Subject: Veterinarski arhiv 69 2
From: <Saved by Windows Internet Explorer 8>
Date: Mon, 8 Jul 2013 09:36:07 +0200

VETERINARSKI ARHIV 69 (2),
87-95, 1999

ISSN 1331-8055 Published in
Croatia

Prevalence of bovine mastitis in
Maiduguri
Borno State, Nigeria

James Agbo Ameh*, Tobias
Edgbe-Nwiyi,
and Lamido Tanko Zaria

Faculty of Veterinary Medicine,
University of Maiduguri, Maiduguri Borno State, Nigeria

* Contact address:
Dr. James Ameh,

Faculty of Veterinary Medicine, Department of Veterinary Microbiology,
University of Maiduguri, Bama Road, P.M.B. 1069, Maiduguri, Borno State, Nigeria

AMEH, J. A., T. EDGBE-NWIYI, L. T.
ZARIA: Prevalence of bovine mastitis in Maiduguri Borno State, Nigeria. Vet.
arhiv 69, 87-95, 1999.

ABSTRACT

Mastitis in cows was investigated by
surveying a number of herds located within and around Maiduguri, Nigeria. Five
thousand cows (in lactation and dry) were examined. The prevalence of mastitis
was assessed by the results of physical examinations of the mammary gland by
palpation, and by evaluation of milk secretion. Bacteriological examination also
was carried out on all milk samples collected from affected cows, as well as
some selected control cows. One hundred and four (2.1%) of the 5,000 cows
examined showed evidence of clinical mastitis. There was no significant
difference in the number of quarters affected in relation to their anatomical
positions (fore- and hindquarters). The survey revealed that the majority of
cases occurred in cows between 4 and 7 years of age and that the incidence
declined as the animals became older. One hundred and fifty-four apparently
normal cow udders (53%) contained bacterial pathogens. On a cultural examination
of 104 milk samples from affected cows, the recovery rate was 77%.
Staphylococcus aureus (34.6%) occurred most frequently in the mastitic
milk, followed by coagulase negative staphylococci (15.4%). Other bacteria
isolated from mastitic cows milk were Streptococcus sp. (9.6%);
Escherichia coli (6.7%); Actinomyces pyogenes (5.8%); Bacillus
spp. (2.9%) and Salmonella sp. (1.9%). The prevalence of bovine
mastitis in this area was sufficiently high as to cause substantial economic
loss to farmers. It is therefore imperative that measures aimed at prevention
and control of the disease (mastitis) be instituted in all the herds.

Key words: bovine mastitis,
disease prevalence, etiology, Nigeria

Introduction

Nigeria has abundant livestock
resources, the majority of animals being concentrated in the northern parts of
the country (AJAYI et al., 1987), although there are numbers of cattle elsewhere
in Nigeria (NAWATHE, 1992). Borno State, located in the extreme north of the
Sahel region, accounts for about one quarter of the total ruminant population
(NGERE et al., 1984).

Milk comprises 16% of the total value
of all food products produced from livestock in sub-Saharan Africa (ANON.,
1986). Milk and milk products constitute a complete food, as they contain
proteins, fats, lactose, minerals and vitamins, together with natural enzymes
derived from milk micro-organisms. (LEWIS, 1986).

Despite the important role of milk in
the national economy, local production is unable to sustain the increasing
demand for milk and milk products, initially at cheaper rates (AJAYI et al.,
1987). This situation has worsened over recent years due to foreign exchange
constraints and the fall in the value of the local currency, the naira.
Currently, high prices are being demanded for milk and milk products, with the
result that such items are denied to average Nigerians.

Mastitis is the most widespread
infectious disease in cattle and, from an economic aspect, the most damaging
(DODD, 1985). Certain udder characteristics, breeds, teat injuries, poor
hygiene, poor management, faulty milking machines, accumulation of milk and the
presence of bacteria in or around the udder, are all factors which predispose
cows to mastitis (SCHALM et al., 1971; ADDO et al., 1980; AMEH et al., 1993;
EGWU et al., 1994).

Mastitis is an inflammatory disease
affecting the mammary gland, characterised by an increased somatic cell count
(SCC) in milk and/or by pathological changes in mammary tissue (ANON, 1971).
Mastitis is usually caused by pathogenic bacteria and other microbes entering
the gland through the teat duct (SCHALM et al., 1971).

The prevalence of this disease in
Nigeria has not been studied in any depth, although there is extensive
literature on mastitis from countries with farming practices similar to those
followed in Nigeria (KALRA and DHANDA, 1964; HAMIR et al., 1978; FALADE et al.,
1989). There is therefore a pressing need to assess its clinical prevalence and
causal agents (bacteria) involved in bovine mastitis in Nigeria.

Materials and methods

The present study was carried out on
selected herds located in a 25-km radius of Maiduguri during the period
1994-1997. This area has numerous smallholdings (farms) and a small number of
larger herds. The standard of milking hygiene is very poor and preventive
measures, such as the use of udder disinfectants, post-milking teat dipping and
dry cow therapy, are infrequent in these herds.

During this period, 5,000 cows were
examined clinically for the presence of mastitis. Mastitis was diagnosed when
there were visible or palpable signs of udder inflammation, change in milk
secretions, or through bacteriological examination of milk. During the study,
104 cases of clinical mastitis were encountered and studied in detail, the
following being recorded for each cow: age, clinical state (acute, subacute,
chronic and gangrenous) (Table 1), and which were classified as follows:

Acute mastitis: Severe inflammation of
the mammary gland without any marked systemic reaction.

Subacute mastitis: Inflammation of the
mammary gland with abnormalities in milk.

Chronic mastitis: Inflammation of the
mammary gland, with little change in milk, often characterised by induration of
glandular tissue. The gland may either be enlarged or reduced in size.

Gangrenous mastitis: Characterised by
swollen mammary gland, cold to the touch and bluish-black in colour. The
affected skin area peels off, with oozing of serous fluid. Milk is usually
bloody and watery.

Milk collection and analysis

Milk samples were collected from 104
cows from the 202 quarters clinically affected, and 154 samples from apparently
normal udders. Samples were obtained using sterilised sample bottles, with the
usual aseptic precautions being taken. They were placed immediately on ice
(Coleman Flask) and brought to the Veterinary Microbiology Laboratory,
University of Maiduguri.

Prior to quarter sampling, initial
streams of milk were discarded. A hundred and four milk samples were collected
and examined bacteriologically from mastitic quarters, and 154 milk samples from
apparently normal cows and quarters were similarly examined (control).

Random number sampling was used in
selecting the 154 apparently normal cows on the farms visited.

A wire loop was used for milk
inoculation onto 5% sheep blood and MacConkey agars. Plates were incubated
aerobically at 37 oC for 24-72 h. Plates were examined for bacterial
growth on a daily basis. Organisms were examined for morphological, staining and
cultural characteristics, and for biochemical reactions according to standard
keys (COWAN and STEEL, 1974; KING, 1983). Staphylococci were studied in
particular for haemolysis and coagulase production (tube method using oxalated
rabbit plasma in a 1:10 dilution in a nutrient broth incubated at 37 °C and
inspected at 30 min intervals for 5-6 h for clot formation). A positive
coagulase test was judged as any degree of clotting from a loose clot suspended
in plasma to a solid clot (LENNETTE et al., 1974).

Statistical analysis

The chi-squared (c2) test was used to compare certain values in the
test. P<0.05 was considered statistically significant.

Results

Prevalence of clinical mastitis

One hundred and four cows from a total
of 5,000 (2.1%) displayed evidence of clinical mastitis, involving 202 quarters.
Data were examined relevant to the position of affected quarters. There was no
significant difference in the number of quarters affected in relation to their
anatomical positions. The number of quarters affected were: left fore, 49; right
fore, 45; left hind, 51; right hind, 57.

The age of affected cows ranged from 4
to 13 years. Results are shown in Table 1. These figures show that the majority
of clinical cases occurred in cows between 4 and 7 years of age. With regard to
the clinical state of the mammary gland, the greatest number were acute cases
(25%), followed by sub-acute cases (21%), chronic (19%), and gangrenous mastitis
(3%) (Table 1). There was no statistical difference in age distribution with
respect to the form of clinical mastitis (P>0.05).

Table 1. Cows
from Maiduguri, Nigeria, with mastitis, grouped according to the clinical state
of the mammary gland in various age groups

Clinical state of the mammary
gland of cows

Age group in years

Total

%

4-5

6-7

8-9

>10

Acute

13

17

6

2

38

36.5

Subacute

6

16

7

3

32

30.8

Chronic

2

15

11

2

30

28.8

Gangrenous

0

2

1

1

4

3.8

Total per age group

21

50

25

8

104

Bacteriological examination of milk

On cultural examination of 104 milk
samples collected from clinically affected cows, recovery rate was 77% (80/104)
(Table 2). In the examination of 154 samples from apparently normal cow udders,
bacteria were detected in 81 (53%) samples; 73 (47%) samples had no bacterial
growth. Staphylococcus aureus (34.6%) occurred more frequently in
mastitic milk, (P<0.001) than in non-mastitic milk. This was followed by
coagulase negative staphylococci (15.4%). Other bacteria isolated from mastitic
milk were Streptococcus spp. (9.6%); Escherichia coli (6.7%);
Actinomyces pyogenes (5.8%); Bacillus spp. (2.9%) and Salmonella
spp. (1.9%). Of the bacteria isolated from apparently normal milk,
Staphylococcus aureus predominated (16%), followed by coagulase negative
Staphylococci (13%), E. coli (6%). Bacillus spp. (2%)
occurred less frequently (Table 2).

Table 2.
Frequency of various types of bacteria isolated from mastitic and apparently
normal milk of Nigerian cows

Bacterial isolates

Cow with mastitis
N=104 (%)

Cow without mastitis
N=154
(%)

Staphylococcus aureus

36 (15.4)*

25 (16)*

Coagulase negative staphylococci

16 (9.0)

20 (13)

Streptococcus spp

10 (15.4)

5 (3)

Escherichia coli

7 (6.7)

9 (6)

Actinomyces pyogenes

6 (5.8)

0 (0)

Bacillus spp

3 (2.9)

3 (2)

Salmonella spp

2 (1.9)

7 (5)

Klebsiella spp

0 (0)

4 (3)

Enterobacter aerogenes

0 (0)

4 (3)

Negative culture/No growth
samples

24 (23.1)

73 (47)

*P<0.001

Discussion

In this survey, the prevalence of
bovine mastitis was evaluated by clinical and bacteriological methods in order
to define the nature of this economically important disease. The prevalence of
clinical bovine mastitis was found to be 2.1% in the Maiduguri area. This figure
is within the range reported elsewhere (BRAMLEY, 1984; WILESMITH et al., 1986)
who reported a prevalence of 4.35% and 3.4% respectively. Similarly, (HAMIR et
al., 1978) observed 2.5%, 3.0% and 3.0% prevalence in three consecutive studies
(1971, 1972 and 1973) in Kenya.

There was greater single quarter
involvement, with hindquarters being more commonly affected. The number of cases
found in fore- and hindquarters showed no statistical difference. Various
authors in India (SHARMA and RAI, 1977) and in Kenya (HAMIR et al., 1978)
observed no significant difference in the number of fore- and hindquarter cases.
However, KALRA and DHANDA (1964) found in their survey that hindquarters were
more frequently affected with mastitis, and that this difference was
statistically significant.

The higher prevalence of clinical
mastitis with increasing age has been reported (KALRA, 1967; SHARMA and RAI,
1977; HAMIR et al., 1978). It was observed (KING, 1981) that the increase in
clinical mastitis with advancing age is entirely due to there being more
infections among older cows. In our present survey, clinical mastitis increased
up to the age of seven years of age, but decreased after that point. There was
no statistical difference in age distribution with regard to the form of
clinical mastitis.

Results of the survey revealed 19%
chronic cases. The reason for this may be due to the fact that veterinarians are
seldom requested to diagnose and treat the acute state of the disease (CHINEME
and ADDO, 1984). The same authors further observed that, typically,
veterinarians are called upon to diagnose and recommend treatment for the
condition when it has progressed to the chronic state.

A predominance of Staphylococcus
aureus mastitis in cows has been reported (KALRA and DHANDA, 1964; WATTS,
1988; FALADE et al., 1989; CARLOS, 1990). In this study, it was found that S.
aureus and coagulase negative Staphylococci were the most frequently
isolated bacteria from mastitic cows. It has been reported by (LAFI et al.,
1994) that coagulase negative staphylococci and S. aureus occurred
predominantly in both clinical and sub-clinical bovine mastitis.

Escherichia coli is an
environmental pathogen, and E. coli mastitis is a major disease in cows.
Previous studies in Nigeria have shown that E. coli is an important
aetiological agent of clinical mastitis (AMEH et al., 1993; EGWU et al., 1994).
In this study, E. coli was found in 6.7% of cases.

The isolation of mastitis pathogens
from apparently normal quarter milk in the present study was in agreement with
previous observations, that is to say, mastitis-causing bacterial pathogens can
be isolated from clinically normal ruminant mammary glands (WALTER, 1967; ADDO
et al., 1980; AMEH et al., 1993; EGWU et al., 1994).

The higher prevalence of intra-mammary
staphylococcal (S. aureus) infection indicates the potential of a food
hazard problem. CARLOS (1990) drew attention to the great public health
significance of this organism in milk.

In conclusion, this study showed that
bovine mastitis definitely poses a serious problem in the Maiduguri area of
Nigeria, and that the disease is caused by a variety of bacterial organisms. We
therefore recommend that measures for the use of udder disinfectants,
post-milking teat disinfection, and prompt treatment of clinical cases designed
to prevent and control the disease (mastitis) be instituted in all the herds.

Acknowledgements
This investigation
was supported by Senate Research Grant (R/ACA. 93/C/9/Vol. xvi), provided by the
University of Maiduguri. Gratitude is also expressed for the advice and
encouragement we received from colleagues during this investigation. Special
thanks are extended to Mr. Samson Onyikokwu for his technical assistance, and to
Mrs. C. Ebenezer for her Secretarial services.

References

ADDO, P. B., C. N. CHINEME, F. I. A.
EID (1980): Incidence and importance of chronic mastitis in Nigeria goats. Bull.
Anim. Health Prod. Africa 28, 225-231.

AJAYI, S. A., Y. SHUAIB, F. D. ABU, M.
A. ASAGBA, A. G. LAMORDE (1987): Sheep and goat production and health management
in Nigeria. Nigeria Livestock farmers 7, 18-21.

AMEH, J. A., P. B. ADDO, J. O. ADEKEYE,
E. O. GYANG (1993): Prevalence of clinical mastitis and of intermammary
infection in Nigeria goats. Prev. Vet. Med. 17, 41-46.

ANONYMOUS (1971): Annual Bulletin. A
monograph of bovine mastitis. Part I International Dairy Federation. Brussels p.
3.

ANONYMOUS (1986): 1986 production year
book 40 (76), FAO, Rome Italia 306.

BRAMLEY, A. J. (1984): Streptococcus
uberis udder infections a major barrier to reducing mastitis incidence. Br.
Vet. J. 140, 328-336.

CARLOS, A. D. M. (1990):
Characteristics of Staphylococcus aureus from subclinical bovine mastitis
in Brazil. Br. Vet. J. 146, 443-448.

CHINEME, C. N., P. B. ADDO (1984):
Chronic mastitis: Clinical microbiological and pathological findings in
spontaneously occurring in Nigeria goats. Goat and Sheep Res. 2, 266-271.

COWAN, S. T., R. J. STEEL (1974):
Manual for identification of Medical Bacteria. 2nd ed. Cambridge
University Press. UK.

DODD, F. H. (1985): Progress in
mastitis control. Kiel Milchwirtsch. Forschungsber. 37, 160-223.

EGWU, G. O., L. T. ZARIA, P. A.
ONYEYILI, A. G. AMBALI, S. S. ADAMU, M. BIRDLING (1994): Studies on
microbiological flora of caprine mastitis and antibiotic inhibitory
concentration in Nigeria. Small. Rum. Res. 14, 223-239.

FALADE, S., L. NWANZA, A. WULAYA
(1989): Bovine mastitis in Lusaka Province. Tropical Veterinarian 2, 18.

HAMIR, A. N., W. GEHRING, S. I.
MUHAMMED (1978): The incidence of bovine mastitis in Kenya. Bull. Anim. Health
Prod. Africa 26, 55-61.

KALRA, D. S., M. R. DHANDA (1964):
Incidence of mastitis in cows and buffaloes in North West India. Vet. Rec. 78,
219-222.

KALRA, D. S. (1967): Observations on
the incidence of mastitis in relation to predisposing factors. J. Res. 4,
249-256.

KING, J. S. (1981): Streptococcus
uberis I: Characteristics of the organism. Br. Vet. J. 137, 36-49.

KING, E. C. (1983): The identification
of unusual pathogenic gram negative bacteria. Centre for disease control.
Atlanta Georgia.

LAFI, S. O., O. F. AL-RAWASHDEH, K. I.
ERAFAJ, N. O. HALLAT (1994): Incidence of clinical mastitis and prevalence of
subclinical udder infection in Jordanian dairy-cattle, Prev. Vet. 18-98.

LENNETTE, E. H., E. H. SPAULDING, P. J.
P. YRAUANI (1974): Manual of Clinical Microbiology. 2nd ed. American
Society for Microbiology. Washington, DC.

LEWIS, M. J. (1986): Advances in the
heat treatment of milk. Modern Tech. 11, 1-50.

NAWATHE, D. R. (1992): Resurgence of
contagious bovine pleuropneumonia in Nigeria. Rev. Sci. Tech. Off. Int. Epizool.
2, 799-804.

NGERE, L. O., I. F. ADU, I. O. OKUBANJO
(1984): The indigenous goats of Nigeria. Animal Genetics Resources Information,
FAO Roma 3, 1-9.

SCHALM, O. W., E. J. CARROL, N. O. JAIN
(1971): Bovine mastitis. Lea and Febiger. Philadelphia, P.A.

SHARMA, S. D., P. RAI (1977): II
subclinical mastitis in Uttar Pradesh. Ind. Vet. J. 435-439.

WALTER, G. (1967): Standard methods for
the examination of dairy products. American Public Health Association Inc. New
York.

WATTS, J. L. (1988): Etiology of bovine
mastitis. Vet. Microbiol. 16, 41-46.

WILESMITH, J. W., P. G. FRANCIS, C. D.
WILSON (1986): Incidence of mastitis in a cohort of British dairy heards. Vet.
Rec. 118, 199-204.

Received: 26 October 1998
Accepted:
30 March 1999

AMEH, J. A., T. EDGBE-NWIYI, L. T.
ZARIA: Ucestalost govedeg mastitisa u pokrajini Maiduguri Borno u Nigeriji. Vet.
arhiv 69, 87-95, 1999.

SAZETAK

Istrazivan je mastitis u krava u nizu
stada u i oko pokrajine Maiduguri u Nigeriji. Pregledano je 5.000 krava u
laktaciji ili suhostaju. Ucestalost mastitisa je ocjenjivana prema rezultatima
pregleda vimena palpacijom i pregledom mlijecnog sekreta. Uzorci mlijeka
prikupljeni od krava bolesnih vimena kao i od nekih odabranih kontrolnih krava
pregledani su bakterioloski. Stotinu i cetiri (2,1%) od 5.000 pregledanih krava
je pokazivalo klinicke znakove mastitisa. Nije bilo znacajne razlike u broju
zahvacenih cetvrti vimena s obzirom na njihov anatomski polozaj (prednje i
straznje cetvrti). Pregled je pokazao da se vecina slucajeva pojavljivala u
krava u dobi od 4 do 7 godina, te da se ucestalost smanjivala s dobi zivotinja.
Bakterijski uzrocnici pronadeni su u 154 (53%) klinicki zdravih kravljih vimena.
Bakterije su ustanovljene u 77% od 104 pretrazena uzorka mlijeka od zahvacenih
krava. U mlijeku iz vimena s mastitisom najcesce je utvrden Staphylococcus
aureus (34,6%), a slijedili su ga stafilokoki negativni na koagulazu
(15,4%). Ostale bakterije utvrdene u mlijeku krava s mastitisom su bile:
Streptococcus sp. (9,6%), Esherichia coli (6,7%), Actinomyces
pyogenes (5,8%), Bacillus spp. (2,9%) i Salmonella sp. (1,9%).
Ucestalost mastitisa u ovom podrucju bila je dovoljno visoka da izazove osjetne
gospodarske gubitke stocarima. Stoga je neophodno da se uvedu mjere prevencije i
kontrole mastitisa u svim stadima.

Kljucne rijeci: govedi mastitis,
ucestalost bolesti, etiologija, Nigerija

Back