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| Source: Backyard Chickens, Corny Caleb NJ Mar 26 2014 |
Note 2022: this post has been updated to reflect the new technology that we using to bring more confidence and convenience to our emu egg incubation. The incubation principles that are described here remain the same.
The first principle is to maintain a constant temperature throughout the incubator. Emu eggs are incubated best at temperatures between 97.0F-97.5F ( see chart 1 below). This will allow for healthy embryo development and a usual hatch time of about 50-52 days. Commercial incubators allow for even air temperature to be circulated around all the eggs from top to bottom. Other styles that have a fan located at the top of the units might require homemade defectors on the glass at the front to redirect warm air evenly to the bottom shelves. It is a good idea regardless of how sophisticated the incubator to have at least a couple of additional thermometers monitoring the inside temperatures. High temperatures during incubation cause more harm than low temperatures.
2014 "We use Thermoworks thermometers as they are handy and accurate in our experience."
Update 2022: With new technology we have successfully switched to wireless temperature and humidity sensors with cloud based alerts for 24/7 monitoring with SensorPush
Access to a generator is a must if power outages are a possibility and a supply of spare parts for the incubator ensures quick reaction time.
The second principle is to maintain constant fresh air exchange in the incubator room and hence in the incubator itself. As the emu eggs incubate they expel carbon dioxide which needs to be exhausted from the incubator. Fresh air can be brought in passively through a cracked window from the outside avoiding a direct draft to the incubator air intake.
2014 "We use a ceiling exhaust fan to circulate the air and exhaust the CO2. One that has a timer will give the flexibility to adjust for local outside weather conditions. We use the one pictured here from Home Depot."
The first principle is to maintain a constant temperature throughout the incubator. Emu eggs are incubated best at temperatures between 97.0F-97.5F ( see chart 1 below). This will allow for healthy embryo development and a usual hatch time of about 50-52 days. Commercial incubators allow for even air temperature to be circulated around all the eggs from top to bottom. Other styles that have a fan located at the top of the units might require homemade defectors on the glass at the front to redirect warm air evenly to the bottom shelves. It is a good idea regardless of how sophisticated the incubator to have at least a couple of additional thermometers monitoring the inside temperatures. High temperatures during incubation cause more harm than low temperatures.
2014 "We use Thermoworks thermometers as they are handy and accurate in our experience."
Update 2022: With new technology we have successfully switched to wireless temperature and humidity sensors with cloud based alerts for 24/7 monitoring with SensorPush
In addition we calibrate our incubators and hatcher every year with a Hanna H198509 Digital Thermometer
The second principle is to maintain constant fresh air exchange in the incubator room and hence in the incubator itself. As the emu eggs incubate they expel carbon dioxide which needs to be exhausted from the incubator. Fresh air can be brought in passively through a cracked window from the outside avoiding a direct draft to the incubator air intake.
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| www. titancontrols.net Apollo 7 - 24 Hour Digital Timer |
2014 "We use a ceiling exhaust fan to circulate the air and exhaust the CO2. One that has a timer will give the flexibility to adjust for local outside weather conditions. We use the one pictured here from Home Depot."
2022 Update: We now provide outside fresh air through overhead piping and exhaust directly from the incubators through another set of overhead piping to the outside of the building. To take the load off the incubators the room itself is conditioned using a floor heater set at 70 deg and a dehumidifier set at 30%.
The third principle is to adjust humidity when required.
Oxygen in the air is absorbed through the shell as the emu
embryo develops over an incubation period about 2.5 times that of a chicken (as noted above the resultant
CO2 will be expelled). The
air cell starts out small and increases to approximately 1/3 of the egg
capacity by hatch time (see update). This predictable air cell growth can be monitored using
a candling device. Due to the thickness
of an emu shell a simple chicken candler will not be useful. Specialized
candlers have been developed and can possibly be sourced over the internet. We
have an Emu Vision 2000 stand alone candler but haven’t used it enough to give
an expert opinion. It has a video monitor and an infrared light source. Commercial
emu egg incubators such as Hatchrite have a candler device included. As the air cell growth is monitored
adjustments to the incubator humidity can be made to speed up or slow down the
growth if needed. Due to the
limited transparency of the emu egg shell we will look at another
facet of egg incubation.
In summary:
Chart 2 to the right then converts those ideal dry and wet bulb readings to the % humidity range of 24-35.
So if the emu egg weight loss is out of spec ie below 13% (1) or above 17% (2) the incubator humidity is:
(1) lowered closer to 24%
Incubating emu eggs is not a difficult process but does require attention to detail and good equipment and record keeping. Good luck with your endeavours and enjoy the rewards!
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| Air In....... Moisture Out |
As the emu embryo develops moisture from inside the egg is
expelled through the pores in the shell. The air coming in weighs less than moisture
going out so the emu egg will decrease in weight. The ideal rate of weight loss for emu eggs is15% of the original egg weight for successful hatch. This weight loss can be
monitored and is the measurement most commonly used by emu farmers.
2014 "As the
weight loss (ie evaporation rate) is determined adjustments to the humidity
conditions in the incubator can be made to speed up or slow down the developmental
process."
Update 2022: The information here of measuring egg weight loss and possibly adjusting humidity in the incubator was a practice followed by many emu farmers including ourselves and perhaps worth the read. We have however come to the conclusion that it is a lot of effort (and stress) with minimal benefits to the process. When setting the eggs and finding one or two with some large pores ie small portions of the egg that didn't get the final dark green shell covering we will use masking tape to cover those pores and reduce the moisture loss. As emu eggs will successfully grow in a range of some 10% humidity fluctuation we have learned to not fixate on this part.
In summary:
- When the air cell growth is too slow then the evaporation rate in the egg is too low and can be identified as a slower than ideal rate of weight loss.
- When the air cell growth is too fast then the evaporation rate in the egg is too high and can be identified as a faster than ideal rate of weight loss.
- So the goal is to maintain the egg weight loss at an ideal of 15% and within a range of 13-17%. At 10% weight loss (or 20% on the other end of the scale) the conditions for proper chick development are severely jeopardized.
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| Click image to enlarge |
A. Measuring weight loss
Good record keeping is the key to this process. As each egg
is collected from the nest its breeder pen ID is noted on the egg with a china marker ie 3/mar 4 means breeder pen 3 and lay date of March 4. When ready to
incubate a batch each egg is weighed and recorded on the shell of the egg as
well as on a paper/computer record for future comparisons. An accurate scale is
necessary when weighing incubating eggs. It must be able to measure in tenths
of a gram rather than in pounds.
A simple set of formulas is applied to the weight of each
egg. To monitor a 15% weight loss progress use the following example:
·
original egg weight of 641g
·
2nd day egg weight of 637g
·
total length of incubation is 50 days
Start Wght Predicted
Final Wght Predicted
Daily Wght Loss Actual Wght
Loss
641g 641–(641 x .15)=545g (641
x .15)/50 days=1.9g (641-637)/2 days=2.0g
Some emu farmers weigh their eggs every day for the first week to ensure the ideal weight loss and then randomly for the remainder of the hatch. Others measure every week for the first 3 weeks. As critical embryo development occurs in the first third of the hatch it is this farmer’s opinion that the first option is the safest.
Some emu farmers weigh their eggs every day for the first week to ensure the ideal weight loss and then randomly for the remainder of the hatch. Others measure every week for the first 3 weeks. As critical embryo development occurs in the first third of the hatch it is this farmer’s opinion that the first option is the safest.
B. Measuring the humidity in the incubator
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| http://www.forestry-suppliers.com/ Taylor® Mason’s Hygrometer |
Emu eggs develop best at humidity readings between 24 and
35% (see charts 1 & 2 below). These conditions are a little more flexible than temperature readings and
can be adjusted.
Incubators frequently have digital readouts to show the humidity
conditions under which the eggs are incubating. To back up this technology we
use a manual system with the aid of a hygrometer. Hygrometers measure dry and
wet bulb temperature conditions. We use the Taylor version.
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| Source: aggie-horticulture.tamu.edu lee-cartwright-incubating-and-hatching-eggs.pdf |
Chart 1 to the left explains the ideal conditions for incubating emu eggs. The hygrometer should read 97.5 deg dry bulb and 70-75 deg wet bulb. To enlarge this chart click on it, search for the pdf and the information is on page 6.
Chart 1 to the left explains the ideal conditions for incubating emu eggs. The hygrometer should read 97.5 deg dry bulb and 70-75 deg wet bulb. To enlarge this chart click on it, search for the pdf and the information is on page 6.
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| http://www.berryhill.ca/ |
Chart 2 to the right then converts those ideal dry and wet bulb readings to the % humidity range of 24-35.
So if the emu egg weight loss is out of spec ie below 13% (1) or above 17% (2) the incubator humidity is:
(1) lowered closer to 24%
(2) raised closer to 35%
There are other options available if raising or lowering humidity is not getting the results that you need:
There are other options available if raising or lowering humidity is not getting the results that you need:
(1) move the egg away from the humidity source, dehumidify
the incubator room, move egg(s) to another incubator with a lower humidity setting
(2) tape off (using electrical or duck tape) some of the
pores on the shell, humidify the room
The fourth principle is to turn eggs (in a rocking motion) through 180 degrees frequently per day.
In the natural setting a male emu will move the eggs that he is incubating many times during the day. This instinct ensures proper contact by the embryo with the food material contained in the egg. In artificial incubation conditions the egg must be rocked back and forth through 180 deg. It is never fully turned through 360 deg. as this will disorient the growing chick. Ideally this rocking is done as frequently as every two hours to a minimum of 3 times in 24 hours so that the egg isn't in the same position through the long period at night.
Well that's a lot of detail to digest. Keep in mind that there are just four main principles to successful emu egg incubation.
Three of them are defined:
The fourth principle is to turn eggs (in a rocking motion) through 180 degrees frequently per day.
In the natural setting a male emu will move the eggs that he is incubating many times during the day. This instinct ensures proper contact by the embryo with the food material contained in the egg. In artificial incubation conditions the egg must be rocked back and forth through 180 deg. It is never fully turned through 360 deg. as this will disorient the growing chick. Ideally this rocking is done as frequently as every two hours to a minimum of 3 times in 24 hours so that the egg isn't in the same position through the long period at night.
- temperature holds at 97.0-97.5 degrees
- constant fresh air needs to be available
- eggs need to be rocked through 180 deg (not 90 deg as with other eggs)
Incubating emu eggs is not a difficult process but does require attention to detail and good equipment and record keeping. Good luck with your endeavours and enjoy the rewards!
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| Source: Wikipedia |
