Ratite: Emu Reproduction
Managing egg production
Emus begin breeding at about 20-24 months. Young adults and other unpaired adults should be run in groups in large pens allowing each emu to choose its own mate thus forming compatible pairs; this increases egg fertility. (Selective pairing will begin to take place from December/January each year.) If each pen has only one pair of emus, they may be incompatible and poor matings will result, so decreasing egg fertility and possible bird injury.
When pairs form, they can then be separated into individual breeding pens. If the pair performs well, they can be left as a pair or, if you wish to split them, they can be put into the large group pen after the breeding season has finished.
Alternatively, breeding emus can be left as a group in a large pen and not segregated into individual breeding pens. If this option is chosen it is important to give them sufficient space to avoid fighting and to sex the birds so that the male:female sex ratio is about equal.
Hens will begin to lay from mid to late April each year, and most females will have finished laying by October/November.
Most adults are not physically aggressive to farm personnel when they are collecting the eggs. The few that get ‘too close for comfort’ can be bluffed by facing them and holding up an arm or other object to make you taller than the bird. Walking towards them will usually make them turn away.
However, as a basic safety rule, do not stand in front of an emu within range of its feet; keep at least 1 m away. Emus kick and strike forwards if they feel threatened or are caught but can’t kick sideways or backwards. The beak can pinch but generally causes little damage. Keep an eye on the feet.
Two basic types of incubation can be used – natural and artificial. To date, most emu farmers use artificial incubation.
In natural incubation, the male emus go broody and are allowed to sit on the eggs.
When young females begin to lay, eggs are commonly laid at random throughout the pen. After a time or the onset of maturity, a nest site will be chosen and eggs are then laid at this site. Dispersed eggs are rolled together and often camouflaged with dry grass, sticks and leaves, etc. by the male emu.
The rate of lay is slow initially with several days between the early eggs. The rate increases to one egg every two days or so towards the end of the clutch.
After some 6-10 eggs have been laid, the mature male will go broody and begin sitting on the eggs. Further eggs laid near him are rolled under to join the others. Over a few days, the male will slow his metabolic rate to a point where he sits on the eggs full-time, will not eat or drink, and only stands several times a day to roll the eggs. It is advisable to remove other birds from the pen when a male begins to sit because group penning may result in fighting and egg damage and the male will not settle properly.
Once a male is fully broody, he can be approached quietly, and gently lifted to check the condition of the eggs.
The incubation period for emus is 56 days but it is good policy to check daily from day 50 to see if any chicks have hatched.
If chicks are to be reared in a brooder house, they should be removed at this daily check and taken to the brooder house. If you are leaving the chicks for the male to rear, you should remove all unhatched eggs after the male moves off the nest. At an early age the chicks are prone to wander and care is needed to prevent predators such as crows, hawks and foxes killing them.
Natural incubation requires more space and pens to move birds into; especially if the male is left to rear the chicks. If you plan to do this, you should get further information on this subject before starting because it will require different procedures.
There are problems associated with natural incubation including the potential for bacterial contamination of eggs, especially in wet conditions. Some eggs will be in the pen for two to four weeks before the male sits. During this time, daily temperature fluctuations may trigger the embryo to begin developing and the low night temperatures may kill the embryo – this is known as pre-incubation.
Despite these problems, reasonable hatching rates are possible using natural incubation.
For artificial incubation, eggs are collected once or twice daily and placed in an incubator.
Eggs should be collected daily if possible to reduce pre-incubation problems and disinfected using a recognised egg-sanitation process and stored in a cool room at a temperature of 10-16oC for up to 10 days. Batches are then set in the incubator at regular intervals (setting batches at 10 day intervals is a common practice).
Specific emu egg incubators are available; however, poultry incubators can be converted to hold emu eggs with good results. The eggs should be taken out of cool storage, allowed to return to room temperature for approximately 12-18 hours, then placed in the incubator. As a guide, the incubator will need to be run at a constant temperature of 35.25-35.5oC (dry bulb) and a relative humidity of 45-50% [26-27oC] (wet bulb) throughout the first 50 days of incubation.
The eggs will require turning a minimum of three times per day. This can be done manually or by using automatic turning devices in the incubator. Automatic turning methods can be installed in most incubators. Note, however that eggs should always be turned an odd number of times per day when turned manually. This makes sure that the embryo does not go into the same position each night with the risk of it becoming stuck to the side of the shell and subsequently dying.
At day 50, the eggs are transferred to a separate, clean, hatching compartment. The hatcher should be operated at a slightly lower temperature, 35oC, and higher humidity, 28-29oC (wet bulb). The higher humidity helps to moisten the internal membranes and soften the shell to assist in the hatching process. Eggs are not turned during this period in the hatcher.
Emu eggs, like all other eggs, are susceptible to bacterial contamination and should be sanitised immediately after collection by using a recommended fumigant or egg washing product. Eggs can also be fumigated at certain stages during incubation. Empty incubators and hatching compartments also need to be sanitised between batches using the same products.
Artificial incubation is a specialised procedure and problems may occur if:
- eggs are not collected regularly, fumigated or stored prior to being placed in the incubator
- incorrect temperatures and humidities are used during incubation and hatching
- incubator and hatching compartments are not cleaned or fumigated adequately.
The egg is a living organism and needs to breathe. Fresh air (oxygen) is absorbed through the shell and stale air carbon monoxide and other gases are dispersed. It is extremely important that each day clean fresh air is allowed into the incubator and hatching chambers in order to satisfy this requirement. This is achieved by opening the doors for short periods of time, which occurs during manual turning or using the normal ventilation mechanisms of the machine.
Authors: Paul Kent and Simon Newg
Queensland Government – Department of Primary Industries and Fisheries