Breeding Chickens: Hatching Chicken Eggs in an
Under normal circumstances a chicken will lay, hatch and brood her own eggs and
chicks without any intervention from the chicken keeper. In some cases however, it may be necessary to
artificially incubate the eggs and brood the newly hatched chicks.
While it seems daunting at first, artificial incubation of chicken eggs is relatively straightforward and with the
use of modern automatic incubators a successful hatch is almost guaranteed.
The success rate of any hatch begins with the use of good quality eggs from geneticly sound breeding stock.
Aside from this, there are four critical factors involved in succesful incubation-
- Hygiene and cleanliness of the collected eggs and the incubating equipment
- An appropriate and consistant incubation temperature
- An appropriate relative humidity level within the incubator
- Proper care and handling of the eggs to be incubated
Care and storage of eggs
Correct handling and storage of the eggs prior to incubation will have a detrimental effect on the outcome of
the hatch. Please read the section on EGG Storage for more information on the
correct way to collect and care for the eggs which you intend to incubate.
Early death, often in the forst 10 days, of newly hatched chicks is often a result of poor hygiene practises
when storing eggs and setting up the incubator.
Before use the incubator must be thorougly washed and steralised with a mild disinfectant solution.
Most household disinfectants are suitable for this or you can purchase a commercial steralising solution from a
Use the disinfectant in warm water to wash all surfaces of the incubator while taking care to avoid electrical and
electronic componants which could be damaged while cleaning.
No matter how clean the equipment, Incubating dirty eggs will introduce bacteria which will quickly thrive in the
warm moist conditions of the incubator. Before setting eggs, wash or dip them in warm water (about 50°F or 10°C)
with a small amount of disinfectant and dry with a paper towel.
Take care not to use water that is too cold or hot as this will affect fertility and allow bacteria to penetrate
the egg shell. When cleaning heavily soiled eggs, don't be tempted to scrub the eggs or use an abrasive cloth or
sponge. Scrubbing too hard will remove the protective film known as the 'bloom' and may allow bacteria to penetrate
the shell more easily.
Just dipping the egg in the cleaning solution and using your fingers to remove mud or dirt should be perfectly
Fumigation is another method of steralising eggs before incubation. Commercial breeders use a combination of
formaldahyde and formalin to thoroughly cleanse the eggs but this is usually only done by large breeders in
Eggs which are incorrectly placed will have less chance of successful hatching so taking time to correctly place
the eggs inside the incubator is worthwhile. Place the eggs either horizontally or ideally at an angle of 45° to
horizontal with the pointed end down. This allows more room for the embryo to develop and an increased area of
exposure for the air cell.
Eggs placed in any other position may result in the embryo dying at a late stage of development and is the main
cause of chicks being 'dead in shell'.
For succesful incubation a consistant temperature, appropriate to the species you are hatching, must must be
meticulously maintained throughout the incubation period.
For hatching chickens the ideal temperature is 99.5°F or 37.7°C. While a small deviation from this temp should
still be successful you shoud aim to be as close to this figure as possible.
Consistancy is the key with incubation. Once the incubation temperature has stabilised and you set the eggs for
hatching, maintain it meticulously.
Modern forced air incubators ensure that this temperature is maintained evenly throughout the inside of the
incubator. When using a still air incubator, extra care should be taken to place the thermometer correctly and
ensure that the correct temperature is maintained at the centre of the egg. Still air incubators may also be more
prone to fluctuations in temperature due to a change in the ambient conditions in the room where the incubator is
As the embryo develops a certain amount of heat is produced within the egg and particualry so in the final days
before hatching. For this reason, it is normal to lower the temperature in the incubator by about 1° for the last
The amount of moisture present in the air is known as relative humidity. Realative humidity is so called because
the moisture level is directly related to the temperature of the air.
Although humidity is an important factor in the successful hatching of eggs its acceptable margin of error is
greater than that for temperature.
For normal hatching of chicken eggs a relative humidity of 45 - 60% is ideal. The developing embryo loses
moisture naturally during development so it is important to maintain the humidity within the accepted
Where the humidity is too low, the embryo will dry out excessively and the chick may die before hatching.
Too much moisture in the air and the egg will be forced to hatch early and the newly hatched chick will have a
reduced chance of survival.
For the last three days of incubation the relative humidity should be raised to about 75% (*see note) to allow
the eggs to hatch easily. In these critical few days before hatching the incubator should only be opened if
absolutely necessary to prevent the loss of the moist air inside. Once all the eggs have hatched the humidity can
be reduced again to allow the chicks to fully dry before being placed in the brooder.
* On occasion it may be difficult to achieve a high level of humidity due to ambient air conditions. If this is the
case you can try placing additional water containers inside the incubator, sometimes, placing a wet sponge in a
shallow dish can be very effective.
Turning the eggs
A brooding hen can turn her eggs as much as 50 times per day. Turning the eggs ensures the prevents
the developing embryo from sticking to the inside of the shell and is most important during the arly stages of
Most modern incubators will automaticly turn the eggs for you but if you dont have an egg turning device in your
incubator you will need to turn them manually. You should do this a minimum of three times per day. Turning the
eggs an odd number of times will prevent the egg spenind long periods lying on the same side.
When seeting the eggs, take a penicil or felt tip pen and mark an X on one side
and an O on the other. This ensure you can keep track of which side of the egg is up and ensure that they have
been turned. All of the eggs in your incubator should have either the X or the O facing upwards at any given
Always turn the eggs in the opposite direction.
For the last three days of incubation it is not necessary to turn the eggs. This allows the chick to settle in
the correct position for the imminent hatch. If you manually turn the eggs just stop turning at the end of day 18.
If you have an automatic incubator just turn off the turning function at this stage.
Once you are sure all of the eggs that are likely to have hatched have done so you can allow the chicks to fully
dry in the incubator for up to 24 hrs and move them to a brooder for growing on.
Setting up an incubator