Studies on Ostrich (Struthio Camelus) - Review

Abstract

Ostrich has been reared in Hungary for decades, but we have limited information on this species. The aim of this review was to provide a concise description of the ostrich (Struthio camelus) based on international studies. We were to investigate some of the most relevant parameters, such as egg, meat and skin production. In this critical review we managed to sum up the most significant features and productivity parameters of ostrich and effecting factors. So as to make an accurate description of the species we have to know its morphological, behavioural and physiological characteristics. Ostrich is a very special bird with special nutritional and environmental requirements. Ostrich products, regarding egg, meat and skin are considered luxury products not only in Hungary but also abroad. Though egg has a significant nutritional value, it is mainly used for hatching chicks. In Europe we can expect roughly 40–50 eggs from a hen yearly. Ostrich has a lean meat with high protein and low fat and sodium content, moreover it is rich in minerals and polyunsaturated fatty acids. Having these advantageous qualities, ostrich meat should be part of our healthy diet. Skin production is not important in our country, but there is a special demand for high quality ostrich leather globally. In the future our aim is to conduct a research on some of the parameters. As low production rate and embryo mortality is a great deal of problem in ostrich industry, we need to investigate the incubation environment. There is an apparent disagreement among researchers on optimal slaughter age. This is also an area for further investigation. The value of skin and effecting factors on our climate as well as adaptability of the species are also worth for further investigation together with the nutrition what differs from other ostrich breeding countries. Nowadays, there is a great emphasis placed on animal welfare too.

Full text

ACTA AGRARIA DEBRECENIENSIS 2020-1
DOI: 10.34101/actaagrar/1/3772
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Studies on Ostrich (Struthio Camelus) – Review
Lili Dóra Brassó – Béla Béri – István Komlósi
Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Doctoral School of Animal Science
brasso.dora@agr.unideb.hu
SUMMARY
Ostrich has been reared in Hungary for decades, but we have limited information on this species. The aim of this review was to provide a
concise description of the ostrich (Struthio camelus) based on international studies. We were to investigate some of the most relevant
parameters, such as egg, meat and skin production. In this critical review we managed to sum up the most significant features and productivity
parameters of ostrich and effecting factors. So as to make an accurate description of the species we have to know its morphological, behavioural
and physiological characteristics. Ostrich is a very special bird with special nutritional and environmental requirements. Ostrich products,
regarding egg, meat and skin are considered luxury products not only in Hungary but also abroad. Though egg has a significant nutritional
value, it is mainly used for hatching chicks. In Europe we can expect roughly 40–50 eggs from a hen yearly. Ostrich has a lean meat with high
protein and low fat and sodium content, moreover it is rich in minerals and polyunsaturated fatty acids. Having these advantageous qualities,
ostrich meat should be part of our healthy diet. Skin production is not important in our country, but there is a special demand for high quality
ostrich leather globally. In the future our aim is to conduct a research on some of the parameters. As low production rate and embryo mortality
is a great deal of problem in ostrich industry, we need to investigate the incubation environment. There is an apparent disagreement among
researchers on optimal slaughter age. This is also an area for further investigation. The value of skin and effecting factors on our climate as
well as adaptability of the species are also worth for further investigation together with the nutrition what differs from other ostrich breeding
countries. Nowadays, there is a great emphasis placed on animal welfare too.
Keywords: ostrich (Struthio camelus), behaviour, ethology, adaptability, egg production, meat production, red meat, skin production
INTRODUCTION
The ostrich was domesticated in South Africa in the
19th century in order to use its feather to make
fashionable women clothes. From 1980 intensive
ostrich industry was initiated on the basis of feather,
meat and leather production. The Struthio Camelus
species has different subspecies as Red Necks (Struthio
camelus massaicus, Struthio camelus camelus) Blue
Necks (Struthio camelus molybdophanes Struthio
camelus australis) and the South African Black Neck
(Struthio camelus domesticus), on which the ostrich
industry is built and was created by the synthetic cross
of the Struthio camelus camelus and the Struthio
camelus australis (Engelbrecht, 2013). There have
been many studies conducted on production and
genetic evaluation of ostrich. In this study our aim was
to compare these results and draw the conclusions.
Three main economic values of the ostrich are egg,
meat and skin. Human consumption of ostrich egg is
not significant, as it is concerned as a luxury. Even
though it is known for its high nutritional value, is
rather used for hatching chicks (Kokoszynski, 2017).
Meat production means mainly raw meat, steak, dry
goods and hamburger meat (Al-Nasser et al., 2003).
The significance of ostrich was that it could replace
beef as an alternative red meat source in the case of
BSE (Poławska et al., 2011). Additionally, ostrich meat
is ideal as a healthy diet due to its low fat and
cholesterol content (Poławska et al., 2011) and high
amount of polyunsaturated fatty acid content (Paleari et
al., 1998). Skin is particularly used for making items,
accessories and jeweleries from it. In the current review
we are to present this species regarding these qualities
and attempt to focus on those parameters which have
been investigated so far and we plan to research them.
MORPHOLOGY AND MORPHOLOGICAL
ABNORMALITIES
Ostriches are the largest flightless birds in the
world, having a maximum 150 kg weight and 1.8–2 m
height (Hallam, 1992). Adult males have black body
feather and white primaries and tail feather, females
and young males are brown or similar to ash (Davies
and Bertrem, 2003). Living in the African Savannah,
ostriches have to rely on their locomotor abilities to
make long distances seeking for nutrition or to survive
from predators or the aggressive ones (Williams et al.,
1993). Ostrich can run at a pace of 60 km/hour, so that
a really special leg anatomy and locomotor system is
expected to achieve it (Deeming, 1999).
There are several morphological abnormalities
observed in ostrich and many of them are related to the
limbs. Pelvic limb deformities are frequent among
captive-reared ostriches, especially tibiotarsal rotation
which results in a decreased meat production. The
rotation occours as a consequence of rapid growth
between the 2nd the 10th week of age. The condition of
chicks steadily worsens until chicks are unable to walk.
It can be caused by various environmental factors, as
well as insufficient nutrition or exercise (Hahulski et
al., 1999). Spread bow leg is also a common disease
among ostrich, which the result of the improper vitamin
supplementation or rapid growth (Cooper et al., 2010a).

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ETHOLOGY AND ADATABILITY
Daily routine and sexual behaviour
Daily routine
The six most common behaviour patterns are
standing, walking, trotting, sitting, foraging and
pecking (Mbaya, 2015). The observations of Mc-
Keegan and Deeming (1997) are in agreement with
Faki (2001), that ostriches spend most of their time
standing, except for bathing, resting and nest-making
(Degen et al., 1989). During the summer, trios and pairs
show the greatest difference in their behaviour (Mc-
Keegan and Deeming, 1997). Layers spend twice more
time with foraging and pecking, than males, but males
pace two times more than females. When ostriches peck
they do not sort out things (Ross and Deeming, 1998;
Degen et al., 1989). As breeding season is coming, hens
and males display a kind of aggression, which becomes
stronger while going into summer. They are violent
toward juveniles, other species and even each other
(Bolwig, 1973). According to Deeming (1997)
ostriches sit more in rainy weather, than in dry periods.
As for the time of the day, they stand more in the
morning, than in noon, and spend more time with
drinking and foraging in the afternoon (Ahmed and
Salih, 2012). Also Mbaya et al. (2015) demonstrate,
that ostriches are more active in the morning and rest
more in the afternoon due to the hot temperature. Most
hours spent with walking in this study agrees with the
observations of Cooper et al. (2010b). We should
mention yawning and stretching as the most important
maintenance activities. Yawning occurs right after
hatching as the consequence of tiredness. Chicks get
tired after moving some meters in the nest, then they
gather, yawn deeply and stretch. Yawning is generally
displayed before sleeping, stretching is showed after
waking up. These activities are endogenous and are to
regulate the work of the breathing and circulatory
system. These activities can be triggered by the lack of
oxygen (Dumpert, 1929), or a homeostatic connection
between the central breathing system and the
extrapyramidal path (Selbach and Selbach, 1953).
Running and dancing can mean a game, but it can be
the sign of threat, when they hear unknown noises.
One-week old chicks run and dance the most compared
to the elder ones. They also like bathing in the sand,
mainly in the afternoon (Amado et al., 2011;
Alvarenga, 2006; Csermely et al., 2007). As for their
thermoregulatory activity, they open their beaks and
pant, and open their wings. They use their wings against
hot climate to regulate temperature, as well as to protect
their chicks and eggs, and to show courtship. To heat
themselves, they lay down and cover their thighs with
their wings. They are able to freeze instead of going
into the pen, that is why we have to close them in winter
(Samson, 1996). Since ostriches do not have uropygial
gland, grooming is not a dominant behaviour. Instead
of grooming they have a bath in the sand or dust
(Samson, 1996). We can also find ostriches trembling
with threats, which is caused by the stress due to being
cornered or transported. This is the sign of concern,
rather than being cold. When they are afraid of
something, they raise their tail feathers up, hiss, open
their wings and ruffle their feathers, especially on their
neck. It can be seen mainly on males. Forward kicking
is mostly performed by juveniles and adults in the
breeding season. When an individual meets an
aggressive one, it runs away or submits itself without
defend. Such animals can even die from stress, injuries
or exhaustion (Samson, 1996).
Sexual behaviour
According to observations 80 % of females make
relationship with one male, 20 % of them mate with
several males during the breeding season (Blach et al.,
2000). It is typical of their courtship behaviour, that
females initiate relationship. If a potential male
appears, they pose in front of him and send other
females and juveniles aggressively away. The female
expresses her physiological readiness to mate by a
clucking sound made by rapidly opening and closing
her beak (Samson, 1996). The redness of the beak and
the skin of neck, thigh and foot can be seen in males,
when they accept the female closing to them. If the
males want to mate, they display courtship to the
female (Sauer and Sauer, 1966). The female lifts its
wings up and down, put down its head and lifts up its
neck and tail and urinate on the ground. Before mating
the male stamps several times, puts one of its legs on
the back of the female and attempt to find cloaca
contact. During mating the male displays the
movements of courtship and groans at the end of the
mating (Sauer, 1972). These patterns were observed by
Bolwig (1973) as well. The mating lasts for about 1
minute, while the female does not show any special
signs except for opening beaks and stretching its neck
ahead. The female which mates with the male first
becomes the major female. It lays eggs first in the
middle of the nest, then the consecutive females
become minor females and start to lay eggs two or three
days after the major one. Females lay eggs every
second day, but major females can visit the nest every
day. In this case, when a minor female comes
sometimes it has to wait for the major one to allow her
lay egg. This waiting time can last for 20 minutes. The
major female waits for her laying eggs then sits back.
Laying takes only a minute, but minor females attempt
to appear to lay eggs when the major hen is not present.
The major hen lays about 9–14 eggs in a nest, altogether
26 during the breeding season, the minor ones
(generally 3) lay 3–20 eggs, with an average 11
(Bertram, 1992; Muhsi et al., 2008; Patodkar et al.,
2009). They lay them in the late afternoon or in the
early evening and to fill a nest they need 30 days. Males
also can display courtship against each other, but this is
the sign of aggression, when they appear on each
other’s territory. Guarding and hatching is the duty of
the major hen and the male, respectively. The male
spend 71 % of his time hatching eggs one day. They
switch in the morning and in the afternoon as well
(Sauer, 1972).

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Abnormal behaviours
Feather pecking
They pick each other’s back and tail feathers. It can
be triggered by stress, overcrowding, boredom and
occurs more frequently in winter due to the long closed
period (Stewart, 1994). Toe and face picking can be a
serious problem, when the ostriches peck even each
other’s eye lids. Causes are the same as in feather
pecking (Samson, 1996).
Stargazing
Individuals showing this abnormal behaviour
permanently raise their head, and put it on their back.
After a while it is difficult for them to walk, eat and
drink. It can appear as the consequence of confinement
or the lack of thiamine (Samson, 1996).
Anorexia
It occurs when in a pan animals displeased by using
feed and water containers and avoid them. It can
happen if they are fed with mouldy feed or water with
high chloride content. If they are not supplied with
other feed they can starve to death and dehydrate
themselves (Samson, 1996).
Dietary indiscretion
Ostriches do not only consume what is good for
them. There are many cases not depending on age, that
they pick up metal pieces and sharp items due to stress
or curiosity. It is very serious, since it causes
perforation or gastric stasis in the gastrointestinal tract
(Honnas et al., 1991; Gamble and Honnas, 1993).
Pica
Eating feces in chicks is a completely right activity,
because they can get microflora which is necessary for
digestion. In captive ones this behaviour can occur
excessively, which can lead to illnesses (Samson,
1996).
Antagonistic behaviour
Ostriches can express aggression against their
mates and also humans. They attempt to chase and kick
the ones who are not favorable for them. It occurs
especially at the onset of puberty. Mainly males show
aggression against people, which fluff their feather, lift
up their wings and tail feathers and attempt to kick the
men.
Among these abnormal behaviours the most
common and dangerous is the dietary indiscretion
especially in chicks during winter (Samson, 1992). If
housing facilities and management techniques are
appropriate these abnormalities can be prevented.
Interspecific contacts
Curiosity and playing among ostriches and other
species are very rare patterns. Meeting other birds or
mammals they are sorely sensible, cautious and shy.
They strictly stick to others in their group regardless of
the sex and age. Ostriches attempt to avoid interaction
with other species. They are usually not concerned
about ¾ of individuals when encountering, ostriches
tolerate and avoid them. Against ¼ of other animals
they show aggression or threat and send them away
from water or nutrition resources (Sauer, 1969).
EGG PRODUCTION, EGG QUALITY AND
HATCHABILITY
Egg production
Ostrich has a longer productive life-period
compared to all poultry species (Ipek and Sahan, 2003).
In the wilderness they mature at the age of 4–5 years
the male and the female, respectively (Reiner, 1995),
while among domesticated circumstances at the age of
3, the females mature earlier, than the males (Smith et
al., 1995). Female lay 12–18 eggs in one breeding
season in wild. Conversely, in farms they produce 40–
60 eggs (Ipek and Sahan, 2006). Layers are able to lay
eggs even until at the age of 40 and reach the peak at
the age of 7–11. In Africa ostriches produce 30–35 %
more eggs than in Europe due to the more ideal climate
conditions (Reiner, 1995). There are many factors
influencing egg production. Some of them are related
to the environment (temperature, feed, health
condition). According to Bowsher (1992) they lay the
most eggs in June and July and the hatchability rate is
the best in August. As we are closer to the end of the
year, the number of eggs decreases. The years spent
with laying eggs is also a significant factor in egg
production. The results of Ipek and Şahan (2003) show
that the more years a layer produces eggs, the more
eggs she lays and also the longer the length of the
breeding season is. The month also has a significant
effect on the quantity of eggs produced. In May they
produce the most eggs and egg production decreases
drastically by February (Wőhr and Erhard, 2005). The
ostrich is a seasonal species, the egg production period
lasts for around 6–8 month. This trait is in relation with
the length of the day-period and it is the most intensive
when the day-period is long (Mellett, 1993).
Lambrechts et al. (2004) examined the effect of sex
ratio on egg production and they found, that comparing
trios with harems, in trios the quantity of eggs produced
can be raised to some extents in contrast to the harem,
but in large populations (harems with 120, 130
individuals) the fertility and hatchability of eggs
decrease. Shanawany (1999) also investigated sex ratio
and found that with 1:1 incompatibility between hen
and male can cause a problem. Natural selection is
better in this case. 1:2 ratio showed to be the best,
because with 1:4 fertility is not that high. Deeming
(1996b) confirms the latter statement, that 1:2 sex ratio
is better than a larger resulting in lower fertility.
Egg quality
Ostrich lay the largest egg among poultry species,
which has a stiff and firm shell. The 1.1–1.5 kg weight
of the egg is affected by subspecies, the weight and age
of hen, and the feeding technology (Deeming, 1996a).
Regarding egg weight, Deeming’s (1996a) statements
are in agreement with Mushi et al. (2007) and Brand et
al. (2003), who found it 1321 grams and 1347–1446
grams, respectively. According to Koutinhouin et al.
(2014) the average length of egg is 15 cm and the width
is 12 cm, found the same by Mushi et al. (2007). Using
these parameters by dividing by each other we can
calculate one of the most important parameter of egg,
which is egg shape index (SI). This parameter is

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calculated by the following formula: (W/L) x100;
W=width of the egg, L=length of the egg (Anderson et
al., 2004). The average shape index in the investigation
of Moreki et al. (2016) is 82.65 %, which is in
agreement with Horbańczuk et al. (2003), Nedomová
and Buchar (2013), Benoît et al. (2014) and Selvan et
al. (2014), who received 83 %, 82.49 %, 83.5–83.86 %
and 82.86 %. In their study Nedomová and Buchar
(2013) found that the minimum of SI was 74.48 %, the
maximum of SI was 89.72 % and the average showed
82.49 %. The egg weight changes during the breeding
season. From the first day to the 40th increases
exponentially, then starts to decrease from the 60th day
(Superchi et al., 2002). The authors suggested also that
the larger is an egg, the larger is the weight/surface
index is. In those eggs, of which the weight/surface
index differs the most from the average (W/S=2.65),
embryo mortality is more likely to happen due to the
abnormal development, suffocation and the bad air
conductance of eggshell. The average thickness of
eggshell is 2.6 mm, which makes up 15–20 % of the
egg size. Eggshell is a curiosity in arts and crafts, which
serves as the base of different jeweleries and furnitures
(Di Meo et al., 2003). As for egg shell thickness, Mushi
et al. (2007), Selvan et al. (2014) and Cooper et al.
(2009) measured much lower values, such as 1.65 mm,
2.4 mm and 2.24 mm, respectively. The porosity of
ostrich egg is an important factor, because the quantity
and size of pores, as well as the thickness of eggshell
have a great impact on the water loss of eggs. If water
loss is inappropriate, embryo mortality increases
(Deeming and Ar, 1999; Brake et al., 1993). According
to Moreki et al. (2016) ostrich egg consists of 60.5 %
of albumin, 26.04 % of egg yolk and 13.36 % of egg
shell. These parameters were also investigated by
Koutinhouin et al. (2014) who found them 57.1–59.4
%, 21–23.3 % and 19.6 % and Selvan et al. (2014) who
observed 57.51 %, 27.64 % and 14.83 %, respectively.
The composition of egg also changes during the
breeding season. In the onset of the breeding season the
quantity of egg yolk is larger, than of the albumin and
the mass and mineral content also increases
exponentially from winter to spring, respectively. The
raw protein content of albumin reaches the maximum
on the 60th day. Albumin poses a bacterial defense,
since if its viscosity increases, it blocks the movement
of bacteria. 30 % of egg yolk is lipid, which component
is essential for the embryos’ nourishment, because it
covers 90 % of their energy intake (Speake et al. 1998;
Noble et al., 1996).
Hatchability
Ostriches lay 60 eggs in a nest per year. The hen and
the rooster hatch them respectively, which lasts 42–44
days. In artificial incubation it is 39–42 days
(Accomando, 2007). Today in farms generally artificial
incubation is applied. Artificial incubation is an
essential part of ostrich breeding, but we still do not
possess sufficient knowledge regarding it. Ostrich
industry is facing a remarkable problem in
reproduction, which means that the mortality among
chicks and embryos extremely high due to incubation
failures. Deeming (1995) mentions bacterial infection
as being one of the most determining causes. Secondly
malpositioning is also a significant effect mentioned by
Ley et al. (1986) causing 55 % mortality in combination
with oedema. Krawinkel (1994) observed 81.8 %
fertility and 16.6 % and 48.2 % hatchability for
naturally and artificially incubated eggs due to these
problems. In their study Rizzi et al. (2002) found
hatchability of set eggs being 51.5 % and of fertile eggs
being 73.9 %. The result of set eggs was lower than the
70 % reported by Dzoma and Dorrenstein (1998). In
order to avoid this situation and to improve in rearing
ostriches we have to take factors affecting hatchability
into consideration and initiate investigations on the egg
production abilities of this species. Hatchability is also
determined by the fertility of female and male. The
quantity of sperm is between 1 and 2 ml. The quantity
and quality of sperm and male libido were the highest
in spring-early summer (Bonato et al., 2014). The
length of incubation depends on many factors. Older
females lay larger eggs, which need more time to hatch
and the size of egg increases by time as well (Laing,
1992). Restoration period and the effect of month are
also crucial aspects. Hatching is shorter in May and
longer in September in its natural environment, but can
be different in other countries depending on the climate
and weather factors. Warm climate and weather
facilitate hatchability. Hatchability is influenced by the
subspecies, the egg size, the egg weight, the quality
parameters of the egg, the length of the restoration
period and the method of restoration (Laing, 1992).
King‘ori (2011) observed the average incubation
temperature to be 37.8 °C, though in their study Hassan
et al. (2004) found that the ideal incubation temperature
is below 37 °C, which has a positive impact on
hatchability. It has a close resonance with the claim of
Foggin and Honywill (1992) that optimal incubation
temperature should be between 36 °C and 36.5 °C and
the relative humidity of between 20 and 30 %. Eggs
should be placed with the sharp side down, leaned in 45
degrees and be turned until the day 39 and we should
candle them on the 2nd week (King’ori, 2011).
Conversely, according to Van Schalkwyk et al. (2000)
improved hatchability can be reached of fertile eggs
turned 60 degrees hourly in eggs set horizontally for 2
or 3 weeks, then vertically for the remaining period.
While the optimal relative humidity demonstrated by
King’ori, (2011) is between 25–50 %, Stewart (1995)
suggests 15–20 %. Relative humidity besides
influencing water conductivity of the eggshell, effects
the available quantity of minerals for the chick and also
for gas exchange (Wilson, 1996). El-Safty (2012)
suggests, that hatchability is influenced by egg weight.
Those eggs hatch easier, with a better percentage,
which are lighter, under 1350 grams, but over 1451
grams hatch the least. The inappropriate water
conductivity of egg leads to large, oedemic, non-viable
chicks. If too much water releases from the egg it
causes that small, weak and dehydrated chicks hatch. It
shows that we should select and breed those animals
which lay good quality eggs with uniform porosity
(Wilson, 1996).

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MEAT PRODUCTION
Ostrich meat is regarded as a healthy red meat with
low content of intramuscular fat content. Most valuable
meat parts found on the thigh, least on the back (Sales,
1999). At the age of 10 month ostriches produce an
adequate quantity of raw meat, with a cut rate of about
57–58 % and the percentage of lean meat is 62.5 %
(Sales, 1999). As for meat composition, it is typical of
the flavour of beef and the low fat and cholesterol
content which is the characteristic of poultry meat
(Poławska, 2011). This statement is supported by
Hoffman et al (2008). Comparing with beef and
poultry, ostrich meat has the same quantity of total fatty
acids, but is richer in polyunsaturated fatty acids, but
has a lower percentage of monounsaturated fatty acids.
Regarding fatty acid content of the different muscles,
neither Sabbioni et al. (2003) nor Horbañczuk et al.
(1998) found a difference between them. Ostrich meat
also contains more minerals, phosphorus, manganese
and iron and less sodium than the mentioned ones
(Paleari et al., 1998). Their study has a close resonance
with Balog et al. (2006) that the iron content of ostrich
meat is higher than of other poultry meat. Less sodium
content is also mentioned by Cooper (1999), adding
that because of this feature, this meat is suggested for
people suffering from hypertension. Comparing the
different muscle types on the subject of these
parameters, Mejewska et al. (2009) stated that all of
them have similar dry matter, protein and ash content.
Regarding the content of vitamins, especially B-group
and vitamin E were found as high as in beef or higher
than that (Lombardi-Boccia et al., 2005; Karklina and
Kivite, 2007). As for slaughtering age, Sales (2002)
found dry matter and fat content of muscle deriving
from older chicks (10–12 month) higher, than of
younger ones (8 month). Juiciness and tenderness of
ostrich meat is similar to beef (Taylor, 1998). The age
of slaughter is also an economically relevant factor, but
is still not obvious at which age should be
accomplished. The results of Jordaan et al. (2008) show
that comparing animals of 8.5, 10.5, 12.5, 14.5 and 16.5
month of age in cold carcass and skin size, the income
was the highest when slaughtering in 14.5 months, but
the gross margin of the 10.5 system was the highest.
The authors suggest that the older the individual is, the
greater the cold carcass yield and skin surface are, but
not only these qualities increase with time, but also the
feed intake and feed conversion rate of animals. So, we
should take into consideration which age we choose for
slaughtering. Deeming (1999) claims that a younger
slaughter age is favourable at the age of 8–10 month,
but conversely according to him the subjective of the
South African market is to slaughter them at the age of
14 month, because optimal leather quality can be
attained at this age, though acceptable meat yield is
already achieved at the age of 10 month. Pollok et al.
(1997) make a difference between subspecies and say
that the optimal slaughtering age for African Black is
12 to 14 month and that for Red and Blue Necks is 10
to 12 month, respectively. According to them these
ostriches reach the best meat, feather and leather quality
in that age.
SKIN PRODUCTION
Even though skin is also a luxury product in the
exotic market (Adams and Revell, 2003), we have a
little knowledge of its features and it’s influencing
factors. In order to have further information on this
parameter, it would be suggested to investigate in
Hungary. The quality of skin depends on the existence
of damages on it and also the market is interested in
tenderness as well to decide whether that piece of skin
is useful or not (Sales, 1999). So called nodules can be
found on the skin, which size, shape and dispersion
have a great significance in terms of market ability of
the product (Holtzhausen and Kotzé, 1990). Cloete et
al. (2004) submit, that it is widely accepted to slaughter
the animals at the age of 14 month, otherwise the shape
of the nodules and the size of skin are unfavourable.
The main measurement points on the skin are the neck,
the middle crown area, upper thigh, flank and the back.
ANIMAL WELFARE
According to OIE (2018) the definition of animal
welfare is the following. An animal is meant to be in a
good condition, if it is healthy, well-nourished, feels
good and safety, has the opportunity to show natural
behaviour, and does not suffer from any displeasing
feelings, such as ache, fear and stress. Ostriches are
large animals, which can pose danger for each other and
also for humans. Knowing their response can help quiet
a lot in how to approach them. Ostriches are usually
transported as day old chicks, 3 month old chicks or 3–
6 month old chicks (Wotton and Hewitt, 2011). Bejaei
and Cheng (2014) examined the response of ostriches
against handlers. Before being hooded, the birds tried
to escape by kicking and jumping inside the holding
paddock. After that they calmed down in less than a
minute and were able to walk into the sampling fold.
During transport those ostriches which were heavier
lost more weight. This defending behaviour regarding
forward kick was also recorded by Wotton and Hewitt
(2011). Mills and Nicol (2000) also underlines that
handling always walks with stress and humans hardly
pay attention not to hurt and cause damages to
ostriches, whereas it would need attention. Other
authors mention the significance of gentle, but
relatively close relationship between human and ostrich
chicks. Reiner et al. (1996) suggest that an everyday
connection between handlers and young ostriches can
help reducing stress during treatments. According to
Muvhali et al. (2018) extensive human presence
including gentle voice and physical connection, can
stimulate the immune system of chicks resulting the
survival rate being higher. Non-living environmental
factors also have influence on ostrich welfare.
Horbanczuk (2002) highlighted, that the photoperiod
should be 24 hours during the first two days with 90–
100 Lux intensity, then it is decreased to 16–18 hours
with 20–40 Lux. As for stocking density, Kreibich and
Sommer (1995) claim that the minimum floor space per
one chick until the age of 8 month is between 0.25 m2
and 5 m2. Shanawany (1999) describes 0.5 m2 floor
space per chicks for the first week. Stunning,
mentioned by Mitchell (1999) applied before

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20
slaughtering also makes part of animal welfare. The
objective is to cause immediate unconsciousness to
make the bird insensible to pain and stress.
CONCLUSIONS
Having data on the productive and reproductive
parameters mentioned in the article, it can be revealed,
that we have a sound knowledge regarding ostrich
breeding. However, to make a comprehensive study,
more parameters and aspects should be examined
besides the mentioned ones, such as adaptability,
embryo mortality, skin production and other traits, all
of them in local conditions. As for reproduction, it
should be useful to know the exact method of artificial
incubation, especially the required egg weight, which is
optimal to reach the best hatchability and humidity,
which is one of the greatest risk factors in incubation.
Since embryo mortality is usually extremely high in
ostrich, we need to examine it in the early, middle and
last part of incubation and attempt to find the
correlation between hatching conditions and the extent
of it in order to provide a better practice for incubation.
It can be interesting measuring the thickness of eggshell
deriving from dead-in-shell embryos so as to find a
relationship between these two factors. We are to
follow the growth performance of chicks and survey the
connection between this trait and of egg quality. In this
case we should know some of the external and internal
features of the egg. We would measure the chick weight
and the size of its body parts at hatching, at the age of
21 days, then monthly and we would make a growth
curve regarding the whole body and the different body
parts, respectively. It would help us determine the right
age of slaughtering, though we should confirm our
results by conducting an economic analysis, too. We
should have more information on skin performance, so
we would use growth curve to follow the skin
production abilities of ostrich. In addition, we should
get more information on the ethology and adaptability
of ostrich and understand the principals of animal
welfare to do our best in practice.
ACKNOWLEDGEMENTS
The work/publication is supported by the EFOP-
3.6.3-VEKOP-16-2017-00008project. The project is
co-financed by the European Union and the European
Social Fund.
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