BLOOD: DIFFERENT STROKES FOR
DIFFERENT ANIMALS
An Inaugural Lecture delivered
at the University of Ibadan
on Thursday, 19May, 2011
By
JOHNSON OLUWAYEMISI OYEWALE
Professor of Veterinary Physiology
Faculty of Veterinary Medicine
University of Ibadan,
Ibadan, Nigeria.
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Ibadan University Press
Publishing House
University of Ibadan
lbadan, Nigeria.
© University of Ibadan 2011
Ibadan, Nigeria
First Published 2011
All Rights Reserved
ISBN: 978 - 978 - 8414 - 52 - 0
Printed by: Ibadan University Printery
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The Vice-Chancellor, Deputy Vice-Chancellor (Adminis-
tration), Deputy Vice-Chancellor (Academic), Registrar,
Librarian, Provost of the College of Medicine, Dean of the
Faculty of Veterinary Medicine, Dean of the Postgraduate
School, Deans of other Faculties, and of Students,
Distinguished Ladies and Gentlemen.
This inaugural lecture is the 29th to be given from the Faculty
of Veterinary Medicine since 1976 when the first lecture was
delivered by Professor Desmond Hill, the founding Dean of
the Faculty. It is also the eighth in the 2010/2011 series of
inaugural lectures and the third lecture from the Department
of Veterinary Physiology, Biochemistry and Pharmacology
(formerly known as the Department of Veterinary Physiology
and Pharmacology). This however, is the second lecture from
the Physiology section of the Department. The first inaugural
lecture from our Department came from the Physiology
section about 26 years ago and was delivered by Professor
Michael O. Olowookorun in May, 1985. It was titled "The
Digestive System: A Perfect Example of United We stand,
Divided We Fall". In April, 1996, Professor Reuben O. A.
Arowolo from our Pharmacology section delivered the
second lecture with the title" Protecting Our Livestock
Resources".
Today, I feel highly honoured to present the third
inaugural lecture from our Department titled "Blood:
Different Strokes for Different Animals". I have chosen this
title because of the significance of blood to the lives of man
and animals. It is also because it encapsulates much of the
thrust of my research activities, having worked on the blood
profiles of several species of normal healthy animals and
birds under various environmental conditions for about three
decades. Although the proverbial saying 'different strokes for
different folks', from where the title of this lecture was
derived, refers to 'different people living or doing things in
different ways', blood can be viewed as containing basically
similar constituents in different animals with each of these
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constituents differing qualitatively and quantitatively to
match the physiology of each species.
What is Blood?
According to the Oxford Enffilish Dictionary, the word
"blood" originated before the 12 century and is derived from
the Old English word "bled", which is akin to the German
word "blut", meaning blood.
Blood is the fluid that circulates through the heart,
arteries, veins and capillaries of multicellular animals
(including human and non-human vertebrates). It carries
oxygen (02) and nutrients to the cells of the body and
removes waste products and carbon dioxide (C02). from
same. It consists of a fluid part called plasma (mainly water,
but with a mixture of hormones, nutrients, enzymes,
electrolytes, gases, antibodies and waste products), which is
in equilibrium with the tissue fluid of the body, and cells
including red blood cells (which carry oxygen), white blood
cells (which help combat infections), and platelets (which
help the blood to clot). The cells ate derived from
extravascular sites (i.e. outside the blood vessels) namely the
red bone marrow and lymphoid tissues and then re-enter the
extravascular spaces, where some of them become
transformed' into connective tissue cells.
Historical Perspective
Blood has always been universally acknowledged as a living
tissue, the very essence of life. "Le sand c' est La vie" (Blood
is life) and similar philosophical expressions of other
languages attest to this. The doctrine of the humors, which
dominated Western medical thinking until the Renaissance,
held that disease is the consequence of imbalance of the four
components of which the human body is composed: blood,
phlegm, black bile and yellow bile.
The English physician, William Harvey (1578-1657)
wrote: "Blood acts above all the powers of the element and is
endowed with notable values and is also the instrument of the
omnipotent creator." He believed that, "blood is the fountain
of life and the seat of the soul."
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An understanding of the structure of blood (that it consists
of cells suspended in a protein-rich fluid known as plasma)
slowly accumulated from the 17tlJc. entury onwards. The first
person to describe red blood cells (or red corpuscles as they
were known then) was the young Dutch biologist, Jan
Swammerdam, who, in 1658, used an early microscope to
study the. blood of a frog. Another microscopic description of
red blood cells was provided 20 years later, in 1678, by
Anton van Leeuwenhoek (1632-1723) who unaware of
Swammerdam's work, provided a more precise description of
red blood cells, even approximating the cell size as "25,000
times smaller than a fine grain of sand". The white blood cells
(called white corpuscles) were first described by the British
physician, William Hewson (1739-1774), who also
discovered the essential features of how blood coagulates,
showing that it is due to the clotting of plasma and not as a
result of changes in the cellular components of blood. It was
in the latter half of the 19th century that blood cells were
found to be the progeny of more primitive cells in the bone
marrow.
The modem science of haematology stemmed from the
work of the Greek pharmacologist, Paul Ehrlich (1854-1915),
who developed a stain that led to a clear distinction between
the different types of blood cells. The knowledge of the
functions (physiology) of blood also evolved over many
centuries. William Harvey described blood circulation in
1628, and some few years later, the English physician,
Richard Lower (1631-1691) reported the change from dark
blue color of venous blood to the bright red color of arterial
blood after its passage through the lungs. In 1790, the French
chemist, Antoine Lavoisier (1743-1794) discovered oxygen
and found it was the constituent of air that is responsible for
the change in the color of blood. In the mid-nineteenth
century, it was found that oxygen combines with a substance
in the red cells which was identified as a protein,
haemoglobin (Hb) by the German biochemist, Felix Hoppe-
Seyler (1825-1895). By 1900, it was appreciated that white
blood cells play crucial roles in defense against infection.
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This idea was first proposed by the Russian zoologist, Ilya
Metchnikoff (1845-1916).
Karl Landsteiner, in 1901, published his. discovery of
three main blood groups-A, Band C (C, he later renamed 0).
Landsteiner described the regular patterns in which reactions
occurred when serum was mixed with red blood cells,
identifying compatible and conflicting combinations between
the blood groups. A year later, in 1902, Alfred von Decastello
and Adriano Sturii, who were two of Landsteiner's
colleagues, identified the fourth blood group, AB. In 1959,
Dr. Max Perutz, using x-ray crystallography, was able to
unravel the structure of Hb, the red blood cell protein that
carries O2. This work resulted in his sharing with John
Kendrew the 1962 Nobel Prize in Chemistry.
Significance of Blood
Since ancient times, blood has been identified with life and,
through the ages, people have produced endless speculations
about that connection. People assigned various sacred and
magical properties to blood and used it in a variety of rituals.
This, ladies and gentlemen, I am sure is well understood by
us in Africa. Some drank it, rubbed it on their bodies and
manipulated it in ceremonies. Some people believed that by
drinking the blood of a victim, the conqueror absorbed the
additional strength of the conquered. By drinking the blood of
an animal, one took on its qualities. As late as the 1ih
century, the women of Yorkshire in England were reported to
believe that by drinking the blood of their enemies they could
increase their fecundity.
The aura created around blood probably derives from its
eye-catching distinctive red colour, and the fact that its exit
(loss) from the body in large amounts, say in battle, led to
loss of life. As a result, redness came to be seen as an
essential characteristic of blood and the vehicle of its power.
Thus, red objects were often endowed with the same potency
as blood. In particular, red wine was identified with blood.
For instance, in ancient Greece, red wine was drunk by the
devotees of the god Dionysus in a symbolic ritual drinking of
his blood.
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Blood was, is, and continues to be seen as somehow
related to the qualities possessed by an individual. Several
beliefs make references to admirable people as having "good
blood" or evil persons as possessing "bad blood". Thus,
blood, in a somewhat literal sense, carries the essential
characteristics of the larger families, clans, national/ethnic
groups, even whole races. Due to its importance to life, blood
is associated with a large number of beliefs. One of these is
the use of blood as a symbol for family relationships through
birth/parentage. For instance, to be "related by blood" is to be
related by ancestry rather than marriage. This is closely
related to sayings such as~"blood is thicker than water" which
literally replaces a biological brother with a "blood brother".
In Islam
The consumption of food containing blood is forbidden by
Islamic dietary laws. This is derived from the statement in the
Qur'an, sura Al-Ma'ida (5:3): "Forbidden to you (for food)
are: dead meat, blood, the flesh of swine, and that on which
has been invoked the name of no other than Allah."
In Christianity
In the book of Genesis Chapter 9 verses 4 - 6, God told Noah:
"But you must not eat the flesh with the life, which is the
blood in it. And further, for your life-blood, I will demand
satisfaction; for every animal will I require it. ... "
In the New Testament, the thought of the early Christians
on the significance of Christ's death was clearly presented in
the Book of Revelation, in which John spoke of Jesus as the
one who "freed us from our sins with his life's blood"
(Revelation 1:5).
It is out of obedience to the commands of the bible such
as "Keep abstaining from anything offered to idols and from
blood" (Acts 15:28, 29), that Jehovah Witnesses refuse to
partake in the consumption of blood or accept transfusions of
blood.
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Composition of Blood
Blood consists of the cellular part, which is made up of red
blood cells, white blood cells and platelets (or thrombocytes),
and the fluid part called plasma.
Cellular Components
Red Blood Cells (Erythrocytes)
Red blood cells (RBCs) are also known as red blood
corpuscles (an archaic term), haematids or erythrocytes (from
Greek "erythros" for "red" and "kytos" for "hollow", with
"cyte" translated as "cell" in modern usage).
Vertebrate Erythrocytes
While in invertebrates various respiratory pigments may be
found in the blood plasma and infrequently in simple cells,
the vertebrates have developed a specialized cell containing
haemoglobin (Hb) called the erythrocyte. The erythrocyte
consists mainly of Hb, a metalloprotein containing haeme
groups whose iron atoms temporarily link to 02 molecules in
the lungs and release them to body tissues. O2 can easily
diffuse through the cell membrane of RBCs. Hb in the
erythrocyte also carries some of the waste product, C02, back
from the tissues. Most of the CO2 is however transported as
bicarbonate dissolved in the blood plasma. The only known
vertebrates without erythrocytes are the crocodile
icefishes (family Channichthyidaei, that live in very O2 rich
cold water and transport 02 freely dissolved in their blood.
Although they don't use Hb, remnants of Hb genes can be
found in their genome (Carroll 2006).
Mammalian Erythrocytes
Among vertebrates, mammalian erythrocytes are unique as
they are non-nucleated in their mature form. The sizes of
individual erythrocytes and their number per unit volume of
blood (RBC count) vary between mammalian species. The
goat has the smallest erythrocyte size and the greatest
erythrocyte number among domestic animals and man,
followed by the sheep as a close second (Schalm et al. 1975).
The ancestors of sheep and goats lived on mountain tops
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where O2 tension is low and efficient respiration is required.
This may partly explain why domestic sheep and goats have
an arrangement for a more efficient respiration than is
required for life during domestication.
Non-Mammalian Erythrocytes
In non-mammalian vertebrates, such as birds, fish, reptiles
and amphibians, the nucleus is not removed during red cell
production (erythropoiesis) and is retained throughout the life
of the red cell in the peripheral blood. The erythrocytes of
these non-mammalian vertebrates are therefore nucleated.
The known exceptions are salamanders of the genus
Batrachoseps and fish of the genus Maurolicus and closely
related species, which are non-mammalian vertebrates
that have non-nucleated erythrocytes (Cohen 1982).
Shapes of Erythrocytes
The observation of the shapes and sizes of erythrocytes of
various vertebrates creates two major impressions: First, that
there is a marked species variation in red cell morphology
among the submammalian forms. Second, mammalian
erythrocytes are relatively similar in size and quite similar in
shape. They appear as biconcave disks in most domestic
animals (dog, cat, cow, horse, sheep and goat) and man (fig.
1a - g), with the exception of the camel family, Camelidae, in
which the normal erythrocyte is of a biconvex, ellipsoid or
oval shape (fig. 1h).
Biconcave Disk-shaped Erythrocytes .
The biconcave shape of most mammalian erythrocytes (which
are flattened and depressed in the center, with a dumbbell-
shaped cross-section) offers maximum surface area for
exchange of 02 and C02 with the surroundings. However, the
proportion of such biconcave erythrocytes and the degree of
concavity vary between species. Typical biconcave erythro-
cytes are present in the dog (fig. l a), cow (fig. lb), sheep (fig.
l c) and man (fig. l d), while horse (fig. Ie) and cat
erythrocytes (fig. If) have shallow concavity and most goat
erythrocytes are flat disk-shaped (fig. l g),
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Fig, La-h, Scanning electron micrographs of erythrocytes from normal (a) dog, (b) cow, (c) sheep, (d) human, (c) horse, (f)
cat, (g) goat and (h) camel. Source: (Dog, cow, sheep, horse, cat, goat and camel - Schalm et al., 1975). Human
erythrocytes -www.6.edullearn/heart/blood/red.html; retrieved 10 June, 2010).
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The peculiar shapes of normal erythrocytes of the camel,
nama and deer have been compared to the aberrant shapes
associated with some human diseases. For instance,
hereditary elliptocytosis is an abnormality of the normally
biconcave human red cells in which an abnormally large
number of erythrocytes are elliptical (fig. 2a) rather than the
typical biconcave disk shape. In the llama (family
Camelidaey, the normal erythrocyte is an elliptical disk (fig.
2b).
Fig. 2.(a) Hereditary elliptocytosis (abnormal erythrocytes from humans).
Lymphocyte at the center.
Source: (en. wikipedia.org/wiki/HereditaT)'_elliptocytosis; retrieved 15 July,
2010).
(b) Normal elliptical anucleate erythrocytes from llama (family Camelidae).
Lymphocyte present at the center.
(Source (1V1V1V,felipedia.org/-felipedi/wiki/indrexphp/Elliprocvtosis; retrieved 20 July,
2010))
Sickle-shaped Erythrocytes
A sickle cell is an abnormal red blood cell that has a crescent
shape and an abnormal form of haemoglobin. The deer
erythrocytes circulate as round cells and are similar in size to
cattle erythrocytes. The normal deer erythrocyte is not sickle-
shaped in-vivo and when first removed from the body, but
sickling takes place as the sample stands at either room or
refrigerator temperatures (fig. 3c). Sickle cell anaemia or
disease is a genetic life-long disorder characterized by red
blood cells that assume an abnormal, rigid, sickle shape. The
disease occurs in a person who has inherited two abnormal
(mutant) haemoglobin genes from both parents. It has been
estimated that over 200,000 infants are born each year in
Africa with sickle-cell disease and 150,000 of these are born
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in Nigeria (WHO, 2006). The sickle-cell gene is caused by a
point mutation in the haemoglobin beta gene that leads to
replacement of glutamic acid by valine at position 6 of the
beta chain of haemoglobin. This results in a haemoglobin of
reduced solubility and, especially in the deoxygenated state,
haemoglobin molecules align themselves and distort the
erythrocyte membranes, taking up the distinctive sickle-cell
shape (fig. 3a, b). However, the sickling phenomenon of the
normal erythrocytes of deer (which was first described by
Gulliver in 1840) is different from that of sickle-cell disease
seen in humans. The occurrence of in-vitro sickling in the
erythrocytes of most species of deer might have remained a
laboratory curiosity had it not been for the existence of
similarly shaped (sickle) cells (figs. 3a, b) in a human disease
called sickle cell anaemia.
(
(a)
. Fig. 3. Scanning electron micrograph of (a) a sickle erythrocyte and a normal
human erythrocyte; and blood smears showing sickle erythrocytes from (b)
human and (c) deer blood.
In contrast to the limited racial and geographical
distribution of sickle cell anaemia in man (the sickle-shaped
human erythrocytes being found most frequently among
people whose ancestors come from Sub-Saharan Africa,
South America, Cuba, Central America, Saudi Arabia, India
and Mediterranean countries such as Turkey, Greece and
Italy), the sickling phenomenon occurs in most species of
deer representing a wide variety of ecological and
geographical areas of the world. In the deer, sickling is an in-
vitro phenomenon which occurs under high 02 tension and
elevated pH and has no apparent pathologic consequences.
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White Blood Cells or Leukocytes
The name 'white blood cell' derives from the fact that after
centrifugation of a blood sample, the white cells settle in the
buffy coat, a thin typically white layer of nucleated cells
between the sedimented red cells and the blood plasma. The
scientific term, leukocyte is derived from the Greek words
leukos (white) and kytos (cell).
Types of White Blood Cells
Five different and diverse types of white blood cells are
known. Thv include neutrophils, eosinophils, monocytes,
lymphocytes and basophils. The various types of leukocytes
in the blood of different animal species (dog, cat, cattle,
horse, and elephant) and man are as shown in figure 4 (a - p).
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Fig. 4. Normal leukocyte types in animal and human blood. a - Dog (1)
Nuclear sex-bud or drumstick of segmented neutrophil from a female dog. b -
Dog. (2) Band neutrophil. (3) Lymphocyte. (4) Two segmented (mature)
neutrophils. c - Dog. (5) Eosinophil. d - Dog (6) Basophil. e - Dog. Three
typical monocytes. f - Cat. (7) Three neutrophils. (8) Small lymphocyte. (9)
Eosinophil. g - Cat. (10) Two basophils. (11) Eosinophil. h - Cattle. (12)
Two neutrophils, i-Cattle. (13) Eosinophil. j - Cattle. (14) Monocyte. (IS)
Lymphocyte. k - Cattle. (16) Basophil. I - Horse. (17) Eosinophil. (18)
Basophil. m - Horse. (19) Three mature neutrophils. n - Elephant. (20) Two
monocytes. 0 - Human. (21) Neutrophil. (22) Lymphocyte. p - Human.
(23) Eosinophil
They are all produced and derived from a multipotent cell
in the bone marrow called haemopoietic stem cells. Their
production and maturation is controlled by a family of
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proteins called haemopoietic growth factors. Following their
release from the bone marrow into the blood, many of the
white blood cells remain in a so-called storage pool, attached
to the wall of blood vessels. The numbers circulating freely in
the blood therefore represent just a fraction of the total white
blood cell count in the body. Species differences occur not
only with regard to the total white blood cell count, but also
in the proportion of different leukocytes in the blood. For
instance, the average total white blood cell count (per
microlitre of blood) in man is 8,000. In the dog, cat, cattle,
and domestic fowl the average values for normal total white
blood cell counts (per micro litre of blood) are 11,500, 12,500,
8,000, and 33,370, respectively (Schalm et al. 1975; Oyewale
1987a). Neutrophils predominate in the human, dog and cat
blood, but in the horse, they slightly exceed lymphocytes and
in ruminants (cattle, sheep and goats) and laboratory animals
(such as rats and mice), neutrophils are outnumbered by
lymphocytes.
Plasma
Plasma is the fluid of blood left after removal of the cellular
elements. Serum is the fluid which is obtained after blood has
been allowed to clot and the clot removed. Serum and plasma
differ only in their content of fibrinogen and several minor
components which are in part removed in the clotting process.
It might appear that plasma is less important than the blood
cells it contains. But this would be like saying that the stream
is less important than the fish that swims in it. You cannot
have one without the other.
Although plasma is composed of over 90% water, it also
contains a mixture of proteins which include albumin,
globulins and fibrinogen. Albumin forms the main bulk of the
plasma proteins, and is of considerable importance in
maintaining osmotic homeostasis, as it prevents the
accumulation of excess fluid in body tissues. Globulins are
subdivided into aI, a2, ~ and S-globulin fractions. The 8-
globulin fraction contains the antibodies. Many substances
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circulating in the blood (e.g. hormones, vitamins, electrolytes,
metabolites etc.) are partially or wholly bound to albumin or
globulin fractions, while fibrinogen participates in the blood
clotting mechanism.
There are many other classes of compounds circulating in
blood plasma. Most of these are smaller molecules which
diffuse freely through cell membranes and are therefore more
similarly distributed throughout all the fluids of the body. In
terms of their concentration and function, the electrolytes are
the most important. They primarily regulate the osmotic
pressure of plasma and contribute also to the control of pH.
The major cations are sodium, potassium, calcium and
magnesium, while anions are chloride, bicarbonate, phos-
phate, sulfate and organic acids. Plasma also contains many
small compounds which are transported to the site of
synthesis of larger molecules in which they are incorporated,
or which are shifted as products of metabolic breakdown to
the sites of their excretion from the body.
Platelets (Thrombocytes)
The blood contains platelets and at least 12 other factors
active in blood clotting. Platelets are small, spindle-shaped or
rod-like structures occurring in large numbers in the
circulating blood. They change their shapes rapidly on
contact with injured blood vessels or foreign surfaces and
take part in clot formation. Platelets are cytoplasmic
fragments broken off from their precursor cells of origin in
the bone marrow, the megakaryocytes, and are therefore not
nucleated in mammals. However, platelets of birds are
nucleated.
Blood in Invertebrates
In insects, the blood, known as haemolymph, is not involved
in oxygen transport. There are openings called tracheae which
allow oxygen from the air to diffuse directly to the tissues.
Haemolymph in insects moves nutrients to the tissues and
removes waste products in an open circulatory system.
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Other invertebrates use respiratory pigments, like the
copper-containing haemocyanin in crustaceans and mollusks
which are freely soluble in the blood, to transport oxygen.
Color of Blood
In man and animals, arterial blood and capillary blood are
bright red as O2 imparts a strong red color to the haeme group
of Hb in the erythrocyte. Deoxygenated blood shows a darker
shade of "red as seen in veins or when venous blood samples
are obtained.
The skink, Prasinohaema virens (fig. 5), which is a
scincid lizard species native to New Guinea, is a green-
blooded land vertebrate. The green blood pigmentation results
from accumulation of the waste product, biliverdin in levels
that would be toxic to other vertebrates. Biliverdin is a
compound formed from the breakdown of Hb, and is
normally converted to bilirubin. It is believed, however, that
mutation in various genes regulating bilirubin formation leads
to formation and accumulation of biliverdin in this species
(Austin and Perkins 2006).
Fig. 5. Green-blooded skink iPrasinohaema virensi (Source:
en.wikipedia.org/wikilPrasinohaema_virens; retrieved 26 November,
2010)
The blood of most mollusks (including cephalopods and
gastropods) and some arthropods (such as horseshoe crabs) is
blue as it contains the copper-containing protein, haemo-
cyanm,
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My Own Contributions
I started my research career in 1980, a year after graduating
from the University of Ibadan. Two weeks after completing
the National Youth Service Corps in Owerri, lmo State, I
travelled to Ibadan to discuss my interest in academics with
my former teacher, Professor M. O. Olowookorun, the then
Head of Department of Veterinary Physiology and
Pharmacology, with whom I had earlier had series of
discussions on the same subject matter. Meanwhile, I had
been offered a job, each by the Civil Service Commission of
Lagos and Kano States and by the Police Service
Commission. I preferred a university appointment and refused
to take up any of these earlier offers. In September 1980, I got
employed as a temporary Lecturer II in the Physiology Unit
of the Department. In the remaining part of that year and for
the next two years that followed, my research work was on
gastrointestinal physiology under the supervision of Professor
Olowookorun. I soon gave up on that field of study because
as a young researcher, I discovered that Professor
Olowookorun had covered so much ground in that field and
breaking a new one within a short time would be a difficult
task for me. I also observed that the available equipment for
gastrointestinal studies in the Department were becoming
obsolete and non-functional and there was no immediate hope
of upgrading them. In addition, I had just a few publications
to show for the 2 years spent on gastrointestinal studies. It
was obvious that the only way forward for me was to make a
new choice of research interest. To start with, I recalled the
field experience during my Youth Service year, when with a
colleague and classmate, Dr. Eric Omogbai (currently
Professor of Pharmacology, University of Benin) and a Sri
Lankan Veterinarian, Dr. S. Tangarajah who was in the
employment of the private farm where I worked, we relied on
the blood data of animal breeds in Europe and America to
assess the health status or treat sick animals in our Nigerian
environment. This is because reference data on blood
parameters of our animals were not available. In an attempt to
fill this gap, I switched over to studying the blood
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characteristics of normal animals and birds in the tropical
environment. This has been my main thrust ever since, and so
far, Ihave investigated and established data on:
(i) Normal blood parameters of domesticated and non-
domesticated animals in the hot humid tropics;
(ii) Osmotic behavior of mammalian and non-
mammalian erythrocytes and factors influencing such
behavior;
(iii) Haematological changes after blood loss in animals.
Normal Blood Data of Animals in the Hot Humid Tropics
Blood Values of the Large Ruminant
Mr. Vice-Chancellor' Sir, cattle commands a prominent
position in our meat supply and livestock industry. Beef
accounts for over 50% of the total meat consumed in Nigeria.
Although developing countries have about two-thirds of the
World Cattle population, about two-thirds of total beef
production is accounted for by developed countries. Cattle
production in developing countries including Nigeria
provides millions of families with good nutrition, family
income and employment opportunities, draft power and a
more balanced agriculture. Our studies on the blood values of
cattle examined two popular breeds: White Fulani and
N'dama (fig. 6a, b). The White Fulani is a white, black-eared
and medium-homed breed with well developed hump and
dewlap and is the most numerous and widespread of all
Nigerian cattle breeds. They are found from Lagos to Sakata,
Katsina and Kano States and spread across the Nigerian
MIddle Belt. The N'dama was brought into Nigeria from
Guinea in 1939 on an experimental basis, because it is
trypanotolerant. The N'dama has a medium-sized compact
body with lyre-shaped black-tipped horns and no hump.
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Fig. 6. Nigerian cattle breeds: (a) Adult N'dama Catte, (b) Adult White
Fulani Cattle
Oduye and Okunaiya (1971), and Oduye and Fasanmi
(1971) compared some haematological and serum bio-
chemical parameters, respectively, in White Fulani and
N'dama breeds of cattle in Nigeria. However, few parameters
were investigated. For instance, the haematological para-
meters were limited to packed cell volume (PCV),
haemoglobin (Hb) concentration and white blood cell count.
My former postgraduate student, Dr. Funsho Olayemi
(currently Senior Lecturer and Acting Head of my
Department) and I compared the various haematological and
plasma biochemical parameters of the adult (2 - 5 year- old)
White Fulani cattle and adult (2 - 6 year-old) N'dama cattle
reared under similar intensive management system at the
International Livestock Research Institute, Ibadan, Nigeria
(Olayemi and Oyewale, 2002a). We found that the Hb, MCH
and MCHC values were significantly higher in White Fulani
than in N'dama cattle (table 1).
This is attributed to genetic differences, as both breeds of
animals were reared under identical systems of management.
The neutrophil count was however lower in White Fulani
cattle (table 2). These observations seem to suggest that
haematological values obtained for one breed of cattle in
Nigeria cannot be accepted as representing the values that
may be found in another breed.
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Table 1: Erythrocyte values (mean ± SD) of the White Fulani and
N'dama breeds of cattle
Whil~ Fulani VI = 28) N'dama (n = 15)
ROC ( x ((f. td) 5.47 ±0.92 5.46! 1 15
rev (t,1 39.00±4.61 37.13:t426
HbllJdJ) 12.28± 1.48 9.88: U3***
MCV(ti'j 72.92±1321 69.90± 10.99
MOi(pg) 23.11 ±5.29 19.00±5.01 *
MGlC(g/dl) 3Li5±5.3i 26.94 ± 4.49"*
Ndama values significantly difterelll from those for White Fulani canle at ·p<O.05, "p<O 01.
tup<O.OOI
Source: Olayemi and Oyewale (2002a)
Table 2: Leukocyte values (mean ± SD) of the White Fulani and
N'dama breeds of cattle
Parameter White Fulani (II = 28) Ndama (11 = 15)
Tmal WBe (x 103/~) 9.11±365 9.19i4.66
Lymphocytes ( x 1O·1/l!l) 6.00 ±0.49 (66.00%:::3.64%) 5.86 to.54 (63.73%±4.76%)
Neutrophils ( x 1031 jJl) 2.23 ± 0.36 (24.54%± 4.35'1'0) 2.53 iO.26 (27.53%± 135<;.W'
Eosinophils [x 10; IjJl) 0.56tO.l1 (6.14'1o± 1.08%) 0.5.1±0.14 (S.BOY,! 1.61/0)
Monocytes(x 10J!!Jl) 031±011 (3.30%±1.13'%) 025 =0.12 (~73%:: IJlfi,)
Percentage data in parentheses
*'Yd'ama values significantly different from that for White Fulani cattle at p <0.01
Source: Olayemi and Oyewale (2002a)
Furthermore, we reported that although the levels of
plasma electrolytes and metabolites were identical in both
breeds, the plasma sodium, total proteins and albumin were
significantly higher in the zebu (White Fulani) than in the
N'dama breed (Olayemi and Oyewale, 2002a; table 3). This
may be due to the fact that zebu cattle have greater ability to
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digest dietary protein and re-utilize nitrogen more efficiently
than other breeds of cattle including the N'dama.
Table 3: Comparison of the plasma electrolyte, protein and
metabolite values (mean ± SD) of the White Fulani and N'dama
breeds of cattle
Parameters White Fulani (n = 19) N'dama (n = 15)
Sodium (mmoIlL) 142.26±9.07 126.}'5 ± 19.15 (13)"
Potassium (mmoI/L) 4.81 ±0.94 (18) 5.13 ± 1.34 (14)
Bicarbonate (mmoj zL) 9.05±:!.91 7.56±2.70
Calcium (mmol zL) 2.15±0.02 2.16±0.03
Inorganic phosphate (mmol/L) L62±0.76 1.57 ±0.76
Total protei n tg/L) 9O.00±8.1O 74.20± 18.20 (14)"
Alhumin (g/L) 28.90±4.30 23.40±6.70 (14).-
Globulin (g/L) 62.00 ±8.80 51.40± 15.40 (14)-
Albumin/globulin ratio O.48±O.IO 0.47±0.13
Urea (mmol/I.) 2.89±2.14 1.8-J± 1.25
C_rea_u cine (I-lIDoI/L) 162.66±47.74 135.25::: 53.04.. .- ---_ ..•_- -..- ..•..-..- ....-.- ....---------------
Numbers of animals are shown in parerubeses
N'dama values significantly different from those for White Fu.bni c:aIIk at ·,<O.JJ:!.. -,<0_01
Source: Olayemi and Oyewale (2002a)
The White Fulani cattle in Nigeria are mainly owned by
the nomadic Fulani, who keep them under a variety of
traditional management systems, from nomadic pastoralism
to intensive backyard management. We investigated the blood
parameters of White Fulani cattle under intensive and
extensive management systems and observed that the RBC
and PCV values were significantly higher in the intensively
managed animals (Olayemi and Oyewale, 2002b; table 4).
This finding, which is consistent with observations in pigs
(Sarror and Satiago, 1981) and sheep (Olayemi et al. 2000),
may have resulted from the higher plane of nutrition and
adequate veterinary care given to the intensively managed
animals. In addition, we found significantly higher total WBC
count due to higher lymphocyte, neutrophil, eosinophil and
monocyte counts in the intensively managed cattle (table 5).
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Table 4: Erythrocyte values (mean ± SD) of White Fulani cattle under
intensive and extensive managements
Parameter Intensive (28) Extensi,,'e (29)
RBC (XlObf ul) 5,47 ±O.92 4.50 ± 1.63*
PCV(%) 39.00± 4.62 32.4 I ± 5.65*·
Hb(gIdl) 12.23 ± 1.48 11.65 ± 1.29
Mev (f].) 72.92 ± 1311 79.84 ± 25.98
MCH (pg) 23.H ± 5.29 29.78 ± 11.92*
MCHC 'fwd!) 31.75 ± 5.37 36.94 ± 6.53*
Number of animals in parentheses
*Values significantly different from intensive management at *P<O.OI and
**P<O.OOI
Source: Olayemi and Oyewale (2002b)
Table 5: Leukocyte values (mean ± SD) of White Fulani cattle under
intensive and extensive managements
-------------------_ ..-, .............•....••.•. , ...
Parameters Intensive (28) Extern••i.ve (29)
Total WBC (X 1<Y/ul) 9.11 ± 3.65 6.26 ± 320·
Lymphocyte (x IOJ/uJ) 6.00±0.49 4.14± 1.01·"
[66.00= 3.69f (80.83 ± 4.79]A .••
Neutrophil (x103ful) 2.23 ± 0.36 0.83 ± 0.33**
[2454.± 4.35J" [16.10± 5.10]"- •••
Eosinophil (xl 03/ul) 0.56 ± 0.11 0.12 ± 0.07"*
[6.14± l.08)" [2.41±1.48]"
Monocyte {xIOJ/ul) 0..31 ±.0.11 0.03 ± 0.03*·
D.30 ±LB]" rO.69± 0.6618
Number of animals in parentheses
"Value expressed as a percentage of total WBC count
Values significantly different from intensive management at *P<O.Ol and
**P<O.OOI
Source: Olayerni and Oyewale (2002b)
Olayemi, Oyewale and Fajimi (2001) had earlier
investigated the plasma electrolyte levels of the White Fulani
cattle reared under intensive and extensive management
systems. We observed that the plasma electrolyte levels were
similar in both systems of management (table 6). However,
we also found the total plasma protein and albumin levels to
be higher in the intensively reared cattle (table 7). This could
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be because they were on a better diet, being fed on improved
pasture supplemented with maize, citrus pulp and brewer's
grains. The extensively reared cattle, on the other hand, did
not receive any feed supplementation.
Table 6: Plasma electrolyte concentrations (mean ± SD)of
White Fulani cattle under intensive or extensive management
Parameters Intensive (n) Extensive (II)
Sodium (mmol/I] 142.2619.07 (19) 141.83± 8.84 (27)
Potassium (mmol/Ll 4.81 ±0.94 (\8) 5.22 ± 1.09 (26)
Bicarbonate (mmollL) 9.05± 2.91 (19) 7.85±2.35 (27)
Calcium (mmoliLl 2.J5±0.02 (19) 2.15±0.03 (28)
Inorganic phosphate (mmoI/L) 1.62± 0.76 (J 9) J.62±O.78 (28)
Source: Olayemi, Oyewale and Fajimi (2001)
Table 7: Plasma protein and metabolite concentrations (mean ± SD)
of White Fulani cattle under intensive or extensive management
Parameters Intensive ~I=19) Extensive (n=28)
TOlal protein (g/L)a 90.00±8.l0 79.HO± 16.70
Albumin (giL)b 28.90±4.38 25.00±6.80
Globulin (gill 62.00±8.80 55.30 ±24.30
Albumin/globulin ratio 0.48±0.1O 0047 iO.17
Urea (mmoliL) 2.89± 2.14 1.93± \.30
( 'rcatinine (iuno[!L) 162.66±47.74 ) 61.77 ± 58.34
Vllhll" differ significantly at '1'<0.02 and bp<O.05
Source: Olayemi, Oyewale and Fajimi (2001)
Blood Volume Changes in Small Ruminants and Birds
In Nigeria, there are over 55 million goats and 34 million
sheep (National Bureau of Statistics, NBS, 2010). Small
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ruminants (i.e. sheep and goats) contribute an estimated 35%
of the total meat consumed, with goats contributing about
20% and the rest (15%) from sheep. The predominant goat
breed in the country is the West African Dwarf (WAD) (fig.
7a) and the predominant sheep breed is the Yankasa.
However, the WAD sheep (fig. 7b) is the predominant breed
of the humid tropics from southern West Africa through
Central Africa.
Although increases in plasma and blood volumes in WAD
sheep and goats during experimental Trypanosoma vivax
infections have been reported (Anosa and Isoun 1976), no
reports are available on these parameters during the
physiological states of pregnancy and lactation in these
animals. We investigated the total blood volume and plasma
volume in WAD goats (Makinde, Durotoye and Oyewale
1983) and WAD sheep (Durotoye and Oyewale 2000) during
pregnancy and lactation. Our results showed that the plasma
and blood volumes in WAD sheep and goats are higher than
in sheep and goats in temperate climate. Both volumes are
greater in lactating than in pregnant animals (tables 8 and 9).
This is similar to the report of Schalm et al. (1975) in
reproducing cows. It suggests that the blood and plasma
volumes which were increased during pregnancy were
probably maintained during lactation, such that the volumes
per unit body weight appeared greater in lactating than in
pregnant animals. Contrary to the common situation in
women, in which pregnancy is accompanied by anaemia, we
did not observe anaemia in our pregnant sheep and goats.
This agrees with a similar finding in pregnant cows (Schalm
et al. 1975).
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Fig. 7a. Pregnant West African Fig. 7b. Pregnant West African
Dwarf (WAD) goat Dwarf (WAD) sheep .
Table 8: Mean values (±SD) for live body weight, packed cell volume
(PCV), haemoglobin (Hb) concentration, plasma and blood volumes
in West African Dwarf goats
Goat Body PCV Hb Plasma Blood
weight (0/0) (g/dl) volume volume
(kg) (mllkg) (ml/kg)
Pregnant 35.00 31.00 10.30 67.60 \05.20
±12.72 ±5.12 ±2.28 ±21.50 ±15.00
(9) (9) (9) (7) (7)
Lactating 22.00 27.00 8.60 89.30 115.60
±8.70 ±3.20 ±1.70 ±18.90 ±19.40
(8) (8) (8) (8) (8)
Non- 27.40 30.40 9.96 81.00 106.99
pregnant, ±8.20 ±4.60 ±11O ±31.10 ±2.50
non- (S) (8) (8) (8) (7)
lactating
Number of animals in parenthesis
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Table 9: Mean values (±SD) for live body weight, packed cell volume
(PCV), haemoglobin (Hb) concentration, plasma volume and blood
volume in West African Dwarf sheep
Parameters Rams Dry Ewes Pregnant Lactating
Ewes Ewes
Body Weight (Kg) 21.89 20.50 28.17 22.57
± 2.71(9) ± 0.59(8) = 1.56112)' ± 1:70m
PCV 1%\ • 30.00 29.63 38.15 32.29
:: 1.09(9) ± 1.67(8) I 1.40(10)* ± 1.93(7)
Hb(g%) 9.41 9.43 12.07 10.57
± 1.17 (9J ± 0.97(6) ± 0.50\12) ± 0.71(7)
Plasma Volume 45.70 40.l6 43.l0 96.16
(ml/kg body weight) ± 5.37(6) ± 7.03(6) :: 3.12i9) ~I.;6).'-)"'(6)"**
Blood volume 64.08 55.74 71.46 147.12
Iml/kg body weight) ± 6.11(6) ± 9.31(6) ± 6.46(8) ± 12.97\6j"
Numbers In parenthesIs represent number of Clmmals used; t = P<O.O-J comparec11o Gata on
the same row; U = P<O.OOl compared to data on the same row.
Our blood volume studies were extended to domesticated
and non-domesticated birds in Nigeria including domestic
fowls, ducks and guinea-fowls. We compared the plasma and
blood volumes of the Nigerian fowl (local strain) and White
Leghorn fowl (exotic strain) reared under identical environ-
mental conditions in order to determine whether or not these
parameters differed between the two strains of domestic fowls
(Makinde, Fatunmbi and Oyewale 1986). The White
Leghorns are among the most popular commercial strains of
laying chickens in the world. The results showed larger
plasma and blood volumes in the local Nigerian fowl (which
though more excitable and more active, is capable of laying
fewer eggs) than the White leghorn fowl.
In a study involving the local Nigerian ducks (Anas
platyrhynchos), Olayemi, Oyewale et al. (2003) found that
although the plasma and blood volumes did not differ
significantly between the young (8 - 10 weeks old) and the
adult bird (52 - 80 weeks old), the values in the adult
Nigerian duck are lower than those of the plasma and blood
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volumes reported in the temperate environment in wild and
domesticated ducks. Apart from the work done on domestic
birds, I investigated the effect of egg-laying on plasma and
blood volumes in the semi-domesticated guinea-fowl
(Numida meleagris galeata, Pallas), which is a seasonal
breeder. The results showed that the plasma and blood
volumes were lowered in the guinea-hen by egg-laying during
the breeding season (Oyewale 1990). Earlier reports have
indicated that the PCV is decreased (Oyewale and Fajimi
1988) and the blood oestrogen level is increased (Ogwuegbu
1987) during egg-laying in the guinea-hen. It seems therefore,
that the decrease in PCV associated with the decrease in
blood volume is seasonally dependent on increase in blood
oestrogen level during egg-laying.
Blood Values of Domestic Fowls, Guinea-Fowls, Ducks and
Turkeys in Nigeria
The haematological and plasma (serum) biochemical data of
several avian species have been studied in the temperate
climate, but reports on birds in our tropical environment are
scanty. mood values may provide, when properly interpreted,
a precise picture of the health condition of an animal at the
moment of sampling (i.e., nutritional status, disease
condition, or stress due to capture and handling in wild
animals) and may also reflect the quality of the habitat or
environment where the animal is kept. Several studies have
been conducted in our laboratory on haematological and
plasma (serum) biochemical parameters of domestic birds in
the Nigerian environment and the way they are affected by
breed, sex, species, egg laying and age.
My research on the haematology of the adult Nigerian
domestic fowl showed that although the PCV and Hb values
are similar to the values found in temperate breeds, the RBC
and WBC counts are lower in the Nigerian fowl (Oyewale
1987b). These observations are attributed to genetic and
environmental differences. In another study, Oyewale and
Durotoye (1988) compared the haematological values of the
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adult male and female Nigerian domestic fowls and adult
male and female Hubbard fowls (exotic domestic fowls)
reared under identical environmental conditions. The results
revealed that the values of PCV and Hb were significantly
higher in Nigerian domestic fowls (which are more resistant
to prevalent Nigerian poultry diseases) than Hubbard fowls
(table 10).
Table 10: Comparison of Haematological Values of the Adult
Nigerian Domestic Fowl and Adult Hubbard Fowl
Parameters &x Nigerian domestic fowls Hubbard fowls
rev ('iI) Male l5· 77± 2'97 (13) 33'25±3-Jl (8)
Female lH9:t1·70 (ll) 28·29±2·16 (12)
Male and female 34-08 ± z.95 (26) 30·2S±3-61 (20)
RBC (lO'/mm~ - Male 2'55±O'42 (13) 2'33±0'17 (8)
Female 2-42 ± 0-38 (13) 2'14±0'2$ (12)
Male and female 2-48! 0'40 (26) 2·22±0·24 (201
Hb (s/dl) Male 1l'31±H16(J3) IO'06±O'95 (8)
Female 9-84:!: 1'01 (13) 9'19±O'65 (12)
Male and female 10'58+ 1'27(26) 9'54+0·89 (20)
Note: Number of birds shown in parentheses Source: Oyewale and Durotoye (1988)
If PCV reflects the total red cell volume in the body, and
if the latter is an indication of the oxygen (02) carrying
capacity of blood, then it can be concluded that the Nigerian
domestic fowl with a higher PCV is better suited than the
Hubbard fowl to survive in the hot humid tropics, where
metabolic activities and 02 requirements would be greater
than in the temperate or subtropical climate. In both breeds of
domestic fowl, the values of PCV and Hb were significantly
higher in males jhan in females. The role of androgens in
increasing RBC, PCV and Hb values in birds has been well
documented (Panda and Juhn 1961; Freid et al. 1964;
Nirmalan and Robinson 1971). In humans, testosterone has
been shown to. increase PCV and Hb values in males
(Coviello et al. 2008).
The above findings of breed and sex differences in the
haematological data of domestic fowls in our tropical
environment challenged us to assess the blood picture of the
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semi-domesticated guinea-fowl (Numida meleagris galeata,
Pallas). The comparison was made of the content of
electrolytes (table 11) and proteins (table 12) in the serum of
adult guinea-fowl and adult Nigerian fowl (Oyewale et al.
1988). Our results showed that the guinea-fowl had
significantly higher values for sodium,· potassium, and
albumin. The Nigerian fowl, on the other hand, exhibited
higher values for calcium, chloride, bicarbonate, inorganic
phosphate, total proteins and globulins, which were also
significant. What this implies is that, although most of the
values in both types of birds are within the range reported for
other breeds of domestic fowls, there is need for caution in
applying the normal blood biochemical values of Nigerian
fowl to assess the health and nutritional status of guinea-fowl
in the same environment.
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Table 11: Mean Serum Electrolyte Values (± SD) in Nigerian Fowl and Guinea-fowl
Purameter Nigerian fowl Guinea fowl
.Male Female Both sexes Male Ferna.le Bor.h sexes
.-~-~-.----
Sodium (mmolyl) 145.73 1.29.17 133.6] 204.10 H)9.06 200.2:1
± 13.84 ± W.2o ± 13.39 ± 11.59 + 23.71 ± 26.85
(11) (30) (41) (10) (33) (43 )
Potaseium (mmolrl) 4.94- 3.M 3.88 .5.18 15.64 5.54
± 2.40 ± 1.50 + 1.83 ± 0.70 ± 0.62 ± 0.67
(10) (:n) (41) (10) (33) (43)
Chloride (mmol/]) 105.00 107.00 106.41 98.18 102.69 101.64-
± 7.35 ± 3.80 ± 5.10 ± 8.99 ± (;.60 ± 7.73
(13) (ill) (44) (11) (36) (47)
Bicarbonate (mmelfl) !.rI.55 20.23 20.59 12.46 15.49 14.711
J. 1.57 ± 1.8\ :1: 1.83 ± 3.73 ± 3.55 ± 3.Sl
(11) (:30) (41) (11) (37) (4Sj
Calcium (lng/dl) 9.<J4 ]0.14 $).89 7.24 7.27 7.26
± 0.71 ± 0.613 ± 0.72 ± 1.22 ± 1.35 ± 1.32
(Ll) (11) (22) (11) (36) (,17)
Enorganic phospho+e 5.53 t!.22 4.04 3.07 3.J2 3.11
(mg/dl) :1: 0.40 ± 1.03 ± 0.96 ± 1.a4 :t 0.64 ± 0.85
(11 ) (31) (42) (ll) (:37) ('~8)
,--
Note: Number of birds in parentheses
Source: Oyewaie, et al. (1988)
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Table 12: Mean Serum Protein Values (± SD) in Nigerian Fowl and Guinea-fowl
Parameter Nigeria.n fowl GWoeafOwl
Male Female Both se::tes llale Female Both" sexes
Total protein (g/dl) 4.72 5.00 4.9.5 3.33 3.AJ8 3.60
±O.50 ±0.50 ± 0.52 ± 0.56 ±1.26 ± LIS
(13) (30) (43) (II) (37) (48)
Albumin (g/dl) 1.46 1.57 1.55 1.56 '1.78· . 1.73.
± 0.30 ±0.23 ± 0:26 +O~ ±O..s7' ± 0.36 ,
(13) (30) (43) (ll) (m) (48)
Globulin (g/dl) 3.25 3.50 3.43 1.76 Utl 1.88
± 0.29 + 0.49 ±O.45 +0.46 ± 1..05 ±O.95-·
(13) (30) (43) (ll) (37) (48)
Note: Number of birds in parentheses
Source: Oyewale, et aI. (1988)
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Although we had earlier shown that the plasma and total
blood volumes were lowered by egg-laying in the guinea-hen,
we desired to know whether the haematological parameters
and plasma electrolytes and proteins were also affected. The
results of our investigation (Oyewale and Fajimi 1988)
revealed that egg-laying in the guinea-hen was accompanied
by decreased PCV and increased plasma Ca level, which are
both attributable to the activity of oestrogen. There was no
significant effect of egg-laying on the Hb concentration. This
agrees with a similar finding in domestic fowl (Jaffe 1960),
but conflicts with reports on turkeys (Paulsen et al. 1950) ;~md
geese (Hunsaker et al. 1964), in which Hb levels are raised
during egg-laying. An observation that was of particular
interest was the significant increases in total plasma proteins,
albumin and globulins in the laying guinea-hen. This again
may be associated with the endogenous activity of oestrogen
in laying birds.
Given that data on the effect of age on blood parameters
of the semi-domesticated guinea-fowl were sparse, Oyewale
(1991a) using male guinea-fowls, compared the haemato-
logical parameters of the 156-week-old and 21-week-old
birds. The results showed that the RBC, PCV and Hb values
were not significantly different between the two age-groups.
We also compared the haematological values of the guinea-
fowl with those of the turkey, domestic fowl and duck in our
tropical environment and found that all the erythrocyte values
studied in the guinea-fowl were similar to those of the turkey
and domestic fowl, but the values in the duck (except the
MCV) were higher than in the guinea-fowl (table 13).
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Table 13: Comparison of haematological values (mean ± SD) of
guinea-fowl, turkey, domestic fowl and duck in the same tropical
environment
Guinea fowl" Turkey" Domestic fowl" Duck"
Number of 20 14 10 II
birds
RBC x 2.44 ± 0.26 2.59 ±0.35 2.45 ± 0.22 2.87 ± 0.30
106/l-lL -
rcv s 38.13±3.14 38.68 ±2.27 36.65 ± 2.50 43.60 ± 2.10
Hb g/dl 12.10 ± 2.21 12.26±0.92 I 1.33 ± 0.28 • 15.1O±1.l4
MCV fl 154.99 ± 9.31 150.48 ± 19.45 148.99 ± 16.55 154.46 ± 14.04
MCHpg 49.58 ±3.30 47.69 ± 5.41 46.29 ± 4.72 53.59 ± 5.34
MCHC 32.01 ± 1.39 31.71 ±1.61 31.79 ± 3.88 34.70 ± 2.56
gldl
Sources: "(Oyewale, 1991 a); b(Oyewale and Ajibade, 1990a); "(Oyewale. 1988);
~(Oyewale and Ajibade, 1990b)
Blood Values of Zoo and Non-domesticated Animals
Part of our research efforts over the years had been the
documentation of the baseline haematological and plasma
biochemical data of zoo and non-domesticated animals in our
environment, which should be useful in diagnosis and
treatment of diseases, metabolic disorders or nutritional
deficiencies in these animals.
The peafowl is one of the most ostentatiously adorned
creatures on earth, with the male (peacock) using its brilliant
plumage to entice the females (peahens). Peacocks (eye akin
in Yoruba) are large colorful pheasants (typically blue and
green) known and admired by humans for their iridescent tail.
Like the late American superstar, Michael Jackson (August
29, 1958 - June 25, 2009) who, with his exceptional singing
and dancing talents, was popularly known to the world as the
'king of pop music', the peacock in the local parlance is
described as the 'king of birds' (eye akin l'oba eye in
Yoruba). The tail feathers spread out in a distinctive train
that is over 60% of the bird's total body length. The large
train is used in mating rituals and courtship displays. It can be
arched in a magnificent fan that reaches across the back of the
bird and touches the ground on the other side. Females select
their mates according to the size, color and quality of this
outrageous feather train. It is the same way women select
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their prospective husbands, using such criteria as physical
appearance, intelligence, race, tribe, skin color, religion and
economic, social or political considerations. I compared the
blood values of the adult peafowl (Pavo cristatus) (fig. 8),
which is a staple resident of many of the world's zoos, with
those of the adult domestic pigeon (Columba livia) (fig. 9),
which is used as food or game bird in many cities of the
world. I observed that no significant sex differences were
apparent in the haematological values of either species, but
the mean RBC, PCV and Hb values were significantly higher
in the pigeon than the peafowl (Oyewale 1994; table 14). This
may be because the pigeon is a smaller-sized and a more
active flying bird than the peafowl.
Fig. 8. A peacock (rear) wooing a peahen Fig. 9. Adult domestic pigeon
(front)
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Table 14: lIaematological Values (mean ± SD) of the Pigeon and Peafowl
Sex Pigeons Peafo'lllris
RBC x 1012/1 Male 2.91 ± 0_17( 8) 2_09 ± 0.10(5)
Female 2.63 ± 0.20( 6) 2_07 ± 0_17(4)
Male and FeJTlaJe 2.79± 0_13(14) 2_08 ± 0_09(9)
PCV% Male 44_00 ± L76( 8) 34.40 ± 1.04(5)
F",rnale 41.33 ± L70( 6) 34.00 ± 0.71(4)
Male and Fexn.a. le 42_86 ± 1.20(14) 34.25 ± 0.68(9)
Hb g/dl Mal", 16.04 ± 0_62( 8) 11-70 ± 0_01(5)
F",snale 15.79 ± OA7( 6) 11.68± 0_01(4)
Male and Female 15.94 ± 0.38(14) 11-69 ± 0.01 (9)
MCV£) Male 154.45± 11.16( 8) 165_98 ± 6.82(5)
P'errral.e 16q.16 ± 1L96( 6) 167_61 ± 10_67(4)
Male and Female 156.90 ± 7-53(14) 166.59 ± 5_93(9)
MCHpg ~le 52_34 ± 2_02{ 8) 56.71 ± 3_06(5)
Female 61.15 ± 4.12( 6) 57_98 ± 4_94(4)
Male and Fexnale 56.12 ± 228(14) 57.19 ± 2.71(9)
MCHCg/dl Male 35.17 ± 1.52( 8) 34_16 ± 1.03(5)
Female 38-28 ± 0.46( 6) 34.41 ± 0.73(4)
Male and Female 3634 ± 0_98(14) 34..26 ± 0.68(9)
Note: Number of birds in parentheses
Source: Oyewalc (1994)
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Tortoises are land-dwelling reptiles with life-spans longer
than those of human beings. There are authenticated cases of
some individual tortoises living for over 150 years. In
humans,· the 2010 estimates of the life expectancy at birth,
which is .the average number of years to be lived by a group
of people born in the same year, for Nigeria, Ghana,
Singapore, Canada, United Kingdom and United States are
47.24, 60.~5, 82.06, 84, 79.92 and 78.24 years, respectively
(CIA - The World Factbook, 2010). These figures compare
poorly to the life-span of the tortoise.
In the late 1990s, with one of my post-graduate students,
Mr. Paul Ebute, I determined the blood profile in the adult
wild West African hinge-backed tortoise, Kinixys erosa
(fig. lOa) and the adult wild desert tortoise, Gopherus
agassisii (fig. lOb) kept under identical environmental
conditions. A comparison between sexes showed the male K.
erosa had significantly higher PCV and Hb concentration and
lower plasma alkaline phosphatase (ALP) values than the
~ female, while no significant sex differences appeared in these
parameters in G. agassizii (tables 15 and 16) (Oyewale, et al.
1988). The haematological parameters and plasma levels of
electrolytes, enzymes, proteins and metabolites did not differ
significantly between the two species (tables 15 and 16),
suggesting that the blood values of K. erosa resembled those
of G.··agassizii under identical environmental conditions.
However, in tortoises and turtles, factors such as season,
nutrition and temperature have been shown to have
significant effects on blood values.
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(a) (b)
Fig. 10. Adult tortoises (a) West African hinge-backed tortoise Kinixys
erosa, (b) Desert tortoise, Gopherus agassizii
In the light of these considerations, the blood values of K.
erosa and G. agassizii are likely to be different if the two
species were studied in their normal habitats, in which diet,
temperature, rainfall, moisture and vegetation differ. G.
agassizii lives in the desert zone of Nigeria, where it rarely
has access to free drinking water and depends on water from
its entirely herbivorous diet. On the other hand, K. erosa stays
on the shore of the river in the rain-forest zone of our country,
where it has unrestricted access to drinking water. It feeds
mostly on plants, which it supplements with insects and their
larvae.
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Table 15: I1aematological Values (mean ± SEM) in Kinixys erosa and Gopherus agassizii
.
Ki"ix)'f tros.1 Gophu"J! (lgajji~7
--- -
Mille Female Both sexes Mie Fonsk Both sexes
(r.;; 6) ~o=6) (n;; 12) (:1=6) (n=7} [n=U;
- ...•--~-
pev ("10) 34.17 ±2.68 1.6.50± 1.93 30.331 1.95 28.17± 1.56 29.86± 1.40 29.0811.03
RBe (X 106/~l) C.712=0.148 O.56&±OJI2 O.G40± 0.091 0.422 ± 0.049 0.529 ± 0.048 0.479± 0.0.%
Hb (~/dJ) 11.37 =0.89 ~:.96±0.47 9.703±OJ:;
JiCV (0) 612.32 = 8,8310.66 10.1O±0.65 9AIJiO.54137.91 563.22± 120.17 587.77 ± 87.71 753,48± 159.56 587.11l-19.19 6G1.82± 7&22
:VfCH Ulf~ 203.90: 46.03 201.38:47.31 202.64 i 31.52 253.17 ± 52.02 195.861 16.5:i 222.31 ±26.88
MCHCWdi) 33.27.: 0.05 33.32:t 0.03 33.29± 0.05 33.46±0.14 33J~±l1.04 33.40 ±1}'G6
~~---------~------ '-'-'~-"---------
n :::r.umbe~of anU1l8s.
Source: Oycwalc, et al. (1998)
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Table 16: Mean (± SEM) Plasma Electrolyte, Enzyme, Protein and Metabolite Levels in Kinixys erosa and Gopherus
agassizii
Kjll;~'J,f crosa
----- -----_._-- (,vph~nJ,faga.ui:r.!;
1'>lale relT~e no\h ecxcs M.le Fernalc Both SI;XCI:'
(n=5) (n;6) (0 = 12) Cn:;-; ~I.l)
._-------'e.n_=,(I~ (n = 7)•...
N? (tJ):"Jtol!~) 122.6/::: 1.C<) 122.00 -1.CO l22.33 ± 0.71 122.113± 1.1l1l 12.~.I>(±, 1.74 12:>..'fI:L 1.0.1
K (m..-nolll) ~.77 ±O.O4 4.97 ±(l.O9 4.87±O.O6 4.98±1l.14 5.00±O.16. 4."9 = 0.10
Cl (mOlal/I) 98.33 ±O.21 98.67 .L 0.34 98.?.Q± 0.; <) 98.83 ±O.17 <)<).297.(.)."l6 99.10=0.2,
HCO, (rnulul/l) 20.17±O.40 20.50±O.34 20.33 ± 0.25 20.01l± II.III 1<).11±(10.;4 19.92:-:-O.llR
Tno"""n;c pno,;>ha,c (mmU:/I) 1.49±O.O2 t.46±O.02 lA8±O.Ql 1.5(l±(UI2 1.47±II.nl 1.19± 0.0\
c. (mmol/l) 2.09±O.OI 2.10±0.O2 2. 10± 0.114 2.09 ± 11.1I2 2.1O±1I.tl2 2.10±O.O2
ALP(i.U/~ 152.17±3.U, 162.00±2.SB 157.08±2.7~ 15t1.lx,± k.2R H.3.71 ± 5.38 161.54± 4,(1.1
G()1' (i.u ,I) 29.6?±O.99 31.67± 1.52 .,(1,(,7± (1,92 21UiJ ± 2. !I') 29_86 -- _\_.5.~ 29.38±2.05
GPT (Lull) \U13±Cl.(,O D.~(\±1I.7(. 12,(.7:±.05~ I2.(i!1±O.6H 14.29±INl 13.?3 + 11.9/\
(;CO'l' (Lull) 2.r.7±OAZ 2.50±o.2~ 2.51\ + (1.2.1 2.113:.1:.(1.40 .~.OO±.O.43 2.92J.ll.3~
TUt-dl protein WI) <,1.15±0.74 (d.o4 +0.(.2 (d.1U±OA4 (,1.47 ± 0.50 61.2li±fJ.") (,1.35 ± 0.33
Albumin WI) 29.211:.1:.0.34 2fUI3:::0.53 2H.(.5 ±0.44 29.27 ±0.44 ~9.36±O.53 29.3~± 0..32
Globulin ~/l) :>2.!J2±O.SI 33.1111..0.64 .~2.46±0.44 .~2.~91. 0.63 31.89±0.44 :12.20± 0.3~
Albumin/Glohulin R:.1UU 7.30= 1.33 7.23 ±O.S4 7.26±O.72 6.73 = 1.34 8.B81.!J.24 7.76±O.Ii'l
t.rrr, (""mol/Ii 9.6.:1±O.43 9.66±0.20 9.(,4 ± 0.2.1 1\).13:::0.55 9.4\ =0.31 9.7~ l:O.3:
Creadnine (,um(\1Il) HI.44±4.42 139.67=2.6.S 140.56±2.65 147.(,3 t 7.07 144.09 ± 4.42 \45.116 ± .;.5·-1
Cholesterol (mmol/I) 1.91±O.OS 1.81 ±O.OS I.RiI±O.M 1.93± n.07 1.86-:1:0.08 1.90±O.O5
Tti~yc.l".·ic:l.(.~ (mlnnl/r) 0.64 ± (1.01
---- 0.61.l0.OJ 0.62±0.')2 C.c,c,.l Cl.02 0.68±0.04 0.67+ 0.Cl2
n = rvumbter of animals.
Na=Sodium; K=Potassium; Cl= Chloride; HC03=Bicarbonatc; Ca=Calcium; Al.Pe Alkaline phosphatase; GOT=Glutamatc' oxaloacetate
transaminase; GPT=Glutamate pyruvate transaminase; GGT=Gama-glutamate transferase .
Source: Oyewale, et al, (1998)
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The pangolin (aka, in Yoruba) is a non-domesticated ant-
eating mammal. Perhaps not many of us are familiar with this
animal, but I suspect that the Vice-Chancellor, coming from
Ilesha, is familiar with the pangolin, which is often on display
as bush-meat along Ibadan-Ife expressway. Their entire body
is covered with protective horny overlapping scales, except
for the belly, snout, eyes, ears and undersides of the limbs.
They are largely semi-arboreal with small heads and long
broad tails and are widely distributed in sub-Saharan Africa.
They are toothless and have no external ears. They have well-
developed sense of smell, but as nocturnal mammals, they
have poor eyesight. The tree pangolin (Manis tricuspid) also
called white-bellied pangolin or three-cusped pangolin, is one
of the extant species of pangolin and the most common of the
African forest pangolins. They are subject to widespread and
often intensive exploitation for bush-meat and traditional
medicine. We studied the blood parameters of the adult
African white-bellied pangolin (Manis tricuspid) (fig. 11)
captured in Ibadan, and compared our findings with those of
the adult African giant rat (Cricetomys gambianus,
Waterhouse) (okete, in Yoruba) (fig. 12), which like the
pangolin, is also a largely non-domesticated nocturnal
mammal found in sub-Saharan Africa, where it serves as a
ready source of supplementary dietary protein for the rural
population. Although it has many of the same mannerisms as
our domesticated laboratory rats (Rattus norvegicus), the
giant rat is bigger in size and displays many of its wild natural
behaviour, even in captivity.
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Fig. 11. Adult white-bellied (tree) Fig. 12. Adult African giant
pangolin (Manis tricuspid) rat (Cricetomys gambianus,
Water-house)
In the first series of experiments, we investigated the
haematological parameters of the pangolin and African giant
rat (Oyewale, Ogunsanmi and Ozegbe 1997; Oyewale,
Olayemi and Oke 1998). The results showed that the
erythrocyte values in both species did not differ significantly
between sexes, but the RBC, PCV and Hb values in giant rats
were significantly higher than in pangolins (table 18). The
MCV in giant rats, similar to pangolins, was significantly
higher than the values in laboratory rats, sheep and goats
(table 18). We reasoned that this could be as a result of the
small number of circulating erythrocytes in giant rats and
pangolins. Our observation that RBC, PCV and Hb values
in giant rats are similar to those of humans is unexpected
in view of the inactivity of giant rats at daytime and at the
time of blood sampling. I recall the expression of a
technologist at the Ahmadu Bello University Teaching
Hospital, Zaria in 2007 who upon analyzing the samples
of blood we obtained at night (lO.OOpm) from giant rats
remarked that "this sample cannot be from a normal
human being" because the RBC, PCV and Hb values were
too high. Yes, he was right. It was obtained from a normal
giant rat at night when the animal was active.
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Table 18: Comparison of Erythrocyte Values (mean ± SD) in African Giant Rats, Pangolins, Humans, Cattle, Goats,
Sheep and Laboratory rats in the same Tropical Environment.
African giant Pangolin" Humane White Fulani Nigerian West African Laboratory
rat'(n=15) (n=IO) (n=5OO) cattle" goat' Dwarf sheep' rat"
(n=150) (n=85) (n=295) (11=36)
RBC (x 1012/1) 5.90±1.56 4. 19±O.68 5.37±O.41 ND 12.30±2.40 7.50±2.1O 6.86±O.79
PCV (%) 48.43±3.93 40.40±4.95 46.50±4.36 30.1O±4.40 26.10±4.10 27.40±4.50 31.16±4.47
Hb (gldl) 14.36±2.45 1O.01±1.44 15.06±1.27 9.04±1.50 8.59±1.31 8.42±1.50 12.98±2.38
MCV (ft) 86.85±22.02 97.75±14.35 87.70±5.70 ND 21.80±4.40 38.30± 10.50 45.72±6.55
MCH(pg) 25.77±6.67 24.13±3.43 27.69±2.16 ND ND ND 19.49±1.90
MCHC (gldl) 29.84±5.44 24. 84±2.46 32.39±O.76 ND 33.10±3.40 30.80±5.40 43.07±4.52
n=No. of animals ND =No data
Sources: Oyewale, Ogunsanmi and Ozegbe (1997)
a(OYEWALE et al., 1998)
b(OYEWALEetal.,1997)
"(EZEILO and OBI, 1983)
d(ODUYE and OKUNAIYA 1971
e(ODUYE, 1976)
'(OYEW ALE 1987c)
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The mean total WBC count in pangolins was lower than
in giant rats, laboratory rats, cattle, sheep, goats and humans
(table 19). This could be due to the low eosinophil count in
pangolins. In giant rats, like in humans, donkeys, sheep, cattle
and pigs, lymphocyte counts are much higher than neutro-
phils, but the reverse is the case in horses, dogs and cats.
However, in pangolins, our results showed that lymphocytes
and neutrophils are present in the blood in, the same
proportion. We decided to investigate further whether the
plasma biochemical parameters in pangolins are different
from those of giant rats in the same environment. Our results
(table 20) revealed that, in both species, the levels of plasma
electrolytes (Na, K, Cl, HC03, Ca, and inorganic P04) and
enzymes (ALP, GOT, GPT and GGT) did not differ
significantly between sexes (Oyewale, Ogunsanmi and
Ozegbe, 1998; Oyewale, et al. 1998). When compared with
the values in pangolins, we found that the plasma Na, Cl and
Ca levels were significantly lower in giant rats. However,
both species have similar K, total protein, albumin and
globulin values. The CI value in the giant rat was
significantly lower than in pangolin, goat, cattle and humans
(table 20).
We observed that plasma Ca value in giant rat or pangolin
was significantly lower than in goats, pigs and cattle. We
reasoned that this could have resulted from the supplementary
feeds, in form of concentrates or salt lick, given to the
ruminants and pigs, whereas these were unavailable to giant
rats and pangolins in the wild.
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Table 19: Comparison of Leukocyte Values (mean ± SD) in African Giant Rats, Pangolins, Humans, Cattle, Sheep
and Goats in the same Tropical Environment.
Parameter African giant rat' Pangolin' l'Iumanh White Fulani West African Nigerian
(n=IS) (n=IO) (n=500) cattle' Dwarf sheep" Goat"
(n=ISO) (n=295) (n=85)
Total WBC x 1O~/l 7.S6 ±2.55 4.80 ± 2.09 6.22 ± 1.43 9.98 ± 2.66 IS.25 ±4.69 16.10 ± 4.55
Neutrophil xIO"!1 1.49 ±1.38 2.44 ± 1.29 2.3S ± 0.85 ND ND ND
(18.71±12.91) (49.30±1 1.7 I) (37.80) (19 .90±9 .30) (35.80±13.60) (46.80 ± 10.80)
Lymphocyte xIO"!1 S.IS±1.88 2.22 ± 1.01 3.IS ±0.87 ND ND ND
(67.07±14.S8) (46.90±9.61) (50.5) (66.t10±9.70) (S4.20± 14.00) (47.00± 1.60)
Monocyte x IO"!I 0.43 ±0.28 O.lO±O.11 0.13 ±0.16 ND ND ND
(5.S7 ± 3.50) (2.70 ± 2.79) (2.13) (4.35 ± 3.10) (1.50 ± 1.60) (0.90 ± 0.90)
Eosinophil xlO"!1 0.21 ±0.17 0.04 ± 0.04 0.60 ±0.64 ND ND ND
(2.71 ± 1.77) (0.90 ± 0.99) (9.60) (8.73 ± 6.80) (4.60 ± 4.50) (4.70 ± 4.50)
Basophil xlO"/l 0.31 ±0.27 0.01 ±0.03 ND ND ND ND
(3.93 ± 2.92) (0.20 ± 0.63) ( 1.0) (0 ± 0) (ND) (ND)
n = No. of animals;
Values in brackets expressed as percentage of total WBe count;
ND = No data.
Sources: OyewaIe, Olayemi and Oke (1998) a~OYEWALE et al., 1998) "(OYEWALE et al., 1997) b(EZEILO and OBI, 1983)
C(ODUYE and OKUNAIY A, 1971) '(ODUYE, 1976) d(ODUYE. 1976)
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Table 20: Comparison ofPJasma Electrolyte and Enzyme Values (mean ± SD) in African Giant Rats, Pangolins,
Goats, Pigs, Cattle and Humans in the same Tropical Environment
Africa giant rat' Pangolin" Nigerian goat" Nigerian pig' White Fulani 1·luman'
cattle"
Na tmm ••I'11 96.85±1 0.29 (J 3) 142.60±6.45 (10) I38.76±9.7 I 85.75±1.84 134.80±19.00 DO.OO±5.20
(70) (270) (147) (948)
K(mmoVI) 5.47±O.52 5.60±O.95 4.44±O.49 33.70±.1.11 4.47±0.80 (147) 3.50±0.80
(14) (10) (70) (270) (963)
Cl(mmoVI) 81.14±4.91 105.10±.1.38 101.79±6.70 NO 102.37±13.70 92.00±7.80
(14) (10) (70) (147) (951 )
HC~ 10.43±O.76 2J.10±2.13 ND NO NO 21.00±3.70
(mmoVl) (14) (10) (922)
Ca(mgldl) 2.72±O.61 8.J8±O.13 9.57±J.51 25.93±O.98 9.81±1.52 NO
(14) (10) (70) (270) (147)
ALP (i.ull) 107.79±18.38 51.30±5.44 34.51 ±42.29 59.94±2.45 NO NO
(14) (10) (70) (270)
GOT (i.ull) 26.36±8.74 48.10±18.56 52.84±19.84 NO NO NO
(14) (10) (70)
GPT(i.uIJ) 15.57±7.64 27.80±14.52 11.02±4.78 NO NO NO
(14) (10) (70)
Note: Number of animals in parentheses ND=No data
Sources: Oycwale, et al. (1998) "(OYEWALE et al., 1998) "COYEWALE et al., 1998) hCODUYE·and ADADEVOH. 1976)
C(ENDELEY,1979) (ODUYEand FASANMI, 1971) e(McFARLANE et al., 1970) .
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UNIVERSITY OF IBADAN LIBRARY
We also observed significantly lower total plasma protein
and urea levels in giant rats or pangolins than those in goats,
cattle, buffaloes and humans (table 21). This low urea level
could probably be due to low protein intake, as reflected in
the low total plasma protein levels of these non-domesticated
mammals, at least during the dry season (January) when the
study was conducted. It is postulated that some changes in the
selective action of the renal tubules in the control of urea
excretion might arise during periods of protein malnutrition,
or alternately that, when dietary protein intake is low, urea
may be utilized as a source of nitrogen in protein synthesis.
Our finding of low urea level in giant rats in the dry season
(November - March) was confirmed in another study
(Olayemi, Oyewale et al. 2001) in which we found a higher
urea level in the wet season (April - October). We also found
that giant rats have higher Hb, MCH, MCHC and total WBC
values, but lower MCV, Na, CI, Ca, creatinine and albumin
values in the wet season than in the dry season. However, the
RBC, PCV and K values did not exhibit seasonal variations.
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Table 21: Comparison of Plasma Protein and Metabolite Values (mean ± SD) in African Giant Rats,
Pangolins, Goats, Cattle, Humans and Buffaloes in the same Tropical Environment.
Africa giant rat" Pangolin" Nigerian White Fulani Human" Buffalo
goat' cattle" (Bas buba/is)'
-
Total protein (g1dl) S.84±O.31 S.96±O.S3 6.36±O.80 7.SS±2.S0 NO 8.80±O.66
(14) (10) (70) (I S I) (12)
Albumin (g1dl) 2.70±0.31 2.80±0.26 2.58±O.41 2.S6±1.04 ND 2.9S±O.26
(14) (10) (70) (lSI) (12)
Globulin (g1dl) 3.14±O.24 3.16±O.32 3.77±O.78 4.96±2.68 ND S.8S±O.S7
(14) (10) (70) (I SI) (12)
Albumin! 0.87±O.12 0.90±0.08 0.68 0.51 ND NO
Globulin ratio (14) (10) (70) (I S I)
Urea (mgldl) 11.71±2.30 16.40±3.89 44.07±10.8 ND 20.00±S.10 ND
(14) (10) 1(70) (1010)
Creatinine (mgldl) 0.S9±O.10 (14) 0.7S±O.11 ND ND ND ND
( 10)
Note: Number of animals in parentheses ND=No data
Sources: Oyewale, et aI. (1998)
'(OYEW ALE et al., 1998)
b(OYEWALE et al., 1997)
'(ODUYE and ADAOEVOH, 1976)
d(OOUYE and FASANMI, 1971)
'(McFARLANE et al., 1970)
f(OLUSANYA et al., 1976)
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UNIVERSITY OF IBADAN LIBRARY
Osmotic Behavior of Mammalian and Non-Mammalian
Erythrocytes
The osmotic fragility of erythrocytes refers to their quanti-
fiable resistance to haemolysis or rupture when exposed to
osmotic stress. Erythrocytes that are immersed in a hypotonic
salt (NaCl) solution take up water from the medium, swell,
and ultimately lyse when the suspending fluid is of sufficient
hypotonicity to cause an inflow in excess of what can be
accommodated by the red cells. This feature is one of the
defining characteristics of the erythrocyte and is well
documented in the human red cell. The osmotic fragility of an
individual's erythrocytes is often determined in the clinical
diagnostic identification of certain populations of abnormal
disease-related red cells, which manifest diminished capacity
to withstand hypotonic challenges. In humans, a classic
example is the recognition of microcytic, spherocytic red
cells in the blood of patients with hereditary spherocytosis
(familial haemolytic anaemia). Increased erythrocyte fragility
has also been found in dogs with immune-mediated
haemolytic anaemia, dyserythropoiesis and polyarthritis of
possible autoimmune origin as well as in cats with haemo-
bartonellosis, and in cattle with anasplasmosis (Schalm et al.
1975). In contrast, there is increased resistance to osmotic
lysis of erythrocytes from porphyric cows attributable to
presence of young erythrocytes with mitochondria.
Apart from human erythrocytes, the osmotic characteris-
tics of other mammalian and sub-mammalian erythrocytes are
imperfectly understood and, as would be anticipated, demon-
strate variation among different species. Among the factors
that have been cited as potentially influencing osmotic
fragility of mammalian and non-mammalian erythrocytes are
cell size, volume and form, age of erythrocytes, structure of
Hb molecule, viscoelastic properties of erythrocyte
membrane, presence or absence of a nucleus and temperature
and pH of the surrounding hypotonic medium (Perk et al.
1964; Oyewale 1994). Although the osmotic fragility of
erythrocytes of a given subject is correctly viewed as one of
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UNIVERSITY OF IBADAN LIBRARY
its quantifiable properties, evaluation as to which physiologic
function it reflects or has an impact upon is usually
incomplete. A significant, though detail-limited exception to
this observation, are camel's erythrocytes, whose osmotic
capacity permits the animal to ingest huge volumes (about
100 liters) of water at a single standing without initiating
haemolysis in its resultant hypo osmotic plasma, which
would occur in equivalent circumstances in other animals
and man. We will examine the osmotic behavior of camel
erythrocytes later.
I have shown earlier in this lecture that the RBC, PCV
and Hb values in the domestic fowl differed between sexes
and breeds. In attempting to determine the effect of sex and
breed on the erythrocyte fragility, Oyewale and Durotoye
(1988) investigated the osmotic behavior of erythrocytes in
both sexes of the adult Nigerian fowl and adult Hubbard fowl.
A cumulative fragility curve was obtained by plotting the
percentage haemolysis against the NaCI concentration, while
the derivative fragility curve was obtained from the values of
percentage haemolysis by using the principle of 'haemolytic
increment' (Oyewale and Durotoye 1988). Our results
revealed that although differences existed between the two
breeds of domestic fowl (with erythrocytes of the Hubbard
fowl showing a greater osmotic challenge than those of
Nigerian fowl), erythrocytes from male fowls in both breeds
were more susceptible to osmotic lysis than those from
females (figs. 13a, band 14; Oyewale and Durotoye 1988).
We also observed in another study that domestic fowl
erythrocytes were more osmotically stable (or less fragile)
than those of guinea-fowl (Durotoye and Oyewale 1988). The
duck offered erythrocytes with osmotic characteristics almost
identical with those of the guinea-fowl, but more sensitive to
osmotic challenge than the domestic fowl (Oyewale and
Ajibade 1990b; fig. 15a). Analysis of the derivative
haemolysis curves (fig. 15b) revealed two or more haemolytic
peaks in the duck and guinea-fowl, indicating the presence of
more than one erythrocyte population in the blood (i.e. young
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UNIVERSITY OF IBADAN LIBRARY
and old erythrocyte populations), while in the domestic fowl,
a single major haemolytic peak was observed which indicated
a homogenous (or one) erythrocyte population, possibly
comprising of predominantly young erythrocytes. We
reasoned that the differences in osmotic fragility of erythro-
cytes between these avian species could be associated with
differences in the metabolic rates of the birds, since fragility
varies -with the age of erythrocyte, the old erythrocytes being
more fragile than the young erythrocytes (Perk et al. 1964),
and the proportion of erythrocytes of different ages in the
blood varies with the level of metabolic activity in the body
(March et al., 1966).
Fig. 13. Cumulative (A) and derivative (B) erythrocyte osmotic fragility
curves for (a) male (0---0, n = 13) and female (e_e, n = 13) Nigerian
fowls and (b) male (0---0, n = 8) and female (e_e, n = 12) Hubbard
fowls. (Oyewale and Durotoye 1988)
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UNIVERSITY OF IBADAN LIBRARY
~..
7u.:
20
~
0
.oJ
Fig. 14. Comparison of the cumulative (A) and derivative (B) erythrocyte
osmotic fragility curves for Hubbard fowls (0---0, n = 20) and
Nigerian fowls (e_e, n = 26). (Oyewale and Durotoye 1988)
100 £0
(b)
(n)
.0
o
oT 61- ~ 0" G', 6'. ~~ t1 ISI ~ -20 O. 0:7 0« iI$ o':r-rtro~J~O
nltCO<T ~ (H.OJ<lCE ftCC~' ~M C~l~
Fig. 15. Cumulative (a) and derivative (b) erythrocyte fragility curves for
ducks (e_e, n = 18) (Oyewale and Ajibade 1990b), domestic fowls
(e~ e, n = 26) (Oyewale and Durotoye 1988) and guinea-fowls (0---
0, n = 35) (Oyewale 1988).
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UNIVERSITY OF IBADAN LIBRARY
· Apart from the age of erythrocyte, we also investigated
the effect of age of bird on osmotic fragility of erythrocytes.
Our observations seemed to differ in different species of
birds. We found a higher fragility of erythrocytes in older
birds than in younger birds in domestic fowl (Azeez, Oyewale
and Okunola 2009) and guinea-fowl (Oyewale 1991a), but a
lower fragility in older birds than in younger birds in turkeys
(Oyewale and Ajibade 1990a). What is of particular interest
in these findings is the similarity of erythrocyte. sizes (i.e.
MeV) in birds of different age groups in each of the avian
species we studied (table 22). An initial obvious conclusion
that could be reached, in regard to at least these subjects, is
that the osmotic capacity is not determined by the size of the
erythrocytes. The issue of erythrocyte size and osmotic
fragility will be revisited later in this lecture.
Table 22: Mean Corpuscular Volume, MCV (± SD) in Birds of
Different Age Groups
Age (n) MeV (fJ)
Turkey" 6 - 8 weeks (14) 147.54 ± 12.71
20 - 22 weeks (28) 155.72 ±33.15
Guinea-fowl" 21 weeks (11) 152.31 ±5.98
156 weeks (9) 160.46 ± 10.96
Domestic fowl' 7 - 9 weeks (20) 145.74 ± 39.80
49 weeks (19) 127.00 ± 35.50
n =Number of birds
Sources: a Oyewale and Ajibade (1990a); b Oyewale (l991a);
C Azeez, Oyewale and Okunola (2009)
Poultry birds are good converters of feed into useable
protein in meat and eggs. The guinea-hen, unlike the domes-
tic hen, does not lay eggs throughout the year in our tropical
environment. I investigated the effect of egg laying on the
fragility of erythrocytes in the guinea-hen. My finding
showed that erythrocytes of the laying guinea-hen exhibited
higher osmotic fragility than those of the non-laying guinea-
hen (Oyewale 1990). This may be associated with the
increased blood level of oestrogen during the laying period,
which probably affects the lipid composition of erythrocyte
51
UNIVERSITY OF IBADAN LIBRARY
membrane through the levels of individual free fatty acids in
the blood.
Mr. Vice-Chancellor Sir, I have shown earlier in this
lecture that goats have the smallest erythrocyte size among
domestic animals and man, followed closely by sheep. I
found that goat erythrocytes exhibited greater osmotic
fragility (i.e. would lyse more easily) than sheep erythrocytes
(Oyewale 1991b, 1993). This is because an erythrocyte
absorbs water from the surrounding hypotonic solution and
swells until it reaches a maximum size, the 'critical
haemolytic volume', after which it will rupture. As expected,
the smaller the erythrocyte volume, as it is with the goat .
erythrocyte, the earlier the critical volume is reached and the
greater the osmotic fragility. However, I did not find any
significant relationship between osmotic fragility and
erythrocyte size. This suggests that the fragility of sheep and
goat erythrocytes may be related to some other feature, rather
than the cell size. For instance, goat erythrocytes are flat disc-
shaped instead of the biconcave shape of sheep erythrocytes. I
extended this study to a number of mammalian species and
found the order of decreasing erythrocyte osmotic fragility to
be: goat, sheep, pig, cattle, mouse, rabbit and rat (Oyewale
1993) (fig. 16). The species differences in the osmotic
fragility of these mammalian erythrocytes are attributable to
factors that vary between species such as the nature of the
erythro-cyte membrane or the physical and chemical
constitution of the cell.
We also found that even within the same animal species,
the erythrocyte fragility differs between breeds. For instance,
we observed that in cattle, erythrocytes of the N'dama breed
were more susceptible to osmotic lysis than those of the
White Fulani (Olayemi and Oyewale 2002) (fig. 17).
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• Goat (ru 111
• Pig tn.101
b Mouse (rh6)
'? Shup (n.12)
o Robbitln.71
100
• Rattnz9)
90
80
70
·'in"
}•'::-
60
E. SO
:0r: •40
~
3(]
20
10
, , , , I
()-O ()-1 0-2 0·3 D" O·S 0-9
"/. Nael
Fig. 16. Osmotic fragility of mammalian erythrocytes. Each point is the mean ±
SEM. Where vertical bars are absent, the SEM is less than the size of the
symbol.
100 "'=-if.,,----
90
80
;!! 70 1\
if) 60
i>n--' 50
.0:E ~o
«UJ 30:.r: 20
10
0 -~
0·0 0" 0·2 0'3 0'4 o-s 0·6 0'7
Noel -i;
Fig. 17. Erythrocyte osmotic fragility of White Fulani (open circles, n=28) and
N'dama (solid circles, n=24) cattle. Values are means ± SD. n=Number of
animals (After Olayemi and Oyewale 2002).
In a comparative evaluation of the osmotic fragility of
peafowl and pigeon erythrocytes, I found that erythrocytes of
the former were more sensitive to osmotic challenge than
those of the latter (Oyewale 1994). I also found that there was
53
UNIVERSITY OF IBADAN LIBRARY
a significant sex difference in the erythrocyte fragility of the
peafowl (with peacocks exhibiting greater fragility than
peahens), but not in the pigeon. I observed further that lizard
erythrocytes were less susceptible to osmotic lysis than. toad
erythrocytes (Oyewale 1994). The differences found in
osmotic fragility between pigeon and peafowl erythrocytes
and between lizard and toad erythrocytes, which are all
nucleated could, as observed with non-nucleated mammalian
erythrocytes, be due to the nature of the cell membrane of the
different species.
We observed changes in the osmotic fragility of
erythrocytes during variation in temperature and pH of the
surrounding hypotonic environment. These changes differed
between animal species. However, the limitation of time
would only allow me to review a very small fraction of our
findings on osmotic behaviour of erythrocytes that are related
to temperature variation. We observed that, similar to human
erythrocytes (Murphy 1967; Aloni et al. 1977), the osmotic
fragility decreased at elevated temperatures with rat (fig.
18a), rabbit (fig. 18b), cattle (fig. 18c), pig (fig. 18d), sheep
(fig. 18e) goat (fig. 18f) and donkey erythrocytes (Oyewale
1991b; 1992a; Oyewale, et al. 2011). In contrast, we found
that camel erythrocytes exhibited increased fragility at
elevated temperatures (fig. 19) (Oyewale et al. 2011).
_-___ Ie •.•. ••-.- -- ,...,~.-...
(H) Rat
-00
;tt ·.0-L-· (I» Rabbit
'~il .•.•.- .....
•
.~. ,. ••... -.- ">10--';.
54
UNIVERSITY OF IBADAN LIBRARY
"•'"..
00
i .0..
,,,
•.•.
•
(". Pig -tV· .._"..,_.,_.".~x ._.•••_•• :•t ••.•..••. •
,.
to
o •......,..,,. ....-......0.-. ,. _ ::'·_~_·-z~••••• v •• __
., O. •• ~. •• 0' •
.."
.,.e. ,...
;!
j (,.) Sheep.....
...
i:.. :j •..•.,
Fig. 18. Osmotic fragility of erythrocytes of (a) rats; and (b) rabbits; (c) cattle (n
= 8); (d) pigs (n = 10); (e) sheep (n = 10); and (0 goats (n = 8) at pH 7.7
and \0 DC.29°C and 45 Dc. Each point is the mean ± SD for 6 animals.
S5
UNIVERSITY OF IBADAN LIBRARY
'2(')
.00
~. ,,0
<> (>Q
•,.~.• "'04/:Q
" !
- Non.
120
'00
•0.• (b) Camelt ao-~ "0200 ••• ••00 01'
...<.NuC.
Fig. 19. Changes in osmotic fragility of erythrocytes of (a) donkeys (n = 8) and
(b) camels (n = 10) at pH 7.4 and 4°C and 28 Dc. Each point is the mean ±
SEM. Where vertical bars are absent. the SEM is less than the size of the
symbol (After Oyewale, et al. 2011).
The above findings with mammalian erythrocytes, which
are non-nucleated (see fig. 20a), are not too different from our
observations with some avian, reptilian and amphibian
erythrocytes, which are nucleated (see fig. 20b).
(a) (b)
Fig. 20. Blood smears showing (a) non-nucleated mammalian erythrocytes from
sheep and (b) nucleated non-mammalian erythrocytes from domestic fowl.
For instance, we observed that at elevated temperatures,
the osmotic fragility of domestic fowl, guinea-fowl, pigeon,
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UNIVERSITY OF IBADAN LIBRARY
lizard, and toad erythrocytes decreased (Oyewale, 1992b,
1994) (fig. 21), while that of the peafowl and duck increased
(Oyewale 1994; Oyewale, Sanni and Ajibade 1991) (fig. 22).
Since duck and peafowl erythrocytes, like erythrocytes of
domestic fowls, guinea-fowls, pigeons, lizards and toads, are
nucleated, and camel erythrocytes, like those of cattle, pigs,
rats, rabbits and donkeys, are not nucleated, it may be
concluded that the differences in osmotic behaviour during
temperature changes are not related to the presence or
absence of a nucleus. Aloni et al. (1977) have shown that
lipids and proteins of the erythrocyte membrane are the sites
for the effect of temperature on osmotic fragility. The
differences between species in osmotic behaviour with
respect to temperature changes, therefore, may be related to
the structural features of the erythrocyte membrane. For
instance, camel erythrocyte membrane differs from that of
humans in having higher protein to lipid ratios and also in
exhibiting some differences in amino acid composition
(Livine and Kuiper 1973).
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UNIVERSITY OF IBADAN LIBRARY
-',-"" -...•._.--
"1~ __ 100·"1(O,. 'l '1 z: :r" -.~~\~ • ..• .,.0""("
•.e. .
!h I \\'\ .~..,
(-.--: t\O •
'OJ \\\ ~ :: (c) PigOO"'~\~. w· \\\ ;;-! .)0
.r ~~. (a) Domestic \\~
20
19j fowl V~ . ~"'''-'::':':!:'-'::';-.(,'c -~'.- \>>-;- -o"T -,,'-;;-- -;;:-:::--11: _:_f!l:"- o ill
-~-;'--'O:-;-'~o-:-JO~;---;G~-O:1--o~e----;-;-
~~~=CIoo'owN=NaC3 ?,~_~ '.:n: ff -e. ~~" ...• , .. :",. ~~~~~,~ ••._ •• 1(1·(''001 _,.()"'C
.;>.
"i".: §~] (l g .: fb) Guinea- ~, t; ,..., t d ~,,~s: T on (d) Lizar \" o ,'" . o<!fowl 1~ 0<
:: t 'h" i-:'~ _~.._o2'0o0' 0'. ~.0--"0 0'6 0'-.7 0:" o·~
0'1 '---- z;;-- -'-'- :~:;:-'- a. - 0'~" ---u'; . • .,"- {I-~o 0.2 0'3 %w/vN,.CI r~-, '/. tIc C.I
Fig. 21. Osmotic fragility of erythrocytes of (a) Osmotic fragility of erythrocytes of (c)
domestic fowls and (b) guinea-fowls at pH 7.7 pigeons (n = 8) and (d) lizards (n = 8) at pH
and 10°C (Ll), 29°C (.) and 45°C (0). Each 7.6 and 10 °c and 30°C. Each point isthe mean
point is the mean ± SD for 8 birds. Where ± SEM. Where vertical bars are absent, the
vertical bars are absent, the SD is less than the SEM is less than the size of the symbol.
size of the symbol.
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UNIVERSITY OF IBADAN LIBRARY
----.:::::. ~~ __ <)to'"C'~~ .• _:1~
"
'~1,:.: (a) Toad ~
;~ )It
.
.:.--'0 -~-~. •".. ..v,- •.."~'-::'::"C:~.";:'::.=f.~--'"No; CI ~ F--K, 'i I ; I ."'~"C,.,."....,
.,~ ~~--i--..... '{1\Jl/ \ I
~~ '
u
,."','.'1''''''--'-''
..'<, "'-1.._
" r-'-~._.--t--- ..~- :~ (0) Duck 1\\(r \1f1 '
:; ; "'-..
~.. "f (b) Peafowl ~'-;'''_._. ~"--1-J '\ ;.\ II,~. ".•••••~~.,..•I. \.~C"~h~~e~e -C1----. -~eLl---;J-'40---O~"'--<.'.""--'"--- --,~ ~----.. ~---.0... 0-,. ~, IH ~,) 0-, t.-\. iI-f, O'l (i. I M'Z~ ~1
•.1. N~ Ct y. ><0(1
Fig. 22. Osmotic fragility of erythrocytes of (a) (c) Effect of temperature on osmotic fragility of
toads (n = 6) and (b) peafowls (n = 8) at pH 7.6 duck erythrocytes at pH 7.7. Each point is the
and 10 !Ie and 30 0e. Each point is the mean ± mean ± SD for 8 birds (After Oycwale, 1991).
SEM. Where vertical bars are absent, the SEM
is less than the size of the symbol.
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UNIVERSITY OF IBADAN LIBRARY
What do all these findings signify? Where temperature of
blood is elevated, for instance, by activities of blood parasites
or other infections, cattle, sheep, goat, donkey, pig, domestic
fowl or pigeon erythrocytes are less susceptible to osmotic
lysis (or rupturing) than those of the camel, duck or peafowl.
Whereas, this observation may be true for erythrocytes of the
duck, peafowl, cattle, donkey and other animals, it is,doubtful
whether this can be so with the camelerythrocytewhich is
capable of swelling to twice its original volume without
rupturing in hypotonic solutions (Perk 1966). This and other
characteristics+such as resistance to lytic effect of snake
venom and resistance to sonic haemolysis (Condrea et al.
1964) indicate some unusual properties of camel erythrocyte
membrane. Ralston (1975) has shown that the major proteins
of camel erythrocyte membrane are similarto ,those of cattle
and man with the major difference being the major membrane
protein 'spectrin' ,which appears to be very tightly bound to
the camel erythrocyte membrane. Concurrent with the total
release of spectrin, camel erythrocytes ,undergo a change in
shape from ellipsoid to spherical, suggesting an important
shape-maintaining role of spectrin in the erythrocytes of the
camel. It is therefore not surprising that, in collaboration with
Prof. Joseph Ayo of the Department of Veterinary Physiology
and Pharmacology, Ahmadu Bello University, Zaria, we
observed that erythrocytes of the camel '(fig. 23) demonstra-
ted considerable resistance to osmotic lysis than those of the
donkey (fig. 24) as shown in figure 25 (Oyewale et al. 2011).
Camel erythrocytes have also been shown elsewhere to be
more resistant to osmotic lysis (or less fragile) than those of
man, cattle, rat, rabbit, sheep, goat, pig, horse and domestic
fowl (Perk et al. 1964; Livine and Kuiper 1973; Al-Qarawi
and Mousa 2004).
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Fig. 23. Adult one-humped camels (Camelus dromedaries) along Kano-Zaria .
road.
Fig. 24. Adult Nubian donkeys (Equus asinus) ..
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12D
100
-+- Camel(n=17)
~ Donkey (n=22)
20
o +-~=T~~r-~~--~~--~--~
0.9 0.7 0.5 0.3 0.1 0
% NaCI
Fig. 25. Comparison of osmotic fragility of camel and donkey erythrocytes. Each
point is the mean ± SEM. n=Number of animals (After Oyewale et al. 2011).
Haematological Changes after Blood Loss
Blood loss (haemorrhage) follows traumatic injuries in man
and animals. As part of efforts to evaluate the physiological
responses of animals to various stress factors in our labora-
tory, Oyewale, Okewunmi and Olayemi(1997) investigated
the haematological changes in the healthy adult female WAD
goats during the first 24 hrs following acute blood loss. Thirty
percent of the calculated blood volume of the goat (Makinde,
Durotoye and Oyewale 1983) was removed through the
jugular vein. We found a significant decrease in Hb con-
centration at the end of blood withdrawal in our WAD goats.
We also observed significant decreases in RBC, PCV and Hb
values 4 or 24hrs after haemorrhage in the goat (table 23),
which are in agreement with similar findings in the horse
(Torten and Schalm 1964). The observations are due to
movement of intestinal fluid into the vascular system to
replace fluid volume lost through haemorrhage (Torten and
Schalm 1964; Schalm et al. 1975). The decrease in Hb value
of the goat after 24 hrs causes the decrease seen in the MCHC
value (see table 24). However, we found increases in the total
WBC counts 4 and 24 hrs after haemorrhage in the goat due
to increases in the number of circulating neutrophils and
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eosinophils. The lymphocyte, monocyte and basophil counts
were not altered by blood loss (see fig. 26a-d). Our observa-
tion suggests that following an acute blood loss in goats, an
increase in total white blood cells in peripheral circulation
(i.e. leucocytosis) should be anticipated. This should not be
interpreted as evidence of an infectious process. We also
found significant increases in neutrophil and eosinophil
counts r hr after bleeding in our goats (fig. 26b and c) which
are probably due to mobilization of marginated white blood
cells that adhere to the walls of blood vessels.
From these results, it appears the WAD goats can
withstand an abrupt loss of one-third of the circulating blood
volume without exhibiting serious signs of distress.
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Table 24: Changes in Haematological Values (mean ± SD) of West African Dwarf Goats after Haemorrhage.
Parameters Pre-hacmorrhage Post hacmorrhage
Zero hr Ihr 4hr 24 hr
(8) (8) (8) (8) (8)
PCV (%) 24.63 ± 4.24 21.69 ± 4.20 20.13 ±4.36 17.56 ± 3.58* 18.63 ± 3.42*
Hb (gldl) 8.44 ± J .54 6.68 ± 1.57** 6.40 ±1.72** 6.15 ± J .95** 4.99 ± 1.23***
RBC (x 1012/L) 9.88 ± 2.32 8.64 ± J .22 8.06 ± 2.90 9.42 ± 4.26** 7.47 ± 1.73**
MCV (fJ) 25.47 ± 6.05 25.09 ± 2.81 27.24 ± 8.45 21.1 J ± 7.09 24.93 ± 5.3 J
MCH (pg) 8.79 ± 1.98 7.50 ± 0.87 8.52 ± 2.81 6.87 ± 2.53 6.08 ± J .38*
MCHC (g/dl) 34.28 ± 2.63 29.84 ± 3.73 3 J .67 ± 3.64 34.42 ± 5.25 26.67 ± 2. J 7***
Number of animals in parentheses.
Asterisks denote significant difference from pre-haemorrhage value: *:1'<0.0 I; **: 1'<0.05; ***: P<O.OOI.
Source: Oyewaie, Okewumi and OIaycmi (1997)
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UNIVERSITY OF IBADAN LIBRARY
t- (al ---- -!
o~·----~~----~----~~~·----~--~----~~.
,~ (~.•, '.._..t r-_.~",:),o•.,~,
~ .
l"""':-'(~/·:.r.""~~I<'~
r 'r"",-(0<04)'"~ ~~-''iI'_l»~'5 rt ~"_i_ ~.-_-(-d_)----- ..-•-•------ -+
~~----~----~;~----3~'----~~~----~~----~~~~4
Ttol9\o" ('H) PO'S, _Na:C'"ff'oOrl'hr.loljle
Fig. 26. Changes in (a) total WBC; (b) neutrophil counts; (c) eosinophil counts;
and (d) lymphocyte counts of the goat after haemorrhage. Each point is the
mean ± SD for 8 animals. Asterisk denotes significant difference from pre-
haemorrhage value (C): *: p< 0.05; **: p<O.OOl (After Oyewale, Okewumi
and Olayemi 1997).
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With the above results, we went further to investigate the
changes in haematological parameters of a non-mammalian
species, the domestic fowl, following removal of 30% of the
total blood volume (fig. 21a-f). This study was carried out in
order to determine whether (1) the haematological changes in:
the bird differed from those of mammals following acute
blood loss, and (2) whether the altered haematological
parameters returned to normalcy within a period of 10 weeks
post-haemorrhage. We found that the RBC, PCV, and Hb
values decreased 1Y2 hrs after haemorrhage, fluctuated and
returned to normal after 10 weeks (Oyewale, Olofintila and
Famakinde 1997) (fig. 27a-d). What is of significant interest
in this finding is the rapidity of the changes in RBC, PCV and
Hb values in the domestic fowl after haemorrhage which has
also been reported in the pigeon (Palmer et al. 1979).
The MCH increased 1Y2 hrs and 4 weeks after
haemorrhage in our domestic fowl (fig. 27d), but the MCV
was not altered by blood loss (fig. 27e). The MCHC was
normal immediately after haemorrhage, but decreased after 2
weeks and returned to normal level after 4 weeks, where it
remained till the tenth week (fig. 27f). Palmer et al. (1979)
however, found increases in Hb and MCHC values in the
pigeon 10 weeks after heamorrhage. This indicates that avian
species, at least domestic fowls and pigeons, differ in their
haematological responses several weeks after haemorrhage.
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UNIVERSITY OF IBADAN LIBRARY
--;- ··..r+- L--t--__+__ ._----0;;-1 '.0/
..• ._..- ~''-:.~.-.----W--t u------~;\"J
- . » , 4 ~•.••.••• C_C.M •• ~T_"- • ....oR.R-""O"'"
-, 'I ..•••.•fI~ 1 , .,.,. to.. '1t~ (WEEKS) PC)S1'_H•••F.....oARHAG!F.'~~~,. .. 1 ______.;.~ ~ ._.--+ 400
~~
»0
....
~ K. (b) 'i >00 t (el 1~=tfr-1~-----_ol}-+
.•·~s~, . 't--Z 3' 4 to
Ta•••E• (W'£EK$)P05T -HAE~R.A.HA.G£ 100
eo
"~5.' , 3 ! • . 'r-to
~'.$[;"~~ A- , ..,,,
"rIME (W'EEKS) POS1-HAEMORRHAGE
~ ~--.--lrl
:•z ~ .. '
(ct -~- :~ .- :0" f t<,
o "f-. If}.-+~ '.'~ ,-+ --- ._- ._-" .....••...........•~ 40 ,."..
1•••••• ; ; i : ' .~
TIME CW£EKSI posy" MAEMORRMACi£ •••••.•.•. '"... ~o
.,..1•...f•l:C..,..~K.-<to.) PO::;>T- •.••••
Fig. 1:7. Changes in (a) red blood cell (RBC) count; (b) packed cell volume (PCV); (c) haemoglobin (Hb) concentration; (d)
mean corpuscular haemoglobin (MCH); (e) mean corpuscular volume (MCV) and (I) mcan corpuscular haemoglobin
concentration (MCHC) of domestic fowl after haernorrhage, Each point is the mean ± SO for 9 birds, Asterisk denotes
significant difference from orc-haernorrhaze (N) value: *=P<O.OS (After Ovewalc, Olofintila and Famakindc 1997).
67
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Conclusions and Recommendations
Ladies and gentlemen, I have attempted to explain to you in
the last 50 minutes or more, the differences in the normal
blood parameters of different animal species. I have shown
that the normal values for haematological parameters and
plasma/serum electrolytes, enzymes and proteins differ
between cattle breeds in our environment and that in each
breed the values also differ with the system of animal
management. I have described to you the role of egg-laying in
domestic fowls and guinea-fowls and that of pregnancy and
lactation in sheep and goats causing changes in plasma
volume and total blood volume. I have shown that the blood
parameters of domestic fowls, ducks, turkeys and guinea-
fowls are altered by breed, sex, species, egg-laying and age. I
have also shown the differences between the blood values of
wild and domestic animals and birds. In addition, r have
described the differences between species in the osmotic
behaviour of mammalian, avian, reptilian and amphibian
erythrocytes and the influence of temperature of the surround-
ing hypotonic solution in causing alterations in the osmotic
fragility of erythrocytes. Furthermore, I have described the
haematological responses of the goat and the domestic fowl
following sudden blood loss. Above all, I have informed you
of my modest contribution to knowledge in all of these,
which have been targeted at highlighting the differences that
exist in the blood parameters of different animal species.
In the evaluation of the health and nutritional status of
animals, blood examination is an issue that has always been
given top priority. One of the measures that can be taken to
ensure proper interpretation of haematological and
plasma/serum biochemical data from animals includes
applying appropriate reference values for each animal breed
or species to minimize the effect of breed or species
differences. These r have provided in my extensive research
on blood values of various mammalian and non-mammalian
species. Other measures which should be taken into account
include the physiological variation in blood parameters
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UNIVERSITY OF IBADAN LIBRARY
(caused by age- and sex- related differences, pregnancy,
lactation and egg-laying) and the quality of the habitat or
environment where the animals are kept (i.e. feed availability,
rainfall, temperature and humidity variations).
I wish to stress at this point that basic science research by
its nature is driven by a sense of curiosity and looking for
fundamental and innate beauty in natural phenomena. Its
main motivation is to expand man's knowledge. In today's
world, basic science research is carried out in most top
universities at biotechnological and molecular biology levels.
However, Nigerian universities are left behind as a result of
lack of appropriate research equipment and facilities in
laboratories, dearth of research grants, low level of funding
by proprietors of universities (Federal and State Governments
and Private Institutions), limited access to Information
Communication Technology (lCT) infrastructure and equip-
ment, decaying and ageing facilities, incessant power
(electricity) outage, and lack of regular water supply. In order
to be listed among the top universities in the world, to which
our University aspires, institutions are ranked by a
combination of indicators of academic and research per-
formance including visible presence on the web, presence of
international staff and students, student-faculty ratio and
research citations. In the 2010 QS World University
Rankings, Harvard University was demoted to second place
by University of Cambridge, having topped the ranking every
year since 2004. In Africa, the only university among the top
200 is the University of Cape Town in South Africa which
ranked 161st. The University of The Witwatersrand,
Johannesburg, South Africa ranked 360th, while Cairo
University, Egypt ranked in the top 500. Sadly, no Nigerian
university ranked in the top 600 in the world. However,
several developmental and advancement programmes have
taken place in the last one decade in the University of Ibadan
to suggest that it will eventually emerge as one of Africa's
top universities. These include the visible transformation of
our teaching, research and learning environment and the
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remarkable achievements recorded through the MacArthur
Foundation Grants which have assisted in the areas of ICT,
staff training abroad and provision of a Central Multi-
disciplinary Research Laboratory. However, a lot more needs
to be done. Staff and student exchange programmes resulting
from local and international linkages with acclaimed
institutions should be further strengthened. The government
should increase the level of funding to universities. Adequate
provision for staff development programmes, such as short-
and medium-term training in international laboratories and
attendance at local and international conferences and
workshops for academic staff and technologists, should be
made and enforced.
In the past, our University Teaching and Research Farm
used to provide research materials for scientific investigations
in agriculture, veterinary medicine, medicine and other
disciplines. It also used to supply livestock products such as
milk, beef, pork, poultry and eggs to this community. Mr.
Vice-Chancellor Sir, the University should reactivate and
reorganize the farm which has been in a state of coma for the
past three decades. There is no doubt that your tenure will
forever be remembered and your name written in gold if the
farm can come alive again.
Acknowledgements
I give praise, honour and glory to Almighty God for making it
possible for me.to be where I am today and to be able to stand
before you to give this inaugural lecture. I thank my late
parents, Pa Julius Oyewale and Madam Sefania Obi Oyewale
for their wonderful support and upbringing. I appreciate my
lovely sisters and brothers and their spouses.
I thank Professor M. O. Olowookorun for being my M.Sc
and Ph.D supervisor and for his positive contribution, during
the preparation of this inaugural lecture. I am grateful to
members of the Committee for my Inaugural Lecture;
Professors S. O. Akpavie, B. O. Oke, A. O. Adeyefa, M. O.
Abatan and my former teachers, Professors V.D. Anosa and
R. O. A. Arowolo. I thank you all for making my problems
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your problems. I will like to show my appreciation to my very
good friend, who is more than a "blood brother" to me, Dr.
Adesoji A. Fasanmade, for numerous years of our interactions
and discussions which have been very rewarding. I am greatly
indebted to all teaching and non-teaching staff in my
Department. I have enjoyed your company. God bless you.
My.gratitude also goes to Professor Tunde Otesile and
Professor (Mrs) Morenike Dipeolu for inviting me to
University of Agriculture, Abeokuta as a Visiting Professor in
2008 - 2009. I thank all my postgraduate students for the
productive collaborations we have had together. I apologize
to those of you whose works were not mentioned in this
lecture. It is not because they are not worthy of being
mentioned, but time does not allow me to do so. Special
thanks to Drs. A. K. Akinloye and O. 1. Azeez, for their
support during the preparation of this lecture and for the
arrangement of the presentation.
Finally, I thank God for blessing me with a happy,
wonderful, loving and supportive family. Some members of
my family are here today, but most are living in other
countries of the world. I thank you for your love and
understanding.
. Mr. Vice-Chancellor, ladies and gentlemen, I thank you
all for listening. God bless you.
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BIODATAOF
PROFESSOR JOHNSON OLVWAYEMISI OYEWALE
Professor Johnson Oluwayemisi Oyewale was born in
Abeokuta on 23rd July, 1954. He attended Saint Peter's
College, Abeokuta for .his secondary education between
January, 1969 and June, 1973. In October, 1973, he was
admitted to read Veterinary Medicine at the Jos Campus of
the University of Ibadan. He was transferred to the Ibadan
Campus of the University in October, 1974 and graduated
with a DVM degree in 1979. He obtained a Master of Science
(M.Sc) degreein 1983 and a Ph.D in Veterinary Physiology
in 1988 from the University of Ibadan.
Professor Oyewale started his teaching career in
September, 1980 as Lecturer II in the Department of
Veterinary Physiology and Pharmacology (now Department
of Veterinary Physiology, Biochemistry and Pharmacology).
He rose through the ranks to become Lecturer I in 1984,
Senior Lecturer in 1988, Reader in 1994 and Professor in
October, 1998. He was a Visiting Senior Lecturer to
University of Maiduguri, from April to June, 1992 and a
Visiting Professor to Ahmadu Bello University, Zaria, from
November, 2006 to October, 2007. He was also a Visiting
Professor to University of Agriculture, Abeokuta, from June,
2008 to May, 2009.
He has supervised the research work of many post-
graduate and undergraduate students in the field of Veterinary
Haematology. He has over 50 journal articles published in
highly reputable peer-reviewed international journals based in
Great Britain, Germany, Croatia, the Netherlands, Nigeria,
Kenya, Russia, Pakistan and Israel, and has attended many
national and international conferences, seminars and
symposia where he presented a number of papers.
Professor Oyewale has held many administrative
positions at the University level. He has served as Acting
Head (1990 - 1992) and as the substantive Head of
Department of Veterinary Physiology and Pharmacology,
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University of Ibadan (2001 - 2004)'. He was Head of
Department of Veterinary Physiology and Pharmacology,
University of Agriculture, Abeokuta (2008 - 2009). He has
been a member of Senate of University ofIbadan since 1990;
Member, Central Appointments and Promotions Committee,
representing the Faculty of Veterinary Medicine, University
of Ibadan (2002 - 2004). He was a member of Senate,
Ahmadu Bello University, Zaria (2006 : 2007) and University
of Agriculture, Abeokuta (2008 - 2009), He -has been a
Consultant to the Veterinary Teaching Hospital; University of
Ibadan since 2001. He was a Consultant" at different times, to
the Veterinary Teaching Hospitals of Ahmadu Bello
University, Zaria (2006 - 2007) and University of
Agriculture, Abeokuta (2008 - 2009).. . "
He has served as External Examiner' and -Extemal
Assessor to University; of Nigeria; Nsukka, University of
Maiduguri, Ahmadu Bello University.i Zaria .and University
of Ghana, Legon; Member, National A:c~reditatibn Board of
Ghana Panel of Assessors for the Accreditation of Bachelor
Programme in Veterinary Medicine and Surgery at University
of Ghana, Legon and Kwame Nkrumah University of Science
and Technology, Kumasi, Ghana (2009). .
His membership of learned professional bodies include
the Nigerian Veterinary Medical Association, Physiological
Society of Nigeria, and African Association of Physiological
Sciences. He is a registered Veterinarian and a Fellow of
College of Veterinary Surgeons of Niger~a(FCVSN).
Professor Oyewale is happily married with children.
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