INFORMATION ON HATCHABILITY
1. Hatchability is more than mere fertility. It is a combination
of two factors, fertility and viability, the strength of spark
of life. The first essential to maximum hatchability is the
quality of egg itself. Egg quality is first determined in
the flock by:-
(a) those inherited characteristics which affect hatchability
(b) nutrition and
(c) the quality of flock management and the health of the
2. Initial egg quality, however essential though, is beyond
our scope as manufacturers of incubators. It is equally important
as to what happens to the egg between the time it is laid
and the time it is placed in the incubator. If initial qualities
of fertility and viability are to be preserved, then proper
cooling, good sanitation, cleanliness, careful handling and
storage (small end down) at correct temperature and humidity,
under proper conditions, and for not over a safe length of
time, are the various factors which have to be observed and
HOLDING OF HATCHING EGGS
1. For maximum results, it is important that proper facilities
be provided both on the farm and hatchery for holding hatching
eggs, under correct levels of temperature and humidity.
2. Chicken eggs should be stored between 50 to 60 degrees
Fahrenheit. 55 degrees F is generally considered the best.
Some experimental results have indicated that 50 degrees is
the best, if the eggs are to be held longer than two days
and 55 degrees, if these are to be held for less than 2 days.
3. Temperature below 50 degrees and above 70 degrees is harmful.
Hatchability sharply declines after holding eggs under such
conditions, even for, as little periods as two or three days
or even less.
4. Adequate humidity in the egg holding room is of extreme
importance. 75% to 80% (i.e. 47 to 55 degrees FWB) is safe
level. Too low level of humidity can contribute to the development
of molds, rots and exploders.
5. If the eggs are to be held longer than a week, these should
be turned daily. It may not be necessary to turn, if the eggs
are to be held for less than a week.
6. With their age, the eggs loose their ability to hatch well
and may even deteriorate, as no good chicks can be produced
from them. It is recommended that eggs should not be held
for more than 7 days in winter and 2 days in summer, prior
to their being placed in the incubator. Even under the best
conditions, hatchability drops rapidly, if eggs are held longer
than one week.
7. In case the eggs are pre-trayed 12 to 24 hours in advance
of setting the racks, holding the trays of eggs must be covered
on all sides to prevent dehydration, particularly if the trayed
eggs are being warmed to room temperature before setting in
the machine, as some operators like to do.
1. Proper embryonic development and metabolism require
the correct balance of oxygen supply, carbon dioxide removal,
heat and moisture. All sides of the eggs must be exposed to
uniform conditions. The essentials for good incubation, therefore,
include correct levels of temperature, humidity, supply and
air circulation, periodic turning and careful sanitation and
2. Even though approximately half of all oxygen consumption,
carbon dioxide elimination, animal heat production etc. occurs
during the hatching period alone, the success of the hatch
is not determined in the hatcher. Unless conditions of incubation
have been right throughout the development of the embryo in
the incubator, no hatcher can produce miracles and salvage
3. Of all the factors of incubation, temperature is the most
dramatic in terms of its affect and is the most important
single factor. Improper temperature can retard or accelerate
the hatch and thereby greatly affect its quality as well as
percentage. Hatch in time is very important. Too much of an
extreme in temperature, either above or below normal, can
kill the entire hatch.
4. Humidity plays a vital role in the percentage of hatch
and even more so in the quality of hatch. The combination
of too high a humidity in both setter and hatcher can result
in drowning the chicks in the shell. Too low humidity in incubator
will result in 'dry sticks' Too high a humidity in hatcher
during the first twenty-four to thirty-six hours can result
in rough and unhealed navels, although this condition is more
frequently due to excessive incubator temperature. Too low
a humidity in the hatcher can result in chicks which pip but
fail to get out of the shell.
5. Proper circulation of air is the key to control temperature
and humidity. It is essential that the three factors of temperature,
humidity and air circulation be properly co-related for supply
of oxygen and the removal of carbon dioxide.
6. An egg which is both fertile and high in viability will
hatch even in the face of astonishing abuse. An egg which
although fertile, is low in viability, will hatch only if
all the conditions are favorable. The greatest source for
success or failure in incubation are the eggs which are marginal
in viability. Such eggs will hatch if everything along the
line is 100%.
7. It is not easy to remember as to what was done to the incubtion
three weeks before. Careful record is therefore, essential
to obtain maximum results. The method by which eggs were handled,
conditions of temperature, humidity and ventilator settings
used throughout the incubation period, should be recorded.
Then you are in a position to analyze your results in an attempt
to determine what might have been the cause of any deficiency
in your hatch. To improve your hatchability, carry out a careful
post mortem of the eggs which fail to hatch. Such post morterns
require time, but they will pay handsome dividends. Through
an analysis of your records and of all the factors of the
incubation, you will be able to correct your procedures so
as to prevent recurrences of any condition which caused trouble.
8. It is advisable to maintain accurate record of the following
data in respect of the incubation:-
(a) Temperature reading-morning and evening.
(b) Humidity once a day.
(c) Method of ventilations, positions of rota-vent openings.
(d) Position of eggs set.
(e) Number of eggs set.
(f) Number of infertile eggs.
(g) Number of dead germs,
(h) Number of chicks hatched.
(i) Number of deformed/crippled chicks.