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| Source: Backyard Chickens, Corny Caleb NJ Mar 26 2014 |
In
part one of The Ins and Outs of Emu Egg Hatching we reviewed the
natural development of the embryo as it is incubating. Now we are going
to look at the environmental conditions necessary to bring that developing chick to successful hatch. There are four main principles to incubation.
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 deflectors 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.
To monitor incubator temperature we previously used Thermoworks thermometers. Now we use and recommend WiFi sensors from Sensor Push as they supply remote information with accuracy and reliability.
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.
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.
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| Air In....... Moisture Out |
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.
Click image to enlarge
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.
(1) lowered closer to 24%
There are other options available if raising or lowering humidity is not getting the results that you need:
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 |
