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THE COMPARATIVE HIS'lULOGY OF THE flCIN
OF HEREFORD AND ANGUS CATTLE

by
Steve Goldsberry

AN ABSTRACT

Submitted to the School of Graduate Studies of'Michigan
State University of Agriculture and Applied Science
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE

Department of Anatomy

Year 1955

Approved

 

STEVE GOLDSBE'RRY ABSTRACT 1

At the time of this investigation, there were few
available references concerned with the bovine skin. ‘Most
available information on skin structure dealt with the Skin
of the human species.

The animals for this study were secured from the Angus
and Hereford herd of the Animal Husbandry Department of
Michigan State University. Each breed consisted.of two non-
castrate males and two females from each of which twenty-
four skin specimens from representative body regions were
taken. The Skin specimens were fixed in ten percent forma-
lin, dehydrated in normal butyl alcohol and embedded in par-
affin. The sections were stained with hematoxylin and eosin
and weigert van Gieson connective stain. For the study of
epidermal pigmentation, sections were deparaffinized in
xylene and.mounted directly without further processing and
studied.microscopically under direct light. Hair density
‘was determined by microscopically counting the number of
hair roots in an area of one square centnneter of horizontal
sections. The thickness of the skin was determined by tak-
ing the average of measurements of five points selected in-
discriminately on vertical sections of Skin.

It was found that the skin consisted of two major divi-
sions, the epidermis and the corium (dermis). The epidermis

consisted of the stratum corneum, stratum lucidum, stratum

360533

STEVE GOLDSBERRY ABSTRACT 2

granulosum, stratum spongiosum.and the stratum cylindricum,
while the corium (dermis) consisted of a stratum papillare
and a stratum.reticulare. comparatively, the stratum core
neum was thicker in the Angus than in the Hereford, while
the stratum genuinetivum.vas thicker in the Hereford than
that of the Angus. When all of the strata of the epidennis
were considered collectively, there were no prominent sex or
breed differences.

In areas where the connective tissue of the stratum pa-
pillare was loosely arranged, fibrous processes extended
from.the basal epithelial layer into the adjacent papillary
layer, but this was not found in areas where the papillary
layer consisted of dense fibers.

In the stratum.papillare, the fibers were found to be
generally fine and loosely arranged, the papillary body was
well developed in areas where there was no hair or where the
hair was very thin.‘ The stratum reticulare consisted of
coarse collagenous fibers which were generally found to be
parallel to the skin surface and extended in all directions
in that plane. It was frequently observed that the capillary
plexuses, which were very prominent in the stratum papillare,
were embedded in very fine and loosely arranged networks of

connective tissue which contain large numbers of cells char-

acteristic of areolar tissue. In addition to this finding,

STEVE GOLDSBERRY ABSTRACT 5

many eosinophilic: cells were also seen. The thickness of
the dermis was greater in the Hereford than in the Angus
and also greater in the males than the females. The colla-
genous fibers of the Hereford ‘were generally thicker and
more densely arranged than those of the Angus. There were
no characteristic sex or breed differences found in the

glands of the Skin or in hair density.

'IHE COMPARATIVE HISTOLOGY OF THE SKIN
OF HEREFORD AND ANGUS CATTLE

by
Steve Goldsberry

A THESIS

Submitted to the School of Graduate Studies of’Michigan
State University of Agriculture and Applied Science
in partial fulfullment of the requirements
for the degree of

MASTER OF SCIENCE

Department of Anatomy
1955

”ft/éf/

Gazer

ACKNOWLEDGMENTS

The author wishes to express his sincere appreciation
to Dr. M. Lois Calhoun, Professor and Head of the Department
of Anatomy, under whose lofty inspiration and unfailing in-
terest this investigation was undertaken and to whom the re-
sults are dedicated. He is also deeply indebted to Mr.
Lyman Bratzler, Professor of Animal Husbandry for his aid in
securing animals for this investigation. Grateful acknowl-
edgments are due to Dr. Esther M. Smith for her help in tak-
ing the photographs, and to Dr. Leo W. Walker, M. D., and
staff of the Clinical Pathology Department of St. Lawrence
Hospital for their unusual cooperation and for the use of
equipment with which much of this investigation was done.
Thanks are also due to the faculty and staff of the Anatomy
Department and others who have been helpful in one way or

another.

TABLE OF CONTENTS

INTRODUCTION . . . . . . .
REVIEW OF LITERATURE . .
Epidemis . . . . . .
Dermis (Cerium) .l. . .
Hair . . . . . . . . . .

Skin Glands . . . . . . .
sebaceous Glands . . .
sweat Glands . . . . .

iMATERIALS AND METHODS . . .
Source of Animals . . . .
Techniques . . . . . . .

Selection and processing of

Stains O O O I O O O
Pigment Determination .
iHair Density .

. Skin Measurements . . .

RESULTS AND DISCUSSION . . .

Skin Thickness
Epidermis .
Stratum Corneum .
'Stratum Spongiosum. .

stratum Cylindricum . .

tissues

PAGE

<0 -q p a: r4

10
10
11
15
15
13
13
14
14
14
15
16
16
18
18
18

PAGE

Stratum Granulosum. . . . . . . . . . . . . . . . l9
Stratum.Lucidnm . . . . . . . . . . . . . . . . . 20
Epidermal Pigmentation . . . . . . . . . . . . . 21
Dermis (Cerium) . . . . . . . . . . . . . . . . . . 22
Stratum.Papillare . . . . . . . . . . . . . . . . 23
StratumReticulare............... 25
ElasticTissue................. 24
Hair . . . . . . . . . . . . . . . . . . . . . . . 25
Skin Glands . . . . . . . . . . . . . . . . . . . . 26
Sweet Glands . . . . . . . . . . . . . . . . . . ‘ 26
Sebaceous Glands . . . . . . . . . . . . . . . . 28
SUMMARY AND CONCLUSIONS . . . . . . . . . . . . . . . 48
LITERATURE CITED . . . . . . . . . . . . . . . . . . 51

iv

LIST OF TABLE

TABLE PAGE
1. ZMeasurements of Epidermal Thickness of Hereford
Cattle in Microns . . . . . . . . . . . . . . 50
2. IMeasurements of Epidermal Thickness of Angus
Cattle in Microns . . . . . . . . . . . . . . 31
3. Measurements of Dermal Thickness of Hereford
Cattle in Microns . . . . . . . . . . . . . . 52
4. Measurements of Dermal Thickness of Angus
Cattle in Microns . . . . . . . . . . . . . . 53
5. Measurements of Total Skin Thickness of Hereford
Cattle in'Microns . . . . . . . . . . . . . . 54
6. ‘Measurements of Total Skin Thickness of Angus
Cattle in Microns . . . . . . . . . . . . . . 35

'7.PigmentEvaluation............... 56

PLATE
I .

II.

III .

IV.

VII.

VIII .

LIST OF PLATES

Designation of Areas from Which Tissues
Were'I‘aken
Vertical Section through the Epidemis of the
Muzzle of Hereford Male . . . . . . . p. . .
Section from Ventral Abdomen Showing Fine
Elastic Fibers in Stratum Papillare . . . .
Cross Section through the Coiled Glands and
Large Excretory ducts of Muzzle . '. h. . . .
Vertical Section through the Stratum Papillare
Showing Follicular Folds . . . . . . . . . .
Vertical Section of Skin from the Achilles In-
sertion Showing Moderately Thick Epidemis
with an Occasional Granular Cell and Poorly
Developed Papillae . . . . . . . . . . . . .
Cross Section of Hair and Large Sebaceous
Glands of Perianal Skin . . . . . .' . . . .
Vertical Section of Hair Follicle Showing Hair
Root and Saccular Sweat Glands of Dorsal
Thorax Containing Granular Materials Which

Were Commonly Found in Sweat Glands . . . .

vi

PAGE

37

39

41

4:2

43

44

PLATE

PAGE
IX. Cross Section of Hair and Small Sebaceous
Glands Showing the Directional Arrangement
of‘Lobules . . . . . . . . . . . . . . . . . . 45
X. Vertical Section of Lateral Neck Region Showu
ing Coarse Elastic Fibers in the Deep Dermis . 46
XI. A.Diagrammatic Sketch of a Typical Vertical
Section Through the Hair Follicle and Glands
of the Skin . . . . . . . . . . 47

vii

INTEDIIICTION

At the time of this study, little of the available lit-
erature was concerned with bovine skin. This is a compara-
tive study of the microscopic characteristics and differ-
ences found in the structure of the skin of Hereford and
Angus cattle. Hereford and Angus cattle are important to
our economic well-being as sources of food and leather prod-
ucts. In the southwestern part of the United States, where
many of our best breeds are raised, fungal and other skin
diseases are often difficult to diagnose and control. The
author believes that if a good description of the normal
histology of the skin is available, it will be of definite
value to the pathologist and the veterinarian in diagnosing
conditions which are abnormal. It is also believed that a
similar description will be helpful to the leather indus-
tries in the selection of raw material. The author hopes
that this paper will serve as a reference to pathologists,
anatomists and the leather industries. It was with these

points in mind that this investigation was undertaken.

REVIEW OF LITERATURE

A careful search of the literature revealed that only a
small portion of the available information concerning skin
structure can be applied directly to the bovine skin.
mlenberger (1906), Sisson and Grossman (1955) , and Trent-
mann and Fiebiger (1952) gave detailed descriptions of bo-
vine skin in their books of gross and microscopic anatomy of
domestic animals. These authors agree that the skin is com-
posed of a superficial layer, the epidermis, and a deeper
layer, the dermis. They also stated that the skin of the ox
is thickest of all the domestic animals, and that it varies
in thickness with age, sex, breed and body location. It
was stated by Sisson and Grossman (1955) that the skin of
the forehead, neck, and tail root of the or is approximately
5 to 6 mm. in thickness, while that of the brisket measures
about 8 mm. Several investigators have made specific stud-
ies of the structure of bovine skin. Histological findings
of cow skin were reported by Trumbower (1904). Muto (1925),
in his study of the mammalian sweat glands, gave a brief
description of his findings in the ox. A comparative study
of the skin of oriental breeds and one western breed of

cattle was made by Yamane and 0110 (1956).

Yang (1952) published several papers on the histology
and histochemistry of the bovine skin. A detailed descrip-
tion of the dermis of cow skin was made by Dempsey (1948) .
The myoepithelial cells of bovine sweat glands were studied
by Yang and Goodall (1952) .

Additional searches of the literature have revealed
that many investigators have devoted their efforts to skin
structure of other species. Frisbees (1920) and 0dland
(1950) studied the attachment mechanism between the epider-
mis and the dermis of man. The afferent innervation of hu-
man skin was described by Kuntz and Hamilton (1958), while
Hass (1959) and Dick (1947) studied the elastic tissue of
the human skin. The mitotic rhythm of the epidermis of the
mouse was described by Cooper and Franklin (1940). The
physiological and pathological aspects of cornification in
the skin of man were described by Meirowsky and Behr (1948) ,
while N111 and Twitty (1950) discussed the embryonic origin of
melanophores in Triturus torosus. Webb and Calhoun (1954)
gave a detailed description of the microscopic anatomy of
the skin of mongrel dogs, while Wilcox (1950) described the
histology of the skin and hair of the chinchilla. Age
changes in the skin of Wistar Institute rats were observed
by Warren (1951). Woolard (1956, 1957) described the intra-
epidermal nerve endings and also the continuity in nerve fi-
bers. The function and structure of the dermis and epider-

mis were studied by Szodoray (1951).

In describing the origin of the skin, Arey (1950)
stated that the skin is of dual origin, the epidermis and
its appendages being derived from ectoderm, while the corium

(dermis) arises from mesoderm.
Epidemis

The epidermis is composed of stratified squamous epi-
thelium and is divided into two major segments. The outer
segnent is called the stratum corneum (horny layer) and the
inner segment is the stratum germinativum (Malpighian layer)
(Trautmann and Fiebiger, 1952) . According to Yamane and Ono
(1956) and Maximow and Bloom (1949) the epidermis varies
greatly in thickness. The thickest portion is always found
over those body surfaces which are often or persistently ex-
posed to physical influences, while the thinnest portions
occur in areas exposed comparatively little. Meirowsky and
Behr (1948) described the keratohyalin of the stratg gran-
u_:_l._o_sl__1m as being a prokeratin mich is later converted to
keratin. It was concluded by Ham (1955) that the true
process by which keratohylin granules of the stratum granu-
losum are converted to keratin is unknown.

The stratum germinativum (Malpighian layer). is the cel-
lular layer of the epidermis. It is divided into three lay-
ers which are determined by morphological cell types. The

superficial layer is the stratum granulosum, the intermedi-

5
ate layer is the stratum spongiosum (prickle layer) and the
deep layer is the stratum gylindricum (Trautmann and Fie-
biger, 1952; Stiles, 1952; and Ham, 1955). Cooper and
Franklin (1940) and Cowdry (1944), in describing the mitotic
characteristics of the epidermis, stated that the basal layer
is primarily regenerative in nature. Maximow and Bloom
(1949) quoted Thuringer as having found 88 percent of the
mitotic figures in the scalp and prepuce in layers other than
the stratum cylindricum, and only 12 percent in the basal
layer itself. Cooper and Franklin (1940) found that mitotic
figures are more prominent during periods of rest than dur-
ing periods of activity. This was based on the observations
that human skin is generally active during the night, while
nocturnal animals show epidermal activity during the day.

The color of the skin is modified by the presence of a
yellowish-brow pigment which is usually confined to the
cells of the epidermis. The quantity of the pignent varies
in different parts of the body and is increased in quantity
by ultra-violet light and sun rays. Both the nuclei and
the mitochondria are believed to take part in the formation
of melanin (Lambert, 1948). Nui and Twitty (1950) found
that in addition to originating from the neural crest,
chromatophores may be formed by macrophages, which engulf
melanin from degenerating cells and undergo transformation.

Strong (1927) found that when the pigment of the epidermis

6
is decreased, that of the dermis becomes increased. Meirow-
sky and Behr (1948) believed that melanin is formed in the
intranuclear vacuoles. Dukes (1947) stated that melanin is
a product of the action of tyrosine upon the melanoblast.
The presence of melanin in other cells is due to phagocytic
action of the individual cells. It was concluded by Maximow
and Bloom (1949) that melanoblasts are positive to the
"dope” reagent and chromatophores are negative to the same
reagent. Yang (1952), in a detailed study of the bovine
skin, perfected a technique by which the pigment may be
evaluated. It was further found that the pigmentation of
the skin is more likely to be influenced by exposure to the
sun, because the dorsal and lateral aspects are more heavily
pigmented than the ventral areas.

It is generally accepted that the basement membrane
separates the epidermis from the dermis, but its true mor-
phology has led to extensive debate. Herxheimer (1916)
stated that the basement membrane is associated with fine
cytoplasmic fibers which extend toward the dermis.

Frieboes (1920) found- that reticular fibers between the
dermis and epidermis terminate in blunt and bulbous endings.
After repeating the work of Herxheimer (1916) and Frieboes
(1920) , it was concluded by 0dland (1950) that cytoplasmic
processes of the basal epithelium fit into the spaces of the

reticular fibers of the subepithelial network. No true and-

ings of the fibers were observed. Robb-Smith (1946) and
Dick (1947) found that, in the human, the basement membrane
is primarily a reticulum. This conclusion was confirmed by

Dempsey (1948) .
Dermis (corium)

The corium or dermis lies directly beneath the epi-
dermis and consists of a superficial layer, the stratum pg-
pillare, and a deep layer, the stratum reticulare. The
stratum papillare is raised into numerous elevations which
penetrate the deep surface of the epidermis. The stratum
reticulare is composed of dense collagenous fibers with
which the finer elastic fibers are interwoven (Lambert,
1948). Dempsey (1948) found that the corium varies in
thickness but the stratum papillare (grain layers) remains
constant. She added that the stratum papillare contains a
dense network of elastic fibers, some of which form liga-
ments by which the arrector pillmuscles are attached.
Dempsey (1948) further stated that bundles of collagenous
fibers are bound by elastic and reticular rings (rings of
Henle) .

Dick (1947) found variations inthe elasticityofthe skin
according to sex, age, and body regions. Females were found
to have generally more elastin than males, and young speci-

men showed numerous fine fibers, while adults showed few-

er and coarser fibers. Dick (1947) also observed that al-
though the elastic network lies close under the epidermis,
there is no continuation of elastin across the basement mem-
brane. Lowery e331; (1941; described amethod by which elastic
and collagenous fibers of the skin may be measured. Yamane
and One (1956) observed that the papillary layer of the H01-
stein-Friesian is more highly developed than that of the
oriental breeds. It was also found that the occurence of
dermal papillae is determined by hair density. It was con-
cluded that the papillae decrease as the hair numbers in-
crease.

According to Trautmann and Fiebiger (1952), the subcutis
consists of loose collagenous trabeculae which contain many
elastic fibers and cross each other to form a meshwork. The
movability of the skin is determined by the elasticity of
these same fibers. Trautmann and Fiebiger (1952) added that
glands were observed in the subcutis which resemble those of
the external auditory meatus.

Trumbower (1904) found that the subcutaneous tissue of
cattle contains large quantities of fat. It was concluded
by Dempsey (1948) that fat is not readily stored in the skin
of the ex, and when present it appearsh) be restricted to the .

lumbar region.

Hair

According to Lambert (1948) hair is an outgrowth of the
skin which appears over the entire body surface. A typical
hair consists of a Shaft which is usually above the skin and
a root which is inserted into an obliquely arranged epithe-
lial tube, the hair follicle. The attached and of the hair
root is enlarged to form a bulb which is invaginated.by con-
nective tissue and capillaries that form the hair papillae.
Arey (1950) described the origin and embryonic development
of the hair. Yamane and Ono (1956) found difficulty in as-
tablishing sex differences based on hair density evaluations.
The hair of the forehead, neck and withers was usually of
greatest density, when contrasted with that of the extremi-
ties which was usually of least density. The hair density
of other areas was unpredictable. It was established, howb
ever, that there are marked differences in the hair counts
of oriental and western breeds.

Trautmann and Fiebiger (1952):made use of a technique
by which mammalian breedSImay be classified by study of the
hair morphology. It was observed by Wilcox (1950) that in
the skin of the chinchilla, the number of hairs in a given
cluster may be as high as 75, but there is always one ar-

rector pili muscle to each hair follicle.

10
Skin Glands

Sebaceous glands. Most authors agree that. the seba-

 

ceous glands are lobular outgrowths of the hair follicles
and are usually found in groups of two or more lobules which
open through small epithelial ducts into the hair follicles.
Trautmann and Fiebiger (1952) , Yamane and Ono (1956) , and
Sisson and Grossman (1955) all agreed that the sebaceous
glands vary in form according to hair density. Wherever the
hair is dense, the sebaceous glands are long and narrow
(neck region), and when the hair is sparse, the sebaceous
glands are spheroid. Sisson and Grossman (1955) found se-
baceous glands to be highly developed near the margins of
natural openings. It was discovered by Trumbcwer (1904)
that the margins of the claws of cattle are rich in highly
developed sebaceous glands. By use of special histo-chemical
techniques, Yang (1952) demonstrated the biochemical nature
of sebum.

Butcher and Parnell (1948) found that a local increase
of temperature is sufficient to increase the activity of the
sebaceous glands of the foreheadof man. The physiology
of the sebaceous glands of the hamster was studied by Mon-
tagna (1949). This study revealed that the sebaceous
glands of the adult male are more active than those of

the adult female. It was also found that sebaceous glands

ll
of castrates were poorly developed, but upon sufficient in-
,jection of androgen they developed to normal size.

Sweat glands. Ellenberger (1906) , Sisson and Grossman

 

(1955) and Trautmann and Fiebiger (1952) found that two
types of sweat glands exist in the skin of domestic animals.
In the horse, sheep, pig and cat, the sweat glands are
coiled. In the ox and dog they are generally saccular. In A
addition to the saccular form in the ox, Sissom and Grossman
(1955) found coiled forms in the muzzle, tips of the hooks,
flexures of the fetlcck and in the peri-anal skin. Yamane.
and Ono (1956) found that sweat glands of the Oriental
breeds of cattle are present in all parts of the body and
are always associated with hair follicles. The secretory
portions are usually deeper than the sebaceous glands. The
excretory ducts are of uniform size, lined with a double
layer of cuboidal epithelial cells which become stratified
squamous epithelium near the opening of the duct. It was
concluded that no sex differences were distinguishable.
Trumbcwer (1904) described the sweat glands of the ox as
small, red, coiled bodies in the subcutaneous fat whose
ducts extended the entire distance of the skin thickness and
opened on the surface of the epidermis. Bikes (1947) and
Marshall and Halnan (1948) agreed that the ox sweats mainly
from the nose and only with difficulty from other body areas.

Sisson and Grossman (1955) found that a well developed modi-

12
fication of the sweat glands is present in the connective
tissue of the muzzle. These are compound tubular glands ar-
ranged in lobules and associated by excretory ducts which
unite to form a single duct which always opens on the sur-
face of the muzzle. It was concluded by Yang and Goodall
(1952) that the sweat glands of the ox are lined with flat
epithelial cells. The nuclei of these cells are spherical
and the cell outlines are indistinct. The functional epi-
thelium.is enclosed by a layer of myo-epithelial cells

whose long axes are always parallel to the long axes of the

gland body.

MATERIALS AND METHODS
Source of Animals

The animals available for this study came from a herd
of Angus and Hereford cattle. Of each breed there were two
noncastrate males and two females, whose ages ranged from 14
to 21 months, except for one female Hereford of 56 months.
They were made available by the Animal Husbandry Department
of Michigan State University. These animals were raised
under ideal nutritional and environmental conditions and ap-

peared to be in excellent condition.
Techniques

Selection and processing of tissues. Skin specimens of
about 5 centimeters square were taken from 24 body areas
(Plate I) of freshly slaughtered animals and fixed in 10
percent formalin for 2 to 5 days, after which pieces of
skin 2 x 6 mm. for vertical sections and 10 x 10 mm. for
horizontal sections were dehydrated in four changes of nor-
mal butyl alcohol. The first three changes were for 6 hours
each and the fourth change was from_18 to 24 hours. They
were subsequently cleared in xylene for approximately 5
hours prior to infiltration with 5 changes of equal parts of
54° C. and 56° C. paraffin for 56 hours, and embedded in

l4
Tissuemat.* Vertical sections were cut at 10 to 12 microns
and horizontal sections were out at 8 to 10 microns.

Stains. Harris' hematoxylin and eosin was used as a
routine stain on all sections. Weigert and Van Gieson's
stain for elastic and collagenous tissues was used on all
vertical sections.

Pigment determination. Pigment values were determined
by a slight modification of Yang's (1952) method. Sections
were deparaffinized in 2 changes of xylene for approximately
2 minutes each and.mounted without staining. Pigment was

classified by the following standards:

0 = absence of pigment

1+ : small patches (minhmal amounts)

2+ = continuous bands with heavier patches

5+ : moderately heavy and involving several layers
of epithelium

4+ = very dense, obstruction of cell outline (maxh

imal amounts)
Color of the pigment granules was not used as an evaluating
factor because of specific breed differences.

Hair density. In order to determine hair density, sev-

 

eral improvisations were made. On a thin glass slide an
area of l centimeter square was marked.with a glass marking
pencil, and divided into four equal segments. The four di-
visions were counted separately and totaled. The average

was taken as the number of hairs per square centimeter of

*Fisher Scientific Company, Pittsburgh, Pennsylvania.

15
skin surface. In order to make counting easier the field of
vision was reduced to the desired size by inserting a small
plastic window into the eyepiece.

Skin thickness. The thickness of the skin was deter-

 

mined by measuring vertical sections of skin from the outer-
most to the deepest border. By use of an ocular micrometer,
measurements were taken at five points which were selected
indiscriminately. The average was taken as the skin thick-
ness. For measuring thick objects, the 16 mm. objective was

used and for small structures, the 4 mm. objective was used.

RESULTS AND DISCUSSION
Skin Thickness

The thickness of the skin varies greatly with bread,
sex and body region. This study of skin thickness revealed
that breed differences were very pronounced in the stratum
.corneum, stratum geminativum, dermis and. total skin. The
stratum corneum was thickest in the Angus, with measurements
ranging from 8 to 80 microns with an average of 25 microns,
while the same layer in the Hereford varied from 8 to 71 mi-
crons with an average of 16 microns. The stratum germina-
tivum was thickest in the Hereford; these values ranged from
26 to 900 microns with an average of 86 microns, while the
comparative values in the Angus varied between 19 and 1,000
microns and averaged 81 microns. A few minor differences
were found in total epidemis, but they were not significant
in comparing breeds and sexes (Tables 1 and 2)..

The dermal thickness varied extensively with sex,
breed and body location. A comparison of sexes revealed
that the Angus male had a dermal measurement of 5,151 mi-
crons, while the female dermis measured only 4,605 microns.
In the Hereford, the male and female averages were 6,059 mi-

crons and 5,758 microns respectively. The total breed

l7
thickness of the dermis in the Hereford was 5,908 and that
of the Angus was 4,605 microns (Tables 5 and 4).

The total skin thickness of the Hereford males and fe-
males was practically equal in all areas included in this
study with respective measurements of 6,081 and 5,944 mi-
crons. The Angus males showed a slight but persistent
thickness advantage in sixteen of the twenty body areas in-
cluded in this study; they were of greater thickness in the
male than the female and showed a comparative average of
5,115 and 4,660 microns, respectively. A comparison of the
total skin showed that a pronounced breed difference was
evident. Of the twenty body areas studied, the Hereford
skin thickness was greatest in all except the tail root and
the forehead (Tables 5 and 6). The total skin average for
the Hereford was 6,012 microns, while that of the Angus was
4,887 microns. According to the findings in this study, it
may be generally stated that the thickest epidermis is found
in the muzzle. The stratum corneum was thickest in the
Angus breed and also was usually of increased thickness
where the stratum germinativum was thinnest. I Skin from the
head, neck, brisket and tail root was usually thickest in
both breeds and sexes, while the thinnest skin was generally

found in the axillary and ventral abdominal regions.

18
Epidemis

In both the Angus and the Hereford breeds, the epider-
mis consisted generally of stratified squamous epithelium,
of which two layers were easily recognized. The superficial
layer was the stratum corneum and the deeper layer the
stratum germinativum (Plate II).

Stratum corneum. The stratum corneum usually consisted
of a layer of cornified cells, but occasionally in thick
layers some cells were still undergoing parakeratosis.. The
stratum corneum was comparatively thicker in the Angus than
in the Hereford, but no sex differences were noticeable.

Stratum spongiosum. The stratum spongiosum consisted
of several layers of polygonal cells which lay between the
stratum corneum and the stratum cylindricum (Plate II). The
cytoplasmic processes and the inter-cellular bridges which
are usually described in the prickle layer were prominent
only in those areas where there were five or more rows of
cells in this layer. In the Angus the stratum spongiosum
was poorly developed and in most areas it consisted of from
three to six layers of cells (Plate VI) . The same layer in
the Hereford was more pronounced than that of the Angus and
generally consisted of from six to twelve layers in which

the inter-cellular bridges and the cytoplasmic fibrils were

easily demonstrated .

l9

Stratum cylindricum. The stratum cylindricum of both
breeds consisted of a single layer of columnar epithelial
cells that varied in height with epidermal thickness. These
cells were tallest in thick epidermis and when the epidermis
consisted of only two or three rows of cells, the cylindri-
cal cells were low columnar. The Hereford was usually
found to have taller cells in the basal layer than the Angus,
but this is believed to be a characteristic of epidermal
thickness and not a breed difference. This conclusion is
supported by the fact that similar cell types were found in
all areas of similar epidermal thickness without regard to
sex or breed. The basal cells of both breeds were found to
have numerous cytoplasmic processes which extended into the
adjacent tissues of the dermis in areas where the dermal
fibers were fine and loosely arranged, but this was not gen-
erally true in areas where the subepithelial fibers were
dense and coarse.

Stratum granulosum. The stratum granulosum was poorly
developed in almost all areas studied in both sexes and
breads. In most areas, the stratum granulosum was repre—
sented by an occasional cell, whose nucleus was undergoing
karolysis while the cytoplasm contained dark staining gran-
ules. These cells were usually found at the border between
the stratum corneum and the stratum spongiosum. In the fet-

lock, where the epidermis was fairly thick, there were two

20
rows of granular cells, but in the muzzle where the epider-
mis was extremely thick, there were only a few of these
cells found.

Stratum lucidum. The stratum lucidum was occasionally
present in areas where the epidermis was moderately thick.
It was absent in the muzzle, the:margins of the hoof and
horns, and perianal skin (Plate II). This layer was found
in the tips of the hooks and the upper legs. There was
little suggestion of the stratum lucidum.in other body areas.
The stratum lucidum, when present, was located on the lower
border of the stratum corneum, which was adjacent to the
superficial cellular layer of the epidermis. These findings
were fairly constant in both sexes and breads.

Although there were sex and breed differences in sep-
arate layers of the epidermis, the total averages were ap-
proximately the same without regard to sex or breed differs
ences (Tablesl.and 2). The epidermis was thickest in the
muzzle of all animals studied and measured approximately 900
‘microns (Plate II). It was uniform in thickness over the
entire surface, except for the papillary pegs, and became
thin abruptly at the margin of the hairy skin. In addition
to the epidermis of the muzzle, the thickest epidermis was
found to lie over areas where the total skin was thinnest,

such as the lumbar and the ventral abdominal regions.

21

Mitotic figures were seldom encountered in either the
Hereford or the Angus breeds.

Epidemal. pigmta’tinn. This Study revealed a distinct
breed difference between the Hereford and the Angus, but
there were no sex differences found. In the Angus, the epi-
dermal pigment was found without exception as fine black
granules without regard to pigment density, while that of
the Hereford was always found to be a variety of brown, even
in the areas of greatest density. Because of the color dif-
ferences of the pigment, it was necessary to modify the:meth-
ed of Yang, S. H.. (1952) who used color, density, and number
of infiltrated epidermal layers as determining factors. In
this comparative study of epidennal pigmentation in the
Hereford and Angus, color of pigment granules was not con-
isdered. Areas which contained no pigment were designated
"0”, while those which contained pigment were evaluated from
1+ to 4+ with the maximum being 4+ and lesser quantities the
corresponding numbers. In the Angus, the hair coat is
grossly black over the entire surface of the body, but mi-
croscopically the epidermal pigment varied with general body
location. By taking an average of pigment values according
to body regions, it was found that the dorsal aspects, and
the muzzle and hoof margin,contained pigment values of 3+,
and the lateral aspects and extremities 2+, while the ventral

areas contained average values of 1+. A shuilar study of the

 

.w

22
Hereford showed that the epidermal pigment was influenced by
body region and gross color of the hair coat. In areas
where the hair coat was white, the underlying skin was gen-
erally free of pigment, without regard to body location, but
in areas where the hair coat was red, pignent was generally
present, but varied with body region. The dorsal and later-
al areas and the extremities contained quantities which va-
riedfrom 1+ to 3+, while those of the ventral surfaces were
generally free from pigment (Table '7) . According to find-
ings in this study, it may be generally stated that epi-
dermal pignentation was primarily influenced by the gross
color of the hair coat, and secondarily by exposure to sun-
light. Pigmentation of the skin which underlay the borders

of red and white hair in the Hereford was found to be unpre-
dictable.

Dermi s ( Co rium)

The dermis (corium) is the thickest portion of the to-
tal skin and lies directly beneath and adjacent to the epi--
dermis (Plate VI) . This part of the skin is divided into
two layers; the superficial is the stratum papillare and the

 

deep layer is the stratum reticulare. In many of the body
areas of the animals investigated, these layers fused in
such manner that their exact borders were indistinct. For

this reason comparative measurements were not taken.

23

Stratum.papillare. In the stratum.papillare, the con-
nective tissue fibers were usually fine and loosely arranged
and the collagenous fibers were coarser than other fiber
types. They were arranged between and at vertical angles
with the hair follicles, but generally parallel to the epi-
dermis (Plate IX) . One of the prominent and characteristic
structures of the stratum.papillare was the papillary body
which, when present, lay adjacent to and invaginated the
basal layer of the epidermis. In both breeds and sexes, it
was most highly developed in the muzzle (Plate II), the hoof
and horn margins, and the perianal akin. It was usually
more prominent where the hair was thin and decreased in fre-
quency of occurrence and in size as the hair density was in-
creased. In this study, the stratum papillare usually ex-
tended from the basal layer of the epidermis to the deepest
portion of the sweat gland, which was slightly deeper than
the papillae of the hair bulb.

Stratum reticulare. The stratum.reticulare, which was
the thicker of the two layers, consisted of collagenous fi-
bers Which were densely arranged with diameters about three
times the diameters of those in the stratum papillare.

These fibers were usually arranged in large bundles which
were generally parallel to the skin surface, extending in
all directions in that plane. On a few occasions smaller

fibers were found to extend toward the Skin surface; however,

24
this was not a characteristic finding. On several occasions
the stratum reticulare was found to be composed of large
bundles which were loosely arranged without any definite
pattern. This observation was not specific for any sex,
breed, or body area. In the perianal skin, the collagenous
bundles were arranged so that they extended in one general
direction and were parallel to the epidermis.

Elastic tissue. The elastic fibers of the corium were
very prominent in the stratum papillare, where they were very
fine and extended in all directions, forming a loosely ar-
ranged.network (Plate III). These fibers were observed to be

very dense in areas of the hair follicle where the arrectores

 

pilorum muscles were attached, but no definite attachments
between the elastic tissue and the muscles were found. In
the dermis the elastic fibers were in most cases associated
with blood vessels and nerve trunks. Capillary and nerve
plexuses were embedded in very fine fibrous networks, in
which large numbers of cell types which are characteristic
of areolar tissue were found (Plate III). These cells were
found in this connection.udthout exception, and were very
prominent in the stratum papillare. In addition to the
above-mentioned cell types, eosinophils were also very prom-
inent. Large, dense elastic fibers similar to those ob-
served in the dog by Webb and Calhoun (1954) were found in

the deepest portion of the dermis and were often associated

25
‘with the large nerve trunks and blood vessels (Plate X).
The collagenous fibers of the Hereford appeared to be slight-
ly coarser than those of the Angus, According to the re-
sults obtained from this study, the major Comparative breed
and sex difference in the dermis was the dermal thiCkness.
Fat was seldom observed in the areas studied, but when pres-
ent it was usually found in sections taken from the dewlap

and briSket.
Hair

The hair and hair follicle were morphologically similar
to the descriptions given by Trautmann and Fiebiger (1952).
In addition to their description of the hair follicle, the
author found a series of folds to exist in the middle third
of the hair follicle and slightly beneath the opening of
the sebaceous duct into the lumen of the hair follicle (Plates
V, VI, XI) . These folds were usually found in numbers which
varied from 10 to 25. They were not of uniform size and
shape, and extended horizontally into the lumen of the hair
follicle. The lengths of the folds ranged from 10 to 40 mi-
crons. They were present without exception. The true na-
ture and function of this structure were not determined.

The angles at which the hair penetrated the epidermis
‘Varied with body area. In anal skin, the angle was approx-

imately 90°, while in the upper foreleg the angle of pene-

26
tration was less than 450. The hair density determination
did not reveal characteristic sex or breed differences. The
average number of hairs per square centhneter was 1,536 for
the Angus:males and 1,508 for the Angus females, while the
similar values for the Hereford 'were 1,194 and 1,010.

In areas of the body where the hair coat was grossly
colored, pigment was prominent throughout the entire length.
of the hair root. The deep end of the hair follicle was
often found to serve as an anchorage for the arrectores pi-
lorum muscle which was usually attached to the side of the
hair follicle which formed the greatest angle with the basal
layer of the epidermis. In no case were the hair follicles

found to contain more than a single hair (Plate IX).
Skin Glands

Sweatpglands. The sweat glands of the Hereford and the

 

Angus breeds were similar to those described by Ellenberger
(1906), Sisson and Grossman (1955) and Yang, S. H. (1952)
for the ox. In this investigation, they were found in all
parts of the body of both sexes and breeds. Two general
types were recognized, a saccular and a loosely coiled type.
The coiled glands were found in the perianal skin, the fet-
lock and tips of the hook. Occasionally the glands at the
Inargin of the hooves and horns were coiled. The epithelium

Of‘the coiled glands was low columnar, in contrast to the

27
flat cells of the saccular types (Plate VIII). Both types
of glands were usually located at a depth which approximated
'that of the hair bulb. They became narrow at the lower lev-
el of the hair follicle to form the excretory duct which
consists of two layers of low epithelial cells. The sweat
duct extends toward the surface in a course which is paral-
lel to the hair follicle and usually passes between the lob-
ules of the sebaceous gland (Plate VII) to open into the
hair follicle near the surface of the Skin.

The observation of the glands of the muzzle agrees fa-
vorably with those described by Sisson and Grossman (1953)
and Zimmerman (1954).

They were compound tubular glands which were found in
1arge,closely coiled masses or lobules which were located
deep in the subepidermal (dermal) tissue. The epithelium
of the secretory tubules varied from cuboidal to pyramidal
forms (Plate IV). The nuclei of these cells were located
near the basal end of the cell, and in those cells which
contain numerous granules, the nuclei appeared flattened.
Granules were usually not found in the cells of the excre-
tory ducts. These ducts,which were found among the tubules,
were easily distinguished by their columnar epithelium which
stained pink with henatoxylin and eosin.. The numerous small
ducts of each individual mass of lobules extended toward the

surface and united to form larger ducts.

28

The uniting of the analler ducts to form larger ones
was easily denonstrated by horizontal sections between the ’
gland masses and the epidermis (Plate IV). By similar sec-
tions the ducts were found to extend toward the surface
through the connective tissue between the papillary pegs of
the epidermis. A short distance from the periphery of the
gland masses the ”epithelium of the ducts was transformed to
stratified squamous epithelium, which contained a 4+ pigment
value (Plate IV) in all of the Angus cattle investigated.
The openings of the ducts on the surface of the muzzle were
seen grossly with the unaided eye and were found to number
from 5 to 12 per square centimeter.

The sweat glands showed no sex or breed differences,
but there was a noticeable breed characteristic in the large
excretory ducts of the muzzle. In all Angus cattle studied,
the ducts were heavily pigmented from the periphery of the
lobule to the basal layer of the epidermis, while pigment
was always absent in the same ducts of the Herefords. In neither
breed was pigment found within the periphery of the gland
masses themselves.

Sebaceous glands. The sebaceous glands observed in
this study were primarily lobulated and were found to vary
from two to approximately twenty lobules. They were usually
attached to the middle third of the hair follicle and lay in

the 811818 formed by the arrector pill muscle and the

29
hair follicle. In areas where the glands were highly devel-
oped, occasional branching of the excretory ducts was fre-
quently observed.

The cells, which were polygonal in type, showed early
degenerative changes in both the cytoplasm and nuclei. The
nuclei appeared shrunken and faded, while the cytoplasm con-
tained many granules of various sizes. These glands were
rarely found to have a lumenfhowever, when the lumen was
seen, it was usually near the area of the excretory duct and
contained a fine granular substance which showed no special
affinity for hematomlin and eosin.

The sebaceous glands of both breeds were found to be
arranged in a specific manner. Highly developed glands fre-
quently encircled the hair follicle, while those less devel-
oped were attached to the follicle so that all of the gland
bodies extended in a common direction (Plate IX).

The excretory ducts were usually short and were lined
with stratified squamous epithelium which extended from the
hair follicle. They were found to open into the hair fol-
licle at a point which was always deeper than the opening of
the sweat ducts. These findings were common to both breeds

.. and sexes studied in this experiment.

 

 

 

 

TABLE 1
MEASUREMENTS 0F EPIDERMAL 'HIICKNESS 0F HEREFORD CATTLE
IN MICRONS
mam“? ‘ Female
Location
0 F ' Av. C E Av.
Forehead 54 66 60 .0 61 54 5'7 . 5
Dorsal neck 64 42 55.0 '70 48 59.0
Dorsal thorax 49 '72 60.5 58 48 55.0
Dorsal lumbar 52 84 58.0 56 120 88.0
Tail root 4'7 56 41.5 68 60 64.0
Ventral dewlap 50 54 52.0 48 48 44.0
Ventral brisket 55 '78 66.5 '74 '72 75.0
Ventral abdomen '75 96 85.5 98 54 76.0
Ventral udder 4O 48 44.0 '70 48. 59.0
Ventral axilla 52 48 40.0 42 58 40.0
Ventral groin '75 56 54.5 ’71 72 71.5
Lateral neck 57 50 55.5 5'7 56 56.5
Lateral thorax 2'7 60 45.5 55 48 50.5
Lateral abdomen 55 48 40.5 55 '72 62.5
Gluteus ' 45 50 56.5 50 50 40.5
Upper foreleg 77 42 59.5 '26 66 46.0
Fetlo ck 51 66 58 . 5 100 42 71 .0
Upper hindleg 65 56 50.5 60 60 60.0
Lower hindleg 45 120 82.5 127 56. 81.5
Achilles insertion 46 24 55.0 220 ' 56 128.0
P erianum 48 64 56 .0 91 90 90 . 5
Muzzle 765 1,550 1,056.5 559 90 889 ._5__

\-—_—i— __:_

 

 

 

 

 

 

51

 

 

TABLE 2
MEASUREIENTS 0F EPIDEFMAL THICEGVESS 0F ANGUS CATTLE
IN MICRONS
W
Location Male Fmale

A D Av. G E AV-
Forehead 72 45 57.5 100 95 ‘ 97.5
Dorsal neck 24 45 54.5 50 57 55.5

Dorsal thorax 16 49 52.5 84 80 82

Dorsal lumbar 5'7 48 52.5 50 50 50

Tall root 115 59 87 66 52 59
ventral dewlap 55 5‘7 56 84 85 84.5

Ventral brisket 45 41 42 58 58 58
Ventral abdomen 48 51 59.5 144 105 125.5

Ventral udder 22 52 27 42 52 4'7
Ventral axilla 50 5O 40 126 145 155.5
Ventral groin 4'7 40 45.5 56 55 54.5
Lateral neck 29 55 51 158 '77 107.5
Lateral thorax 42 58 40 60 '70 65.0
Lateral abdomen 49 45 4'7 56 55 54.5

Gluteus 42 40 41 56 40 58
Upper foreleg 56 24 50 48 55 41.5
Fetlock 58 46 42 50 41 55.5

Upper hindleg 5O 54 52 42 42 42

Lower hindleg 49 50 59.5 42 42 42

Achilles insertion '76 52 64. 108 92 100

Perianum 280 65 172.5 72 76 74
Muzzle 1,650 975 1,511.5 1,100 1,107 1,105.5

 

 

WW

52

 

 

 

 

 

 

TABLE 5
MEASUREMENTS 0F DEIMAL THICKNESS 0F HEREFORD CATTLE
IN MICRONS
A fl :— ~=:Male Female

1100813103 B F iv. 0 17. Av. .
Forehead 7,660 5,450 6,545 4,910 5,580 5,245
Dorsal neck 7,440 6,960 7,200 6,190 8,040 7,115
Dorsal thorax 6,420 4,950 5,675 5,570 6,950 6,260
Dorsal lumbar 6,170 7,170 6,670 5,560 5,880 4,720
Tail root 7,280 7,960 7,620 5,750 5,440 5,585
Ventral devdap 14,950 5,450 10,190 6,000- 9,450 7,725
Ventral brisket 6,020 7,920 6,940 6,000 7,450 6,715
Ventral abdomen 7,890 5,660 6,775 5,500 5,950 5,775
Ventral udder 6,190 4,450 5,520 4,190 5,450 4,820
Ventral axilla 7,000 4,700 5,850 7,270 5,460 6,565
Ventral groin 5,950 6,710 6,520 5,710 5,950 5,820
Lateral neck 7,770 5,940 6,855 5,150 5,460 5,505
Lateral thorax 5,250 .4,440 4,845 6,260 6,950 6,605
Lateral abdomen 4,540 5,950 4,255 6,040 5,450 5,755
Gluteus 7,550 4,220 5,775 5,450 5,970 5,710
Upper foreleg 5,120 4,210 4,665 5,650 4,950 4,290
Fetlock 5,980 4,680 5,550 5,950 4,960 4,455
Upper hindleg 5,820 6,210 5,015 4,520 6,440 5,480
Lower hindleg 4,550 4,880 4,615 5,980 4,460 ‘ 5,220
Achilles insertion 5,920 5,480 4,700 5,540 6,250

6,960

55

 

 

TABLE 4
MEASUREMENTS OF DERMAL THICKNESS OF ANGUS CATTLE
IN MICRONS
Male Female _
L°°at1°n A D Av. G. H Av.
Forehead 6,450 8,080 7,255 6,900 6,100 6,500
Dorsal neck 6,750 5,850 6,500 4,950 6,550 5,640
Dorsal thorax 5,710 5,510 4,610 5,670 5,990 5,850
Dorsal lumbar 6,520 7,090 6,705 4,470 5,070 4,770
Tail root 4,580 6,070 5,225 4,950 6,550 5,740
Ventral dewlap 8,920 6,290 7,605 7,410 6,000 6,705
Ventral brisket 4,950 5,020 4,985 2,440 4,007 5,225
Ventral abdomen 4,570 4,620 4,495 5,610 4,400 4,005
Ventral udder 5,990 5,570 5,780 4,960 5,000 4,980
Ventral exilla 5,580 5,750 5,555 2,570 2,570 2,470
Ventral groin 5,250 4,050 4,640 5,210 4,560 4,785
Lateral neck 9,090 7,160 8.125 5,460 5,580 4,520
Lateral thorax 4,470 5,520 4,995 5,190 2,950 4,060
Lateral abdomen 5,850 5,510 5,570 2,960 4,970 5,965
Gluteus 4,170 5,650 4,900 5,460 6,000 5,750
Upper foreleg 5,980 4,550 4,155 4,950 5,170 4,060
Fetlock 5,020 5,990 5,505 2,970 5,270 5,120
Upper hindleg 4,580 4,570 4,575 5,210 5,550 4,280
Lower hindleg 2,270 4,280 4,275 2,960 5,180 4,070
fillies insertim 4,240 5,900 4,070 2,890 4,440 5,665

 

 

 

I

TABLE 5

54

MEASUREVIENTS OF TOTAL SKIN THICKNESS 0F HEREFORD CATTLE

 

IN MI CRONS

 

 

-‘—1—

‘4:—

 

 

Location Male Female
B F AV. 0 E Av.

Forehead 7,715 5,500 6,606 4,967 5,655 5,501
Dorsal neck 7,497 7,000 7,248. 6,555 8,085 7,220
Dorsal thorax 6,725 5,000 5,816 5,625 7,000 6,512
Dorsal lumbar 6,205 7,250 6,726 5,616 6,000 4,808
Tail root 7,550 8,000 7,665 5,796 5,500 5,648
Ventral dewlap 14,979 5,500 10,259 6,056 9,500 7,768
Ventral brisket 6,076 8,000 7,058 6,755 7,500 7,116
Ventral abdomen 7,962 5,750 6,856 5,601 6,000 5,800
Ventral udder 6,228 4,500 5,564 4,985 5,500 5,241
Ventral axilla 7,027 4,750 5,888 7,511 4,500 5,905
Ventral groin 6,007 6,750 6,578 5,782 6,000 5,891
Lateral neck , 7,811 6,000 6,905 5,189 9,500 7,544
Lateral thorax 5,272 4,500 4,886 6,512 7,000 6,656
Lateral abdomen 4,577 4,000 4,288 6,091 5,500 5,795
Gluteus 7,575 4,250 5,812 6,000 6,000 6,000
Upper foreleg 5,194 4,250 4,722 5,680 5,000 4,540
Fetlock 6,051 4,750 5,590 4,050 5,000 4,525
‘Upper hindleg 4,586 6,250 5,418 4,591 6,500 5,545
ILower hindleg 5,881 5,900 4,890 6,105 4,500 5,502
giphilles inserthnl 4,590 5,500 5,445 5,756 7,000 6,57

 

 

 

 

55

 

 

 

 

 

 

TABLE 6
MEASUREMENTS OF TOTAL SKIN TI—IICKNESS OF ANGUS CATTLE
IN MICRONS
j Wale Female ——
Locatim A D Av. G H Av.

Ferehead 6,497 8.118 7,508 7,000 7,005 7,001
Dorsal neck 6,777 5,890 6,555 5,000 6,585 5,692
Dorsal thorax 5,724 5,562 4,645 5,750 6,071 5,910
Dorsal lumbar 6,570 7,140 6,755 4,500 5,098 4,799
Tail root 4,508 6,128 5,518 5,000 6,500 5,750
Ventral dewlap 8 , 954 6, 551 7 , 644 7 , 500 6, 081 6 ,760
Ventral briSKet 4,998 5,061 5,050 2,500 4,071 5,285
Ventral abdomen 4 , 410 4 , 655 4, 555 5, 750 4, 500 4, 1 25
Ventral udder 4, 018 5, 604 5, 811 4,000 5,050 4, 525
Ventral axilla 5,450 5,759 5,595 2,500 2,710 2,605
Ventral groin 5,292 4,581 4,856 5,250 4,589 4,819
Lateral neck 9,114 7,189 8,151 5,500 5,655 4,577
Lateral thorax 4, 508 5, 562 5,055 5, 250 5,000 4,125
Lateral abdomen 5,880 5,551 5,615 5,000 4,999 5,999
Gluteus 4,214 5,669 4,942 5,500 6,055 5,767
Upper foreleg 4,018 4,572 4,295 5,000 5,200 4,100
Fetlock 5, 254 4,055 5, 655 5,000 5,510 5,155
Upper hindleg 4,410 4,405 4,408 5,250 5,587 4,518
Lower hindleg; 4,520 4,512 4,516 5,000 5,221 4,110
Achilles insertion 4, 520 5,954 4,157 5,000 4, 555 5,766

‘1

.3

 

K—r

 

W

~_-:
tr“

Li

PIGMEN T EVALUATION

TABLE 7

56

 

”-
”v—

T

A:

 

 

 

 

 

Angus Hereford
Location Male Female Male Female

A D G H B F C E
Forehead 1-B 4-B 2—B 2-B O-W O-W O-W O-W
Dorsal neck 5—B 2—B 5-B 5-B O-W l-R 5-R 1-EV
Dorsal thorax 2-B 5-B 2-B 5-B O-W O-W 5—R 5—R
Dorsal lumbar 5-B 5-B 4-B 5—B 2-R- 2-R 5-R 5-R
Tail root 2-B 5-B 4-B 4-B l-R l-B 5-R 5-R
Ventral dewlap 2-B 1-B 28B 5-B O-W O-W O-R O-W
Ventral brisket l-B 1-B O-B 1-B O-W O-W 0-R O-W
Ventral abdomen l-B 1-B 1-B l-B O-W O-W O-R O-W
Ventral udder 5-B 2-B O-B O-B O-W 5-W O-R O-W
Ventral axilla 1-B l-B l-B l-B O-W O-W O-W l-R
Ventral groin 2-B 1-B l-B 1-B O-W O-W O-W O-W
Lateral neck 2-B 2-B 1-B l-B O-W 1-R 5—R l-R
Lateral thorax 2-B 5—B 4-B 2-B l-R l-R 5-R 1-R
Lateral abdomen 5-B 5-B 2-B 2—B 1-R 1-R 2-R 2-R
Gluteus 5-B 2-B 2-B 5—B 1-R 5-R l-R l-R
Upper foreleg 1-B 1-B l-B 1-B l-R O-RW l-R 1-R
Fetlock l-B l-B l-B l-B O-W O-m l-R l-R
Upper hindleg 2-B 1-B l-B l-B O-R O-R O-W l-R
Lower hindleg 2-B 2—B l-B l-B l-W O-W 2-R O-W
Achilles insertion 5-B 4—B 2-B 1-B O-W’ OéRW 4-R l-R
Perianum 4-B 2-B 5-B 2-B 2-W 2-R 2-W 5-W
Hoof margin 4-B 4-B 5-B 2-B O-W' O-W’ O-W’ 14W
Horn:margin * * * * * O-W' *
Muzzle 4-B 4-B 4-B 4-B 2-W O-W O-W O-W

Key: 0 : absence of pigment
Numbers : quantitive pigment values
(10- a minimal, 44- a maximal)
Alphabets :- Gross color of hair coat

B = Black

R = Red

W .1: White

RW 2 Red and white borders

*Animals without horns.

 

Plate I. Designation of areas from which tissues were

taken
1. Forehead 15. Lateral Thorax
2. Dorsal Neck l4. Lateral Abdomen
5. Dorsal Thorax 15. Gluteus
4. Dorsal Lumbar 16. Upper Foreleg
5. Tail Root ‘ 17. Fetlock
6. Ventral Dewlap 18. Upper Hindleg
7. Brisket (Sternum) 19. Lower Hindleg
8. Ventral Abdomen 20. Achilles insertion

(Hook)

9. Udder or Scrotum 21. Perianal Skin
10. Axilla 22. Hoof-Skin Margin
ll. Groin 25. Horn- :in Margin

12. Lateral Neck 24. Muzzle

5'7

 

 

 

,v

«N

5.

\4

 

 

Plate II. Vertical section through the epidermis of the
muzzle of Hereford male. H. and E. stain.
170X.

A. Stratum corneum
B. Stratum genuinativmn
C. Papillary body of dermis

 

 

Plate II .

Vertical section through the epidermis of the
muzzle of Hereford male. H. and E. stain.
1701:.

A. Stratum corneum
B. Stratum germinativum
C. Papillary body of dermis

,__.‘____,,_,

-

 

 

Plate III. Section from ventral abdomen showing fine elas-
tic fibers in stratum papillare. Weigert's
elastic stain without counterstain. 250K.

A. Epidemis
B. Stratum papillare
1. Areolar type cells and eosinophiles
around blood vessels and nerve
trunks
2. Elastic fibers

 

 

 

Plate IV.

Cross section through the coiled glands and
large excretory ducts of muzzle. 2H. and E.

stain.
1.
2.

5.
4.

210K.

Large pigmented excretory ducts (4+ pig-
ment value) -

Coiled glands of muzzle (serial sections
show that the ducts anastomose to form a
common excretory duct)

Small non-pigmented intraplobular duct
Nerve trunk

 

 

Plate IV. Cross section through the coiled glands and
large excretory ducts of muzzle. H. and E.
stain. 210x.

1. Large pigmented excretory ducts (4+ pig-
ment value) -

2. Coiled glands of muzzle (serial sections
show that the ducts anastomose to form a
common excretory duct)

5. Snail non-pigmented intra—lobular duct

4. Nerve trunk

 

 

 

“Plate V. Vertical section through the stratum papillare
shovdng follicular folds. H. and E. 290x.

10 Hair Shaft

2. Hair follicle

5. Opening of sebaceous duct
4. Follicular folds

 

‘Plate V. Vertical section through the stratum papillare
shomdng follicular folds. H. and E. 290x. ‘

1. Hair shaft ,

2. Hair follicle

5. Opening of sebaceous duct
4. Follicular folds

 

 

 

 

 

 

41

Plate VI.

Vertical section of skin from the achilles in-
sertion showing moderately thick epidermis with
an occasional granular cell and poorly developed

papillae. H. and E. stain. 260x.
A. Epidemis
B. Dermis
1. Granular cell

2.
5.
4.
5.
6.

Stratum.corneum.

Stratum germinativum

Hair follicle

Sebaceous gland

Oblique section of the follicular
folds

 

Plate VI.

Vertical section of Skin from the achilles in-
sertion showing moderately thick epidermis with
an occasional granular cell and poorly developed

papillae. H. and E. stain. 260x.
A. Epidemis
B. Dermis
1. Granular cell

2.
5.
4.
5.
6.

Stratum.corneum.

Stratum germinativum

Hair follicle

Sebaceous gland

Oblique section of the follicular
folds

‘h

I»:

.‘4 .

‘u-I‘.‘ "

 

42

Plate VII. Cross section of hair and large sebaceous
glands of perianal skin. H. and E. stain.
270x.

1. Sebaceous gland

‘2. Hair follicle

5. Sweat ducts passing between the lobules
of the sebaceous glands

 

Plate VII. Cross section of hair and large sebaceous
glands of perianal skin. H. and E. stain.

27032.

1. Sebaceous gland
2. Hair follicle
5. Sweat ducts passing between the lobules

of the sebaceous glands

 

6,:

..__ l.—— '

LI

 

45

Plate VIII. Vertical section of hair follicle showing
hair shaft and saccular sweat glands of dorsal
thorax containing granular materials which

. were commonly found in sweat glands. H. and
E. stain. 250x.

1. Hair shaft
2. Sweat glands

5. Flat cells of sweat gland
4. Hair bulb

e- ,. £545 area... A».

t ..
. 1‘0... flit): /

 

Plate VIII. Vertical section of hair follicle showing
hair shaft and saccular sweat glands of dorsal
thorax containing granular materials which

. were commonly found in sweat glands. H. and
E. stain. 250x.

1. Hair shaft

2. Sweat glands

5. Flat cells of sweat gland
4. Hair bulb

   

4.
4

 

Plate IX. Cross section of hair and small sebaceous
glands showing the directional arrangement of

lobules.

l.

H. and E. stain. 250K.

Sebaceous glands (Nete that these glands

. are situated similarly with respect to

2.
5.
4.

each hair follicle)

Hair follicle

Sebaceous ducts near the hair follicle
Stratum papillare .

 

Plate IX. Cross section of hair and small sebaceous
glands showing the directional arrangement of
lobules. H. and E. stain. 250x.

1. Sebaceous glands (Note that these glands
- are situated similarly with respect to
. each hair follicle)
2» Hair follicle
5. Sebaceous ducts near the hair follicle
4. Stratum.papillare .

 

 

, WI

&\ . \
._ \fi
'

h "

. .

V‘s

 

(fl

Ilatc X. Vertical section of lateral neck region ShOWh
ing coarse elastic fibers in the deep denuis.
Weigcrt's elastic stain without a counter
stain. 260K.

 

Plate XI. A diagrammatic sketch of a typical vertical
section through the hair follicle and glands
of the skin of the ox.

l.
2.
5.

QOEUHP-

Epi dermis

Sweat duct

Sebaceous duct
sebaceous gland
Sweat gland

Papilla of hair bulb
Follicular folds

SUKQARY AND CONCLUSIONS

Specimens were secured from the Angus and Hereford
herds of the Animal Husbandry Department of Michigan State
University for this experiment. or each breed studied,
there were two noncastrate males and two females, from which
skin specimens representing twenty-four areas of the body
were taken (Plate I).

This investigation was primarily comparative and in-
cluded a study of all layers of the skin, the hair density,
epidermal pigmentation and the glands of the skin.

The stratum corneum was thickest in the Angus, and the
stratum germinativum was thickest in the Hereford, but the
total epidermal thickness of both breeds was practically
equal. The stratum granulosum and stratum lucidum were not
prominent in most areas of the body, but were found in the

Skin of the extremities.

The dermis consisted of the stratum papillare and the
stratum reticulare. The papillary layer was composed of
fine fibrous networks while the fibers of the reticular lay-
Ior were coarser and more densely arranged. The elastic fib-
ers of the stratum papillare were usually fine and formed a
very loose network. Those of the stratum reticulare were

usually restricted to capillary plexuses and in the deep

49
portion of this layer,they were very coarse and were fre-
quently parallel to the larger blood vessels. There were
no prominent sex or breed differences found. This finding
is in disagreement with Dick (1947), who found that females
have more elastin than males.

The results of this investigation agreed with Dempsey
(1948) in her finding that fat is not readily stored in the
Skin of the ox but disagreed with her observation that fat
is restricted to the lumbar region. This study showed fat
to be stored in the skin of the dewlap and brisket and
usually absent from other body regions.

Epidermal pigmentation was found to have specific-
breed characteristics which were easily demonstrated. The
pigment of the Angus was always black, while that of the
Hereford was always brown. Colors did not change with in-
crease or decrease in density.

The hair was morphologically similar to that described
for the ox by other authors, with one emception. A series of
folds which was always present in the upper one-third of the
hair follicle and slightly deeper than the opening of the.
sebaceous ducts into the lumen of the hair follicle, were
observed as horizontal projections into the follicle. These.
projections were not described in the available literature.
Hair density showed no sex or breed difference, and at no

time were the hair follicles found to contain more than one

50
hair. The hair count of the four animals obtained in early
winter was compared with that of the four amimals procured
in the spring but no apparent differences existed.

The sebaceous glands varied in size and form with hair
density. In areas where the hair was thin, at the margins
of the hooves and around the natural openings, they were
highly developed. The lobules were generally oval and tend—
ed to encircle the hair follicles. On several occasions they
were found to range from fifteen to twenty lobules per hair
follicle. In areas where the hair was dense (neck regions),
the sebaceous glands were comparatively small and narrow.
There were usually two or three lobules per hair follicle.
These findings agreed with the observations of Sisson and
Grossman (1953). In addition to the above observations, the
small sebaceous glands were found to be attached to the hair
follic1e_so that the lobules of a given area extended in the
same direction. This directional arrangment of sebaceous
glands was not described in the available literature. They
were always associated with the hair and opened into the hair
follicle through a short epithelial duct.

The sweat glands were found to be of three types, a
loosely coiled form found in the fetlock, prianal skin and
the achilles insertion, a closely coiled modification of the
latter peculiar to the muzzle, and a saccular form present in

all other body areas. The sweat glands of the hairy skin

51
opened into the hair follicle through sweat ducts, while
the ducts of the muzzle opened directly on the surface of
the epidermis. These findings agreed with Sisson and
Grossman (1955). They disagree with the observations of
'Trumbower (1904) who found that the sweat glands of the ox
are small and red coiled bodies in the subcutaneous tissue
with the ducts opening directly on the skin surface.
Trautmann and.Fiebiger' (1952) found additional glands in the
subcutaneous tissue which are similar to those of the ex-
ternal auditory meatus. The author found no such gland
types to be present in this investigation.

From the results of this study it was concluded that
although breed and sex differences were frequently found
upon critical analysis of the skin, the color of the epi-
dermal pigmentation is the most dependable factor when dif-
ferentiating between Angus and Hereford cattle microscOp-

13811370

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Cowdry, E. V.
1944 Localization of maximum cell division in the epi-
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Dempsey, Mary
1948 The structure of the skin and leather manufacture.
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55

qr

herxhehmng a. .
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1‘1'18Xj.mOVI, A. A. , and W. A 0 B10 0171
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lnu to, I]; o
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\
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