What types of incubators are
available?
The two main main types are:
- "Forced-air" or "Cabinet" or "Walk-in"
(which covers all large capacity incubators)
- "Still-air" or "Table-top"
Because still-air incubators can only
have one layer of eggs in each compartment, they are small
capacity incubators, up to only 100 eggs. But unfortunately still-air
machines do not have the same ability to tolerate outside temperature
changes without thermostat readjustment, and cannot easily handle eggs
of different sizes together because at different levels in the cabinet
there are widely different temperatures, with hot air above the eggs
and cold air below them. Small forced-air incubators are more expensive
to produce but are little affected by ambient changes, so are more
stable. All air in them is the same temperature, so egg size is
irrelevant. Small eggs are most vulnerable to temperature changes so
when users want maximum hatchability, especially with small and/or
valuable eggs, they will give preference to forced-air incubators.
Back to Top Setter / Hatchers Explained
The Setter is the unit, which is used to mature the eggs, until just before hatching. These units control both temperature and humidity to ensure the ideal environment for incubation is maintained. There needs to be different levels of humidity when setting and hatching eggs. When you have separate hatchers and setters, then this process is simplified and more productive as the humidity levels don't need to be frequently adjusted.
A Hatcher is a separate unit for the actual hatching of the eggs. The benefit of having a separate Hatcher unit is two fold. Firstly, it provides for a healthier hatching environment. When chickens hatch, their fluff contains germs that infect eggs that are still being incubated. In the case of a separate hatching unit, the eggs are close enough to hatching that the germs transmitted on the fluff pose no health concerns. The Second relates to adjusting of the humidity levels.
A Setter/Hatcher is a combination of these two units. Although cheaper than having a separate Settler and Hatcher, the combination unit requirs more special management.
Most hatcheries operate on weekly hatches with one-third of setting capacity being transferred into the hatcher incubators every week.
There are two different functions or types of incubator, though in small commercial incubators they can both be in the one cabinet. In medium and large commercial hatcheries they involve 2 separate cabinets. With hen eggs, for the first 18 days eggs must be wide-tilted or roll-turned frequently to stop the developing embryo getting squeezed against the inside of the shell and killed. The trays facilitating this tilting or roll turning are called “setter” trays. For the final three days of the total 21 hatch, the eggs must not be turned, but the chicken must be able to get clear out of the shell when it is ready, so these “hatcher” trays have a flat mesh or metal floor and high sides. By the end of 21 days the chicks will have finished hatching and so can be removed form the incubator and put into boxes, and the debris and shell chips washed out of the hatcher trays. Eggs should not be set if they are older than 7 days from being laid, because their germs will be weaker leading to poor hatching results. Also you do not need as many hatching trays as setter trays because of the waste space. Both these problems are solved with “weekly cycle hatching” which is universal. For each 3-setter trays you have one hatcher tray, preferably in the other cabinet, and each week you set fresh trays of eggs. Only fresh eggs are set. From half way through week 3, every week from then on, eggs in the setter tray, set 2.5 weeks earlier; get transferred into the hatcher tray for their final 3 days and hatching process.
On hatching ratios, it used to be accepted that you could count on a 3:2 ratio of eggs set to good chickens with most of the losses through infertile eggs and the rest as weak germs and hatching failures. However, since high frequency auto-turning of eggs in setter incubators became standard, the percentage of both weak germs and hatching failures dropped markedly so that the ratio of egg set to chickens improved in good conditions from 3:2 to 4:3. On this basis, using the simpler figure of 75 percent, with auto-turning incubators and the 75% Hatchability factor (4:3) would mean the need to set 100 eggs per week, for each 75 chickens.
Back to Top How can I find the best incubator for
me?
Submit an obligation-free request to
locate the most ideal incubator for you with Dominion Incubators. You
can email Dominion
Incubators or fax your request to +64 (New Zealand) 7 846 5401. Dominion
Incubators has connections with manufacturers in both Europe and USA
and so is able to advise on and assist with the purchase of anything
from small build-it-yourself (DIY) kit sets up to walk-in
mammoths.
Back to Top Are there any incubators for use in
schools? (See Hatching notes below)
The safest and most educational little
classroom incubator first went into New Zealand production, designed by
a schoolteacher. It has a transparent, round top and can hold up to 18
hen eggs (or equivalent), and only draws 50 watts of power while
heating. It is still-air; only runs on 12 volt power so is safe even
for children to use and is economical to buy. Its supplied Operators
Manual has been extended to tie in with primary school curricula at an
8+ year reading level. It's trade name is Minilab and is
available for supply to any country.
Another small incubator for school use
(mainly) went into early use as the "Electric Hen" in the USA, but in
the last decade there has been no mention of it still being in production.
Around 1970 Marsh Farms Coy produced the first Turn-X incubator
being about the same size as the Minilab, but with a forced air
system. Main buyers were schools and family homes, and thousands
of them were sold both in North America and internationally.
Although the Marsh Farms has gone, the Turn-X is still in
production. It has a higher power consumption and initial outlay, but
being forced air has good temperature stability. It is offered with
auto-turning (although a manual turning model can be supplied on
request). Auto-turning and running directly on 110 or 230 volt
electricity makes for more convenience, and reasons for not allowing
children unsupervised access to them. Consequently the "involvement" of
pupils turning the eggs twice daily in the Minilab by hand,
which the low voltage allows them to do safely, creates a higher
interest level. Such factors like those should be taken fully into
account. (The competitive effort children will turn on for the
privilege of turning the eggs is amazing.)
Back to Top Can I build my own incubator?
Yes, but with care. Although looking
simple, an incubator has some parts which are critical, with special
functions, and cannot be made by lay people. One of these that is
critical is the the Thermostat. It controls the supply of electricity
to the heater. There are two main types of Thermostats. One involves
and expanding Ether Wafer Capsule connected to a microswitch which cuts
of the heater power when the warmth reaches the controlled level. When
the temperature drops slightly and pressure of the capsule on the
microswitch eases, the microswitch switches the heater on again, and
this on-off regulation maintains an even temperature; usually within a
one degree range. The 12volt Minilab Incubator uses such a thermostat.
Both the 12volt Minilab or just the Ether Wafer Thermostat can be
purchased from Dominion Incubators. The other type of thermostat is
called an Electronic Thermostat and consists of a temperature sensitive
element, commonly called a thermistor, connected to what looks like a
tiny radio. Its solid-state switch also turns off the heater when
warmth reaches the cut-off temperature, and then when the temperature
eases down only a quarter of a degree, the heater switches on again;
and so on, indefinitely. The best deal we know of involving an
Electronic Thermostat is the Ecostat DIY Kit set. It consists
of plans to make an insulated box or cabinet from commonly available
materials, plus a safety-sheathed heater and electronic, proportional
thermostat which produces very fine temperature control. An alternative ready made "cabinet"
is a foamed plastic freezer box with a lid top and thick walls. The Kit also includes a simple, color-digital thermometer and basic Operating Instructions.
So far it is only available for 230 volt AC or 12 volt DC power, for 50
egg or 100 egg models; but other models must follow in due course. Main
potential would seem to be in very rural situations, and agricultural
colleges where there are woodworking facilities and budget constraints
or a wish to provide a full involvement with poultry production.
Back to Top Must eggs be turned?
Yes, during incubation, until within 2 or
3 days of hatching, eggs should be turned at least twice daily. That
should produce about 2 chickens from each 3 eggs set. An extra turning
each day can raise that about 3%, and another turn may raise that a
further 1.5%, with each additional turn adding a diminishing
improvement. Most auto-turning incubators are set for hourly turning
which is in the "natural" frequency which floats between 20 and 50
turns in each 24 hours. Smaller birds like Quail are more in the 40 -
60 turns, and ratites (including Emu) commonly 10 - 25. Eggs being
stored for incubation should preferably be turned 1 or 2 times daily
after first 3 days.
Back to Top
Hatching chicks in the classroom
Problems
and Resources for solving them.
Source of basic
information?
www.dominc.net
has FAQ and specifications of
several available Incubators, and Brooders.
Operating Manuals
for use in schools.
Sources of Supply
for Fertile Hatching Eggs?
Across
Australasia, where this project has been in limited use, for 20
years,
main source was relatives and friends of pupils living out in the
country with
small backyard flocks, but with some assistance from some poultry club
members,
and commercial hatcheries, which supply chickens for networks like KFC
and
Tegel.
Daily Turning of
Eggs for 18 days? (i.e 3 weekends)
Main two
alternatives were either: Having an Auto-turning incubator, or having a
teacher
or pupil living close to school to take the manual model home for
weekends.
Other options
included help from a teacher or cleaner who is in the building on
weekends.
Third Alternative
is semi-hatched chicks:
o
In some cities
suppliers exist who supply and deliver eggs no longer needing any
“turning” (at
day 18 or 19) and so only need final extra moisture for their normal
Day 21
hatching.
Safety Concerns for
Pupils and/or Buildings?
Use of incubators
from experienced manufacturers; with minimum capacity heaters. eg: The Minilab or Dominc Black Chick SI-12A.
Subsequent well
being of chickens?
As chickens do
not need feed or water for 48 hours from hatching, there is enough time
if
needed for transport in standard chicken boxes.
Various options
to match particular resources include the following:
o
Return day old
chicks to source of eggs, such as pupil connexions,
o
Poultry Club
Members
o
Commercial Sale
to rural families, or
o
Keep in metal
cage brooders at school, or a nearby pupil property.
Equipment other
than by purchase?
Some retailers
are willing to hire incubators and brooders, and some Education Boards
and
Teachers Colleges have a small number of units available for borrowing. So too does Dominion Incubators.
Responsibility
for the Project
It is important that
every school involved with a chicken hatching project establishes which
staff
member is responsible to ensure that a fertile egg supply is available,
and
which family is going to receive the resulting chickens and that they
have a
suitable brooder with space and feed to rear them.
Back to Top |
