Post on 03-Feb-2023
STUDY ON GROSS TESTICULAR DISORDERS OF BULLS SLAUGHTERED AT ADDIS ABABA
ABATTOIRS ENTERPRISE
1Migbaru K., 2Sisay. G. and 3Kasa T.1, 2College of veterinary medicine, Haramaya University, Dire Dawa,
Ethiopia.3Aklilu Lema institute of Pathobiology, Faculty of veterinary medicine,
Addis Ababa university, Debire Zeit, Ethiopia.
ABSTRACT
A cross-sectional study using systematic random sampling was conducted
on antemortem and postmortem examination of 384 intact bulls slaughtered
at Addis Ababa Abattoirs Enterprise (AAAE) from November, 2009 up to
April, 2010 to identify different types of testicular disorders of the
bull presented to the abattoir and to determine the rate of occurrence
of each disorder and also to assess the associated risk factors. Out of
384 intact bulls examined 337 were local, 29 cross and 18 exotic breeds
brought from different market areas in the country, of which 117 (30.4%)
have scrotal and testicular disorders. During study time various
testisticular defects such as scrotal torsion, scrotal wound, orchitis,
epididymitis, testicular hematoma, testicular degeneration, testicular
hypoplasia and cryptorchidism with the prevalence of 1%, 4.7%, 4.4%,
3.4%, 2.1%, 8.1%, 3.6% and 2.6% respectively were identified. Only
testicular degeneration has significant association with age (χ2 = 8.9,
P < 0.05).
Key words: Addis Ababa Abattoirs Enterprise, Intact bull, Infertility, Testicular disorder.
INTRODUCTION
Agriculture (mainly crop and livestock production) is the mainstay of
the sub-Saharan countries and for 85% of Ethiopian population. Livestock
production accounts for approximately 30%of the total agricultural gross
domestic production and 16% of national foreign currency earnings
(Lobago, 2007). The population of cattle in the country is estimated at
41.5 million comprising 99.4% indigenous (zebu), 0.5% cross and 0.1%
exotic breeds which are mainly kept under smallholder subsistence
farming (EASE, 2003), from this 43.12 million cattle population are for
the rural sedentary areas of, of which 55.41% are females and 44.59 are
males (CSA, 2006).
In Ethiopia the productivity like meat, milk, cheese, butter, export
commodities (live animals, hide, skin) and draught power (EASE, 2003) of
livestock does not commensurate with the large size due to various
reasons such as occurrence of diseases, poor management systems,
inadequate nutrition and animal health services, selection and
improvement for productivity (Lobago, 2007).
Reproductive performance is one of the major determinants of cattle
productivity in any production systems. The contribution of the bull
either through the natural mating or artefitial insemination (AI) is the
determinant factor, because each bull represents half of the genetic
composition of its progeny and many cows can be inseminated with the
semen of a single bull (Faulkner and Pineda, 1980).
Failure of many bulls to breed consistently and efficiently has been
reported to be associated with the production of poor quality semen due
to the pathology of testes and accessory glands. Gross testicular
pathology is classified as congenital causes like hypoplasia and
criptorchidism and acquired causes like testicular degeneration,
orchitis, calcification, testicular hematoma and epididymis. All of the
abnormalities have a negative effect on productivity and fertility of
the bull (Hafez, 1993).
Pathologic condition of testes, epididymis, and seminal vesicle have
been recognized to interfere with fertility by disturbing
spermatogenesis or sperm maturation, leading to abnormal semen
characteristics or preventing the passage of spermatozoa from testes to
urethra (Van Camp, 1997). Some of such disease conditions include:
testicular degeneration, orchitis, hematoma and epididymitis (Hafez,
1993). The possible causes of these acquired testicular abnormalities
are infectious agents, nutrition, managemental factors, thermal
influence, and age (Rao and Bane, 1985).
Infertility is a global problem, but the highest prevalence is within
low resource countries, particularly in sub-Saharan Africa where
infection related tubal damage is the commonest case. Acute or chronic,
localized or systemic infectious diseases are common causes of bull
infertility and testicular degeneration in Ethiopia due to wide spread
presence (Mamo, 1988).
Bulls which are older than seven years have 0.3 to 0.5% reductions in
fertility due to lower sperm production owing to higher incidence of
lesions such as testicular fibrosis and tubular calcification that
develops testicular degeneration (Sullivan, 1978).
Testicular disorders of bull has a great economic effect due to
reduction in fertility rate of cows in Ethiopia because most of the
people are dependent on pastoral and agro pastoral practices and this
practice is mostly extensive farming system (CSA, 2006). The farmers
didn’t use artificial insemination rather they use their bulls for
natural mating without selecting healthy, good sexual desire or good
fertilization capacity bulls (Coulter and Foote, 1979). The objectives
of this study were: (1) to identify the different types of gross
testicular disorders of the bull presented to AAAE, (2) to determine the
rate of occurrence of the observed disorders and (3) to examine the
associated risk factors.
MATERIALS AND METHODS
Study Area
The study was conducted in Addis Ababa, the capital city of Federal
Republic of Ethiopia, at Addis Ababa Abattoirs Enterprise. Addis
Ababa is located at an elevation of 2020-2500 meters above sea
level.
Study animals and sampling strategy
A cross-sectional study design was employed to identify major
testisticular disorders and possible risk factors on intact bulls.
The study was conducted on intact bulls slaughtered at Addis Ababa
Abattoirs Enterprise from November, 2009 to April, 2010. The study
animals comprise of male indigenous, exotic and cross breeds of
cattle which brought from different areas of the country like
Harare, Jima, Nazreth, Wolayta and others. Age of the animal was
estimated by dentition (de-lahunta and Habel, 1986).
To determine gross testicular disorders of bulls, antemortem and
postmortem examination were employed. During examination attention
was given to the scrotum and testes of intact bulls to identify
scrotal defects and gross testicular disorders by careful
visualization and palpation followed by postmortem examination by
making lateral dissection to visualize the cut surface whether it
bulges out or not according to Hafez (1993). Accordingly; 384 intact
bulls were selected and examined using systematic random sampling
technique according to Thrusfield (2005) with 95% confidence
interval; at 5% desired absolute precision and 50% expected
prevalence to give maximum sample size.
Data Management and Analysis
Data generated from antemortem and postmortem inspection was
recorded in the Microsoft excel 2007 program. The data was analyzed
by using SPSS version 17. Point prevalence of defects was calculated
as percentage by dividing the frequency of each defect to the total
number of bulls examined in the abattoir and the proportion of each
disorder was calculated by dividing the frequency of each case to
the total number of cases. The significance of association among the
risk factors and the case was determined by Chi-square test at p ≤
0.05.
RESULTS
Prevalence and proportion of Antemortem and Postmortem Examination
Disorders
The possible defects of the scrotum on antemortem examination were
scrotal torsion and scrotal wound with the prevalence of 1% and 4.7%;
and 3.4% and 15.4 % case proportion respectively. Among the lesions on
postmortem examination testicular degeneration, orchitis, testicular
hypoplasia, epididymitis, cryptorchidism and testicular hematoma were
identified with 8.1%, 4.4%, 3.6%, 3.4%, 2.6% and 2.1% prevalence and
26.5%, 14.4%, 12%, 11%, 10.3% and 6.8% case proportion respectively
(Table.1).
Table 1: prevalence and case proportion of
antemortem and postmortem examination
disorders.Antemortem Post mortem
ST SW Tot Orc Ep TH THyp TD Cryp tota
lFrequency 4 18 22 17 13 8 14 31 12 95
Prevalence 1 4.7 5.7 4.4 3.4 2.
1
3.6 8.1 3.1 24.7
Case
proportion
3.
4
15.4 18.
8
14.4 11 6.
8
12 26.5 10.3 81.2
SW= Scrotal Wound, ST= Scrotal Torsion, TH= Testicular Hematoma, TD=
Testicular Degeneration, Orc= Orchitis, THyp= Testicular Hypoplasia,
Cryp= Cryptorchidism Ep= Epididimitis Tot=total
Antemortem Examination Disorders
During antemortem examination, 5.5 % of examined bulls have scrotal
defects like 1 % scrotal torsion and 4.7 % scrotal wound. These defects
were observed 6.2 % on local, 3.4 % on cross and no observed defects on
exotic breeds. Based on age 3.7 %, 5.8 % and 6.1 % were observed on
below four years, between four and six and above six years age
respectively. Origin wise 2 %, 6.6%, 6.1% and 4.3 % were from Harar,
Jimma, Nazreth and wolayta respectively but the remaining 8.4% were from
unknowen sources (Table 2).
Table 2: Summary of antemortem examination defects based on breed, age
and origin of bulls slaughtered in AAAE.
variables Total
examined
Scrotal Torsion
(%)
Scrotal Wound (%) Total (%)
Breed
Local 337 4 (1.1) 17 (5) 21 (6.2)Cross 29 0 (0) 1 (3.4) 1 (3.40Exotic 18 0 (0) 0 (0) 0 (0)Total 384 4 (1) 18 (4.7) 22 (5.7)
χ2 = 0.56, P =
0.75
χ2 = 1.09, P =
0.582
Age<4 54 (14.1) 1 (1.9) 1 (1.9) 2 (3.7)4-6 104
(27.1)
1 (0.96) 5 (4.8) 6 (5.8)
>6 226
(58.9)
2 (0.88) 12 (5.3) 14 (6.1)
Total 384 (100) 4 (1) 18 (4.7) 22 (5.7)χ2 = 0.4, P =
0.82
χ2 = 1.2, P = 0.56
OriginHarar 97 (25.3) 0 (0) 2 (2) 2 (2)Jima 76 (19.8) 0 (0) 5 (6.6) 5 (6.6)Nazreth 33 (8.6) 1 (3) 1 (3) 2 (6.1)Unknown 131
(34.1)
2 (1.5) 9 (6.8) 11 (8.4)
Wolayta 47 (12.2) 1 (2.1) 1 (2.1) 2 (4.3)Total 384 (100) 4 (1)
χ2 = 3.94, P =
0.42
18 (4.7)
χ2 =4.39, P = 0.355
22 (5.7)
Post Mortem Examination Disorders
Among the postmortem examination disorders, age has significant
association with testicular degeneration (χ2 = 8.9 and P = 0.012) (Table
3).
Table 3: Summary of postmortem examination gross testicular disorders
based on breed, age and origin of bulls slaughtered in AAAE.
variabl
es
Total No (%) Hypoplas
ia (%)
Cryptorchi
dism (%)
Orchitis
(%)
Epididymit
is (%)
Hemato
ma (%)
Degenera
tion (%)Breed
Local 337(87.8) 13
(3.8)
11 (3.3) 16
(4.75)
12
(3.6)
7 (2) 28 (8.3)
Cross 29 (7.6) 1 (3.4) 1 (3.4) 0 (0) 1 (3.4) 1
(3.4)
2 (6.8)
Exotic 18 (4.7) 0 (0) 0 (0) 1 (5.6) 0 (0) 0 (0) 1 (5.5)Total 384 (100) 14
(3.6)
12 (3.1) 17
(4.4)
13
(3.4)
8
(2.1)
31 (8.1)
χ2
p-
value
0.73
0.69
1.87
0.76
1.47
0.477
0.663
0.718
0.648
0.723
1.12
0.57
Age<4 54 (14.1) 2 (3.7) 2 (3.7) 1 (1.9) 1 (1.9) 0 (0) 1 (1.9)4-6 104 (27.1) 4 (4) 3 (2.9) 5 (4.8) 4 (3.8) 3
(2.9)
4 (3.4)
>6 226 (58.9) 8 (3.5) 7 (3.1) 11
(4.9)
8 (3.5) 5
(2.2)
26
(11.5)Total 384 (100) 14
(3.6)
12 (3.1) 17
(4.4)
13
(3.4)
8
(2.1)
31 (8.1)
χ2
p-
value
0.02
0.99
7.4
0.115
0.99
0.61
0.47
0.79
1.5
0.47
8.9
0.012
Origin Harar 97 (25.3) 3 (3) 3 (3) 3 (3) 2 (2) 1 (1) 3 (3)Jima 76 (19.8) 2 (2.6) 2 (2.6) 3 (3.9) 3 (3.9) 1
(1.3)
6 (4.9)
Nazreth 33 (8.6) 2 (6) 1 (3) 2 (6) 1 (3) 1 (3) 3 (9)Unknown 131 (34.1) 6 (4.5) 4 (3) 8 (6.1) 6 (4.6) 4 (3) 16
(12.2)Wolayta 47 (12.2) 1 (3) 2 (4.2) 1 (2.1) 1 (2.1) 1
(2.1)
3 (6.4)
Total 384 (100) 14
(3.6)
12 (3.1) 17
(4.4)
13
(3.4)
8
(2.1)
31 (8.1)
χ2
p-
value
1.49
0.83
2.2
0.97
2.1
0.71
1.4
0.82
1.5
0.88
6.5
0.17
Figure 1: Testicular calcification Figure 2:
Scrotal torsion
Figure 3: Testicular hematoma figure 4: Unilateral
testicular degeneration
Figure 5: Testicular abscess Figure 6: unilateral
hypoplasia of testes
DISCUSION
The prevalence of gross testicular disorders from antemortem and
postmortem examination during the study period was 30.4% (117 cases from
384 intact bulls examined). This result is not far below with the report
of 41% by Joe et al., (2001) in UK. Out of this 18.8% (22 out of 117 cases)
were scrotal defects found during antemortem examination which is not
far below from 28%, the report of Jubb and Kennedy, (1970) in Israel.
This variation might be due to the exclusion of penile disorders in this
study. These scrotal defects were scrotal torsion (1%) and scrotal
wounds (4.7%) are similar with 1.03% and 4.3% respectively (Kastelic et
al., 2001) in Canada. None of the scrotal defects have significant
association (p > 0.05) with the risk factors.
The presences of these scrotal defects have a negative effect on
fertilization capacity of breeding bulls. For instance scrotal torsion
or wound results circulatory interference and infarction of the testes
which can be produced by manually or naturally occurring scrotal
torsions or contusions mostly in animals with vigorous exercise and the
testes would be swollen, congested and leads to degeneration and also
interferes free movement of the scrotum up and down, that prevents
counter current mechanism of thermoregulation (Hafez, 1993).
During postmortem examination of 384 intact bulls 95 bulls have gross
testicular disorders that are 24.7% from the total (384) and 81.2% of
the total cases (117) of both antemortem and postmortem defects. This
result was not far above that of 72% reported by Jubb and Kennedy,
(1970) in Israel. In this study testicular degeneration was the most
frequently encountered (8.1%) among the gross testicular disorders which
are comparable with the report of 7.6 ± 1.9% in Belgian Blue bulls and
10 ± 4% in Holstein Frisian bulls in Belgium by Hofka et al., (2009).
Testicular degeneration is the leading because most adverse conditions
like high ambient temperature or pyrexia from disease stress due to
excessive physical work and also produced by other gross lesions like
orchitis, epididymitis. Orchitis and epididymitis were the second and
third prevalent defects with 4.4% and 3.4% prevalence respectively
(Trojian et al., 2009). The rest were testicular hypoplasia 3.6% which has
a negative effect on semen quality and volume (Barth and Oko, 1989) and
Cryptorchidism with the frequency of 3.1% which affects spermatogenesis
by inhibiting testicular thermoregulation (Marcus et al., 1997) and also
testicular hematoma with 2.1% prevalence. Testicular degeneration and
testicular hypoplasia are difficult to differentiate during antemortem
examination but during postmortem examination testicular degeneration is
firm on palpation and does not budged out while dissection (figure 4)
but testicular hypoplasia has flaccid consistency and bulged out while
dissection (figure 6) (Van Camp, 1997).
In this study only testicular degeneration had significant association
(χ2 = 8.9, p < 0.05) with the age but not to the other risk factors. The
absence of significant association between the antemortem and postmortem
examination defects with the risk factors except testicular degeneration
might be due to different possible reasons, considered as limitations of
this study. Depending on age that might be due to low number of young
bulls came to the abattoir that makes the data sensitive with the
presence of very small number of cases. On species wise even if exotics
and cross breeds were managed with intensive and semi intensive farming
system they have low resistance to the adverse environmental conditions
than local zebus (MOA, 1996). Also some intensive farm owners might cull
bulls with reproductive disorders that increase the occurrence in the
abattoir. On the other hand extensive farm owners might use the bulls
for natural mating with the problem that reduces the case during the
study. In case of origin there was no great variation of the occurrence
that might be due to most of the bulls have collected in different
environmental conditions even if they recorded as the same origin.
Therefore, to know the effect of these risk factors on reproductive
organ disorders of intact bulls needs farther research by taking
proportional samples from each type of management system, age group,
breed and also environmental conditions (Leke et al., 1993).
CONCLUSION AND RECOMMENDATIONS
The result of this study indicates that high number of intact bulls have
gross testicular disorders which can affect the fertilization capability
of breeding bulls. From this study antemortem disorders are due to poor
management like scrotal trauma by noxious agents and kick wounds and
also ectoparasite infestation around the scrotum that causes scrotal
dysfunction. Postmortem disorders may be due to localized/ systemic
diseases and congenital defects like cryptorchidism and testicular
hypoplasia. Also the study indicates that high rate of gross testicular
disorders were on aged intact bulls (≥6 years). Even if there are many
reproductive organ disorders that have impact on the reproductive
performance of bulls and cows researchers have given attention only for
cows.
Based on the above conclusion the following recommendations are
forwarded:
Bull selected for breeding should be free from gross testicular
lesions, small or unequal sized and incomplete descended testes
and scrotal problems.
Selected breeding bulls must be kept in good management system and
should not be aged.
Research must be done routinely on the problem regard to the
reproductive performance of bulls.
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