent or by writing to the Department of Poultry
Science, University of Florida, Gainesville, Florida.
COOPERATIVE EXTENSION WORK IN
AGRICULTURE AND HOME, ECONOMICS
(Acts of May 8 and June 30, 1914)
Agricultural Extension Service, University of Florida
United States Department of Agriculture, Cooperating
M. O. Watkins, Dean