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.

Hatching Emu Eggs

Source: Wikipedia

The physical characteristics of an emu egg introduces a unique set of challenges for the farmer. The average emu egg ranges from 550-700 g with a multilayered shell about 3/4 mm thick. In addition it takes about 3 times as long as that of a chicken egg to hatch. So what are the egg hatching options?




Natural Incubation  Source: Wikipedia

After 6-10 emu eggs have been laid the male goes broody and sits on them for approximately 50 days. As the female averages 20 eggs a season it wouldn’t be practical for an emu farmer with segregated breeding pairs to cut the production of fertile eggs by a possible 60%. So each egg on our farm is collected every 3-4 days and stored until a workable hatch volume can be started. 

 
During the early 1990's hayday of emu farming typically the farmer’s business plan was to hatch as many eggs as possible. The chicks would then be sold to entry level emu farmers. Proven breeding pairs were going for as much as $40,000.00. As an emu egg is quite large, the garden variety chicken and duck incubators if modified would not produce the volumes necessary. So highly priced incubators came on the market and it was not uncommon to spend $10-15,000.00 for a machine that held hundreds of eggs. A few examples:



Hatchrite Incubator



N'Kobi Big Bird Series Incubator

Now 20+ years later most of these manufacturers have gone out of business. If one can acquire a used machine stored in a shed somewhere and is mechanical or has a friend, these cabinet incubators can be functional again. We had our N’Kobi Big Bird incubator in for repairs at Boulter Machine Works in Duncan this egg laying season and we were told that it was extremely well made and we should expect to use it for a good long time. The Hatchrite has a very strong following with a lot of people still using them since the 90’s. There is an enthusiast in Washington who has instruction manuals, parts resources and wiring diagrams etc, etc. His name is Kevin G. McCoy. Kevin has also recorded some YouTube videos that might help with Hatchrite refurbishing.

On a smaller scale the very reliable GQF incubator does come in an emu egg version. There are specific trays that can be purchased separately and it can hold 36 eggs at a time.


GQF Cabinet Incubator 1500

Large Egg setting tray and positioners

  

Still another option would be to import from another country such as China.

One of many designs from Alibaba

The price is often affordable and shipping by sea inexpensive if you have lots of time. However keep in mind that their mass target market is chicken and duck producers. One needs to ensure that manufacturer customisation of the egg trays and rotating shelves for emu incubation will do the job correctly.

Now finally, on a very large scale an insulated room can be dedicated for incubation and hatching. We toured this California emu farm linked here and were very impressed with their facility.

So as you can see there are many incubation options available. Start by deciding what size of an emu farm is it that you want and can afford. Then do your research. Remember that incubation is only one part of the infrastructure costs.

This final point brings up a whole other strategy to increase the size of your "mob".  You can source out a farmer that is selling hatched chicks. They are usually sold no younger that a week old from the farm gate rather than shipped. The going rate of around $100.00 factors in the partial expenses of the breeding pair and the operating costs of the 7 weeks of incubation. Sexed chicks would be more as this information would provide one extra leap forward in the plan.

Source: Wikipedia



Going With The Flow

Spring is well upon us and emu egg laying is almost at an end. Only a few weeks ago this alpha male was "very interested" in spreading the love with anything that walked by his fence line. His manner and his appearance (he will soon loose his black head feathers) have changed (turned off like a tap) to that of a docile "coming up 2": only interested in food consumption and catching some rays. That's good for us as we have been plagued with incubator problems this year and we are looking forward to hatching time.

taraxacum ruderalia maskros - wikimedia commons

Yes that's real farming (not the postcard version) and will need a lot more
discussion in subsequent posts.


What is not at an end this spring is the overabundance of dandelions. Having grown up in suburban Toronto, I have developed a killer instinct for these dreaded yellow weeds in the grass and the rose garden. And now living in farm country I find it is impossible to eradicate them if avoiding pesticides. However this year I have learned to embrace these nutrition laden delicacies as the emu love them. So at morning chore time I collect a bucket of dandelions and congratulate myself in avoiding vet bills and completing some square foot gardening all in one fell swoop.


So in the spirit of my new found happy dance I need to share two videos with you. The first shows a male emu courting his new prospective mate, however she will have the last word. (youtube.com Animal Planet)

 

And the second shows a music box version of the dance created by Di Holdsworth an Australian Music Box artist who lives in the Blue Mountains west of Sydney where the emus roam. (youtube.com Di Holdsworth)

                   
                   

Would you like some ham with that ...... green egg?

Yes we are livestock farmers here on Mt. Sicker Road and raising emu for their meat and fat. But as it is Spring and the Easter weekend we should probably talk about eggs.


By Zureks at Wikimedia Commons


An emu egg is about 10 times the size of a large chicken egg so one emu egg omelette will probably feed the whole family.  It has a very thick (3 thick layers and 4 paper thin layers) shell as the 125 lb. Emu Dad will be sitting on it and rolling it around for 52 days before the chick is hatched. Some people carve designs in the shell which exposes the lighter shades of green underneath. The inside looks very much like a chicken egg except that the paler looking and milder tasting yolk is almost half of the contents. It stands to reason as the yolk is used to nourish a developing emu chick and that takes 3 times as long as a chicken.

For cooking purposes the white has a little less water content and so will beat to a fluffier texture and the larger yolk is great for baking cakes.  Some mail order companies such as Clarence Court outside of Plymouth UK send out their edible emu eggs nestled tight in fancy boxes. Their website has fantastic egg recipes from quick and easy to complex. 

And from a health perspective, Japanese researchers report in 2010 that emu egg white has an unusually low allergenicity and suggest that emu egg white could replace its chicken equivalent in “industrial products”.

So no matter what kind of egg experience you have this Easter weekend we at Mt. Sicker Family Farm wish you a happy one.

In Australia when "fall is in the air" (Mar-May) it signals Emu Breeding Time

An illustration based on aboriginal style of dot painting
depicting emu (http://www.123rf.com/profile_deboracilli)

As this emu farm is well into breeding season I thought it was time to reflect on Australian emu roots.

Using an aboriginal symbol glossary as reference here is one Canadian emu farmer's interpretation of this dot painting by Debora Cilli.

Bottom right:  The concentric circles portray the social camaraderie of the emu community. Their nomadic travels through the temperate and grassland areas of Australia are depicted by the emu footprints entering and leaving the circle. Similarly when emu bed down for the night they gather in circle formation with their heads at the centre.

Centre Line:  The meandering centre line represents a river and depicts the constant searching by emu for this life force. It also separates the 6 months of social behaviour from the mating activities of breeding pairs.

Top Left:  Shows emu mating responsibilities: after she has laid 8-12 eggs he will know it is time to go broody and he will drive her away to find another mate.