STUDIES ON SOME FACTORS AFFECTING
OSTRICH PRODUCTION IN EGYPT
BY
NASHAT SAEID IBRAHIM AMER
B.Sc. Agric, (Animal and Poultry Production)
Ain –Shams University, ١٩٩٩
THESIS
Submitted in Partial Fulfillment of
the Requirements for the Degree
OF
MASTER OF SCIENCE
IN
AGRICULTURAL SCIENCES
(Animal Production - Animal Physiology)
Department of Animal Production
Faculty of Agriculture
Al-Azher University
١٤٢٦ A.H.
٢٠٠٥ A.D.
١
TITLE:
TITLE: STUDIES ON SOME FACTORS AFFECTING
OSTRICH PRODUCTION
PRODUCTION IN EGYPT
NAME:
NAME: NASHAT SAEID IBRAHIM AMER
THESIS
Submitted in Partial Fulfillment of
The Requirements for the Degree
OF
MASTER OF SCIENCE
IN
AGRICULTURAL SCIENCES
(Animal Production - Animal Physiology)
Department of Animal Production
Faculty of Agriculture,
Al-Azher University
١٤٢٦ A.
A.H.
٢٠٠٥ A.
A . D.
Supervision Committee:
Dr.
Dr. Hesham Hussien Khaliefa
Prof. of Animal Physiology, Fac. of
Agric., Al -Azher Univ. (Supervisor)
Dr.
Dr. Medhat Hussien Khalil
Prof. of Animal Physiology, Fac. of
Agric., Al -Azher Univ. (Supervisor)
Dr.
Dr. Mohammed Osama Fahmy
Associate Prof. of Animal Physiology,
Biological Application Department,
Nuclear Research Center, Atomic
Energy Authority (Supervisor)
٢
APPROVAL SHEET
NAME: NASHAT SAEID IBRAHIM AMER
TITLE: STUDIES ON SOME FACTORS AFFECTING
OSTRICH PRODUCTION IN
EGYPT
THESIS
Submitted in Partial Fulfillment of
The Requirements for the Degree
OF
MASTER OF SCIENCE
IN
AGRICULTURAL SCIENCES
(Animal Production - Animal Physiology)
Department of Animal Production
Faculty of Agriculture,
Al-Azher University
١٤٢٦ A. H.
٢٠٠٥ A. D.
Approved By:
Dr: Hesham Hussien Khaliefa……………………..
Prof. of Animal Physiology, Fac. of Agric., AlAzher Univ.
Dr: Abd El-Hady Amer ……………………………
Prof. of Poultry Nutrition, Fac. of Agric., Al- Azher
Univ.
Dr: Nagwa Abd El-Hady Mostafa………………….
Prof. of Avian Physiology, Fac. of Agric., Cairo Univ.
Date: …./ …./ ١٤٢٦ A.H.
٣
…./…./ ٢٠٠٥ A.D.
ACKNOWLEDGEMENT
ACKNOWLEDGEMENT
Prayerful thanks, at first to our Merciful God who
gives me every thing I have.
My deepest gratitude and appreciation are to
Prof. Dr. M.H., Khalil, Professor of Animal
Physiology, Department of Animal Production,
Faculty of Agriculture, Al-Azhar University, for his
supervision
strong,
his
useful
criticism,
encouragement and support.
I’m greatly indebted to Prof. Dr. H.H., Khalifa,
Professor of Animal Physiology, Department of
Animal Production, Faculty of Agriculture, Al-Azhar
University, for supervision, planing the experimental
design, text revision and his continuos encouragement
during the course of this study.
I wish to express my sincere gratitude and
deepest thanks to Associate Prof. Dr. Mohammed
Osama Fahmy, Associate Professor of Poultry
Physiology, Biological Application Department,
Nuclear Research Center, and Atomic Energy
Authority, Egypt. For his kind guidance, valuable
advance, suggestion, supervision, planing the
experimental design providing the facilities and text
revision and his continuos encouragement during the
course of this study.
I would like to thanks all ostrich producers
especially, H. Faried general manager of (Shammp
International company) for his available supports and
providing me most of the facilities needed for the
completion of this experiment.
٤
My thanks are also extended to my family, for
their continuous encouragement, patience, interest
and helpful co-operation, which made this study
possible.
Finally grateful acknowledgment and sincere
thanks are extended to my dearly Sheriene El-Nagdy,
my model role for her support, kind understanding,
patience, help me, complete love and continuos
encouragement to finish my study.
٥
LIST OF CONTENTS
Title
Page
١-INTRODUCTION
١
٢-REVIEW OF LITERATURE
٣
٢-١-
Factors affecting hatchability of ostrich eggs
٣
٢-١-١-
Hatchability of the ostrich eggs
٣
٢-١-٢-
Effect of egg quality on Hatchability
٣
٢-١-٣-
Effect of environmental factors on hatchability
٦
٢-١-٤-
Effect of inbreeding on hatchability
٦
٢-١-٥-
Effect of breeding season on hatchability
٦
٢-١-٦-
Effect of egg size on hatchabilty
٧
٢-١-٦-١- Factors affecting egg size
٨
٢-١-٦-١-١ Laying seasons
٨
٢-١-٦-١-٢-Breeder nutrition
٨
٢-١-٧-
Effect of egg storage time on hatchabilty
٨
٢-١-٨-
Effect of egg storage conditions on hatchabilty
٩
٢-١-٩-
Effect of artificial incubation conditions on
hatchability
٢-١-٩-١- Turning regime
٢-١-٩-٢- Temperature
٢-١-٩-٣- Relative humidity
٢-١-٩-٤- Incubator oxygen and carbon dioxide
٢-١-١٠- Effect of ostrich egg weight loss on hatchability
٢-١-١٠-١- Factors affecting egg weight loss
٢-٢Factors affecting embryonic mortality
٢-٢-١- Oedema
٢-٢-٢- Anasarca
٢-٢-٣- Hypoxia and myopathy
٢-٢-٤- Malposition
٢-٢-٥- Hatching assistance
٢-٢-٦- Trace minerals
٢-٢-٦-١- Breeder nutrition and trace minerals
٦
١٠
١١
١٢
١٣
١٤
١٤
١٥
١٧
١٧
١٨
١٨
٢-٢-٦-٢- Eggshell structure and mineral content
٢-٢-٧- Eggshell porosity
٢-٢-٧-١- Eggshell porosity and oxygen supply
٢-٢-٧-٢- Factors affecting eggshell porosity
٢-٢-٧-٢-١- Eggshell Mg
٢-٢-٧-٢-٢- Eggshell Ca
٢-٢-٧-٢-٣- Shell thickness
٢-٣Post-hatch chick mortality
٢-٣-١Factors affecting post-hatch chick mortality
٢-٣-١-١- Yolk sac infection
٢-٣-١-٢- Nutrient deficiencies
٢-٣-٢Leg deformities (Tarsometatarsus bones) and
factors affecting it
٢-٣-٢-١- Factors affecting leg deformities
٢-٣-٢-٢- Rapid growth rate
٢-٣-٢-٣- Effect of mycotoxins, Infection, stress, ambient
temperature and inflammation on bone weakness
٢-٣-٢-٤- Effect of genetic defects and bone weakness
٢-٣-٢-٥- Nutritional problem
٢-٣-٢-٦- Vitamins and deformation
٢-٣-٣Thyroid hormones
١٩
١٩
١٩
١٩
٢٢
٢٥
٢٥
٢٥
٢٥
٢٦
٢٦
٢٨
٢٨
٢٨
٢٩
٣٠
٣- MATERIALS AND METHODS
٣٢
٣-١- First trial, factors affecting hatchability
٣٣
٣-١-١- Egg collection
٣٣
٣-١-٢- Egg incubation
٣٥
٣-١-٣- The following parameters were measured on each
٣٥
egg:
٣٩
٣-١-٣-١- Egg weight
٤١
٣-١-٣-٢- Eggs size
٣-١-٣-٤- Egg fertility
٤٢
٣-١-٣-٥- Percentage of egg weight loss during
٤٢
incubation
٣-١-٣-٦- Egg hatchability %
٤٢
٣-١-٣-٧- Eggshell parameters
٣-١-٣-٧-١- Eggshell percent
٣-١-٣-٧-٢- Egg shell porosity
٧
٤٣
٣-١-٣-٧-٣- Egg shell thickness
٣-١-٣-٧-٤- Eggshell minerals
٣-١-٣-٧-٥ Post-hatch chicks weight
٤٣
٣-٢- Second trial:
٤٤
٣-٢-١- Collection and preparation of tarsometatarsus
bones for mineral detection
٣-٢-٢- Collection of blood samples
٣-٢-٢-١- Serum total proteins
٣-٢-٢-٢- Serum albumen
٣-٢-٢-٣- Serum globulin
٣-٢-٢-٤- Albumin: globulin ratio (A/G ratio)
٤٤
٣-٢-٢-٥- Serum urea
٤٥
٤٣
٤٣
٤٤
٤٤
٤٥
٤٥
٤٥
٣-٢-٢-٦- Serum cholesterol
٤٦
٣-٢-٢-٧- Serum total Lipids
٣-٢-٢-٨- Determination of serum alkaline phosphatase in ٤٦
serum:
٤٦
٣-٢-٢-٩- Hormonal assay
٤٦
٣-٢-٢-١٠- Determination of minerals
٤٧
٣-٣- Statistical analyses
٤٧
٤- RESULTS AND DISCUSSION
٤٧
٤-١-
Factors affecting ostrich egg fertility and
hatchability
٤-١-١- Fertility and hatchability of ostrich eggs
٤-١-٢- Physical and chemical ostrich egg characteristics
affecting hatchability
٤٧
٤٧
٤٧
٤٧
٤٧
٤٧
٤-١-٢-١ Effect of physical ostrich egg characteristics on
hatchability
٤٨
٤-١-٢-١-١ Effect of ostrich egg weight loss
٤٨
during incubation on hatchability
٤٨
٤-١-٢-١-٢ Effect of ostrich eggshell porosity on
٨
hatchability
٤٩
٤-١-٢-١-٣ Effect of eggshell thickness on hatchability
٤-١-٢-١-٤ Effect of ostrich egg size on hatchability
٤-١-٢-١-٥ Effect of ostrich chick weight (gm) at
hatch on hatchability
٤-١-٢-٢- Effect of chemical ostrich egg characteristics
(eggshell minerals) on hatchability
٤-٢- Factors affecting ostrich post-hatch chick leg
٤٩
٤٩
٥٣
٥٣
deformation
٤-٢-١- Post-hatch chick mortality
٥٣
٤-٢-٢- Effect of bone mineral content on legs deformations
٤-٢-٣- Effect of serum mineral content on legs deformations
٤-٢-٤- Effect of serum blood chemistry on legs
deformations
٥-SUMMARY AND CONCLUSION
٥٥
٥٦
٥٧
٦- REFERENCES
٥٨
٧- ARABIC SUMMARY
٦٤
٦٨
٦٨
٧١
٧٥
٧٨
٨١
٩
٨٦
LIST OF TABLES
Title
Page
Table (١): Fertility and hatchability of ostrich eggs in two
farms.
٥٢
Table (٢): Mean±S.E. of hatched and non-hatched ostrich
eggs physical characteristics.
Table (٢-a): Prevalence of percentage weight loss in hatched
and unhatched eggs.
٦٠
٦١
٦٢
Table (٢-b): Prevalence of eggshell porosity in hatched and
unhatched eggs.
٦٣
Table (٢-c): Mean±S.E. of hatched and unhatched ostrich
chicks weight.
٦٧
Table (٣): Mean ± SE of Eggshell mineral content of hatched
٧٠
and unhatched ostrich eggs.
١٠
٧٤
Table (٤): Prevalence of mortality and leg
deformation in ostrich chicks
during the first ٨ weeks of age.
٧٧
Table (٥): Mean±SE of the normal and deformed ostrich
chick's tarsometatarsus bone mineral content
٨٠
.
Table (٦): Mean±SE of serum mineral content of ostrich
chicks with normal and deformed tarsometatarsus
bone.
Table (٧): Mean±SE of serum blood chemistry of ostrich
chicks with normal and deformed
tarsometatarsus bones.
LIST OF FIGURES
Title
Page
Fig. (١): Prevalence of percentage weight loss in
hatched and unhatched eggs.
٦١
Fig. (٢): Prevalence of eggshell porosity in hatched
and unhatched eggs.
Fig. (٣): Mortality rate during the first ٨ weeks of
age.
١١
٦٢
٧٠
١-INTRODUCTION
The ostrich (Struthio camelus) is a flightless bird
belonging to the ratite family and known as the largest
living bird. The adult live body weight ranged between ٧٠
and ١٥٠ kg. Ostrich is native to semi-arid and desert areas
of Africa, they have been raised intensively in South
Africa for more than ١٠٠ years and reared commercially
mainly to produce usable products, including meat, hides,
feathers, and eggs (Kreibich and Sommer, ١٩٩٥).
The most important on-farm constraints to
productivity for ostrich industry are: the high rate of
embryonic mortality in the last ١٠-١٤ days of incubation
and chick wastage (particularly during the first ٨ weeks of
life). These are the major problems and result in a
significant economic loss to the ostrich industry. Under
uncontrolled conditions, hatchability may reach ٥٠٪ of all
eggs and ٤٠٪ of the hatching survived to slaughter age.
This means that proportion of eggs laid producing
surviving chicks is only ٢٠٪ due to embryonic and post
hatching mortality.
Another important factor which has a serious effect
on hatchability is the shell porosity. Shell porosity has
been implicated with embryonic mortality of ostrich. Both
too many pores and too few pores have been shown to
affect hatchability. Also, the mineral content of ostrich
eggshells may influence embryo physiology and
١٢
hatchability causing embryonic mortality during pipping
and hatching.
Another important problem which faced ostrich
farmers is the unbalanced nutrition. Unbalanced nutrition
has led to severe long bone deformities and muscle
degeneration causing angular deformities of the tibiotarsal
and tarsometatarsal bones and developed skeletal
abnormalities.
Tibiotarsal rotation (TTR) was considered a serious
problem and an important cause of mortality in farmed
ostrich chicks during the first ١٠ weeks after hatching.
Scarce literature is available concerning the incidence and
cause of TTR in ostrich chicks.
Mineralization of the osteoid matrix has also been
associated with deficiencies in the micro-minerals zinc,
copper, calcium, phosphorus, magnesium and manganese.
The investment base of the Egyptian Ostrich
Industry has increased dramatically over the last ten years.
This new industry has attracted an increasing number of
investors, who have decided to add ostrich to their
projects income stream. The most important challenges
which have been widely felt in Egypt and causes
considerable financial loses to ostrich farmers and chick
wastage are leg disorder and the unusual embryonic
mortality percent during incubation. As the industry
develops, additional efforts must be made to address the
causes and solutions to these inevitable causes of chick
wastage.
Therefore, the main objectives of the present study
are: ١- To study some factors affecting hatchability ٢- To
study some factors affecting leg deformation during first
١٠ weeks after hatch.
١٣
٢-REVIEW OF LITERATURE
There are many factors affecting ostrich (Struthio
camelus) production and acts as major obstacle and
difficulties to the development of ostrich farming and has
limited success to the ostrich’s world industry elsewhere.
For instance, hatchability, incubated technique, high dead
in shell and high mortality of chicks during ٣ month of
rearing after hatch. On average ٥٠٪ of all eggs hatched
and only ٤٠٪ of the hatching survived to slaughter age
(Mellett ١٩٩٣ and More et al., ١٩٩٤).
٢١ Factors affecting hatchability of ostrich eggs:
٢-١-١- Hatchability of the ostrich eggs:
Hatchability of the ostrich eggs is very low when
compared with poultry, this reduction resulted in part
from high rate of infertility, embryonic mortality caused
by poor understanding of the artificial incubation and
chick rearing are the most constraint on the development
of the ostrich industry world wide. Deeming (١٩٩٥) stated
that hatchability of artificially incubated ostrich eggs was
generally low and it was less than or about ٥٠٪,
Moreover, ٢٨ – ٥٠٪ of the fertile egg failed to hatch.
Kocan (١٩٩٥) reported that hatchability of ostrich
eggs was only (٣٧٢-٥١٪) due to high rates of infertility
(٢٢-٥٠٪) and contamination (٢٠-٢٢٪). In South Africa,
Zimbabwe and USA during the breeding season, egg
hatchability varied between different farms.
٢-١-٢-Effect of egg quality on hatchability:
Hatchability of the egg and the production of a
healthy chick depend on two main factors combine to give
good quality. First, the contents of egg at laying must
supply all the water and chemical energy in the form of
macronutrients needed for embryo development. Second,
١٤
the eggshells allow into the egg sufficient oxygen to meet
the demands of the embryo and the appropriate quantities
of water vapour and carbon dioxide to pass out (Ar, ١٩٩١
and Vleck, ١٩٩١).
Egg quality is considered one of the most important
factors affecting hatchability of ostrich eggs due to
increasing embryonic mortality during pipping and
hatching. Good quality refers to the egg contents and to
the eggshell. The contents with shell are very important to
provide the nutrients needed for embryo to develop into a
healthy chick. So, any deficiencies will result in abnormal
embryo growth. However, the different nutrients
requirements of ostrich embryo are not known with any
accuracy. Stewart (١٩٩٥) attributed the difficult in ostrich
artificial incubation to the great variation in the egg
quality between the incubated eggs compared to chicken
eggs which were more consistent in size and shell
characteristics. In this respect, Deeming, (١٩٩٣a &
١٩٩٥a) reported that the hatchability depends firstly on
the characteristics of the egg itself which were determined
prior to laying and then on the management practices and
the environmental conditions imposed after the egg was
laid. Consequently, the successful artificial incubation as
measured by maximizing hatchability of fertile eggs
depends upon having good egg quality and proper egg
management during the pre-incubation and incubation
periods and providing the optimum conditions for
incubation and hatching.
Aaron (١٩٩٤) added that albumen pH was one of
the most important factors which affect hatchability.
In addition, Black (١٩٩٤) indicated that poor
quality shells such as high or low porosity, thin or thick
shells, excessive ridging rebilling or stress lines and other
deformities which interfere with gas exchange are
common in immature hens and in hens under any stress or
١٥
with oviduct infections. All these
significantly the percent of hatchability.
factors
affect
Ostrich eggs are difficult to incubate and usually
require special incubation conditions and hatching
depends to a large extents on having good quality eggs
from healthy breeders birds fed a well balanced diet and
good egg management was required after laying to ensure
that the eggs hatch into healthy chicks (Black, ١٩٩٤).
However, Naber (١٩٧٩) and Angle (١٩٩٣) found that the
chemical composition of the ostrich eggs (protein, fat,
water and ash) was not influenced by the parent dietary
intake, while many vitamins were very responsive to
dietary changes. On the other hand, Deeming (١٩٩٤)
cleared that nutrition of breeding ostriches, age, genetics
and its environment were several factors affected variable
characteristics such as egg composition, eggshell
conductance (porosity) and egg size all of which were
affecting hatchability.
The effect of egg shell porosity on egg hatching
was studied by Deeming (١٩٩٩) who found that “Tight“
eggs with low porosity, lose little water and this may
cause oedema (water retention) in ostrich embryos which
makes hatching more difficult. He added that the late
embryos in this eggs were suffers from a shortage of
oxygen at the time of greatest need and dies of hypoxia.
Satteneri and Saterlee (١٩٩٤) found that high and low
pore numbers in ostrich eggshells were associated with
reduced hatchability.
٢-١-٣- Effect of environmental factors on the
hatchability:
Different studies were carried out on the effect of
the environmental factors on the hatchability of ostrich
eggs. In this respect, Gonzalez (١٩٩٤) reported that
temperature was the most important environmental factors
affecting egg weight, egg composition, eggshell weight
and thickness and shell porosity. High environmental
١٦
temperature results in a decrease in albumen and yolk
weight with a reduction in egg quality and hatchability.
Philbey et al., (١٩٩١) found that the syndrome of ostrich
chicks that died at or within ١ week after hatching (which
had anasarca, degenerative changes in the complexs and
pelvic limb muscles and fibrinoid degeneration of
arterioles) was related to high relative humidity during
incubation. Malpositioning, was also a cause of embryo
mortality, may be related to high relative humidity or
turning rate.
٢-١-٤- Effect of inbreeding on hatchability:
Another important factor which affects hatchability
is the inbreeding between the birds. Hermes (١٩٨٩)
reported that high level of inbreeding causes embryonic
mortality as a result of genetic mutations and negatively
affected hatchability but the specific lethal genes have not
yet been recorded in ostriches.
٢-١-٥- Effect of breeding season on hatchability:
Wilson et al., (١٩٩٧) reported that hatchability of
ostrich eggs dropped as the breeding season progressed.
At the start and end of the season the egg number were
low and hatchability was very low, although this may
reflect low rates of fertility or unfavorable conditions in
partially empty incubators. Meanwhile, More et al.,
(١٩٩٤) found that hatchability of ostrich eggs was poor at
the beginning of the laying season and this may be
associated with the low yolk weight.
٢-١-٦- Effect of Egg size on hatchability:
The wide range in egg masses in the ostrich poses a
problem for incubation. It was not be possible to provide
an optimum environment for eggs of ١٢٠٠ or ١٨٠٠g
within an incubator set for an average egg mass of ١٥٠٠.
Krawinkel (١٩٩٤) reported that egg size and weight had a
significant effect on hatching rate and Jost (١٩٩٣)
postulated that eggs weighing ١٣٠٠-١٧٠٠g had the best
١٧
hatchability. Ar et al., (١٩٩٦) showed that hatchability of
large and small eggs are ٢٨ and ١٤ %, respectively, lower
than average eggs and may cause the problem of whether
the eggs will fit within the egg trays in the machine.
Moreover, Deeming (١٩٩٤b) studied the effect of egg size
on the hatchability and found that the hatchability of
ostrich eggs was decreased by increasing egg size. Larger
eggs were failed to hatch and contain late dead embryos.
He also reported that weighing over ١٦٠٠g gave ٥٠٪
hatchability compared with ٧٠٪ for eggs weighing
between ١٠٠٠–١٤٠٠g.
The effect of egg size on hatchability was explained
by Deeming (١٩٩٧). He stated that the different surface
area : volume ratios of the differently sized eggs mean
that temperature profiles of the eggs may differ, with
larger eggs of higher metabolic rate retaining more heat.
A ١٥٪ loss of the initial mass for a ١٥٠٠ g. egg was
achieved for one humidity setting, but this setting was
unsuitable for smaller and larger eggs of different water
content and shell conductance which may lose too much
and too little mass, respectively. In practice, larger ostrich
eggs also have a lower hatchability).
٢-١-٦-١-Factors affecting egg size:
٢-١-٦-١-١- laying seasons:
French and Tullet (١٩٩١) showed that in laying
season, egg size and yolk size were increased with time,
while, the proportion of albumen, shell and total water
content declined with time. However, egg size,
composition and shell conductance changes with hen age,
both within a laying season and from one laying season to
the next.
٢-١-٦-١-٢- Breeder nutrition:
Gonzales (١٩٩٤) found that egg size in breeder
ostriches was influenced by levels of fats and proteins in
١٨
the diets. A reduction in the feed intake was associated
with a reduction in egg weight and egg production.
٢-١-٧- Effect of egg storage time on hatchability:
Aaron (١٩٩٤) showed that maximize hatchability of
ostrich eggs was achieved by storing eggs for one week
before incubation in order to reduce albumen thickness
and viscosity which affect and in turn increased water loss
and amino acids absorption by the embryo which will
influence hatchability. On the other hand, the prolonged
storage of egg with high temperature and humidity
negatively affected albumen quality and this was
associated with a reduction in the hatchability, this
reduction may be due to deterioration in the albumen.
Length of ostrich egg storage was considered an
important predictor of hatchability for ostriches (Jensen et
al., ١٩٩٢). In this respect, Stewart (١٩٩٥) showed that
increasing storage time was associated with a reduction in
the hatchability, delay in the hatch, reduction in the chick
quality and growth rate. However, they stated that storage
time of ٧ days was generally accepted after which
hatchability starts to decline with a significant reduction
after ١٤ days and chick survivability was significantly
reduced by the longer storage time.
Wilson et al., (١٩٩٧) reported that hatchability was
declined linearly with storage time, although, storage for
up to ٧ days had relatively little effect on hatchability.
Brake and Walsh (١٩٩٣) and Brake et al., (١٩٩٤)
reported that albumen quality have an important role in
embryo development. So, storage time, storage conditions
and duration was need to be adjusted to take into account
the quality of albumen. They demonstrated that setting
fresh ostrich eggs particularly from young hens resulted in
increased early embryonic mortality. Also, Williams
(١٩٩٢) and Aaron (١٩٩٤) cleared that storage eggs too
long or those with poor quality the albumen (older or late
١٩
season hens) loosed water too quickly and caused early
embryo failure.
٢-١-٨- Effect of egg storage conditions on
hatchability:
Jost (١٩٩٣) reported that the hatchability of eggs
stored at ١٥-٢١٠C for ٣-٥ days before incubation was
better than that of eggs stored for less than ٣ days or more
than ٥ days. However, Krawinkel, (١٩٩٤) showed that
storage of eggs for ٢-٧ days before incubation improved
hatchability.
Hermes (١٩٨٩) and Deeming (١٩٩٣a) reported that
ostrich eggs was normally held at ١٥-٢٠ْC when stored for
up to ٧ days but over ٧ days eggs should be stored at ١٣ْ C
and ٥٠-٧٥ RH in order to reduce water loss.
Meijerhoff (١٩٩٢) and Deeming (١٩٩٣) reported
that hatchability can be improved under prolonged egg's
storage by enclosing eggs in plastic bags to reduce the
quantity of carbon dioxide losses from the egg after laying
resulting in arise in albumen pH. However, a reduction in
albumen acidity does not seem to affect hatchability.
Moreover, a high relative humidity should be maintained
around ٧٠٪ during storage in order to reduce water loss
and a break down in albumen quality.
Deeming (١٩٩٣a) and Stewart (١٩٩٥) showed that
storage ostrich eggs horizontally were given good results.
In addition, eggs stored longer than ٧ days should be
turned daily and storage temperature should be decreased
with extended length of storage. Deeming (١٩٩٣a) add
that the hatchability was improved when eggs was
allowed to warm up to room temperature first before
setting.
٢-١-٩- Effect of artificial incubation conditions on
hatchability:
Artificial incubation has become an essential part of
any commercial ostrich farming enterprise. However, the
٢٠
understanding of artificial incubation requirements in
ostriches is poor compared with poultry (Deeming, ١٩٩٣)
and problems are still commonly include achieving the
correct weight loss from egg during incubation and poor
understanding of the pattern of embryonic development
especially during hatching. All these acts as limiting
factors in the expansion of the ostrich industry worldwide
and has had limited success with only ٥٠٪ hatchability of
all eggs set (Deeming and Ayres ١٩٩٥ and Deeming
١٩٩٥; ١٩٩٥a&b). Brown et al., (١٩٩٦) stated that the
ostrich industry experiences a high rate of embryo
mortality during artificial incubation most of this
mortality takes place in the last ١٠-١٤ days of incubation
before hatching.
Lundy (١٩٦٩) indicated that the physical
environment in the incubator will have a major influence
on the hatchability of the egg. The main factors to be
considered are the temperature, humidity, gaseous
environment and egg turning.
٢-١-٩-١-Turning regime:
Deeming (١٩٨٩a&b) reported that insufficient
turning results in retarded growth of the area vasculosa, a
reduction in growth of the chorioallantoic membrane
(which limit oxygen uptake), reduced albumen (protein)
uptake and malpositioning which result in dead in shell
embryos or weak chicks. Also, Wilson (١٩٩٦) reported
that absence of egg turning resulted in adhesion of the
embryo to the inner shell membrane, premature, increased
incidence of malpositions, decreased albumen utilization,
abnormal fluid distribution in the egg, decreased oxygen
exchange surface of the chorioallantois and a poorly
developed the yolk sac.
Wilson (١٩٩١a) cleared that the best turning regime
for artificially incubated ostrich eggs was not known yet.
However, he reported that best hatchability for chicken
٢١
eggs require that eggs to be turned about ٢٠ times / d and
failure to turn reduce hatchability from ٧٠٪ to about ٥٠٪.
However, Deeming (١٩٩٧) stated that the critical period
for turning ostrich eggs is thought to be during the first
two weeks of incubation. An optimal turning frequency
has not been determined for ratite eggs. However, ٢٤
times per day is practical and appears to give satisfactory
results. Eggs set air cell end up hatch best when turned
٩٠° to rest at a ٤٥° angle, whereas those set horizontally
hatch best when turned approximately ١٨٠°. Turning
horizontally set eggs only in one direction will cause
rupturing of membranes and blood vessels resulting in
mortality. Brown et al., (١٩٩٦) added that ostrich eggs
horizontally incubated for the first ١٠–١٤ days was
improved hatchability in comparison to eggs incubated
either horizontally or vertically for the full incubation
period. Moreover, Krawinkel, (١٩٩٤) observed that the
maximum hatchability ٨٥٧٪ was attained for eggs
incubated in a vertical position and turned ٨ times daily.
٢-١-٩-٢- Temperature:
The effect of the incubator temperature on the
hatchability of the ostrich eggs has been the subject for
many authors. Deeming (١٩٩٣) and Angle (١٩٩٣)
reported that excessive incubator temperature has been
implicated as a potential cause of the incidence of
congenital deformities. Schalkwyk et al. (١٩٩٩) found that
shell deaths of ostrich eggs were significantly higher in
fertile eggs incubated at ٣٧٣ْC than in those incubated at
٣٦ْC. They also assumed that younger embryos were less
susceptible to excessive heat than older embryos.
Moreover, Wang-Wenjing and Wang (١٩٩٩) reported that
more embryos died at the constant temperature of ٣٦٥ C
ْ
during ٣٨ days of incubation than eggs set at varying
temperature from ٣٦٥ ْC to ٣٦٣ْC at the same period.
٢٢
Wilson (١٩٩٦) stated that common incubator
temperature for ratite range from ٩٦٦ to ٩٧٧°f for multistage machines. Incubators without fans are normally run
about ٢°f higher than those with fans. Furthermore, posthatch growth may also be affected by incubation
temperature. The hatcher temperature should be
approximately ١°f lower than that of the incubator
because of the large amount of heat generated by the latestage embryos. Moreover, Brooks and May (١٩٧٢)
revealed that bone growth during the latter stages of
embryonic development was accelerated or retarded by a
respective increase or decrease in incubation temperature.
They indicated that such external control over skeletal
metabolism was related to the poikilothermic nature of the
embryo.
٢-١-٩-٣- Relative humidity:
Horbanczuk et al., (١٩٩٩) reported that ostrich eggs
can be incubated successfully in relative humidity
between ٢٢ and ٤٠٪ with taken into consideration egg
weight, eggshell thickness and porosity. Moreover, they
found that the hatchability of ostrich eggs incubated at the
same dry bulb temperature of ٣٦٤ ْC and initial RH of ٥٠,
٤٠, ٣٠ or ٢٥٪ was ٦٥, ٧٢, ٧٥ and ٨٢٪ respectively. They
also reported that eggs from the batch incubated at the
highest initial RH (٥٠٪) had the greatest number of
malpositioned chicks, the most chicks with unabsorbed
yolk sacs, and a day old chicks had poorer viability than
chicks from other groups.
Christesen et al., (١٩٩٦) and Ar et al., (١٩٩٦)
suggested that incubator humidity for ostrich eggs should
be less than ٢٥٪ to allow a ١٥٪ loss of initial egg mass
during the ٤٥ days incubation period and /or a useful way
to optimize egg mass loss and maximize embryo survival
and chick quality. However, Philbey et al., (١٩٩١)
indicated that a humidity of ٣٤–٣٧٪ at the recommended
incubator temperature of ٣٦ ٠C was to be more
٢٣
appropriate and result in improved hatchability.
Furthermore, Jarvis et al., (١٩٨٥) found that high relative
humidity levels in the incubator appear to cause oedema
in chicks. Only those incubated at humidity levels above
٢٥٪ were affected. They added that ٤٠٪ to ٥٠٪ RH in
hatchers was the most successful for hatching and chick
health. They concluded that the weight loss of the egg
during incubation was the best guide for setting humidity
levels, with a target of ١٣٪ to ١٧٪ weight loss during the
٤٢ day incubation period. Sahan et al., (٢٠٠٣) concluded
that incubator humidity should be low (٢٥٪) to allow
enough mass loss of ١٣ to ١٥٪ which is necessary during
incubation period from the eggs. However, Brown et
al.,(١٩٩٦) stated that it is difficult to reach low humidity
during artificial incubation.
٢-١-٩-٤- Incubator oxygen and carbon dioxide:
Wilson (١٩٩٦) recommended incubator levels of
٢١٪ oxygen and ٠٠٥ to ٠١٪ carbon dioxide for ratite
eggs incubated at less than ٣٠٠٠ ft. altitude.
٢-١-١٠- Effect of ostrich egg weight loss on
hatchability:
Egg weight loss during incubation was considered
an important factor in ostrich egg hatchability for some
time, with too much or too little weight loss resulting in
reduced hatchability. The weight loss of egg during
incubation was affected by the porosity of the eggshell
and the humidity of the air around the egg. In this respect,
many authors reported different percent of egg weight loss
to achieve successful hatching percent under artificial
conditions. Wilson (١٩٩٦) showed that normal
hatchability should be expected in ostrich eggs that lose
١٢ to ١٧٪ of initial weight from setting to ٣٨ days of
incubation. Jarvise et al., (١٩٨٥) reported ١٥٥ percent
loss, ١٣٢٪ loss and ١٢٪. Meanwhile, Bowsher (١٩٩٢)
and Deeming (١٩٩٣) reported ١٠-١٣٪ loss. Simon and
More (١٩٩٦) reported that fertile eggs were most likely to
٢٤
hatch with weight loss during incubation between ١٢ and
١٥٪ of the egg weight at the beginning of incubation.
Moreover, Saito et al., (١٩٩٩) reported that both lower
and higher water losses resulting decreased hatchability
and the eggs that do hatch with water losses below ١٠٪
produced oedemetons, sluggish and unabsorbed yolk
chicks. Deeming and Ferguson (١٩٩١) stated that the egg
start to lose weight from the moment was laid. An average
١٥٪ of the initial egg weight was lost during incubation
with an additional ٦٪ lost between piping and hatching.
Stewart (١٩٩٥) showed that much lower relative
humidity of ١٨-٣٦٪ was used for incubating ostrich eggs
to achieve the desired weight loss of ١٢-١٥٪. Blood et al.,
(١٩٩٨) and Saito et al., (١٩٩٩) showed that embryonic
deaths were curve linearly related to evaporative water
loss to day ٣٥ of incubation and the higher death rates
occurred in eggs with <١٠٪ and >١٩٪ water loss. They
postulated that the percentage weight losses during the
incubation of the egg hatched were ٠٣٣٪ per day and the
fertile eggs that did not hatch had higher or lower
percentage weight loss. In addition, Nahm (١٩٩٩)
reported that the weight loss of fertile ostrich eggs (١٤٢٪)
during the ٤٠ days of incubation was significantly higher
in the egg that hatched than in those that failed to hatch.
He added that the longer periods of storage between
laying and incubation resulted in significantly more
unhatched eggs. They stated that pore density was
positively correlated with egg mass loss.
٢-١-١٠-١- Factors affecting egg weight loss:
Wilson (١٩٩٦) stated that the major factors that
determine egg weight loss are shell porosity and relative
humidity. Secondary factors are egg size, altitude and
incubation temperature. Approximate relative humidity
requirements are ١٥-٢٠٪ for the ostrich. Although, the
primary effect of humidity on water loss from the
incubation egg, it also affects utilization of minerals from
٢٥
the shell, gas exchange and other functions. Insufficient
water loss results in large, sluggish, edematous chicks
which are often in a malposition in the egg causing
problems in pipping the shell and in hatching. Excessive
water loss results in small, dehydrated, weak chicks that
may not be strong enough to hatch. Chick's weights of ٦٠
to ٦٥٪ of the egg weight at setting appear to be in the
normal range for ratites, as it is for other domestic species.
At the hatcher, the embryos begin to pip the shells, so the
humidity should be increased (to approximately ٤٠٪) to
prevent membranes from drying too quickly which causes
the embryo to stick in the shell. Moreover, Deeming
(١٩٩٣) reported that excessive water loss results in
reduced hatchability through dehydration of embryos and
prevent hatching.
Bowsher (١٩٩٢) reported that the most practical
way of regulating the amount of water loss from the eggs
during incubation depended on the number and area of
pores (shell thickness) and by altering the incubator
humidity. So, earlier recommended humidities were
between ٥٠ and ٥٢٪. On the other hand, Deeming (١٩٩٣)
suggested that a potential solution to water loss problems
is to tailor incubator humidity to the mass of the egg. So
that, heavier eggs was incubated at lower humidities and
lighter eggs at higher humidities.
Packard and Packard (١٩٩٣) suggested that
hypercalcaemia attending excessive water loss may be the
causal link between increased mortality and dehydration
in near term embryos. In ١٩٩٥, Block suggested that the
amount of weight loss of eggs during incubation can be
readily manipulated by producers in modern artificial
incubators, emphasizing the need for producers to
routinely monitor incubator humidity, both directly and by
regularly weighing eggs during incubation.
٢-٢- Factors affecting embryonic mortality:
٢٦
Philbey et al., (١٩٩١) found that the syndrome of
ostrich chicks that died at or within ١ week after hatching
(which had anasarca, degenerative changes in the
complexes and pelvic limb muscles and fibrinoid
degeneration of arterioles) was related to high relative
humidity during incubation. Furthermore, myopothy,
gross lesions of internal organs, haemorrhage, bacterial
infections and congenital deformities was also found to be
causes for embryonic mortality (Deming ١٩٩٥b).
٢-٢-١- Oedema:
Jarvis et al., (١٩٨٥) found that high relative
humidity levels in the incubator appear to cause oedema
in chicks. Button (١٩٩٣) and Terzicht and Vanhooser
(١٩٩٣) reported that oedema in artificially incubated
ostrich embryos is a common problem causes embryonic
mortality. Also, Davis et al., (١٩٨٨) showed that the
failure of eggs to lose water leads to storing the excess of
water in the embryo's skeletal muscles and under the skin
resulting in a characteristic oedema.
Angle (١٩٩٥) found that most oedema was
generally considered to result from insufficient water loss
from the egg during incubation. Moreover, he confirmed
Deeming (١٩٩٣) when he reported that most bird eggs
need to lose about ١٥٪ of their initial mass before pipping
takes place. He added that, insufficient water loss result in
poorly developed air cells, poor gas exchange and wet or
‘water-logged ‘oedematous embryos, many of which die
at or near point of hatch or soon after.Moreover, Burton
and Tullett (١٩٨٣) observed that embryos in egg which
lose insufficient water during incubation die probably not
through an excess of water but rather through hypoxia
induced by the low shell conductance.
٢-٢-٢- Anasarca:
Shivaprasad (١٩٩٣) observed that anasarca was a
common problem in ostrich eggs which failed to hatch.
٢٧
This problem was associated with embryos from eggs
above the average mass of ١٥٠٠g which had below
average weight losses.
٢-٢-٣- Hypoxia and myopathy:
Davis et al., (١٩٨٨) showed that hypoxia was the
proximal cause of death in oedematous embryo as a result
of impaired oxygen diffusion across the moist shell
membranes.
Rigdon (١٩٦٧) and Burger and Bertram (١٩٨١)
reported that myopathy was found in pelvic muscles of
embryos that had pipped the shell, showing symptoms of
muscular degeneration, including necrosis of the
complexes (hatching) muscle resulted from exertions
during hatching and swollen complexes muscles were
common in ostrich chicks that straggle to hatch.
Deeming (١٩٩٥) found that myopathy was
contributed to muscular fatigue and failure to hatch. He
noticed that chicks died at point of hatch or within a week
of hatching showed some degree of muscular lesions in
the leg muscles which were used to break the shell in
hatching. Myopathy was thought to occur secondarily to
exertion, hypoxia and respiratory acidosis and this may be
more direct causes of death in chicks which exhibiting this
symptom. Embryos with low incidence of pelvic muscle
lesion and was pipped the air cell or shell broken was
assisted to hatch.
٢-٢-٤- Malposition:
Angle (١٩٩٣) reported that malpositioning of
embryos results in failure to hatch and may be caused by
setting eggs upside down (air cell to the bottom),
inadequate turning of the eggs (especially during the first
third of incubation), insufficient water loss and possibly
genetic factors. In addition, deficiency or excess of Vit.A
in parent bird diets has been implicated.
٢٨
Deeming (١٩٩٥b) noted that malpositioning was
the predominant symptom in dead in shell ostrich embryo
and was also been reported to be common else where. The
malpositioning generally results from incorrect setting of
the eggs or inadequate turning and oedema.
٢-٢-٥- Hatching assistance:
Ar et al., (١٩٩٦) and Deeming (١٩٩٧) reported that
high chick mortality occurred in assisted chicks with poor
growth rates in the survivors.
٢-٢-٦- Trace minerals:
٢-٢-٦-١- Breeder nutrition and trace minerals:
Richards (١٩٩٧) documented that changes in the
environmental conditions during incubation can impact
trace mineral metabolism.
The supply of nutrients in the egg originates in the
diet of the hen and from her metabolism. All of the
minerals required by the developing avian embryo in the
egg had to be supplied in the diet of the hen (Wilson
١٩٩٧). In this respect, Richard and Miles (٢٠٠٠) essential
that breeder diet should be adequate in all nutrients to
develop the embryo inside the egg normally. A deficiency
or toxicity of trace mineral in the diet of the breeder hen
affected egg hatchability via impaired growth and
abnormal development of all major organ systems and
chick quality. Moreover, fifteen trace elements such as
Zn, Cu, Mn, Fe, Se, Co, Ni, I, Mo, Va, Si and Pb are
considered to be essential in animal. These traces have a
physiological role and functional role in many metabolic
processes in cellular metabolism.
Brake et al., (١٩٩٤) reported that very little is
known about the role of parent nutrients and the effect of
nutrient deficiency in the embryonic mortality and
hatchability of ostrich eggs. Nutrient deficiencies, most
٢٩
gross deficiency in the egg at laying, resulted in
embryonic failure (embryo mortality mid way through
incubation) and reduced hatchability. They stated that
much more researches are needed to determine the
nutrient requirements of breeding ostriches. Several
vitamins and minerals such as vitamin A,D,E, pantothenic
acid, folic acid (Vit. B), biotin, riboflavin, linoleic acid,
manganese, zinc, selenium and calcium were implicated
in late embryonic mortality or deformities and reduced
hatchability or in short supply caused embryo mortality or
deformities at different stage.
Abdallah et al., (١٩٩٤) cleared that the manganese
deficient breeder diet reduced hatchability and lead to
embryonic abnormalities. These abnormalities were
similar to those observed in a biotin deficiency include
increased mortality peaks prior to ٥ days or after ١٧ days
of incubation and includes a chondrodystrophy or micro
media condition with shortened bones and "parrot beak".
Supple et al., (١٩٥٨) and Romanoff and Romanoff
(١٩٧٢) postulated that Zn-deficient embryos have low
hatchability, increased mortality, and impaired
development of the skeleton and feathers. In some cases a
zinc deficiency is associated with embryos having no
wings or legs tufted down.
Savage (١٩٦٨) revealed that a copper deficient
breeder diet is associated with a severe decline in
hatchability. However, the inter relationship between
copper and zinc has proven to affect hatchability because
an excess of zinc will aggravate a copper deficiency.
Signs of a Cu–deficiency in the embryo include early
mortality with anemia and a high incidence of hemorrhage
following ٣ to ٤ days of incubation.
Kinder et al., (١٩٩٤) reported that a deficiency of
selenium in breeder diets will result in decreased
hatchability. Sign of a deficiency were weak chicks that
٣٠
had gizzard muscle myopathy and leg extended backward
and curved up ward. Toxicosis due to excess selenium has
been shown with natural diets abnormal signs due to
excess selenium include dwarfing, shortened bones of the
legs and wings, and short or missing lower beak. On the
other hand, Stahl et al., (١٩٨٨) reported that increasing the
dietary concentrations of Zn, Cu, and Fe did not result in
higher egg concentrations of these minerals but the age of
the hen and environmental conditions also exert an
influence on the mineral content of the egg.
Dewar et al., (١٩٧٤) reported that during the first
few days of incubation the developing chick embryo has
the ability to transfer and concentrate trace minerals Zn,
Mn, Cu and Fe from the egg. Whole chick embryo
concentrations of zinc, copper, iron, and manganese were
initially high on day ٥ of incubation and that they had
declined sharply by day ١٠. Romanoff (١٩٦٧) proposed
that in the early stages of development of the chick
embryo higher trace mineral concentrations were required
to support the very rapid expansion of embryo mass.
Carisle (١٩٧٢) showed that silicon plays a
physiological role in the bone calcification process and
required in the normal growth and skeletal development in
the chick. Also, silicon is essential for normal chick
embryo metabolism.
Miles et al., (١٩٩٧) observed a significant decline
in hatchability of fertile eggs at ٦٠ ppm vanadium and the
number of unpipped eggs increased, but no embryonic
abnormalities or malpositions were observed.
٢-٢-٦-٢- Eggshell structure and mineral content:
The eggshell structure is considered to be correlated
with the hatching sequence in the ostrich. Abnormal shells
described by Sauer et al., (١٩٧٥) were all commonly
associated with failure of normal embryonic development.
٣١
The mineral content of eggshells might influence
embryo physiology and hatchability. Tuan and Zrike
(١٩٧٨) reported that after the early period of embryonic
growth, the primary source of Ca (over ٨٠٪) and Mg (over
٣٠٪) was mobilized via shell absorption (dissolution of
the shell) by the chorioallantoic circulation by
mechanisms similar to bone resorption and the shell was
the only sources of Ca and Mg late in incubation.
Meanwhile, Tuan (١٩٨٣) and Ono and Wakasugi (١٩٨٤)
reported that during embryonic development of the
chicks, Ca and Mg are supplied from two sources, the egg
yolk and eggshell.
Richards
(١٩٨٢)
postulated
that
until
approximately ١٠ days of incubation the yolk appear to be
the solo supplier of Ca and Mg in chicken embryos, but
this to be true for turkey embryos until about day ١٥ of
incubation. Bowsher (١٩٩٢) cleared that the shell was a
source of Ca to provide the embryo in the latter stage of
incubation. Tronter et al., (١٩٨٣) found that Mg was lost
from membranes of chicken eggs between ٣ and ٩ days of
incubation and Mg concentration of membranes increased
after ١٨ days of incubation so they suggested that Mg
played a more complex physialoyical role during
incubation than simply as a structural component of the
shell.
Mountcastle (١٩٧٤) and Christensen and Biellier
(١٩٨٢) cleared that increased plasma Ca to Mg ratio in
embryos at the time of pipping and hatching increased
physiological muscular mechanism for breaking the shell
and hatching and may play a role in hatchability. On the
other hand, ionic Ca stimulates muscular contraction
whereas Mg inhibits contraction. So, they suggested that
the influx of these ions into the egg membranes or
embryonic circulation may influence embryonic survival
during incubation by some as yet undefined physiological
mechanism.
٣٢
Ono and wakasugi (١٩٨٤) cleared that the increased
concentration of Ca and Mg in turkey blood plasma
during pipping and hatching may be dependent upon the
composition of the shell, which was the major source of
these minerals, during the latter stages of embryonic
development.
Christensen and Edens (١٩٨٥) assumed that the
relatively low Ca in turkey eggshells may not affect
hatchability as much as the relatively lower Mg
concentration. Grabowski (١٩٦٦) and Christensen and
Eden (١٩٨٥) found that injections of Ca and Mg at setting
and at a ٢٥ days of incubation (a time selected to coincide
with the yolk supplying Ca and Mg to the turkey embryo)
significantly depressed hatchability. However, latter in
incubation specifically at day ٢٥ of incubation, they found
that the injections of Ca and Mg affected hatchability
divergently sense injections of Mg depressed hatchability
whereas Ca injections improved hatchability. Moreover,
they cleared that increasing the ratio of Ca to Mg in turkey
eggs at ٢٥ days of incubation improve hatchability
whereas decreasing the ratio suppresses hatchability.
Romanoff (١٩٦٧) observed that egg shell Pi
concentrations varied among hatchability groups.
Christensen et al., (١٩٨٢) studied the concentration
of Ca, Mg and Pi in the turkey eggshell during the egg
production season and in the hatched, pipped and non
pipped dead embryos. They found that the concentration
of Ca was significantly greater in eggs laid in the early
season than in eggs laid in the mid season or late eggshells
laid in the late season. Meanwhile, no significant
differences were observed in the Ca concentration of non
pipped, pipped or hatched eggshells, while a significant
increase in Mg was observed in early and mid season
eggshell than in late shells. However, they found that
hatched egg shells contained significantly more Mg than
pipped or non pipped eggshells, the ratio of Ca to Mg
٣٣
increased significantly in the hatched eggshells than
pipped or non pipped eggshells and the percent egg Pi
didn’t change across the laying season in early, mid, late
eggshells. On the other hand, the pipped eggshells
contained significantly more Pi than non pipped or
hatched eggshells.
٢-٢-٧- Eggshell porosity:
٢-٢-٧-١- Eggshell porosity and oxygen supply:
Shell porosity has been implicated with embryonic
mortality, both too many pores and too few pores have
been shown to affect hatchability. Paganelli (١٩٩١) and
Button et al., (١٩٩٤) stated that pore numbers vary greatly
between ostrich eggs and average around ١٥ pore / Cm٢.
Also, they reported that ostrich eggs as well as most of the
bird species were on average more pores at the air cell at
the end of the egg than at the equator side. They added
that the shell thickness was varies between eggs but
increases with egg size.
The increase in eggshell porosity is associated with
a greater need for oxygen by the embryo towards the end
of incubation. Deeming (١٩٩٣) suggested that low
eggshell porosity may limit oxygen supply to the embryo,
resulting in suffocation without obvious symptoms and
the death resulted from hypoxia. Sahan et al., (٢٠٠٣)
showed that there were no significant differences between
hatched and unhatched eggs with respect to pore density
and mass loss. However, Pore density correlated with
hatchability. Hatchability was less in low pore density
eggs (٤٠٩٪) than in intermediate (٧١٨٪) and high pore
density eggs (٨٠٩٪).
٢-٢-٧-٢- Factors affecting eggshell porosity:
٢-٢-٧-٢-١- Eggshell Mg:
Board and love (١٩٨٠), Christensen (١٩٨٣) and
Christensen and Edens (١٩٨٥) showed that Mg
concentration may be the structural component of the
٣٤
eggshell and it is very important in determining optimal
pore formation and shell porosity. The lower shell Mg
concentrations of non hatched egg seen may simply
reflect a decreased shell porosity that may result in
embryonic mortality. They indicated that greater porosity
of the eggshell was related to an increased Mg
concentration and greater hatchability.
٢-٢-٧-٢-٢- Eggshell Ca:
Christensen and Edens (١٩٨٥) reported that no
differences were seen in the amount of Ca in eggshells
containing non hatched or hatched turkeys. Meanwhile,
Booth (١٩٨٩) and Davis and Christensen (١٩٩٥) showed
that the pores became wider during ostrich egg incubation
this may due to a reduction in the shell thickness with
inner surface shell erosion and Ca mobilization.
٢-٢-٧-٢-٣- Shell thickness:
Saleh, (١٩٨٨) showed that shell thicknesses of
different shell regions are consistent with the removal of
Ca from eggshell for bone formation during the
embryonic development. Moreover, he reported that the
thin shell of hatching eggs may be due to the more
consumption of Ca by the live embryos than the dead ones
in the unhatching eggs. In addition, his results indicated
that the embryos used the equator Ca more than from
large or small regions. Sateneni and Satterlee (١٩٩٤) and
Deeming and Ar, (١٩٩٩) demonstrated that hatchability
was less in egg with thicker shell and lower shell porosity,
which lose less water than optimum and in eggs which
lose more water than optimum.
Gonzales et al., (١٩٩٩) stated that although shell
thickness did not significantly affect hatchability the shell
was thinner in hatched eggs than in the unhatched ones,
and that shell thickness and egg mass loss were negatively
correlated.
Peeples and Brake (١٩٨٥) demonstrated that
eggshell was a major respiratory component of the
٣٥
developing embryos and the thicker shell produce greater
resistance to gaseous diffusion and the shell thickness was
associated with increased embryonic mortality. On the
other hand, Vick et al., (١٩٩٣) indicated that there are
some factors other than shell thickness affected embryonic
mortality and development of chicken eggs such as the
poor albumen quality and thinner cuticle and shell
membrane.
Christensen et al., (١٩٩٦) showed that hatchability
was depended upon a proper relationship between pore
concentration and shell thickness (pore length) which
provided proper weight loss for optimum embryo growth.
Button et al., (١٩٩٤) reported that the eggshell porosity
depends on the number of pores and the thickness of the
shell which affects the loss of water vapour across the
pores of the shell.
Regarding egg shell thickness, Sahan et al., (٢٠٠٣)
studied the effects of egg shell thickness and egg shell
porosity on water and hatchability of ostrich eggs. They
found that shell thickness didn’t correlate significantly
with hatchability. Although the hatchability of high shell
thickness eggs (٦٣٦٪) was somewhat lower than those of
intermediate shell thickness eggs (٧٤٢٪) and low shell
thickness eggs (٧١٤٪), however, this difference was not
significant. On the other hand, eggs of low shell thickness
lost more mass (١٣٠٣٪) than those with intermediate
(١١٢٢٪) and high (١٠٣٦٪) shell thickness. Mass loss
during incubation was higher in hatched (١١٩٨٪) than in
unhatched eggs (١١٠٩٪) although it was not significant.
Accordingly, Shell thickness was negatively correlated to
egg mass loss, while the pore density was correlated with
hatchability.
٢-٣- Post-hatch chick mortality:
In South Africa, typical chick mortality is reported
to be ٤٠٪ (Allwright, ١٩٩٦) or ٥٠٪ up to ٣ months of age
and ١٠٪ from ٣-٦ months of age (Smith et al., ١٩٩٥).
٣٦
While, Verwoerd et al., (١٩٩٨) reported that typical
mortality at ١ week of age is ١٠-٢٠٪, and at ٣ months it is
١٠-٣٠٪. From ٣ to ١٢ months of age mortality is typically
٥٪. Moreover, mortality of chicks which required no
assistance to hatch was ٩٨٪ compared with ٧٥٪ for
chicks helped to externally pip (Deeming and Ayers
١٩٩٤).
Deeming (١٩٩٩) reported that in Israel, mortality
rates ranges from ١٥-٥٠٪. Low mortality (<١٠٪) was
observed at the beginning of the season whilst a sharp
increase in mortality occurs when temperatures was high
and during the last months of the season (about ٥٠٪).
٢-٣-١-Factors affecting post-hatch chick mortality:
Shivaprasad (١٩٩٣) found that mortality of ostrich
chicks was sometimes as high as ٦٠-١٠٠٪ as a result of
gastro-intestinal diseases, yolk sac infections, liver
diseases, haemopoietic disorders and respiratory diseases.
In addition, Musara and Dziva (١٩٩٩) investigated the
effect of disinfection on hatchability of ostrich (Struthio
camelus) eggs and found that streptomyses is suspected to
have caused early embryonic mortality.
٢-٣-١-١- Yolk sac infection:
Deeming (١٩٩٥) studied the role of yolk sac
utilization and the incidence of yolk sac infection in
ostrich chicks which died or were culled and full term
embryos which had failed to hatch and found that there
was a high correlation between yolk mass and initial egg
mass at hatching. The yolk sac was around ١٥-١٧٪ (٢٠٠٣٠٠g) of the initial mass of the egg and ٣٠-٤٠ % of chick
weight. Larger yolk sacs in mass were infected, so,
antibiotic treatment should be used, while surgery should
be a last resort.
٢-٣-١-٢- Nutrient deficiencies:
The design of successful feeding programs for
ratites (ostriches and emus) is a special challenge to
٣٧
nutritionists and production managers. There is little
scientifically based information on nutrient requirements
and efficiency of nutrient utilization by ratites. Since the
first publication on ostrich nutrition appeared in ١٩١٣
(Dowsley and Gardiner), a considerable amount of
research has been conducted on the subject in South
Africa. Scientific publications on ostrich nutrition are,
however, scarce since plenty of this information is not
published in international scientific journals yet.
Nevertheless, successful feeding programs have been
developed by using basic physiological and historical
information available about ostriches and emus combined
with knowledge about the nutrient requirements of poultry
and other species (Scheideler ١٩٩٧).
Angle (١٩٩٦) reported that like pigs and poultry,
ostriches are monogastric herbivores (plant–eaters) and
their digestive system has adjusted to cope with largely
amounts of low–quality fiber–rich plant material
(roughage). Deeming and Ayres (١٩٩٤) suggested that the
toe deformities in several ostrich chicks were not
primarily a problem associated with poor incubation but
were related to the breeding paddock and hens.
٢-٣-٢-
Leg deformities (Tarsometatarsus
bones) and factors affecting it:
Leg deformities were reported to be the most causes
of ostrich chick wastage (More, ١٩٩٦). He demonstrated
that the limb deformities were the single most important
cause of culling (١٥,٣ %) of ostrich chicks raised during
one ostrich breeding season. Foggin (١٩٩٢) postulated that
limb deformities in ostrich chick include a rotated or
twisted leg, perosis, slipped tendon, straddle leg, rolled
toes, bowed leg and rickets where the affected chicks were
culled resulting in considerable financial losses to ostrich
farmers. Bezuidenhout et al., (١٩٩٤) stated that tibiotarsal
٣٨
rotation in ostrich chick is a serious problem that accounts
for considerable financial loss to ostrich farmers.
Mushi et al., (١٩٩٩) stated that the health of the legs
of chicks is of critical importance. Four key problems
exist: Tibiotarsal rotation, rolled toes, slipped tendons,
and bowed legs, and all of these categorized as “leg
problem”, however, their aetiologies are quite different.
The frequency of incidence can be critical in determining
the survival of any batch of chicks. Tibiotarsal rotation
involves a deformation of the distal Tibiotarsus bone
resulting in the hock joint twisting outwards, with extreme
cases leading to birds standing with each leg facing in
opposite directions. Limb deformities were detected in
١٥,٣ % of ostrich chicks. Tibiotarsal rotation (the
metatarsal bone had a lateral deviation) affected ٧٣٪ of the
chicks with limb deformities (around ٥-١٠٪ of birds can
develop Tibiotarsal rotation), whereas, rolled toes
accounted for ٣٦٪.
They also observed that the right leg was often
affected more than the left leg and the incidence of limb
deformities reached peak levels in ٢-٣ weeks old.
Meanwhile, the lowest incidence was recorded at ١٠
weeks of age and no cases were observed thereafter. They
added that at the beginning of the breeding season the
incidence of limb deformities was very high and reached
its minimum at the end. However, Foggin (١٩٩٢) found
that the peak incidence of leg deformities was found to be
around between ٤-٧ weeks of age. Squire and More (١٩٩٨)
stated that tibiotarsal rotation (TTR) was an important
cause of mortality in farmed ostrich chicks during the first
١٠ weeks after hatching and was considered a serious
problem. They concluded that improved pen design,
٣٩
access to water and nutrition could reduce the incidence of
TTR.
Morrow et al., (١٩٩٧) reported that many ostrich
chicks developed swelling of the hock joint at ٦ to ١٢
weeks old. The swelling was localized to the proximal
extremity of the tarsometatarsus. However, the birds
became unthrifty and stunted with torsional and angular
deformities of the tibiotarsal and tarsometatarsal bones.
The basis of the Tibiotarsal rotation condition is a
structural twisting of the distal Tibiotarsus by up to or
beyond ٩٠° (Deeming et al., ١٩٩٦a). Although, Speer
(١٩٩٦) found that bone mineralization was poor in affected
bones, the exact cause for the condition is not exactly
known, over feeding, malnutrition, inadequate exercise,
trauma, poor flooring and genetics have all been
suggested. Bezuidenhout and Burger (١٩٩٣) concluded
that pelvic appendicular skeletal abnormalities and lateral
rotation of tibiotarsus (affected ostrich chicks between ٢
weeks and ٦ month of age) make a significant
contribution to mortalities, the lesion affected the right
pelvic limb almost exclusively and very rarely the left
limb.
Cook (٢٠٠٠) and Steinman et al., (٢٠٠٠) reported
numerous causes of skeletal deformations and angular
limb deformity in poultry. They have been identified as
nutrients (toxicities, deficiencies, and imbalances),
genetic, pathogens, infections diseases, mycotoxins, and
many managerial factors. Practices (lighting programs,
trauma litter or floor conditions, rate of growth, air quality
and biosecurity) all have been shown to directly affect
normal skeletal growth and development. The exact
etiology is unknown.
٢-٣-٢-١- Factors affecting leg deformities:
٤٠
In attempt to explain the causes of leg deformities
in ostriches Reece and Butler (١٩٨٤) suggested that
deformities caused by numerous factors including
nutritional deficiencies and imbalances, excessively rapid
growth rates, high protein concentrated diets and
inadequate exercise. This results in the development of
osteodystrophy, rotation of the distal tibia, which
progresses of luxation of the gastroenemius tendon. The
chick was then unable to stand or walk. Also,
Huchzermeyer (١٩٩٤) reported that the causes of limb
deformity was considered to be multi-factorial; genetics,
nutrition and excessive growth rates. It may be due to
management factors included inadequate exercise and
deficiencies of Ca, P, Vit. E and selenium (Bruning and
Dolesenk, ١٩٧٨), as well as deficiencies in Mn, Zn,
methionine or choline (Wallach, ١٩٧٠).
٤١
٢-٣-٢-٢-Rapid growth rate:
Hallam, (١٩٩٢); Deeming et al., (١٩٩٦) and Mushi
et al., (١٩٩٨) attributed the ostrich leg's deformities to the
rapid growth and increasing the length of the metatarsus
bones. They cleared that the metatarsal bone of ostrich
chicks was shown to grow at rapid rate of ٢,٥ cm per week
in the first ١٠ weeks of life. Therefore, the high rate of
tibiotarsal rotation in the ostrich chick at ٢ –٣ weeks of
age might be due to their rapid growth rate. Also,
Deeming et al., (١٩٩٦a) suggested that young ratites
certainly have large cartilaginous growth plates in the
long bones of the leg. So, Traumatic damage to the lateral
aspect of the distal growth plate of the bone may be
considered as one of the important factors which causes
the bone to deform.
٢-٣-٢-٣-Effect of mycotoxins, Infection, stress, ambient
temperature and inflammation on bone weakness:
Reece (١٩٩٢) and Manolagas (١٩٩٨) reported that
infection, stress and inflammation can be risk factors for
bone integrity leading to bone weakness. Bone infections
such as osteomyelitis and osteonecrosis cause focal bone
loss leading to bone weakness.
Duff et al., (١٩٨٧) found that a nutrients such as
mycotoxins affect bone growth, strength, metabolism and
matrix constituents indirectly by affecting the metabolism
of factors such as Vit. D that is essential for bone health.
Black (١٩٩٥) and Dick and Deeming (١٩٩٦)
reported that in older chick the gastroenemius tendon can
be dislocated from the condyles of the tibiotarsometatarsal joint. The damage can be extensive,
leading to a compound dislocation as the recumbent bird
kicks out, and soft-tissue damage is bilateral. Causes of
٤٢
slipped tendons are unknown but the role of nutritional
deficiencies (e. g. manganese) needs to be investigated
further. In many of the cases observed, dislocation of the
tendon is usually related to some trauma or sharp
movement while running and nutritional deficiency.
Bezuidenhout and Burger (١٩٩٣) stated that the
pathogenesis of proximal and distal tibiotarsal rotation in
ostrich chicks is not entirely understood. The greatest
incidence of twisted or rotated leg syndrome is seen in ٤-٨
week-old birds. They suggested that nutrition, strain,
housing, sex, exercise and growth rate are factors
involved in deformities.
Huchzermeyer (١٩٩٤) mentioned other possible
causes of paresis resulting in recumbency such as gastric
stasis, botulism, weakness, leg injuries and intramuscular
injections.
Furthermore, seasons and ambient temperature may
have some effects on leg deformities. Kreibich and
Sommer (١٩٩٥) reported that leg deformities depended on
the season and that fewer leg problems were encountered
in ostriches reared during the summer months than those
reared during the winter months. Also, Mushi et al., (١٩٩٩)
observed that only a few causes of limb deformities were
seen in ostrich chicks raised during the warmer months,
while, the highest numbers of leg problems were observed
when the environmental temperature was relatively low at
٦ْ C and ٢١ْ C. They also observed a significant negative
correlation between the incidence per month and
temperature.
٤٣
٢-٣-٢-٤-Effect of genetic defects and bone weakness:
Boskey et al., (١٩٩٩) reported that bone density has
been shown to be a heritable trait. Tibial dyschondroplasia
has been shown to be heritable and could indirectly
contribute to bone weakness in poultry during early
growth periods. Wong–Valle et al., (١٩٩٣) stated that
mutations in collagen can affect collagen synthesis,
fibrillogenesis, or their post transnational modifications,
which could alter matrix chemistry and mineralization and
predispose bone to fragility.
٢-٣-٢-٥-Nutritional problem:
Bezuidenhout et al., (١٩٩٤) stated that there are
many factors may affect bone formation and development
such as rapid growth, age, sex, internal parasites, breeding
season all of which may affect the absorption and
metabolism of the various minerals involved in bone
formation.
Gandini et al., (١٩٨٦) noticed that ostrich chicks
developed enlarged hocks and bowing of the
tarsometatarsus at ٦-٧ weeks of age when the chicks
examined radiographically. The chicks showed widening
and poor mineralization of the metaphysis and epiphyseal
plate. Administration of calcium borgluconates improved
the birds and showed increased mineralization.
The role of nutritional factors is probably most
relevant to poultry bone health and strength such as Ca, P.
In this respect, Rath et al., (٢٠٠٠) showed that adequate Ca
is necessary to decrease bone turnover. Perry et al., (١٩٩١),
reported that high levels of phytate and cellulose fibres in
the diet, can interfere with Ca absorption and result in
hypocalcemia and decrease bone strength. They
concluded that it is necessary to judiciously balance the
٤٤
mount of Ca and P added in the poultry diet. Chen-Yan et
al., (١٩٩٧) showed that lameness in young ostriches was
caused by phosphorus deficiency (if the diet given to the
ostriches had a very high Ca or low P in the diet) so that
lameness in young birds occurred with ٩٠٩٪ morbidity.
When the content and the ratio of Ca and P were
corrected, the morbidity decreased to ٥٪. Also, Bissinger
and Huchzermeyer (١٩٩٨) found that leg deformities in
ostriches partially caused by calcium or phosphorus
imbalances.
Tibial dyschrondroplasis (TD) is a leg disorder or
skeletal disease characterized by a vascular plug of
abnormal cartilage adjacent to the epiplyseal growth plate
of the Tibia. In this respect, Yalcin et al., (٢٠٠٠) reported
that a decrease in Ca absorption from the intestinal lumen
could play a role in broiler leg weakness, abnormalities or
both. They suggested that high dietary Ca could prevent
development of lesions. Meanwhile, Nelson et al., (١٩٩٠)
found that high dietary levels of P (from ٠٣٣٪ to ٠٤٨٪)
did not cause leg abnormalities nor did Ca:P ratios from
١٦:١ to ٢٩٤:١.
Atia et al., (٢٠٠٠) showed that very low phosphorus
concentrations (about ٠,٣ of recommendations) were
associated with locomotor abnormalities.
Hocking et al., (٢٠٠٢) failed to demonstrate a strong
relationship between dietary calcium and available
phosphorus concentrations and the prevalence of TD. Low
Ca was associated with low tibial plateau angles and high
Ca with increased radio density and bone width.
Bowlegs are characterized by a bending of the
tarsometatarsal bones (Guittin, ١٩٨٦). The problem of
bowlegs is almost certainly due to a nutritional problem.
Gandini et al. (١٩٨٦) suggested that it was prevalent in
٤٥
birds on a high-protein diet (٢٠٪), but there are many
instances where commercial diets of ٢٢ % protein are used
without problems being seen (Deeming et al., ١٩٩٦a).
Guittin (١٩٨٦) suggested that it may be due to problems
with calcium metabolism. Severe rickets has been
observed in ostrich chicks fed with breeder diets
containing about ٣٪ Ca. He suggested that the levels of
available phosphorus and the Ca: P ratio may be also
important in the prevention of this disorder.
Bezuidenhout et al., (١٩٩٤) reported that deficient
formation or poor mineralizotion of the osteoid matrix
was associated with the deficiencies in the micro-minerals
including Zn, Cu, Ca, P, Mn and Mg. They added that Zn
works as co-enzyme in the process of osteoid–matrix
formation and plays an important role in mineralization of
the osteoid. They also cleared that deficient formation or
poor mineralization of the osteoid matrix lead to deficient
bone formation and subsequent bone abnormalities.
Sunde (١٩٧٢) found that the leg bones of many
pheasant chicks appeared deformed at about ٢ weeks of
age; the type of deformity was almost entirely various
deviation of the tarsometatarsus distal to the tarsal joint
(bow–legged) and was similar to leg deformities of Zn
deficient. Scott et al., (١٩٥٩) demonstrated that pheasant
chicks fed diets deficient in Zn have an abnormal feather
and leg development. Moreover, Cook et al., (١٩٨٤)
reported that the addition of Zn to the commercial mixed
diet successfully decreased the severity of leg deformities
or weakness.
Huchzermeyer (١٩٩٤) stated that high Ca levels in
plants and water on farms on calciferous soils can induce
malabsorption of Mg and Zn. Morrow et al., (١٩٩٧) added
٤٦
that the skeletal abnormalities in the ostriches were caused
by the ingestion of an excess of dietary Ca. Ross and
Cooper (٢٠٠٠) stated that it is important to avoid too
much dietary calcium as this may lead to depressed uptake
of manganese and zinc. Mn deficiency has been
implicated in deformed leg syndrome and porosis. Zn
deficiency may lead to limb deformities, enlarged joints
and thickening of the skin on the feet and legs. Smith and
Sales (١٩٩٥) added that selenium deficiencies lead to
lameness in ostrich chicks. This emphasises the need for
strict diets and feed supplementation as shown by Cilliers
and Van Schalkwyk, (١٩٩٤).
Morrison and Sarett (١٩٥٨) and Kienholz et al.,
(١٩٦١) stated that increasing dietary Ca has been
demonstrated to increase the requirement for Zn and to
precipitate Zn deficiencies in chickens. Gandini et al.,
(١٩٨٦) concluded that dietary deficiency in Ca was shown
to be the cause of the bone abnormalities. In addition,
Underwood (١٩٧٧) noted that excesses of Cu and Fe were
adversely affected Zn absorption.
Osphal et al., (١٩٨٢) showed that a deficiency of Cu
decreased collagen cross-link formation and lowered
mineralization. Renine et al., (١٩٩٧) demonstrated that
fluoride was found to be increasing bone density in
chickens. However, Wilson and Ruzler (١٩٩٨) found that
supplementation boron to dietary laying hens improved
bone strength. Huff et al., (١٩٩٦) added that excess
aluminum in feed produces generalized growth depression
and reduces bone strength.
Mushi et al., (١٩٩٩) compared affected ostrich
chicks with tibiotarsal rotation with serum mineral
analysis of normal ostrich chicks of comparable age, sex
and body mass and raised under identical conditions.
٤٧
Their data showed that the mean serum Zn and Mn levels
were significantly elevated in deformed chicks, while the
mean level of serum Cu in the deformed chicks was
slightly low. Kaneko (١٩٨٩) added that the noticeable
muscle catabolism which due to muscular dystrophy may
be a result of the increase in the levels of plasma Zn.
Heany (١٩٩٨) and Wohl et al., (١٩٩٨) reported that
supplemental protein and carbohydrate as energy sources
are important for bone health. However, excess protein
intake produced negative Ca balance and stunt bone
growth. Therefore, supplemental Ca with protein may be
necessary to maintain optimal Ca balance and bone health.
Similarly, diets consisting of highly saturated fats can
have adverse effect on bone mineralization and low-fat
diets can increase cancellous bone strength and bone
mineral content.
٢-٣-٢-٦-Vitamins and deformation:
Vitamins are important feed additives in poultry
diets. Because vitamin D is a calcitrupic hormone
involved in Ca absorption in the intestine and has a major
regulatory role in bone metabolism and bone strength, it is
widely used as a feed supplement (Newman and Leeson,
١٩٩٩).
Weber (١٩٩٩) stated that because egg laying causes
a heavy demand for Ca, it is essential to supplement Vit.
D to maintain optimal bone's health in laying hens.
Occasional field rickets in certain flocks of birds can
produce a major disaster due to poor mineralization and
weak bones, which can be traced to Vit. D deficiency or
vit. D metabolism.
Besides Vit D, Vit. B٦, C and K are integral to
bone health because of their involvement in the synthesis
٤٨
of matrix constituents, such as collagen and osteocalcin
and formation of collagen cross links (Weber, ١٩٩٩).
Mushi et al., (١٩٩٨) observed that adult ostriches
developed sudden onset paresis and were unable to stand
up. They found that these ostriches were suffering from
myonecrosis. Histopathological examination showed
degeneration of skeletal muscles, low serum selenium
levels, high serum levels of AST, (Aspartate amino
tranferase) and CK (Creatine kinase), the serum mineral
levels of Ca, P, Mg and Cu were within normal values and
the levels of α-tocopherol (vit.E) were relatively low.
Moreover, when they analyzed the ostrich breeder mash
they found that protein, crude fiber and minerals were
within normal levels. But tocopherol was low at ٤٩
mg/µg. They reported that when ostriches at risk were
given multi–mineral and Vit. supplements the affected
birds failed to respond to therapy, meanwhile no more
cases were observed. Similar results were found by Van
Heerden et al., (١٩٨٣). Vorster (١٩٨٤) found that ostrich
chicks which became lame at ٦ weeks of age and have
muscular dystrophy was responded to treatment with
vitamin E and selenium.
Dick and Deeming (١٩٩٦) reported that the
incidence of rolled toes is variable in ٠-٢٥٪ of birds. This
condition is characterized by the medial displacement of
the pad under the large too and is common in chicks under
٢ weeks of age .The etiology of this condition is unknown
although deficiency of B-complex vitamins has been
suggested. However, Dunn (١٩٩٥) suggested that almost
all cases spontaneously revert to normal by ٤ weeks of
age. The persistence of rolled toes in older chicks appears
to be related to rotation of the phalangeal bones. Also,
Liswaniz (١٩٩٦) suggested that this problem is associated
٤٩
with poor muscle tone, which affects the tension of
tendons holding the foot pad in place, with lack of
exercise or a nutritional deficiency.
٢-٣-٣-Thyroid hormones:
No available information had been reported on the
effects of thyroid hormones on legs deformation in ostrich
chicks.
٥٠
٣- MATERIALS AND METHODS
The present study was carried out in co-operation
between the Ostrich Production Farm, Nuclear Research
Center, Atomic Energy Authority, Cairo, Egypt and the
Faculty of Agriculture, AL-Azhar University, Nasr City,
Cairo, Egypt. Data were collected during the period from
August ٢٠٠١ till October ٢٠٠٣. Ostrich eggs were obtained
from two commercial farms e.g. Egy-Tec Farm, Gerza
Village, Giza, Egypt and Shamp International Company
for Ostrich Production. Normal and deformed legs were
obtained from chicks belonging to Egy-Tec Farm, Gerza
Village, Giza, Egypt.
Two trials were carried out:
٣-١- First trial, factors affecting hatchability:
A total of ١٠٠ ostrich eggs weighed between ١٣٠٠
and ١٥٠٠ g were obtained from each farm. Eggs were
collected weekly in patches of ٢٥ eggs from Shamp
International Company for Ostrich Production and ٢٥ eggs
from Egy-Tec Farm, Gerza Village, Giza, Egypt.
٣-١-١- Eggs Collection:
Eggs were collected daily as soon as possible after
laying from the breeder stock and cleaned immediately
with a dry clean cloth or a soft abrasive, disinfectant
solution sprayed on the surface of the eggs and the shell
was wiped dry with a clean toilet paper for each egg
(Deeming ١٩٩٧). Each egg was numbered and identified
with a permanent marker. Eggs were stored for up to ٧
days in a clean storage room at ١٨ ٠C and ٦٩ % relative
humidity as recommended by Gonzalez et al., (١٩٩٩).
٥١
٣-١-٢- Egg Incubation:
The eggs were set in metal – framed egg trays in a
vertical position, placed in a commercial multistage
incubator with a maximum capacity of ١٠٠٠ ostrich eggs.
Eggs were artificially incubated at ٣٦٥ ٠ C and ٢٥ % RH
and the eggs were turned every ٣ hours through ٤٥° (٨
times a day) up to ٣٩ days. Eggs were candled at weekly
intervals during incubation period using a homemade
candling lamp or powerful ‘pen light’ torch to light the
eggs in a darkened room, unfertile eggs were excluded.
On day ٣٩, the viable (fertile) eggs were transferred to
plastic hatcher baskets in the hatcher up to ٤٥ day. The
temperature and humidity profile during hatch were ٣٦ ٠ C
and ٤٠ % RH. Eggs were candled and checked during
hatching period. The eggs were allowed to hatch as
possible, although, some chicks which had pipped were
helped by using the method described by Deeming et al.,
(١٩٩٣a,b).
٣-١-٣- The following parameters were measured on
each egg:
٣-١-٣-١- Egg Weight:
The egg weight at day ١ of incubation (at the time
of setting) was recorded with an electronic digital balance
(Salter) accurate to ± ٠,٠١ g.
٣-١-٣-٢- Egg size:
The egg maximum length (long axis, L) and width
(short axis, W) were measured in cm by using caliber (١
mm accuracy).
٣-١-٣-٤- Egg Fertility:
٥٢
Fertility was calculated by the following
formula:
% Fertility = All setting eggs – Infertile egg X ١٠٠
All setting eggs
٣-١-٣-٥- Percentage of egg weight loss during
incubation:
Percentage of egg weight loss (EWL%) during
incubation was determined according to Gonzalez et al.,
(١٩٩٩). by the following formula:
EWL % = (Egg weight day١ – Egg weight day٤٠ ) X١٠٠
Egg weigh day١
٣-١-٣-٦- Egg hatchability %:
Hatchability (%) from fertile eggs were calculated
by the following equation:
Hatchability % = Number of eggs hatch X ١٠٠
Number of fertile eggs
٣-١-٣-٧- Eggshell parameters:
At the end of incubation period (٤٥, days) the fertile
eggs were classified into ٢ groups; hatched and unhatched
eggs. The eggshells of each group were collected and
cleaned of adhering shell membrane and washed with
distilled water to remove all albumen and dried over night
at ٦٠ ٠ C and then wet ashed according to method
described by Charles et al., (١٩٨٤) . The following
parameters were taken .
٣-١-٣-٧-١- Eggshell Percent:
٥٣
The eggshell percent was calculated as follow
according to Christensen et al (١٩٩٦).
Eggshell %= Egg shell weight X ١٠٠
Egg weight
٣-١-٣-٧-٢- Egg shell porosity:
Eggshell porosity was determined by a averaging
pore count obtained from discretionary sampling at ٥
independent ١Cm ٢ sites on an egg surface. The sites were
chosen approximately equidistant along the equator to
better visualize and facilitate a more accurate counting of
porosity, each selected site was dyed with a food-grade
blue dye before counting. A clear dichotomy of pore size,
small and large, was observed according to Gonzalez et
al., (١٩٩٩).
٣-١-٣-٧-٣- Egg shell thickness:
Eggshell thickness was obtained by a averaging
thick measurement made at the same five shell sites used
to determine porosity. A slip clutch micrometer was used
to make individual thick estimate to the nearest ٠,٠١ mm.
٣-١-٣-٧-٤- Eggshell minerals:
The eggshell content of Ca, Mg, Zn and Mn, were
determined by using Atomic Absorption Spectrophotometer
(Buck Scientific, Model ٢١٠ VGP). Shell P was determined
using the calorimetric technique of Goldenberg and
Fernandez(١٩٦٦).
٥٤
٣-١-٣-٧-٥ Post-hatch chicks weight:
Post-hatch chicks were weighed just after hatching
completely using an electronic balance (Salter) accurate
to + ١ g.
٣-٢- Second trial:
Tarsometatarsus bones of ٦٠ normal and ٦٠
deformed chicks aged from ٢-١٠ weeks were collected
from Egy-Tec Farm, Gerza City, Giza, Egypt and
analyzed for minerals content (Ca, P, Mg, Zn and Mn).
٣-٢-١- Collection and preparation of tarsometatarsus
bones for mineral detection:
Normal and abnormal tarsometatarsus bones for
chicks aged from ٢ to ٨ weeks were collected, cleaned of
all adhering tissues, rinsed with distilled water and dried
over night at ١٠٠٠ C. A portion of each bone was grinded
using steel mixture then ١ g was subjected to wet ashing
according to method described by Charles et al., (١٩٨٤).
Ca, Mg, Zn and Mn were determined by using Atomic
absorption spectrophotometer (Buck Scientific, Model ٢١٠
VGP). While, P content was determined using the
calorimetric technique of Goldenberg and Fernandez
(١٩٦٦).
٣-٢-٢- Collection of blood samples:
Blood samples were collected from the right jugular
vein of the normal and deformed chicks through a clean
dry needle ٢١ G into ١٠-ml test tube. Blood samples were
left at room temperature for ٣٠-٦٠ minutes then
centrifuged for ٥ minutes at ٤٠٠٠ r.p.m. Serum was
separated and transferred into ١,٥ ml apondorf tubes and
stored at -٢٠٠ C until analysis.
٥٥
The following blood serum parameters were measured:٣-٢-٢-١- Serum Total proteins:
Serum Total protein was measured colorimetrically
according to Henry (١٩٦٤ ).
٣-٢-٢-٢- Serum Albumen:
Serum albumen was determined colorimetrically
using Albumen-Kit (bioMerieux Vitek , Inc.USA).
٣-٢-٢-٣- Serum globulin:
The concentration of globulins in each sample was
obtained by subtracting the albumin values from the total
protein concentration.
٣-٢-٢-٤- Albumin : globulin ratio (A/G ratio):
The A/G ratio was determined by dividing the value
of albumin on the value of globulin in the serum.
٣-٢-٢-٥- Serum Urea:
Serum urea was determined according to Patton and
Crouch (١٩٧٧).
٣-٢-٢-٦- Serum Cholesterol:
Determination of serum cholesterol was carried out
according to the method of Watson (١٩٦٠).
٣-٢-٢-٧- Serum Total Lipids:
Serum total lipids was determined according to
Lxingth et al., (١٩٧٢).
٣-٢-٢-٨-
Determination
of
serum
alkaline
phosphatase in serum:
Alkaline phosphatase was determined colorimetrically
using TECO kit, (TECO ,diagnostic, California, U.S.A).
٥٦
٣-٢-٢-٩- Hormonal assay:
Total thyroxine (T٤) and triiodothyronine (T٣) were
measured in serum by radiimmunoassay Kits (Coat-ACount. PC Diagnostic Products Corporation Los Angles,
CA٩٠٠٤٥).
٣-٢-٢-١٠- Determination of minerals:
Serum inorganic phosphorus was determined
colorimetrically by phosphorus kit (BioAdwic, El-Nasr Co.
Egypt, (A.E.P).Total calcium, manganese, magnesium and
zinc contents in blood serum were determined in five times
serum dilution for trace elements and in ٥٠ times for macro
elements, by using Atomic Absorption Spectrophotometer
(Buck Scientific‫ ﻭ‬Model ٢١٠).
٣-٣- Statistical analyses:
The data obtained in this study were analyzed using
statistical analysis system software (SAS, ١٩٩٩).
٥٧
٤- RESULTS AND DISCUSSION
٤-١- Factors affecting ostrich egg fertility and
hatchability:
٤-١-١- Fertility and hatchability of ostrich eggs:
Table (١) indicates that the fertility and hatchability
of ostrich eggs were affected by management system
(may be due to nutrition). They were higher in farm ٢
(good management) than in farm ١ (poor management).
The fertility was ٦٣٪ in poor management vs. ٧٩٪ in good
management farms. Furthermore, poor management
decreased hatchability as percentage of fertile eggs from
٦٥,٨٪ to ٤٧,٦٪. The lower hatchability in poor
management farm was due mainly to higher late death
percentage (٣١,٧٪ vs. ١٣,٩٪ in good management farm),
meanwhile there was no noticeable difference in infection
rate and percentage of early death.
The percentage of infertility in the two farms (٣٧
and ٢١٪ in farm ١ and ٢, respectively) was within the
range reported in ostrich eggs by many authors (Deeming
et al., ١٩٩٣a; Mellett, ١٩٩٣; Deeming and Ayres, ١٩٩٥ and
More, ١٩٩٧).
Badley (١٩٩٧) concluded that the average fertility rate
in farmed ostriches is low and must improve significantly
to allow the industry to move into available production
phase. The lower fertility rate may be due to nutrition
status, genetic, breeding behavior, and egg treatment before
incubation (collecting, disinfecting and storage of eggs).
Deeming and Ayres (١٩٩٥) stated that factors
affecting fertility of eggs include the genetic and
٥٨
nutritional status of the breeding as well as the mating
behavior and efficiency of the birds. Badley (١٩٩٧) added
that fertilization of the egg depends upon breeding
behavior, bird condition and environment. Nutrition status
includes deficiency of vitamins and minerals including
Vit. A and E and selenium and sever malnutrition all have
been linked to decreased fertility (Iron, ١٩٩٥). Effect of
genetic was postulated by Dzama et al., (١٩٩٥) who
reported that a high level of inbreeding decreased egg
fertility. Huchzermeyer (١٩٩٨) explained behavioral effect
on fertility. He reported that behavioral disorders often
lead to a failure to copulate such as excessive aggression,
obsessive territorial behavior, incompatibility between
males and females and human imprinting on reproductive
success. Moreover, More (١٩٩٧) demonstrated the effect
of laying season on fertility where it was low at the
beginning of the seasons and rose to a plateau of over ٨٠٪
by week ١٠ of laying which was maintained until around
week ٢٦ of lay and decreased thereafter.
The hatchability rate from all eggs in the present
study is in agreement with the average of ٥٠٪ reported by
Mellett (١٩٩٣), More et al., (١٩٩٤) and Deeming (١٩٩٥).
Moreover, Deeming (١٩٩٥) stated that ٢٨ – ٥٠٪ of the
fertile egg failed to hatch which is in accordance with the
٣٤٢ to ٥٢٤٪ in the present study. Badley (١٩٩٧) added
that hatchability (proportion of fertile eggs hatching) and
survivability (proportion of chicks surviving to three
months) were ٥١٪ and ٦٢٪, while More et al., (١٩٩٤) found
better results (٦٧٪ hatchability and ٦٨٪ survivability).
Deeming (١٩٩٣a & ١٩٩٥a) stated that the
hatchability depends firstly on the characteristics of the
egg itself which were determined prior to laying and then
٥٩
on the management practices and the environmental
conditions imposed after the egg was laid. The successful
artificial incubation as measured by maximizing
hatchability of fertile eggs depends upon having good egg
quality and proper egg management during the preincubation and incubation periods and providing the
optimum conditions for incubation and hatching. In
addition, Deeming (١٩٩٤) cleared that nutrition of
breeding ostriches, age, genetics and its environment were
several factors affected variable characteristics such as
egg composition, eggshell conductance (porosity) and
egg size all of which were affecting hatchability.
Furthermore, More et al., (١٩٩٤) found that hatchability of
ostrich eggs was poor at the beginning of the laying
season and this may be associated with the low yolk
weight. The effect of environmental factors were
explained by Gonzalez (١٩٩٤) who stated that temperature
was the most important environmental factors affecting
egg weight, egg composition, eggshell weight and
thickness and shell porosity. Another important factor
which affects hatchability is the inbreeding between the
birds (Hermes, ١٩٨٩).
٦٠
Table (١): Fertility and hatchability of ostrich eggs in
two farms.
Farm ١
Out come
No
%T
Infertile eggs
٣٧
٣٧
Fertile eggs
٦٣
٦٣
Infection eggs
٦
٦
Early death
٧
٧
Late death
٢٠
٢٠
Hatched eggs
٣٠
٣٠
Total eggs
١٠٠
١٠٠
%F
= % from fertile eggs
%T
= % from total eggs
Farm١ = poor management
Farm٢ = good management
٦١
%F
٩٥
١١١
٣١٧
٤٧٦
١٠٠
No
٢١
٧٩
٦
١٠
١١
٥٢
١٠٠
Farm ٢
%T
٢١
٧٩
٦
١٠
١١
٥٢
١٠٠
%F
٧٦
١٢٧
١٣٩
٦٥٨
١٠٠
٤-١-٢-
Physical and chemical ostrich egg
characteristics affecting hatchability:
٤-١-٢-١ Effect of physical ostrich egg characteristics
on hatchability:
Hatchability of ostrich eggs and production of a
healthy chick depend on egg quality, which refers to the
egg contents and the eggshell. So, increasing or not the
embryonic mortality during pipping and hatching depends
first on the characteristics of the egg itself, which were
determined prior to laying. Therefore, the successful
artificial incubation as measured by maximizing
hatchability of fertile eggs depends on studying some
physical characteristics of the hatched and non-hatched
ostrich eggs.
Table (٢) reveals that there were no significant
differences between hatched and unhatched ostrich eggs
in mean initial egg mass at set, egg sizes (length and
width in cm), eggshell weight after hatch, eggshell
thickness (mm) and mean egg shell porosity.
٤-١-٢-١-١ Effect of ostrich egg weight loss
during incubation on hatchability:
Although Table (٢) indicates that the percent weight
loss was significantly higher in hatched than in unhatched
eggs, Table (٢-a) reveals that the percentage of egg weight
loss lower than ١٣٪ and higher than ١٧٪ were significantly
higher in unhatched than in hatched eggs. Consequently,
the recommended egg weight loss during incubation
period (١٣-١٧٪) was significantly higher in hatched
(٩٥,٥٪) than in unhatched eggs (٤٠,٠٪). Similar results
were reported by Nahm (١٩٩٩)
٦٢
Who found that the weight loss of fertile ostrich
eggs (١٤٢٪) during the ٤٠ days of incubation was
significantly higher in the egg that hatched than in those
that failed to hatch? He added that the longer periods of
storage between laying and incubation resulted in
significantly more unhatched eggs. Blood et al., (١٩٩٨)
and Saito et al., (١٩٩٩) showed that embryonic deaths
were curve linearly related to evaporative water loss to
day ٣٥ of incubation and the higher death rates occurred
in eggs with <١٠٪ and >١٩٪ water loss. They postulated
that the percentage weight losses during the incubation of
the egg hatched were ٠٣٣٪ per day and the fertile eggs
that did not hatch had higher or lower percentage weight
loss.
Many authors reported different percent of egg
weight loss to achieve successful hatching percent under
artificial conditions e.g., ١٢-١٥,٥٪ (Jarvise et al., ١٩٨٥ and
Simon and More, ١٩٩٦), ١٠-١٣٪ (Bowsher, ١٩٩٢), ١٣,٢٪
(Wilson et al., ١٩٩٧), ١٤,٢٪ (Nahm, ١٩٩٩) and ١٥٪
(Deeming, ١٩٩٣). Moreover, Saito et al., (١٩٩٩) reported
that both lower and higher water losses resulting
decreased hatchability and the eggs that do hatch with
water losses below ١٠٪ produced oedemetons, sluggish
and unabsorbed yolk chicks. The failure to lose sufficient
weight can result in water retention by the chick (Davis et
al., ١٩٨٨) which can reduce hatchability. Furthermore,
Angle (١٩٩٥) stated that most oedema was generally
considered to result from insufficient water loss from the
egg during incubation. Deeming (١٩٩٣) demonstrated that
insufficient water loss result in poorly developed air cells,
poor gas exchange and wet or ‘water-logged ‘ oedematous
embryos, many of which die at or near point of hatch or
soon after. Also, low water losses (<١٣٪) indicate low
permeability of the eggshell to water vapour and other
٦٣
gases. If the permeability is very low then additional
problems of oxygen supply or carbon dioxide removal can
complicate the survival of the embryos later in
development (Tullett and Deeming, ١٩٨٢).
Reduction in hatchability due to high egg weight
loss during incubation was explained by Deeming (١٩٩٣)
who reported that excessive water loss results in reduced
hatchability though dehydration of embryos and prevent
hatching.
٤-١-٢-١-٢ Effect of ostrich eggshell porosity
on hatchability:
Table (٢) shows that the fertile eggs which did
hatch had an insignificantly higher porosity than the
unhatched eggs (١٥,٦٢ vs. ١٤,٤ pore/cm٢ for hatched and
unhatched eggs, respectively). Paganelli (١٩٩١) and
Button et al., (١٩٩٤) stated that pore numbers vary greatly
between ostrich eggs and average around ١٥ pore / Cm٢
which is in agreement with the present results.
However, Table (٢-b) shows that the percentage of
eggs with low porosity (٨-١٢ pore/cm٢) was significantly
(p≤٠,٠٥) higher in unhatched eggs (٣٠٪) than in hatched
ones (٦,٥٢ % shell porosity has been implicated with
embryonic mortality and had a significant effect on
hatchability (Ar, ١٩٩١ and Bowsher, ١٩٩٢). Christensen
and Edens (١٩٨٥) and Satteneri and Saterlee (١٩٩٤) stated
that the porosity of the eggshell may be play a big role in
hatching egg, both too many pores and too few pores have
been shown to affect hatchability. Also, Sahan et al.,
(٢٠٠٣) showed that pore density correlated with
hatchability where hatchability was less in low pore
density eggs (٤٠,٩٪) than in intermediate (٧١,٨٪) and high
٦٤
pore density eggs (٨٠,٩٪). Gonzales et al., (١٩٩٩) reported
positive correlations between pore density and egg mass
loss and between pore density and hatchability in ostrich
eggs.
The effect of porosity on hatchability was explained
by Deeming (١٩٩٣ & ١٩٩٣a). He reported that “Tight“
eggs with low porosity lose little water and this may cause
oedema (water retention) in ostrich embryos which makes
hatching more difficult. He also suggested that low
eggshell porosity may limit oxygen supply to the embryo
resulting in suffocation without obvious symptoms and
the death resulted from hypoxia.
In addition, Wilson (١٩٩٦) reported that the
tremendous variation observed in shell porosity and
weight loss of ostrich eggs indicates wide genetic
variability among hens. So, improved hatchability is likely
to be achieved through selecting hens that lay eggs with
good shell quality and adequate, uniform shell porosity.
٤-١-٢-١-٣ Effect of eggshell thickness on hatchability:
Table (٢) shows that eggshell thickness had no
significant effect on hatched and unhatched ostrich eggs
in the present study. This result is in agreement with
Sahan et al., (٢٠٠٣) who found that shell thickness didn’t
correlate significantly with hatchability. They stated that
although the hatchability of high shell thickness eggs
٦٣٦٪ was somewhat lower than those of intermediate
shell thickness eggs ٧٤٢٪ and low shell thickness eggs
٧١٤٪, meanwhile, these differences were not significant.
However, eggs of low shell thickness lost more mass
(١٣٠٣٪) than those with intermediate (١١٢٢٪) and high
(١٠٣٦٪) shell thickness. So, shell thickness was
negatively correlated to egg mass loss. Also, Gonzales et
al., (١٩٩٩) reported that although shell thickness did not
significantly affect hatchability the shell was thinner in
٦٥
hatched eggs than in the unhatched ones and that shell
thickness and egg mass loss were negatively correlated.
Vick et al., (١٩٩٣) indicated that there are some factors
other than shell thickness affected embryonic mortality
and development of chicken eggs such as the poor
albumen quality and thinner cuticle and shell membrane.
On the other hand, Peeples and Brake (١٩٨٥)
demonstrated that eggshell was a major respiratory
component of the developing embryos and the thicker
shell produce greater resistance to gaseous diffusion and
the shell thickness was associated with increased
embryonic mortality. It is of interest to note that
hatchability was depend upon a proper relationship
between pore concentration and shell thickness (pore
length) which provided proper weight loss for optimum
embryo growth (Button et al., ١٩٩٤; Sateneni and
Satterlee, ١٩٩٤; Christensen et al., ١٩٩٦ and Deeming and
Ar, ١٩٩٩). Moreover, Saleh (١٩٨٨) showed that shell
thickness of different shell regions is consistent with the
removal of Ca from eggshell for bone formation during
the embryonic development.
٤-١-٢-١-٤ Effect of ostrich egg size on hatchability:
Table (٢) shows that egg weight, egg length and egg
width did not differ significantly between hatched and
unhatched eggs indicating that in the present study egg
weight and dimentions did not affect hatchability because
they were within the normal ranges reported for ostrich
eggs. Meir and Ar (١٩٩٠) stated that the length and width
of normal ostrich eggs were ١٥,٣٢ cm and ١٢,٥٦ cm,
respectively, which are in accordance with that found in
the present study. On the other hand, Simon and More
(١٩٩٦), Krawinkel (١٩٩٤) and Ar et al., (١٩٩٦) reported
that egg size and weight had a significant effect on
٦٦
hatching rate which was due to lower hatchability in large
and small eggs (٢٨ and ١٤ %, respectively, lower than
average eggs). It is worth noting that the mean egg weight
in the present study (١١٥٣ vs. ١١٩٠ gm for hatched and
unhatched eggs, respectively) was far from the range of
low and large eggs weights that affecting hatchability.
Wilson (١٩٩١) postulated that eggs weighing less than
١٠٠٠g or more than ١٨٠٠g have reduced hatchability. The
effect of egg size on hatchability was explained by
Deeming (١٩٩٧) who stated that the effect of egg size on
hatchability was due to a reduction in the surface area to
volume ratio with increasing egg size making the gas heat
exchange more difficult.
٤-١-٢-١-٥ Effect of ostrich chick weight
(gm) at hatch on hatchability:
In unhatched eggs, chick weight (gm) at hatch was
more significantly higher (٩٤١١±١٥٣) than that in
hatched eggs (٧١٧٣±١٦٥) (Table, ٢-c). This higher chick
weight at hatch in unhatched eggs may be due to water
retention by chick as a result of failure to lose sufficient
egg weight during incubation. Davis et al., (١٩٨٨), Wilson
(١٩٩١), Button (١٩٩٣) and Terzicht and Vanhooser
(١٩٩٣) showed that the failure of eggs to lose water leads
to storing the excess of water in the embryo's skeletal
muscles and under the skin resulting in a characteristic
oedema.
The above results indicate that the low eggshell
porosity and percentage weight loss the main factors
caused the reduction in hatchability. These results are
confirmed by the low hatchability. In due to high late
death percentage (Table, ١).Burton and Tullett (١٩٨٣) and
Davis et al., (١٩٨٨) concluded that hypoxia was the
proximal cause of death in oedematous embryo as a result
of impaired oxygen diffusion across the moist shell
٦٧
membranes. Furthermore, death of near term chicks may
be due to myopathy. Deeming (١٩٩٥) found that
myopathy was contributed to muscular fatigue and failure
to hatch. Myopathy was thought to occur secondarily to
exertion, hypoxia and respiratory acidosis and this may be
more direct causes of death in chicks which exhibiting this
symptom. Embryos with low incidence of pelvic muscle
lesion and was pipped the air cell or shell broken was
assisted to hatch.
٦٨
Table (٢): Mean±S.E. of hatched and non-hatched
ostrich eggs physical characteristics.
Egg physical characteristics
Initial Egg wt. at set (gm)
Egg wt. at ٣٩d of incubation (gm)
Egg length(cm)
Egg width(cm)
Eggshell wt. (gm)
Percentage wt. loss
Eggshell porosity (pore/cm٢)
Eggshell thickness (mm)
Egg Class
Hatched
Unhatched*
a
١٣٥٥±٣٤٦٨
١٣٧٨± ٤٤٣ a
١١٥٣± ١٨٨ a
١١٩٠±٢٤٠٣ a
١٥١٢± ٠١١ a
١٥٣١± ٠١٥ a
١٢٢٣± ٠٠٧ a
١٢٢٥± ٠٠٩ a
٢٣٧±٥٤٣ a
٢٤٩± ٦٩ a
١٤٦±٠٢ a
١٣٦±٠٢٦ b
١٥٦٢± ٠٥٧ a
١٤٤± ٠٥٧ a
١٨٣٥± ٠٠٠٢٩ ١٨± ٠٠٠٣٧ a
a
*late dead in shell
a,b means in the same row with different superscripts are significantly different
P<٠,٠٥
٦٩
Table (٢-a): Prevalence of percentage weight loss in
hatched and unhatched eggs.
Egg wt. Loss (%)
Hatched
No.
%
٢٠ ٤٥٥
٤٢٠ ٩٥٤٥
٠٠ ٠٠٠
٤٤٠ ١٠٠٠٠
<١٣٪
١٣-١٧٪
>١٧٪
Total
<13
13-17
Unhatched
No.
%
١٢
٤٠٠٠
١٢
٤٠٠٠
٦
٢٠٠٠
٣٠
١٠٠٠٠
>17
95.45
100
80
%
60
40
40
40
20
20
4.55
0
Hatched
0
Unhatched
Fig. (١): Prevalence of percentage weight loss in
hatched and unhatched eggs.
٧٠
p
≤٠,٠١
Table (٢-b): Prevalence of eggshell porosity in hatched
and unhatched eggs.
Hatched
No.
%
٣
٦٥٢
٣٥ ٦٧٠٩
٦
١٧٣٩
٤٤ ١٠٠٠
٠
Egg shell porosity
(pore/cm٢)
٨-١٢
١٢-١٨
>١٨
Total
8-12
12-18
Unhatched
No. %
٩
٣٠٠٠
١٦ ٥٣٣٣
٥
١٦٦٧
٣٠ ١٠٠٠
٠
p
≤٠,٠٥
>18
76.09
80
70
60
53.33
%
50
40
30
30
17.39
20
10
16.67
6.52
0
Hatched
Unhatched
Fig. (٢): Prevalence of eggshell porosity in hatched and
unhatched eggs.
٧١
Table (٢-c): Mean±S.E. of hatched and unhatched ostrich
chicks weight.
Chick wt. at hatch (gm)
Hatched
٧١٧٣±١٦٥ b
Non-hatched
٩٤١١±١٥٣ a
a,b means in the same row with different superscripts are
significantly different P<٠,٠٥.
٧٢
٤-١-٢-٢- Effect of chemical ostrich egg
characteristics
(eggshell minerals) on hatchability:
The mean eggshell mineral content of hatched and
unhatched ostrich eggs are presented in Table (٣). The
statistical analysis indicated that the eggshell content of
calcium (Ca), manganese (Mn), calcium to phosphorus
ratio (Ca/P) and calcium to magnesium ratio (Ca/Mg)
were significantly higher in unhatched eggs (late dead in
shell) than in hatched ones. On the other hand, the
eggshell content of phosphorus (P) and Magnesium were
significantly higher in hatched eggs than in unhatched
eggs. Meanwhile, eggshell content of zinc (Zn) did not
differ significantly in hatched and unhatched eggs.
The significantly higher Ca/P ratio in unhatched
than in hatched eggshells was due to a significantly lower
eggshell Ca in hatched than in unhatched eggs (١٤,٩ vs.
١٧,٣, respectively), while eggshell P was significantly
higher in hatched than in unhatched eggs. The lower Ca
content in eggshell of hatched eggs may be due to Ca
mobilization from eggshell for bone formation during the
embryonic development during incubation. Saleh, (١٩٨٨)
showed that shell thicknesses of different shell regions are
consistent with the removal of Ca from eggshell for bone
formation during the embryonic development. Moreover,
he reported that the thin shell of hatching eggs may be due
to the more consumption of Ca by the live embryos than
the dead ones in the unhatching eggs. Also, Davis and
Christensen (١٩٩٥) showed that the pores became wider
during ostrich egg incubation may due to a reduction in
the shell thickness with inner surface shell erosion and Ca
mobilization. Furthermore, Tuan and Zrike (١٩٧٨)
reported that after the early period of embryonic growth,
the primary source of Ca (over ٨٠٪) and Mg (over ٣٠٪)
was mobilized via shell absorption (dissolution of the
٧٣
shell) by the chorioallantoic circulation by mechanisms
similar to bone resorption and the shell was the only
sources of Ca and Mg late in incubation. Meanwhile,
Christensen and Edens (١٩٨٥) found that there were no
significant differences in the amount of Ca in eggshells
containing non hatched or hatched turkeys. The higher P
in hatched than in unhatched eggshells are in agreement
with Christensen et al., (١٩٨٢) who found that the pipped
eggshells contained significantly more P than non pipped
or hatched eggshells.
Also the significantly higher Mg in hatched than in
unhatched eggshells (Table, ٣) caused a significantly
lower Ca/Mg ratio in egshells of hatched than of
unhatched eggs. Similar results were found by
Christensen et al., (١٩٨٢) who reported that hatched egg
shells contained significantly more Mg than pipped or non
pipped eggshells, the ratio of Ca to Mg increased
significantly in the hatched eggshells than pipped or non
pipped eggshells. Tronter et al., (١٩٨٣) found that Mg was
lost from membranes of chicken eggs between ٣ and ٩
days of incubation and Mg concentration of membranes
increased after ١٨ days of incubation so they suggested
that Mg played a more complex physialogical role during
incubation than simply as a structural component of the
shell.
The higher Ca/Mg ratio in hatched than in
unhatched eggshells in the present results is contradecting
with the high requirement for plasma Ca/Mg ratio during
hatching. Christensen and Biellier (١٩٨٢) stated that
increased plasma Ca to Mg ratio in embryos at the time of
pipping and hatching increased physiological muscular
mechanism for breaking the shell and hatching and may
play a role in hatchability and that the increased muscular
activity due to increased plasma Ca:Mg ratio may be
required for the embryo to break and free itself from the
shell. Also, Grabowski (١٩٦٦) and Christensen and Eden
٧٤
(١٩٨٥) found that increasing the ratio of Ca to Mg in
turkey eggs at ٢٥ days of incubation improved
hatchability whereas decreasing the ratio suppresses
hatchability. This contradection can be explained by the
less mobilization of Mg from eggshell in hatched eggs.
Christensen and Biellier (١٩٨٢) reported that ionic Ca
stimulates muscular contraction whereas Mg inhibits
contraction and suggested that the influx of these ions into
the egg membranes or embryonic circulation may
influence embryonic survival during incubation. Thus the
lower Mg content in eggshell of unhatched eggs may
indicate that more Mg was mobilized from the eggshell
causing the inhibition of muscle contraction and failure to
hatch.
The significantly higher Mn in eggshells of
unhatched than of hatched eggs may reflect the lower
mobilization of Mn from shells of unhatched eggs and
may affect the ability of chick to hatch. Wallach (١٩٧٠)
stated that deficiencies in Mn, Zn, methionine or choline
may cause limb deformity.
٧٥
Table (٣): Mean ± SE of Eggshell mineral content of
hatched and unhatched ostrich eggs.
Mineral
Hatched
Unhatched*
b
١٧,٣ ± ٠,٠٥a
Ca%
١٤,٩ ± ٠,٠ ٤
P%
٠,٣٩٨ ± ٠,٠٣a
٠,١٦٧ ± ٠,٠٤b
Mg%
٠,٧ ± ٠,٠٥ a
٠,٦٠ ± ٠,٠٦b
Zn%
٠,١١٤ ± ٠,٠٠٨٤ a
٠,١١±٠,٠١٠٧ a
Mn%
٠,٠٧٧ ± ٠,٠٠٥b
٠,١٣٣ ± ٠,٠٠٦٥a
٣٧,٥ ± ١,٣b
١٠٣,٩ ± ١,٣a
٢١,٣٨ ± ٠,٨b
٢٨,٧ ± ٠,٨٣a
Ca / P ratio
Ca / Mg ratio
*late dead in shell
a,b,c means in the same row with different superscripts are
significantly different P<٠,٠٥
٧٦
٤-٢- Factors affecting ostrich post-hatch chick
leg deformation:
٤-٢-١- Post-hatch chick mortality:
Chick mortality during the first ٨ weeks after hatch
ranged between ١٠ to ٢٥٪. Mortality due to leg
deformation represented ٥ to ١٥٪ of total chicks and ٥٠ to
١٠٠٪ of dead chicks (Table, ٤). The overall average of
chick mortality due to leg deformation was ١٠٪ (٨ out of
٨٠ chicks) which represent ٦٦,٧٪ of the total chicks died
during this period (٨ out of ١٢). Table (٤) and Fig. (٣)
reveal that from ٤ to ٨ weeks of age mortality rate ranged
between ١٠-١٥ %, however, mortality due to leg
deformation (as percentage from total mortality) tended to
increase by age. In South Africa, Allwright, (١٩٩٦) found
that the typical chick mortality is reported to be ٤٠٪ or
٥٠٪ up to ٣ months of age and ١٠٪ from ٣-٦ months of
age (Smith et al., ١٩٩٥). While, Verwoerd et al., (١٩٩٨)
reported that typical mortality at ١ week of age is ١٠-٢٠٪,
and ١٠-٣٠٪ at ٣ months. From ٣ to ١٢ months of age,
mortality is typically ٥٪. Moreover, mortality of chicks
which required no assistance to hatch was ٩٨٪ compared
with ٧٥٪ for chicks helped to externally pip (Deeming and
Ayers ١٩٩٤). In Israel, Deeming (١٩٩٩) reported that
mortality rates ranges from ١٥-٥٠٪. Low mortality (<١٠٪)
was observed at the beginning of the season whilst a sharp
increase in mortality occurs when temperatures was high
and during the last months of the season mortality rate is
about ٥٠٪. Mortality rate in the present study is in
agreement with that found by Verwoerd et al. (١٩٩٨) and
Deeming (١٩٩٩) but it is lower than that reported by
Allwright, (١٩٩٦).
٧٧
Leg deformities were reported to be the most
important cause of ostrich chick wastage (More, ١٩٩٦ and
Mushi et al., ١٩٩٩) and its incidence reached peak levels
in ٢-٣ weeks old. Meanwhile, the lowest incidence was
recorded at ١٠ weeks of age and no cases were observed
thereafter. Limb deformities in ostrich chick include a
rotated or twisted leg, perosis, slipped tendon, straddle
leg, rolled toes, bowed leg and rickets (Foggin, ١٩٩٢).
Bezuidenhout and Burger (١٩٩٣) stated that pelvic
appendicular skeletal abnormalities and lateral rotation of
tibiotarsus (affected ostrich chicks between ٢ weeks and ٦
month of age) make a significant contribution to
mortalities. The peak incidence of leg deformities was
found to be around between ٤-٧ weeks of age (Foggin,
١٩٩٢). Morrow et al., (١٩٩٧) added that many ostrich
chicks developed swelling of the hock joint at ٦ to ١٢
weeks old. The swelling was localized to the proximal
extremity of the tarsometatarsus. However, the birds
became unthrifty and stunted with torsional and angular
deformities of the tibiotarsal and tarsometatarsal bones.
Furthermore, Squire and More (١٩٩٨) stated that a
deficiency in one or more of the Ca, P, Mg, Mn and Zn
may contribute to limb deformities as a result of poor
mineralization.
The causes of mortality due to other factors during
the early post-hatch period were explained by Shivaprasad
(١٩٩٣) who found that mortality of ostrich chicks was
sometimes as high as ٦٠-١٠٠٪ as a result of leg
deformities gastro-intestinal diseases, yolk sac infections,
liver diseases, haemopoietic disorders and respiratory
diseases.
٧٨
Table (٤):Prevalence of mortality and leg deformation
in ostrich chicks during the first ٨ weeks of
age.
Age
٠-١week
Category
Died due to leg deformities
No
٣
Died from other reasons
٤-٦
weeks
No %
٢
١٠
٦-٨ weeks
%
١٥
١-٤
weeks
No %
١
٥
No
٢
%
١٠
٢
١٠
١
٥
١
٥
٠
٠
Alive
١٥
٧٥
١٨
٩٠
١٧
٨٥
١٨
٩٠
Total
٢٠
١٠٠
٢٠
١٠٠
٢٠
١٠٠
٢٠
١٠٠
0-1 week
1-4 weeks
4-6 weeks
6-8 weeks
30
25
25
%
20
15
15
15
10 10
10
5
0
5
10
10
5
10
5
0
Mortality due to leg Mortality from other
deformities
reasons
Total mortality
Fig. (٣): Mortality rate during the first ٨ weeks of age.
٧٩
٤-٢-٢-
Effect of bone mineral content on legs
deformations:
The bone-mineral content in normal and deformed
tarsometatarsus bones of the ostrich chicks are presented
in (Table, ٥). The levels of calcium, manganese and zinc in
deformed tarsometatarsus bones were significantly lower
than that in the normal tarsometatarsus bones. Meanwhile,
phosphorus and magnesium levels were significantly
higher in the deformed tarsometatarsus bones than the
normal tarsometatarsus bones. As a result, the Ca/P and
Ca/Mg ratios were significantly lower in deformed than in
normal tarsometatarsus bones.
The lower Ca content in deformed tarsometatarsus
bones is in consistent with the previous results that Ca
deficiency may cause limb deformity (Levy et al., ١٩٨٦;
Huchzermeyer, ١٩٩٤ and Mushi et al., ١٩٩٩). Also,
Bezuidenhout et al., (١٩٩٤) stated that the bone calcium of
deformed chick with tibiotarsal rotation was significantly
lower compared with the values in normal chicks. The
reduction in Ca content in deformed tarsometatarsus bones
may be due to low calcium intake i.e. diet deficient in Ca
(Bezuidenhout and Burger, ١٩٩٣; Rath et al., ٢٠٠٠;
Creedon and Cashman, ٢٠٠١ and Bar et al., ٢٠٠٣), to a
decrease in Ca absorption from the intestinal lumen (Yalcin
et al., ٢٠٠٠) or ingestion of an excess of dietary calcium
(Morrow et al., ١٩٩٧). Perry et al., (١٩٩١) added that high
levels of phytate and cellulose fibers in the diet can
interfere with Ca absorption and result in hypocalcemia
and decrease bone strength. Furthermore, Heany (١٩٩٨)
and Wohl et al. (١٩٩٨) postulated that supplemental Ca
with protein may be necessary to maintain optimal Ca
balance and bone health, similarly diets consisting of
highly saturated fats can have adverse effect on bone
٨٠
mineralization and low fat diets can increase cancellous
bone strength and bone content.
On the other hand, the significantly higher P content
in the deformed tarsometatarsus bones than normal ones
disagrees with results of Huchzermeyer (١٩٩٤) and Mushi
et al., (١٩٩٩) who found that deformed tibiotarsal bones
had a significant reduction in P content. This may be due to
imbalance between diet Ca and P as suggested by Bissinger
and Huchzermeyer (١٩٩٨). Chen-Yan et al., (١٩٩٧)
showed that lameness in young ostriches was caused by
phosphorus deficiency (if the diet given to the ostriches
had a very high Ca or low P in the diet) so that lameness in
young birds occurred with ٩٠٩٪ morbidity. Nelson et al.,
(١٩٩٠) found that Ca:P ratios from ١٦:١ to ٢٩٤:١ did not
cause leg abnormalities which coincided with the ratio in
normal
tarsometatarsus
bones,
while
deformed
tarsometatarsus bones had lower Ca:P ratio (١,٠٥).
The significantly lower Mn in deformed than in
normal bones agrees with Black (١٩٩٥); Dick and
Deeming (١٩٩٦) and Ross and Cooper (٢٠٠٠) who
reported that Mn deficiency has been implicated in
deformed leg syndrome, slipped tendons and porosis.
The obtained results of significantly lower Zn
content in deformed than in normal bones agree with that
reported by Sunde (١٩٧٢) who found that leg bones of
many chicks appeared deformed at about ٢ weeks of age
(various deviation of the tarsometatarsus distal to the
tarsal joint) which was similar to leg deformities of zinc
deficient. Therefore, chicks fed diets deficient in zinc have
abnormal log development and deformed leg. Ross and
Cooper (٢٠٠٠) reported that zinc deficiency may lead to
limb deformities, enlarged joint, and thickening of the
skin on the feet and legs. Romanoff and Romanoff (١٩٧٢)
reported that Zn deficiently increased impaired
٨١
development of the skeleton or legs tufted down. Also,
Cook et al., (١٩٨٤) found that additional zinc to the diet
was successful in decreasing the severity of leg
deformities.
On the other hand, Bezuidenhout et al., (١٩٩٤)
demonstrated that there was no difference between the
bone zinc content of affected and normal bird. They
explained that the increase in Zn in affected birds may be
due to an attempt by the body to produce more osteoid
(bone matrix) in response to the bone abnormality (poor
mineralization).
The significantly higher Mg% and lower Ca:Mg
ration in deformed than in normal bones may be explained
by the decreased muscle activity in deformed leg birds.
Christensen and Biellier (١٩٨٢) stated that increased
plasma Ca to Mg ratio may play a role in increased
muscular activity and ionic Ca stimulates muscular
contraction whereas Mg inhibits contraction.
From the above-mentioned results, it can be
concluded that deficient formation or poor mineralization
of the osteoid matrix is associated with deficiencies in the
micro mineral, Zn, Ca, Mn, Ca:P ratio and Ca:Mg ratio.
Meanwhile, it may be affected by higher Mg content in
bones.
٨٢
Table (٥): Mean±SE of the normal and deformed
ostrich chick's tarsometatarsus bone
mineral content.
Normal
Tarsometatarsus
١٨,٤٣±٠,٠٦ a
Deformed
Tarsometatarsus
٩,٥٩± ٠,٠٥ b
٧,٩٢±٠,٠٢ b
٩,٣٨± ٠,٠٣٣ a
٢,٣٥±٠,٠٢٣ a
١,٠٥±٠,٠١٥ b
٠,٠٩٤±٠,٠٠٢ b
٠,٢٢٦± ٠,٠٠٢٥ a
١٩٦,٦±٢,٧ a
٤٢,٧±٢,١ b
Mn%
٠,٠٠٣٣±٠,٠٠٠٣ a
٠,٠٠٢٧±٠,٠٠٠٥ b
Zn%
٠,٢٤٦±٠,٠٠١ a
٠,١٦٩±٠,٠٠١ b
Minerals
Ca%
P%
Ca / P ratio
Mg%
Ca / Mg ratio
a,b means in the same row with different superscripts are
significantly different (P≤٠,٠٥)
٨٣
٤-٢-٣- Effect of serum mineral content on legs
deformations:
Serum mineral content (Mean±SE) of ostrich
chicks with normal and deformed tarsometatarsus bones
are presented in (Table, ٦). Statistical analysis indicated
that the mean serum calcium, manganese, calcium to
phosphorus ratio (Ca/P), and calcium to magnesium ratio
(Ca/Mg) were significantly lower in ostrich chicks with
deformed than with normal tarsometatarsus bones.
Meanwhile, the mean serum phosphorus and zinc were
significantly higher in the serum of chicks with deformed
tarsometatarsus bones than in normal ones. No significant
difference was found between mean serum magnesium of
ostrich chicks with deformed and normal tarsometatarsus
bones.
Limb deformity in ostrich chicks were found to be
due to deficiencies of calcium, phosphorus, manganese,
magnesium, copper and zinc (Bruning and Dolesenk,
١٩٧٨; Bezuidenhout et al., ١٩٩٤; Huchzermeyer, ١٩٩٤;
Mushi et al., ١٩٩٨ and Squire and More, ١٩٩٨). Guittin
(١٩٨٦) stated that severe rickets has been observed in
ostrich chicks fed with breeder diets containing about ٣٪
Ca. The levels of available phosphorus and the Ca:P ratio
may be also important in the prevention of this disorder.
The deficiency in serum Ca, Mn, Ca:P ratio and Ca:Mg
ratio of deformed chicks in the present results are in
agreement with the previous literature. However, the
significantly higher serum P and Zn in deformed than in
normal chicks in the present study are in contrast with that
in literature. Squire and More (١٩٩٨) stated that a
deficiency in one or more of the Ca, P, Mg, Mn, Zn, and
Cu may contribute to limb deformities as a result of poor
mineralization, however, the elevated levels of these
minerals in the serum of birds with leg deformities was a
٨٤
paradoxical finding. Bezuidenhout et al., (١٩٩٤) found that
serum Zn level was significantly elevated in the affected
ostrich chicks with limb deformities compared with
normal chicks which agrees with the present result. They
added that Zn works as co-enzyme in the process of
osteoid–matrix formation and plays an important role in
mineralization of the osteoid which may explain the
increase in serum Zn of deformed chicks as an attempt by
the body to produce more osteoid. Also, Kaneko ١٩٨٩
reported that the noticeable muscle catabolism, which due
to muscular dystrophy may be a result of the increase in
the levels of plasma Zn.
٨٥
Table (٦): Mean±SE of serum mineral content of
ostrich chicks with normal and deformed
tarsometatarsus bone.
Normal
Tarsometatarsus
٢,٥٦ ± ٠,٠١٤a
Deformed
Tarsometatarsus
٢,٠٧ ± ٠,٠١٣b
١,٨ ± ٠,٠١٩b
٢ ± ٠,٠١٥a
١,٥ ± ٠,٠١٢a
١,١٥ ± ٠,٠١٤ b
Mg%
Ca / Mg ratio
٠,٥١٣ ± ٠,٠٠٤a
٠,٥٥ ± ٠,٠٠٥ a
٥,٤٥ ± ٠,٠١٥a
٤,١٢ ± ٠,٠٢٣b
Mn%
٠,٦٨ ± ٠,٠١١a
٠,٤١ ± ٠,٠١٢b
Zn%
٢,٣ ± ٠,٠٤b
٤,٠٤ ± ٠,٠٧a
Minerals
Ca%
P%
Ca / P ratio
a,b means in the same row with different superscripts are
significantly different (P≤٠,٠٥)
٨٦
٤-٢-٤- Effect of serum blood chemistry on legs
deformations:
Table (٧) shows that mean serum concentrations of
alkaline phosphatase, urea, cholesterol, total protein,
albumen and globulin were significantly higher in
deformed than in normal chicks with tarsometatarsus
bones. While, triiodothyronin (T٣), tetraiodothyroxine (T٤)
and albumen to globulin ratio (A/G) were significantly
lower in deformed than in normal chicks. There was no
significant difference between serum levels of total lipid in
normal and deformed chicks.
The significantly higher serum alkaline phosphatase
(Alkp) in deformed than normal chicks may be due to
physiological increase in osteoclastic activity or
decalcification. Levy et al., (١٩٨٦) showed that activity due
to serum alkaline phosphates (Alkp) elevations may be due
to physiological increase in osteoclastic activity. AlBustany et al., (١٩٩٨) stated that elevated plasma Alkp and
loss of bone material were found in calcium deficient hens
irrespective of supplemental phosphorus. Hurwitz and Paul
(١٩٦٠) reported that decalcification rather than calcification
of bone is associated with increased alkaline phosphatase
levels.
The significant increase in blood urea in deformed
chicks may be due to the catabolism of body protein.
Palomeque et al., (١٩٩١) reported that high blood urea in
ostriches and birds may result from catabolism of body
protein and dietary deficiency in essential amino acids may
elevate levels of urea.
Perry et al., (١٩٨٦) demonstrated that higher levels
of fat and low protein may result in high serum cholesterol
and vice-versa. Thus the significantly higher serum
٨٧
cholesterol in deformed than in normal chicks may be due
to low protein in their diet.
Results in Table (٧) indicates that the significantly
higher plasma total proteins in deformed than in normal
chicks was due to significant increase in plasma albumin
and globulin. The increase in serum globulin was more
pronounced than that in albumin causing a significant
reduction A/G ratio. The significant increase in globulin in
deformed chicks may be due to increased antibody
formation because they are more susceptible to diseases.
Kwak et al (١٩٩٩) indicated that globulin portion mainly
involved in antibody formation as well as cell membrane
activities and cell division and cell proliferation. Also,
Soliman (٢٠٠٠) showed that antibodies are globulin in
nature and are involved in immune reactivity
(immunoglobulins, Igs),
The significantly higher serum thyroid hormones (T٣
and T٤) in normal than in deformed chicks is in accordance
with Biellier and Turnner (١٩٥٠) who stated that the
thyroxin secretion rate appear to be correlated with the
faster growth rates. Gado (١٩٧٣) indicated that thyroid
hormones are essential for normal growth in fowl and the
overall body growth, maturation and growth of specific
tissue being affected. Also, thyroid gland plays a major role
in the regulation of growth in birds and thyroid hormones
play a major role in regulating the oxidative metabolism in
birds (Scanest et al., ١٩٨٤ and Peebles and Marks, ١٩٩١).
Moreover, Ebling and Hale (١٩٧٠) reported that thyroid
hormones influence most body functions. They directly
affect a number of physiological processes and are required
for the permissive actions of other hormones on these
processes. For example they are obligatory with
somatotropin (STH) for early growth and development.
٨٨
Table (٧): Mean±SE of serum blood chemistry of
ostrich chicks with normal and deformed
tarsometatarsus bones.
Serum parameter
ALK.P IU/l
Normal
Tarsometatarsus
١٩١ ± ٣,٨b
Deformed
Tarsometatarsus
٢٩٣,٢ ± ٢,٦a
Urea mmol/l
٣,٠٢. ± ٠,٠٣b
٤,١ ± ٠,٠٢٥a
T.lipid mmol/l
١,١١ ± ٠,٠٣ a
٠,٩٩ ± ٠,٠٢a
Cholesterol mmol/l
١,٧٩ ± ٠,٠٣b
٢ ± ٠,٠٢a
T.prot g/dl
٣,٤٤ ± ٠,٠٣b
٤,٢ ± ٠,٠٢a
Album g/dl
١,٨٦ ± ٠,٠٢b
١,٩٣ ± ٠,٠١٥a
Globu. g/dl
١,٦ ± ٠,٠٣b
٢,٥ ± ٠,٠٢a
A/G ratio
١,١٧± ٠,٠١٤a
٠,٧٣ ± ٠,٠٢b
T٤ µg/dl
٠,٤٤ ± ٠,٠٢a
٠,٤٢ ± ٠,٠٢b
T٣ µg/dl
١٧٦,٦ ± ١,٧a
١٦٦,٥ ± ١,٦b
a,b means in the same row with different superscripts are
significantly different (P≤٠,٠٥)
٨٩
٥-SUMMARY AND CONCLUSION
The present study was carried out in co-operation
between the Ostrich Production Farm, Nuclear Research
Center, Atomic Energy Authority, Cairo, Egypt and
Ostrich Farm belonging to Faculty of Agriculture, ALAzhar University.
The objectives are: to study some factors affecting
hatchability and leg deformation as the major factors
affecting ostrich production.
Two trials were carried out:
١- First trial
A total of ١٠٠ ostrich eggs were collected from
Shamp International Company for Ostrich Production and
Egy-Tec Farm, Gerza Village, Giza, Egypt.
Egg weight, egg size, egg fertility, egg weight loss
during incubation and egg hatchability were determined
on each eggs.
Eggshells were collected from the hatchery and
classified into ٢ groups: eggshell from normally hatched
eggs and eggshell from unhatched (late dead in shell)
eggs. Eggshell percentage, egg shell porosity, egg shell
thickness and shell minerals contents (Ca, Pi, Mg, Zn, and
Mn) were determined as factors affecting hatchability.
Second trial:
Tarsometatarsus bones of ٦٠ normal and ٦٠
deformed chicks aged from ٢-١٠ weeks were collected
from Egy-Tec Farm, Gerza City, Giza, Egypt and
analyzed for minerals content (Ca, P, Mg, Zn and Mn).
٩٠
Blood samples were collected from ٦٠ normal and
٦٠ deformed chicks aged from ٢ to ١٠ weeks and analyzed
for minerals content (Ca, P, Mg, Zn and Mn). The
following biochemical analysis were determined in blood
serum: serum total proteins, albumen, globulin,
albumin/globulin ratio (A/G ratio), urea, cholesterol, total
lipids, alkaline phosphatase, T٤ and T٣.
Results indicated that:
١- Good management increased fertility rate from ٦٣٪
to ٧٩٪ and hatchability rate from ٤٧,٦٪ to ٦٥,٨٪.
٢- The lower hatchability in poor management farm
was due mainly to higher late death percentage.
٣- There were no significant differences between
hatched and unhatched ostrich eggs in mean initial
egg mass at set, egg sizes (length and width in
cm), eggshell weight after hatch, eggshell
thickness (mm) and mean egg shell porosity.
٤- The percentage of egg weight loss lower than ١٣٪
and higher than ١٧٪ were significantly higher in
unhatched than in hatched eggs indicating that the
reduction in hatchability may be due to low or
high egg weight loss during incubation.
٥- The fertile eggs which did hatch had an
insignificantly higher porosity than the unhatched
eggs and the percentage of eggs with low porosity
(٨-١٢ pore/cm٢) was significantly higher in
unhatched eggs (٣٠٪) than in hatched ones (٥,٥٪).
٦- Eggshell thickness did not differ significantly
between hatched and unhatched ostrich eggs.
٧- Egg weight, egg length and egg width did not
differ significantly between hatched and
unhatched eggs indicating that in the present study
egg weight and its dimensions did not affect
٩١
hatchability because they were within the normal
ranges reported for ostrich eggs.
٨- In unhatched eggs, chick weight (gm) at hatch was
significantly higher (٩٤١١±١٥٣) than that in
hatched eggs (٧١٧٣±١٦٥) may be due to water
retention by chick as a result of failure to lose
sufficient egg weight during incubation.
٩- The eggshell content of calcium, manganese, Ca/P
ratio and Ca/Mg ratio were significantly higher in
unhatched eggs than in hatched ones.
١٠- The eggshell content of phosphorus and
Magnesium were significantly higher in hatched
eggs than in unhatched eggs.
١١- The significantly higher Ca/P ratio in unhatched
than in hatched eggshells was due to a
significantly lower eggshell Ca in hatched than in
unhatched eggs while eggshell P was significantly
higher in hatched than in unhatched eggs.
١٢- There was no significant difference in eggshell
content of zinc between hatched and unhatched
eggs.
١٣- The significantly higher Mg in hatched than in
unhatched eggshells caused a significantly lower
Ca/Mg ratio in eggshells of hatched than in
unhatched eggs.
١٤- Chick mortality during the first ٨ weeks after
hatch ranged between ١٠ to ٢٥٪. Mortality due to
leg deformation represented ٥ to ١٥٪ of total
chicks and ٥٠ to ١٠٠٪ of dead chicks and the
overall average of chick mortality due to leg
deformation was ١٠٪ which represent ٦٦,٧٪ of the
total chicks died during this period.
١٥- Mortality rate from ٤ to ٨ weeks of age ranged
between ١٠-١٥ %, however, mortality due to leg
٩٢
deformation (as percentage from total mortality)
tended to increase by age indicating that leg
deformities were the most important cause of
post-hatch chick culling or mortality.
١٦- The levels of calcium, manganese and zinc in
deformed tarsometatarsus bones were significantly
lower than that in the normal tarsometatarsus
bones.
١٧- Phosphorus and magnesium levels were
significantly
higher
in
the
deformed
tarsometatarsus bones than in the normal ones. As
a result, the Ca/P and Ca/Mg ratios were
significantly lower in deformed than in normal
tarsometatarsus bones.
١٨- The mean serum calcium, manganese, Ca/P
ratio and Ca/Mg ratio were significantly lower in
ostrich chicks with deformed than with normal
tarsometatarsus bones.
١٩- The mean serum phosphorus and zinc were
significantly higher in the serum of chicks with
deformed tarsometatarsus bones than in normal
ones.
٢٠- No significant difference was found between
mean serum magnesium of ostrich chicks with
deformed and normal tarsometatarsus bones.
٢١- Mean serum concentrations of alkaline phosphate,
urea, cholesterol, total protein, albumen and
globulin were significantly higher in deformed
than in normal chicks with tarsometatarsus bones.
٢٢- Thyroid hormones (T٣ andT٤) and albumen to
globulin ratio (A/G) were significantly lower in
deformed than in normal chicks.
٢٣- There was no significant difference between serum
levels of total lipid in normal and deformed
chicks.
٩٣
It can be concluded that:
The lower hatchability was mainly due to high late
dead percentage resulting from high (>١٧٪) or low (< ١٣٪)
egg weight loss during incubation period or to low
eggshell porosity which affects egg weight loss and
embryo respiration. Thus low eggshell porosity is the
main factor affecting hatchability as eggs with low
porosity lose little water and this may cause oedema
(water retention) in ostrich embryos which makes
hatching more difficult. Also, low eggshell porosity may
limit oxygen supply to the embryo resulting in suffocation
without obvious symptoms and the death resulted from
hypoxia.
The main causes of leg deformation in ostrich
chicks aged from ٢ to ١٠ weeks is the deficient formation
or poor mineralization of the osteoid matrix which
associated with deficiencies in the micro mineral, Zn, Ca,
Mn, Ca:P ratio and Ca:Mg ratio. Meanwhile, it may be
affected by higher Mg content in bones.
Leg deformation was due to a significant reduction
in mean serum calcium, manganese, Ca/P ratio and
Ca/Mg ratio. Meanwhile, serum phosphorus and zinc
were significantly higher in the serum of chicks with
deformed tarsometatarsus bones than in normal ones
which need further studies.
Reduction in thyroid activity may be one of the
factors lead to leg deformation which needs further
studies.
Leg deformation affects muscle activity (causing a
significant increase in serum alkaline phosphatase), body
protein catabolism (increased blood urea) and immunity
(increased serum globulin concentration).
٩٤
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١٢٠
‫ا
ا‬
‫أ‪ *+,-‬ه)( ا'را& ‪#‬ون ‪ ! "#‬ر إج ام ه‬
‫ا‪ /0‬ا)ر‪,! -+‬آ ا‪356‬ث ا‪3‬و‪ +‬ا‪8‬ه‪,‬ة‪ ,9! -‬و ! ر‬
‫م آ‪ :‬ا را ‪ !-‬ا<زه‪.,‬‬
‫أه'اف ه)( ا'را&‪:‬‬
‫! ف ا إ درا&‪ %‬ﺏ‪ "#‬ا‪5#‬ا‪ 34‬ا‪/01*2‬ة ‪%)*+ *,-‬‬
‫ا‪ 7**89‬و‪ ;5<* :‬ا>ر=**‪ ?**@ 3‬آ‪DE‬آ‪ A**B‬ا‪D**#G‬م وا‪ 3**H2: ?**E‬أه**‪I‬‬
‫ا‪5#‬ا‪ 34‬ا‪/012‬ة ‪ ,-‬إ‪DE+‬ج ا‪D#G‬م‪.‬‬
‫ﺕ‪ AB9‬ا@‪:#,‬‬
‫ا‪/OE‬ﺏ‪ %‬ا‪N‬و‪:‬‬
‫أ=‪ A!/‬ا‪/OE‬ﺏ‪ ,- %‬ﺏ‪PE&D‬ام ‪-‬د ‪ ١٠٠‬ﺏ‪ Q4 %RB‬آ‪S4 3‬ر‪:%*-‬‬
‫ﺵ‪ U4D‬او‪DE+T %B‬ج ا‪D#G‬م و‪S4‬ر‪ %-‬ا= ‪ .W:‬و‪ /!*8: I:‬آ*‪Q*4 3‬‬
‫وزن ا‪ -"B‬ﺡ‪ IO‬ا‪ – "B‬ا *‪5‬زن ا ‪5*892‬د ‪ Q*4‬ا‪ %R*B‬ﺥ*]ل‬
‫ا‪ %)+ - _!/9E‬ا‪5`P‬ﺏ‪ %‬و‪ %)+‬ا‪.789‬‬
‫و‪ a2= I:‬و‪ /<c IB)8:‬ا‪ "B‬ا‪ Q4 b:DG‬ا‪ 7892‬إ ‪-:QBE-52O4‬‬
‫‪ /<c -١‬ﺏ‪.7cD@ "B‬‬
‫‪ /<c -٢‬ﺏ‪ "B‬آ‪D‬ﺏ‪59+) 7‬ق ‪eE4‬ﺥ‪.(/‬‬
‫‪ /!8: I:‬ا‪ ?@ ?:N‬ه‪h‬ا ا‪:/<8‬‬
‫‪ %B4D)4‬ا‪/<8‬ة ‪ W2*& -‬ا‪/<*8‬ة ‪/<*c %)*+--‬ة ا*‪ Q*4 "B‬ا‪%R*B‬‬
‫ا‪ .%B,i‬و‪5*E4 /!*8: I:‬ى ه*‪h‬ا ا‪ Q*4 /<*8‬ا‪5B)*Di‬م‪-‬ا‪59*&59‬ر‪-‬‬
‫ا‪5B)GkD2‬م‪-‬ا‪-SBGOG2‬ا‪. W+S‬آ‪5#‬ا‪ %)+ ?@ /01: 34‬ا‪.789‬‬
‫ا‪/OE‬ﺏ‪ %‬ا‪:%B+DH‬‬
‫‪ I:‬ا&‪PE‬ام ‪-‬د ‪D& %2l- ٦٠‬ق ‪DEi‬آ‪5<4 AB‬ه‪ %‬ا>ر=*‪ 3‬و ‪٦٠‬‬
‫‪D& %2l-‬ق ‪DEi %B#Bm‬آ‪/E! %B#Bm AB‬اوح أ‪D2-‬ره‪Q4 D‬‬
‫‪١٢١‬‬
‫ة‬SBO‫ا‬- ‫ط‬DB- - ‫زا‬/= - W: =‫ ا‬%-‫ر‬S4 Q4 W‫ وذ‬aB‫ﺏ‬D&‫ أ‬١٠-٢
%*B+#2‫ ا‬/‫ﺹ‬DG#‫ ا‬Q4 Il#‫ا ا‬h‫ى ه‬5E4 3B,: I:‫ و‬.‫م‬D#G‫ج ا‬DE+T
.W+S‫ ا‬-SBGOG2‫ ا‬-‫م‬5B)GkD2‫ ا‬-‫ر‬59&59‫ ا‬-‫م‬5B)Di‫ ا‬:%B:N‫ا‬
‫ق و‬D)*‫ ا‬%‫ه‬5<2‫ ا‬AB‫آ‬DEi‫ ا‬Q4 3‫ آ‬Q4 ‫ دم‬%GB- ٦٠ ‫د‬- a2= I:
-٢ Q*4 D*‫ره‬D2-‫اوح أ‬/*E! ‫ق‬D)*‫ ا‬%*B#Br‫ ا‬AB‫آ‬DEi‫ ا‬Q4 ‫ دم‬%GB- ٦٠
‫ة‬S**BO‫ ا‬- ‫ط‬D**B- – ‫زا‬/**= - W**: **=‫ ا‬%**-‫ر‬S4 Q**4 W**‫ وذ‬aB‫ﺏ‬D**&‫ أ‬١٠
Q**4 QBE-5**2O2‫ ا‬D**E,‫م @** آ‬/B)**‫ى ا‬5**E4 /!**8: I**:‫و‬.‫م‬D**#G‫ج ا‬D**E+T
/!**8: I**: Wh**‫ آ‬W*+S‫ا‬-S**BGOG2‫ا‬-‫م‬5B)**GkD2‫ا‬-‫ر‬59**&59‫ا‬-‫م‬5B)*Di‫ا‬
****‫ ا‬QB45****BN‫ ا‬%)****+-QB5****B‫ﺏ‬5,O‫ا‬-QB45****BN‫ا‬-****,i‫ ا‬QB:‫و‬/****‫ا‬
-‫***ى‬-D8‫ ا‬SB:D9***&59‫ ا‬-%***B,i‫***ات ا‬B,‫ ا‬-‫ول‬/E)***5i‫ا‬-QB5***B‫ﺏ‬5,O‫ا‬
.( T٤ ‫ و‬T٣) %Bc‫ة ار‬t‫ت ا‬D+54/‫ه‬
:I‫ إ‬D‫ﺹ‬3‫ ا‬A‫ ﺕ‬F‫ ا‬G‫ اﺉ‬A‫أه‬
%٦٣ Q*4 %‫ﺏ‬5`*P‫ ا‬%)*+ ‫دة‬D*!‫ة ا ز‬BO‫ ا‬%!D-/‫ أدت ا‬-١
.% ٦٥٨ ‫ إ‬% ٤٧٦ Q4 789‫ ا‬%)+‫ و‬%٧٩ ‫إ‬
‫ع‬D*9:‫م إ* ار‬D*#G‫" ا‬B*‫ @*? ﺏ‬7*89‫ ا‬%)*+ ‫ض‬D*9P+‫ ا‬a*=/! -٢
.%G=w /‫ﺥ‬eE2‫ق ا‬59G‫ ا‬%)+
7B!D**82‫**" ا‬#‫** ﺏ‬,- D** x‫ا‬/=‫ إ‬I**: ?**E‫ ا‬%**&‫ ارا‬/** l: I** -٣
**G- "B**‫ وزن ا‬y**&5E4 ) _!/**9E‫" ا‬B**‫دة ﺏ‬5**O %**B#Br‫ا‬
( /B`*8‫ر ا‬52 ‫ و ا‬3!5r‫ر ا‬52 ‫" )ا‬B‫ ا‬IO‫ ﺡ‬-_!/9E‫ا‬
%B4D)4 -789‫ ا‬#‫ ﺏ‬%RB, ,i‫ ا‬/<8‫ وزن ا‬- ‫ة‬/<8‫ ا‬W2& 7cD*9‫" ا‬B*‫ @*? ا‬789‫ ا‬%)+ ,- ‫ي‬5G#4 /B0e: ‫ة( {ي‬/<8‫ا‬
.7cD@ /Bt‫و ا‬
%١٣ Q***4 3***c>‫" ) ا‬B***‫*** @***? وزن ا‬89‫ ا‬%)***+ A***+D‫ آ‬-٤
Q**- 7cD**@ /**Bt‫" ا‬B**, %**!5G#4 /**H‫ ( أآ‬%١٧ Q**4 /**‫وا>آ‬
‫ ﺥ***]ل‬7***89‫ ا‬%)***+ ‫ض‬D***9P+‫ أدى إ*** ا‬D***24 7cD***9‫" ا‬B***‫ا‬
._!/9E‫ا‬
‫ظ‬5*,4 ‫ي‬5*G#4 /B0e*: ‫ك‬D*G‫ ه‬Q*i! I* ~*+‫ ا‬%*&‫ت ارا‬/ |‫ أ‬-٥
/***Bt‫ ا‬Q***- 7cD***9‫" ا‬B***‫ ا‬/<* *8 (%B4D)***2‫ر) ا‬5***tH‫***د ا‬#
١٢٢
?**@ %B4D)**2‫ض ا‬D**9P+€ ‫ي‬5**G#4 /B0e**: ‫ك‬D**G‫ن ه‬D**‫ آ‬D**2GB‫ﺏ‬.7cD**@
A*+Di@ (a*‫ﺏ‬/4 /E2BEG*& 3*i /*t0 ١٢-٨ ) 7cD@ /Bt‫" ا‬B‫ا‬
.7cD9‫" ا‬B, % ٥٥ ‫ ب‬%+‫ر‬D84 %٣٠ %)G‫ا‬
7cD**9‫" ا‬B**‫ ا‬/<**c QB**‫ي ﺏ‬5**G#4 ‫]ف‬E**‫ك اﺥ‬D**G‫ ه‬Q**i! I** -٦
.‫ة‬/<8‫ ا‬W2& ?@ 7cD@ /Bt‫وا‬
/Bt‫ وا‬7cD9‫" ا‬B‫ ا‬/<c QB‫ى ﺏ‬5G#4 ‫]ف‬E‫ك اﺥ‬DG‫ ه‬Qi! I -٧
‫ﺽ*‚ أن وزن‬5! D*24 %R*B‫رى ا‬5*4‫" و‬B*‫ @* وزن ا‬7cD@
%**&‫; ارا‬h**‫ @**? ه‬/B`**8‫ وا‬3**!5r‫ ا‬%R**B‫رى ا‬5**4‫" و‬B**‫ا‬
.‫م‬D#G‫" ا‬B ?#Br‫ى ا‬2‫ @ ا‬a8:
/*Bt‫" ا‬B‫ت @? ا‬5iEi‫!~ @ وزن ا‬5G#4 ‫دة‬D!‫ك ز‬DG‫ن ه‬D‫ آ‬-٨
7cD****9‫ت ا‬5****iEi‫ وزن ا‬Q****- (I****= ١٥٣ ± ٩٤١١ ) 7cD****@
‫ت‬5*iEi‫ز ا‬D*OE‫ إ اﺡ‬W‫ ذ‬a=/! D2‫( ورﺏ‬I=١٦٥ ± ٧١٧٣)
‫ء‬D*G0‫زن أ‬5*‫ا ا‬h*‫* ه‬8@ *,- ~*:‫ر‬c ‫*م‬-‫*~ و‬,‫ء داﺥ‬D*2‫ ا‬Q*4 %B2i
._!/9E‫ا‬
/**Bt‫م ا‬D**#G‫" ا‬B**‫ ﺏ‬/<**c **,- %**BxDB2Bi‫ ا‬%**&‫ت ارا‬/** |‫ أ‬-٩
‫ و‬S*BGOG2‫م وا‬5B)*Di‫ ا‬Q*4 ;‫ا‬5*E2 %*!5G#4 ‫دة‬D*!‫د ز‬5=‫ و‬7cD@
***‫م إ‬5B)***Di‫ ا‬%)***+ DR***!‫ر وأ‬59***&59‫م إ*** ا‬5B)***Di‫ ا‬%)***+
.7cD@ "B‫ ا‬/<8‫ ﺏ‬%+‫ر‬D84 ‫م‬5B)GkD2‫ا‬
‫ر و‬59****&59‫ ا‬Q****4 7cD****9‫" ا‬B****‫ ا‬/<****c ‫ى‬5****E4 ‫ن‬D****‫ آ‬-١٠
.7cD@ /Bt‫" ا‬B‫ ا‬/<c Q- %!5G#4 /H‫م أآ‬5B)GkD2‫ا‬
/*Bt‫" ا‬B*‫ ا‬/<*8‫ر ﺏ‬59*&59‫م إ* ا‬5B)*Di‫ ا‬%)*+ A+D‫ آ‬-١١
**‫ إ‬W**‫ ذ‬a**=/!‫ و‬7cD**9‫" ا‬B**‫ ا‬/<**c Q**4 %**!5G#4 /**H‫ أآ‬7cD**@
/Bt‫ ا‬/<8‫ ا‬Q- 7cD9‫ ا‬/<8‫م @? ا‬5B)Di, ‫ي‬5G#2‫ض ا‬D9P+€‫ا‬
7cD*9‫" ا‬B*‫ ا‬/<*c ?*@ D*!5G#4 /H‫ر أآ‬59&59‫ن ا‬D‫ آ‬D2GB‫ ﺏ‬7cD@
.7cD@ /Bt‫ ا‬Q*@ ‫ي‬5*G#4 ‫]ف‬E*‫ك أى اﺥ‬DG‫ ه‬Qi! I ~+‫ أ‬%&‫ت ارا‬/ |‫ أ‬-١٢
.W+S‫ ا‬Q4 7cD@ /Bt‫ وا‬7cD9‫ ا‬/<8‫ى ا‬5E4
7cD*9‫" ا‬B‫ ا‬/<c @ ‫م‬5B)GkD2, ‫ي‬5G#2‫ع ا‬D9:‫ن ا€ر‬D‫ آ‬-١٣
‫م‬5B)**Di‫ ا‬%)**G ‫ي‬5**G#4 ‫ض‬D**9P+D‫ب ﺏ‬5`**4 7cD**@ /**Bt‫ ا‬Q**.7cD@ /Bt‫ ا‬/<8‫ ا‬Q- 7cD9‫" ا‬B‫ ا‬/<c ?@ ‫م‬5B)GkD2‫إ ا‬
١٢٣
**#‫ ﺏ‬aB‫ﺏ‬D**&‫ أ‬٨ ‫ ﺥ**]ل أول‬A**B‫آ‬DEi‫ق ا‬5**9+ %)**+ A**‫اوﺡ‬/: -١٤
3=‫ت ا>ر‬D‫ه‬5<: ‫ق إ‬59G‫ا ا‬h‫ ه‬a=/!‫ و‬% ٢٥-١٠ QB‫ ﺏ‬789‫ا‬
–٥٠ Q***4‫ و‬A***B‫آ‬DEi‫ ا‬D***2=‫ ا‬Q***4 %١٥-٥ %)***G‫د ﺏ‬5***=52‫ا‬
‫ق‬5***9G ‫م‬D***#‫ ا‬y***&5E2‫ن ا‬D***‫ وآ‬%***8@DG‫ ا‬A***B‫آ‬DEi‫ ا‬Q***4 %١٠٠
%٦٦٧ 3H2! ‫ي‬h‫ وا‬%١٠ 3=‫; ا>ر‬5<: ‫ إ‬a=‫ا‬/‫ ا‬AB‫آ‬DEi‫ا‬
.‫ة‬/E9‫; ا‬h‫ ﺥ]ل ه‬%EB2‫ ا‬AB‫آ‬DEi‫ ا‬D2=‫ ا‬Q4
١٥-١٠ aB‫ﺏ‬D&‫ أ‬٨-٤ /2- AB‫آ‬DE‫ق @? آ‬59G‫ ا‬%)+ At,‫ ﺏ‬-١٥
Q**4 %)**G‫ )آ‬3**=‫; ا>ر‬5<**: **‫ إ‬a**=‫ا‬/‫ق ا‬5**9G‫ن ا‬e* ‫ ﺏ‬D**2,- %
‫ت‬D‫ه‬5<*: ‫* أن‬,- ‫ !*ل‬D*24 /2#‫دة ا‬D!S‫داد ﺏ‬S! ( …@DG‫ ا‬D2=‫ا‬
.789‫ ا‬#‫ ﺏ‬AB‫آ‬DEi‫د ا‬D#E&‫ وا‬89 ‫م‬D‫ ه‬U& A+D‫ آ‬3=‫ا>ر‬
%**2l- ?**@ W**+S‫ وا‬S**BGOG2‫م وا‬5B)**Di‫ت ا‬D!5E)**4 A**+D‫ آ‬-١٦
.%B#Br‫ق ا‬D)‫ ا‬%2l- Q4 D!5G#4 3c‫ أ‬%‫ه‬5<2‫ق ا‬D)‫ا‬
‫ق‬D)*‫ ا‬%*2l- ?*@ ‫ر‬59&59‫م و ا‬5B)GkD2‫ت ا‬D!5E)4 A+D‫ آ‬-١٧
%)**+ ‫ن‬D**‫ وآ‬%**B#Br‫ق ا‬D)**‫ ا‬%**2l- Q**4 D**!5G#4 /**H‫ أآ‬%‫ه‬5<**2‫ا‬
**@ ‫م‬5B)**GkD2‫م إ** ا‬5B)*Di‫ ا‬%)**+‫ر و‬59**&59‫م إ** ا‬5B)*Di‫ا‬
Q**- %‫ه‬5<**2‫ق ا‬D)**‫ ا‬%**2l- ?**@ D**!5G#4 3**c‫ أ‬%‫ه‬5<**2‫م ا‬D**l#‫ا‬
.%B#Br‫ا‬
‫م‬5B)Di‫ ا‬%)+ ‫ و‬SBGOG2‫م وا‬5B)Di‫ى ا‬5E)4 y&5E4 ‫ن‬D‫ آ‬-١٨
?*@ D*!5G#4 3*c‫م أ‬5B)*GkD2‫م إ* ا‬5B)Di‫ ا‬%)+‫ر و‬59&59‫إ ا‬
.%B#Br‫ ا‬Q- %‫ه‬5<2‫ق ا‬D)‫ ا‬%2l- ‫م ذات‬D#G‫ ا‬AB‫آ‬DE‫م آ‬/B&
**@ D**!5G#4 /**H‫ أآ‬W**+S‫ر وا‬59**&59‫ى ا‬5E)**4 y**&5E4 ‫ن‬D**‫ آ‬-١٩
.%B#Br‫ ا‬Q- %‫ه‬5<2‫ق ا‬D)‫ ا‬%2l- ‫م ذات‬D#G‫ ا‬AB‫آ‬DE‫م آ‬/B&
@ ‫م‬5B)GkD2‫ى ا‬5E)2 %!5G#4 ‫ت‬D@]E‫ك أي اﺥ‬DG‫ ه‬Qi! I -٢٠
%B#Br‫ و ا‬%‫ه‬5<2‫ق ا‬D)‫ ا‬%2l- ‫م ذات‬D#G‫ ا‬AB‫آ‬DE‫م آ‬/B&
‫***ى و‬-D8‫ ا‬SB:D9***&59‫ ا‬Q***4 ‫م‬/B)***‫ ا‬S***B‫آ‬/: y***&5E4 ‫ن‬D***‫ آ‬-٢١
QB45*******BN‫******* وا‬,i‫ ا‬QB:‫و‬/*******‫ول وا‬/E)*******5i‫ وا‬D*******!‫ر‬5B‫ا‬
‫ق‬D)*‫ ا‬%‫ه‬5<*2‫ ا‬A*B‫آ‬DEi‫م ا‬/B*& ?@ D!5G#4 /H‫ أآ‬QB5B‫ﺏ‬5,O‫وا‬
.%B#Br‫ ا‬AB‫آ‬DEiD‫ ﺏ‬%+‫ر‬D82D‫ﺏ‬
T٤ ‫ و‬T٣) %Bc‫ة ار‬t‫ت ا‬D+54/‫ ه‬Q4 ‫م‬/B)‫ى ا‬5E)4 ‫ن‬D‫ آ‬-٢٢
‫م‬/B***& ***@ D* *!5G#4 3***c‫ أ‬QB5***B‫ﺏ‬5,O‫ ا*** ا‬QB45***BN‫ ا‬%)***+‫( و‬
..%B#Br‫ ا‬AB‫آ‬DEi‫ ا‬Q- %‫ه‬5<2‫ ا‬AB‫آ‬DEi‫ا‬
١٢٤
‫‪ -٢٣‬أوﺽ‪ A‬ا‪]B,E‬ت أ‪ Qi! I ~+‬ه‪DG‬ك @‪/‬ق ‪5G#4‬ي ‪5E2‬ى‬
‫ا)‪/B‬م ‪ Q4‬ا‪B,‬ات ا‪DEi, %B,i‬آ‪ AB‬ا‪ %B#Br‬وا‪5<2‬ه‪.%‬‬
‫!‪ GJ K6& B‬ا‪M‬ﺕ‪:L‬‬
‫!‪ a=/‬ا‪D9P+‬ض ‪ %)+‬ا‪ 789‬أ&‪ D&D‬إ ار‪D9:‬ع ‪ %)+‬ا‪5*9G‬ق‬
‫ا‪ GBGO‬وا‪ Q*4 b:DG‬ز!*‪D‬دة ‪ %)*+‬ا‪ *@ *89‬وزن ا‪ %R*B‬أآ‪Q*4 /*H‬‬
‫‪ %١٧‬أو ا‪D9P+‬ﺽ*** ‪ % ١٣ Q***- D‬ﺥ***]ل @‪/***E‬ة ا‪ _!/***9E‬أو ا***‬
‫ا‪D9P+‬ض ‪ %B4D)*4‬ا‪/<*8‬ة وا‪ *,- /01*: ?*E‬وزن ا‪ %R*B‬ا‪5*892‬د‬
‫و‪ 79G**:‬ا‪e**@ Wh** .QB**GO‬ن ا‪D**9P+‬ض ‪ %B4D)**4‬ا‪/<**8‬ة !‪Q**4 /**E#‬‬
‫ا‪5#‬ا‪ 34‬ا>&‪ %B&D‬ا‪/012‬ة ‪ %)+ ,-‬ا‪ 789‬ﺡ‪*#4 38! B‬ل @‪*8‬‬
‫ا‪D2‬ء @ ا‪ "B‬ذا ا‪ %B4D)2‬ا‪ U)! D24 %R9PG2‬ذ‪ W‬ا‪N‬ود!‪D*2‬‬
‫) اﺡ‪DOE‬ز ا‪D2‬ء( @? أ=‪ %G‬ا‪D*#G‬م وا*‪h‬ي !*‪ %*B,2- *,- /01‬ا‪.7*89‬‬
‫أ!***‪1***! DR‬دى ا‪D***9P+‬ض ‪ %B4D)***4‬ا‪/<***8‬ة إ*** ‪ 3***B,8:‬ا‪***4T‬اد ‪Q***4‬‬
‫ا>آ***)‪1***! D***24 QB***GO, QBO‬دى إ*** اﺥ‪ ~***cDGE‬ﺏ***ون أي أ‪/***-‬اض‬
‫‪ %|5,4‬وﺏ‪5i! ?DED‬ن ا‪59G‬ق ‪ †8G %OBE+‬ا>آ)‪.QBO‬‬
‫!‪ †**8+ /**E#‬ا‪ Q!5**iE‬ا‪D**2, ?+**#2‬دة ا‪ %**B2l#‬وا‪y:/**2‬‬
‫ﺏ**‪ ?**@ †8G‬ا‪DG#‬ﺹ**‪ /‬ا‪ 3**H4 %**B+#2‬ا‪5B)**Di‬م وا‪ W**+S‬وا‪S**BGOG2‬‬
‫و‪ %)+‬ا‪5B)Di‬م إ ا‪59&59‬ر و‪ %)*+‬ا‪5B)*Di‬م إ* ا‪5B)*GkD2‬م‬
‫أو ار‪D9:‬ع ‪5E4‬ى ا‪ Q4 Il#‬ا‪5B)GkD2‬م ‪ Q4‬أه‪ I‬أ&‪D‬ب ‪5<*:‬ه‪D‬ت‬
‫ا>ر=‪ ?@ 3‬آ‪DE‬آ‪ AB‬ا‪D#G‬م ا‪/E! ?E‬اوح ‪/2-‬ه‪ ١٠-٢Q4 D‬أ&‪D‬ﺏ‪aB‬‬
‫!‪ ;5<**: a**=/‬ا>ر=**‪ **@ 3‬آ‪DE‬آ‪ A**B‬ا‪D**#G‬م ا** ا€‪D**9P+‬ض‬
‫ا‪5****G#2‬ى @**** ‪5E)****4 y****&5E4‬ى ا‪5B)****Di‬م وا‪ S****BGOG2‬و‪%)****+‬‬
‫ا‪5B)**Di‬م ا** ا‪59**&59‬ر و‪ %)**+‬ا‪5B)**Di‬م ا** ا‪5B)**GkD2‬م @**‬
‫ا)‪/B‬م‪.‬ﺏ‪ D2GB‬آ‪D‬ن ‪5E)*4 y&5E4‬ى ا*)‪/B‬م ‪ Q*4‬ا‪59*&59‬ر وا‪W*+S‬‬
‫أ‪/B& @ D!5G#4 ,-‬م ا‪DEi‬آ‪ AB‬ذات ‪ %2l-‬ا*)‪D‬ق ا‪5<*2‬ه‪Q*- %‬‬
‫ا‪ %B#Br‬وا‪h‬ى !‪DE‬ج ا ا‪ Q4 !S2‬ارا&‪.%‬‬
‫‪١٢٥‬‬
‫‪N+ '/‬دى ا‪TU‬ض ‪R‬ط ا‪'V‬ة ا'ر‪ /‬إ‪ F‬ﺕ‪ (3R‬ا<ر‪D-‬‬
‫وا)ي ﺕ‪5‬ج إ‪ "! '+ ! F‬ا'را&‪.‬‬
‫ﺕ‪ ,XN‬ﺕ‪3R‬هت ا<ر‪ F: D-‬ا‪R‬ط ا\‪ F:‬ﺡ‪Z‬‬
‫‪'5+‬ث ز‪+‬دة !‪3J! F] +3‬ى &‪,‬م ‪^:‬آ* ا‪3RB‬ه !"‬
‫ا‪T&3T‬ﺕ ا‪'8‬ى وه'م ‪,#‬وﺕ" ا@‪ ) AJ‬ز‪+‬دة !‪3J‬ى ‪3+‬ر‪+‬‬
‫ا'م ( وا‪ ) B‬ز‪+‬دة ﺕ‪,‬آ ا@‪.( "3#3:‬‬
‫درا ! ا اﻡ اة إج ام ﻡ‬
‫ر&ـ !‪"! !'8‬‬
‫('ت ‪ %#‬إاه‪ "#‬ﻡ‬
‫‪3^#‬ر‪3+‬س ]‪ F‬ا‪3:‬م ا راــ )إج ﺡ‪3‬ا‪ L‬ودوا‪("-‬‬
‫‪ " !-‬ﺵ‪ ١٩٩٩ & – cB‬م‬
‫ا&‪D9BE‬ء ‪D,rE2‬ت ا`‪5‬ل ‪ ,-‬در=‪%‬‬
‫ا ) ا‪(#*+‬‬
‫@ ا‪5,#‬م ا‪S‬را‪) %B-‬إ‪DE+‬ج ﺡ‪5B‬ا‪ =55B)@ -?+‬دوا=‪( Q‬‬
‫‪١٢٦‬‬
‫ﻗﺴﻢ ﺍﻹﻧﺘﺎﺝ ﺍﳊﻴﻮﺍﱐ‬
‫آ‪B,‬ــــ‪ %‬ا‪S‬را‪-‬ــــ‪%‬‬
‫=ــ‪#4D‬ــــ‪ %‬ا>زه‪/‬‬
‫‪ ١٤٢٦‬ه‬
‫‪٢٠٠٥‬م‬
‫درا ! ا اﻡ اة إج ام ﻡ‬
‫ر&ـ !‪"! !'8‬‬
‫('ت ‪ %#‬إاه‪ "#‬ﻡ‬
‫‪3^#‬ر‪3+‬س ]‪ F‬ا‪3:‬م ا راــ )إج ﺡ‪3‬ا‪ L‬ودوا‪("-‬‬
‫‪ " !-‬ﺵ‪ ١٩٩٩ & – cB‬م‬
‫ا&‪D9BE‬ء ‪D,rE2‬ت ا`‪5‬ل ‪ ,-‬در=‪%‬‬
‫ا )ا‪(#*+‬‬
‫@ ا‪5,#‬م ا‪S‬را‪) %B-‬إ‪DE+‬ج ﺡ‪5B‬ا‪ =55B)@ -?+‬دوا=‪( Q‬‬
‫‪ 6‬ا‪5‬ﺵاف‪:‬‬
‫أ‪.‬د‪ /‬ه(م >*‪ =#‬ﺥ
‪;#‬‬
‫أ&ذ ]‪ F-33J‬ا‪35‬ان‬
‫آ‪:‬ـ ا راـ‪!- -‬ـ ا<زه‪,‬‬
‫أ‪.‬د‪ /‬ﻡ‪ =#*> ?>%‬ﺥ
‪#‬‬
‫أ&ـذ ]‪ F-33J‬ا‪35‬ان‬
‫آ‪:‬ـ ا راـ‪!- -‬ـ ا<زه‪,‬‬
‫‪١٢٧‬‬
‫د‪ /.‬ﻡ@‪ %‬أﻡ ‪A‬‬
‫أ&ـذ !‪J‬ـ' ]‪-33J‬ى‪35‬ان‬
‫ﻣﺮﻛـﺰ ﺍﻟﺒﺤـﻮﺙ ﺍﻟﻨﻮﻭﻳـﺔ‬
‫هـ ا‪/0‬ـ ا)ر‪+‬ـ‬
‫درا& ‪ g#‬ا‪3‬ا!‪ D‬ا‪,XNB‬ة ‪ F:‬إج ام ]‪,9! L‬‬
‫ر&ـ‪Q4 %484 %D‬‬
‫‪hR‬ت &' إ‪,#‬اه‪,! A‬‬
‫‪3^#‬ر‪3+‬س ]‪ F‬ا‪3:‬م ا راــ )إج ﺡ‪3‬ا‪ L‬ودوا‪("-‬‬
‫‪ " !-‬ﺵ‪ ١٩٩٩ & – cB‬م‬
‫ﺍﺳﺘﻴﻔﺎﺀ ﳌﺘﻄﻠﺒﺎﺕ ﺍﳊﺼﻮﻝ ﻋﻠﻰ ﺩﺭﺟﺔ‬
‫ا‪ ) i9U‬ا‪(,J-B‬‬
‫@ ا‪5,#‬م ا‪S‬را‪) %B-‬إ‪DE+‬ج ﺡ‪5B‬ا‪ =55B)@ -?+‬ﺡ‪5B‬ان (‬
‫أ‪-‬زه‪:‬‬
‫…………………‬
‫أ‪.‬د ‪ /‬ه‪R‬م ﺡ‪ "J‬ﺥ‪T:‬‬
‫أ&‪E‬ـ‪D‬ذ @)‪ =55B‬ا‪5B‬ان آ‪B,‬ـ‪ %‬ا‪S‬را‪-‬ـ‪#4D= – %‬ـ‪%‬‬
‫ا>زه‪/‬‬
‫أ‪.‬د ‪ '6 /‬ا‪I‬دى !‪........……………… ,‬‬
‫‪١٢٨‬‬
‫أ&‪E‬ـ‪D‬ذ ‪ %!ht:‬اوا=‪ Q‬آ‪B,‬ـ‪ %‬ا‪S‬را‪-‬ـ‪#4D= – %‬ـ‪ %‬ا>زه‪/‬‬
‫أ‪.‬د ‪3@ /‬ى ‪ '6‬ا‪I‬دى !‪...........……… FT09‬‬
‫أ&‪DE‬ذ @)‪ =55B‬اوا=‪ Q‬آ‪B,‬ـ‪ %‬ا‪S‬را‪-‬ـ‪#4D= – %‬ـ‪%‬‬
‫ا‪D8‬ه‪/‬ة‬
‫‪ ٢٠٠٥ / /‬م‬
‫‪/ /‬‬
‫‪ ١٤٢٦‬ه‬
‫‪١٢٩‬‬