Ostrich Breeding, Egg Handling, Egg Collection

Ostrich Breeding, Egg Handling, Egg Collection - Incubation and Hatching

1) Ostrich breeding
2) Handling Ostrich eggs
3) Egg collection and storage
4) Incubation
5) Embryonic development
6) Hatching
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Ostrich Breeding

Ostrich hens become sexually mature when they are between two and three years old, males usually a year later.
In the Northern hemisphere the breeding season runs from March till October.
In the Southern Hemisphere the breeding season runs from August till February.
The increase in day-length is the determining factor for the start of the breeding-season.
At the beginning of the breeding season, males show a distinctive reddening of the shins, the beak and the rims of the eyes.
The intensity of the reddening is correlated with the virility of the male, and consequently with the fertility rate of the eggs.
Sometimes they fill their oesophagus with air so that their neck looks like an inflated balloon. They then make a low monotonous booming sound.
When breeders are kept in a larger group, breeding pairs or groups will form naturally.
The males will draw attention by performing a mating dance in front of the females.
Virile males can serve several hens. But if the number of females per male is too high, there is a risk of getting a lower fertility rate of the eggs.
Ideally each breeding group (one male with one to three females) is kept in a separate paddock. Otherwise males will spend too much time and energy fighting with each other.
Before the season, the breeder paddocks should be ploughed and replanted to get rid of all microbes that may otherwise infect the eggs. If there is enough space available, one can fill only half the paddocks, using every other one.
This gives time to clean and replant the paddocks not in use.
When the breeding groups are formed, they will pick a territory and the male will make a nest by scraping out a hole of 15-20cm deep and 1-3m in diameter.
After the nest is made, a simple shelter can be placed over it to keep the eggs dry.
Before mating the male performs 'kantling'; while on his knees he flaps his wings in a rowing motion.
His neck is bent in an 'S' and he swings his head from left to right hitting his rump.
The hen assumes a submissive position with her head and neck close to the ground, her wings held away from her body and pointed downward.
During copulation, the males' penis deposits semen in the hen's cloaca close to the oviductal opening.
The semen is transported to the oviduct by ciliary action.
During their first laying season, hens lay between 10 and 30 eggs, later this increases to between 40 and 70 eggs.
Hens lay their eggs in clutches; she will lay an egg every 2-3 days until up to 20 eggs. Then she will pause a while before starting another clutch.
Unseasonal weather variations can disrupt this pattern.
A good breeding group produces eggs with a fertility rate of at least 90%. Early season and late season eggs may be less fertile.
When kept healthy and in good condition ostriches remain productive for 25-35 years, which means that the purchase of breeders can be considered as a long-time investment.
Ostriches should be allowed to sit on one cluster of eggs within their first 6 years or some may give up laying eggs altogether.
Some people recommended separating the sexes for about two months before the actual mating season. This increases the mating mood when they meet again at the start of the season.
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Eggs and their Handling

The egg:
The Ostrich egg is oval with a glossy porcelain-like shell, pitted with hundreds of pores.
The eggs vary in shape, size, weight, shell structure and shell porosity.
The average size is 13cm x 16cm and the weight ranges between 1.1 and 1.9 kg.
The shell is about 2mm thick and is covered with an anti-bacterial coating; the cuticle.
The shell mostly consists of calcium carbonate. It is a source of Ca for the growing embryo.
The shell membranes which are on the inner side of the shell obstruct bacterial penetration by molecular size exclusion.
The egg yolk, which makes up 1/3rd of the volume, provides energy and most of the nutrients needed for the development of the chick.
The yolk is held in the centre of the egg by two arms or chalizes.
In a fresh egg the embryo can be seen as a whitish disk on the surface of the yolk.
The development of the embryo starts inside the hen's body right after fertilisation, but stops when the egg is laid until it is brooded or incubated.
The albumen supplies water and some proteins, vitamins and trace elements.
It also provides physical and anti-microbal protection for the embryo; albumen is bactericidal due to its high pH and to the action of lysosymes.
The vitamin and mineral content of the egg is determined by the diet given to the hen before the laying season.
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Egg collection & storage:

Eggs should be collected as soon as possible after being laid, at least once a day.
Each egg should be put in a separate plastic bag to avoid contamination.
The identification number can be recorded on the egg.
Eggs can become infected either from the outside, by bacteria passing through the eggshell, or internally by the hen before the shell is formed (e.g. salmonella).
Storage of eggs for a few days allows the albumen of the egg to settle down prior to incubation.
They should be stored at 12 - 18 degrees C in a dry clean room.
They need to be turned twice a day in alternative directions(forward in the a.m. back at p.m.)This stops the chalizes from twisting.
Dirty eggs have to be dry-cleaned before storage.
Some people disinfect the eggs, for example with formaldehyde gas.
Others prefer to wash:
After dirt is removed with a soft brush, the egg is submerged in a sanitary solution (vircon)(10% warmer than the egg) for 60 seconds,wiped clean with a soft cloth, dipped in warm rinse water and air dried.
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Incubation

Incubation parameters:
In nature both males and females brood the eggs, hens during the day, cocks mostly during the night.
The eggs are in contact with the parent bird's bare skin.
The temperature at the top of the egg is always higher than at the bottom.
When changing shifts, the eggs are turned and aired.
Incubation of an ostrich egg takes 42 days on the average.
In artificial incubation the temperature has to be around 97.5 degrees F.
Towards the end of incubation the temperature may be a bit lower since the embryo also produces heat at a later stage of development.
Relative humidity is set between 20 and 35%.
During the 42 days of incubation the egg loses 11-18% of its total weight by exuding of water and carbon dioxide.
The rate at which water is lost depends on the relative humidity of the incubator as well as on the pore density and shell thickness of the egg.
Since each egg is different, the rate at which weight is lost also differs.
Ideally the eggs should have lost 13% of their weight at 42 days.
In practice the weight loss is measured for all eggs at 21 days.
At that time the water-loss should be half-way (6-7%).
Good ventilation inside the incubator is also essential because the embryo has to breathe; it takes oxygen and it produces water and carbon dioxide, which have to be removed.
If the airflow is insufficient, the embryo may suffocate.
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Incubator room

The environment (temperature, relative humidity) of the incubator room has to be controllable.
The room should be ventilated, exhausting air directly to the outside rather than re-circulating the same air.
All parts of the room should be washable.
No visitors must be allowed, and a foot bath and hygienic clothing for the personnel is necessary.
Before introducing eggs the incubator and all equipment must be cleaned and disinfected, using hot water and a disinfective soap or Vircon.

Fumigation with Formaldehyde is also a common practice:

20 cc Formalin per 10 g Potassium Permanganate (KMnO4) per sq. m of incubator, this for two hours at 25 degrees C during pre-heating.
Fumigation can also be done with eggs inside the incubator.
Then the concentration has to be reduced to half, and all vents must be open.
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Embryonic development

Eggs should be placed in the incubater with the air gap upwards. Eggs must be turned 2 to 8 times daily. This helps avoiding build-up of waste products inside the egg.
The embryonic development can be followed by candling the egg, with a torchlight for instance.
Candling is usually done once a week. Photos
Infertile eggs (egg totally clear and clean) or eggs with early embryonic death should be removed since if they start to rot they can contaminate other eggs. Normally you will smell a sulphur type odour when an egg has started to go off and by smelling each egg you should be able to find and remove the culprit.
Often contamination is spread by human hands, during candling.
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Hatching

The temperature in the hatcher has to be 2 - 3 degrees C lower and the R.H. slightly higher.
Eggs are transferred to the hatcher room at 39 days or as soon as internal pipping can be heard.
This happens when the fully formed embryo breaks through the membrane into the air sac for its first breath of air.
It is than able to 'cheep'. The neck muscles then stiffen and the chick's head breaks through the shell.
Now the chick has unlimited oxygen supply and can work its way out. After internal pipping, the chick can survive for 2-3 more days.
Some chicks are malpositioned inside the egg or don't have the strength to break the shell, these need some help.
Before hatching, the yolk sac is absorbed inside the chick's belly. After hatching, the navel, where the umbilical cord makes the connection with the yolk sac, has to be sprayed with a disinfectant (e.g. iodine).
The chicks should stay in the hatcher till completely dry and their feathers fluffed out.

Raising Chicks