I Whistle A Happy Tune.............so no one will suspect I’m afraid **

 

Mr. Dad (Emu) by Gwenn Liberty Seemel, Portland, Oregon. 2012 acrylic on panel

So...the emu eggs have been in the incubator for 48 days. You have checked every day that all the mechanics are working right: eggs turning 160-180 degrees every 2-3 hours, humidity holding in a range of 25-35%, your germicidal lights in the incubator (if you have them) still glowing, fresh air coming into the room and carbon dioxide being expelled and hopefully you didn’t need that generator that you have been keeping close in case of a power failure. Now the moment of truth as you check each egg for whistling sounds inside the shell. 

 

This should be done frequently so that when you hear that the chick has pipped through the inner membrane into the air sac and starts talking to the world, you can remove that egg from the incubator so that it is not subjected to any more turning. Some eggs will incubate for 50, 52 and even 54 days before you hear the chick. After pipping has started the eggs are moved to a hatcher where the temperature is about one degree less ie 96.5. 

Some people raise the humidity in the hatcher however if you think about hatching in nature the male emu doesn’t have this capability. You on the other hand might choose to do this if a chick is having a hard time breaking the shell. It would require another hatcher to adjust the humidity and you would also need to ask yourself if the difficulty getting out of the shell is a sign of a weak chick. Breaking out can take a few hours or more and the chick can be left in the hatcher if it pips through during the night as it will need time and heat to dry its feathers. The chicks can then be moved to a brooder. 

The red hue is reflection from the heat lamp above

We use plastic see-through storage containers from Walmart. They are easy to move and clean and soft sided. A heat lamp is used to keep the chicks warm at 90 deg initially and gradually adjusted down to 80 deg. A digital thermometer is hung inside the brooder so that close monitoring of the temperature can be done. Each chick has iodine applied to its navel with a Qtip and is leg banded to track its parentage. The chicks stay in the brooder for 4-5 days in groups of 6 until they can walk around the brooder and eat and drink.

 

Water is introduced the first day which includes a vitamin electrolyte powder and non medicated turkey starter can be held off until day three to ensure that the egg sack is totally absorbed. Early hatchers are usually early to the feed and water bowls and set an example for the rest.

 

As important as water and later food is to the chicks the composition of the floor of the brooder is critical to the safe development of leg tendons. We use plastic kitchen drawer liners because they are non slip and porous so that the liquid from the feces can somewhat drain away. They are also easily washed for reuse. Mortality in chicks is frequently related to splay leg and can simply be prevented by careful handling, good feed (for the breeder pairs as well as the new chicks) that supplies the necessary protein levels for quick growing heavy bodies and the use of a non slip substrate until they can get out on dirt and grass and exercise those tendons (very important as they are a running machine). We will talk more about emu feed in a future blog.

**OscarHammerstein

 

The Ins and Outs of Emu Egg Hatching - Part 2

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.

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

In addition we calibrate our incubators and hatcher every year with a Hanna H198509 Digital Thermometer

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.


 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.

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.

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

·         2^nd 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.

B. Measuring the humidity in the incubator

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.

 



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.

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:

(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:

• 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)

The fourth is intended to be flexible to ensure ideal egg weight loss by making humidity adjustments early on in the incubation period if you choose to.


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!

Source: Wikipedia

The Ins and Outs of Emu Egg Hatching - Part 1




Source: Backyard Chickens, Corny Caleb NJ Mar 26 2014



Most emu farmers would agree that incubating eggs is both a science and an art form. It is much more than just leaving it up to the incubator if you are interested in maximizing your hatch rate. We need to start with a strong foundation of "eggology" (not my term but I like it) and then we can tweak our reactions (this is the art) to problems as they arise. More on the scholarship but first some craftsmanship.


Nguna nynda ?, carved emu egg 2003,
 Barry Bellotti



Barry Bellotti's carved emu egg won the 20th Telstra National Aboriginal & Torres Strait Islander Art Award in 2003. According to Australia's Museums and Art Galleries of the Northern Territory website, Bellotti is a self-taught artist from Carnarvon, WA. Wow, the detail is amazing. The artistic message communicated to this emu farmer is one of caution: "these little beings will be in your charge....be respectful."



Source: The Digital Morphology Library

And on the flip side or the inside as it were another form of artistry is captured in the 2D and 3D visualizations of the internal structure of vertebrates as performed by Digital Morphology, part of the National Science Foundation Digital Libraries Initiative. Here we can see how the fully developed emu chick is positioned. At hatch it will pip in a downward motion through the internal membrane to reach the air supply. A second pip of the outer shell will expose the beak and one foot. With a push, the second foot and spine will fracture the shell and release the chick fully breathing and able to stand in only a few hours.

So let's start with an overview of the anatomy of an egg:
 




Egg Anatomy. Source

http://people.eku.edu/ritchisong/avianreproduction.html

An egg consists of 4 primary components:

 a yolk which provides the food supply to the embryo

the albumen is the source of water supply and also a shock-absorber

the shell membranes protect the egg from external bacteria and help prevent rapid evaporation of egg moisture

the egg shell has thousands of pores which allow for gas exchange



The diagram shows a generic avian egg and we should ask the question as to whether generic avian eggs and their development would be the same for emus. According to the Laboratory for Early Embryogenesis, RIKEN Center for Developmental Biology, Kobe, Japan "emu and chick embryogenesis proceeds through similar stages, but developmental heterochrony between these two species is widely observed." In other words the developmental stages are the same but the timing of size and shape will differ.

Having said that, this video depiction of the development of a chicken embryo will help with our science of emu egg hatching. 

So stay tuned for the next blog when we will talk about managing the necessary egg weight loss as the embryo develops during incubation.