Evening star., 1919-03-16
CARING FOR THE HOME FLOCK
BY H. W. RICKEY.
Poultry Specialist, Maryland State Collere.

1ncubators have not reached thas
state Of development where 1t can DC
said of them that they take the place
of the hen in every particular.
The success of artificial incubation
depends upon many factors. which are
primarily under the control of the
operator, such as the selection OF the
type or make of the incubator. its en-
vironment, the quality of eggs set. the
method of handling the eggs. the
matter of temperature and moisture
and the operation of the incubator.
There is no great difference in eff
cheney of the standard makes of well
tested incubators But the difference
in environment or location of the ma
chine in operation has great influence
upon the results obtained.
Hot-air and hot-water incubators
hatch equally well under conditions
particularly favorable to the require
mentS of each type of machine. IN
der normal conditions of our atmos-
phere. however. it may safely be said
that hot-water machines hatch some
what better than those of the hot-air
type. unless additional moisture be
supplied to the air surrounding the
eggs within the egg chamber of the
hot-air machine. The difference IN
methods of ventilation is mainly re-
sponsible for this condition.
The fresh air which is so necessary
for the growth of the embryo is
drawn into the egg chamber of the
hot-air incubator through a section
OF the heater around the lamp. there
it is superheated and some of the
moisture driven off, while with the incu-
bator heated with hot water, the fresh
air with its normal moisture content
enters the egg chamber direct through
vents in the side or bottom. This
method of ventilation is used in all
mammoth incubators.
Examination Of the air under sit
ting hens resulted in the finding OF
excess moisture, and for time there
seemed to be no satisfactory explana-
tion for this apparent phenomenon. 1t
was known that there were no swea t
glands or pores in the skin of the
fowl through which moisture could
escape from it's body, and the popular
theory that the hen carried moisture
from the wet grass to the eggs on her
feathers was clearly shown to be
false But the specialists at the Ca
! madam University again came to the
front with the explanation that
though there was constant circulation
of air under the sitting hen. sufi-
through the pores in the shells to
maintain a constant moist condition.
While within the incubator it was
found that owing to the large air
space and proportionately great
amount of air surrounding the eggs
there was not sufficient moisture to
meet the requirements.
Stress has been placed upon this
question of moisture. as its presence
is one of the most important factors
governing successful incubation.
Many incubators are furnished by the
manufacturers with moisture pans or
trays. to be filled with wet sand and
placed under the eggs during the
process of incubation. This wet sand
makes the best evaporating surface
known. Much better than water
alone. Sand trays are of no special
use when the incubator is operated
in very moist place. A well ven-
tilated, damp cellar or one with a
concrete floor kept flooded with water
will usually furnish all additional
moisture required.
Pals or tubs of water placed under
the incubator do not answer the pur-
pose. While some operators sprinkle
the eggs daily throughout the period
of incubation. or during the last few
days only, this practice is of COM
paratively little value because the
distribution of the moisture is not
even or constant.
Directions for operating the incu-
Dat0r ana hanQllnS the eggs during
incubation are furnished with each
incubator by the manufacturer, but
there are certain principles involved
in the turning and the cooling Of the
eggs, the ventilation of the incubator
and in the supply of moisture to
which l have already referred, which
are common to all makes Of ma
chimes.
The usual method of handling the
eggs in the incubator during incu-
baton is to turn the eggs for the
first time on the third day and cool
first on the fifth or seventh day, then
continue to cool to blood tempera-
ture once and turn twice each day
until the end of the eighteenth day
At that time the incubator door is
closed and not opened again until
the hatch is completed.
The setting hen. however. does not
wait until the third day to turn the
eggs, nor does she wait until the
fifth or seventh day before she leaves
her nest for feed. neither does she
stop turning or cooling on the eight
eenth day, and there seems to be no
logical reason for not initiating the
hen. Eggs are turned in order to
prevent the embryo from resting in