EPIDEMIOLOGIC AND BACTERIOLOGIC STUDIES OF CALF COLIBACILLOSIS IN HERDS OF CATTLE IN ZARIA
EPIDEMIOLOGIC AND BACTERIOLOGIC STUDIES OF CALF COLIBACILLOSIS IN HERDS OF CATTLE IN ZARIA
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Date
1994-03
Authors
LAZARUS, BABA TEKDEK
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Abstract
A total of 479 calves in 27 herds were examined for
diarrhoea and enteric pathogens. The overall prevalence of
diarrhoea was 13.6%. The characteristics of diarrhoea
faeces viz, the consistency, colour and smell were evaluated
and related to the causative agents. A loose greenish nonsmelly
diarrhoea was suggestive of helminthic infections
while whitish, bloody or mucoid diarrhoea was suggestive of
coccidial and bacterial diarrhoea. The proportion of calves
which survived for 12 0 days without diarrhoea was 91.3%.
The probability of calves having diarrhoea was high among
age-group 0-30 days. This indicated the high risk period.
There was no significant difference between the occurrence
of diarrhoea and either geographical locations of herd, year
or season. Odds ratios indicated associations between some
enteric pathogens and diarrhoea. These enteric pathogens
were E. Coli + Toxocara sp; E. coli + Coccidia; E. coli +
Strongyloides sp. (in older calves); and E. coli + Toxocara
sp. + Coccidia. Important pathogens responsible for
diarrhoea in the first 30 days of life were E. coli +
Coccidia; E, coli + Toxaocara sp; and E. coli + Toxocara sp.
+ Coccidia. It is suggested that E. coli may be an
important factor to be present for gut parasites to cause
diarrhoea. The presence of E. coli enterotoxins were not
related with the occurrence of diarrhoea. Thus if E. coli
caused the diarrhoea observed, it might have done it by the
Abstract vii
presence of other factors other than enterotoxins in E. coli
responsible for diarrhoea. One of these factors was the
ability of E. coli to haemagglutinate Ox RBC. E, coli
strains isolated from 65 and 41 diarrhoeic and nondiarrhoeic
calves respectively were characterized. In this
work, serogroup 08 was among the commonest 0 serogroups
identified. Mixed infections of enterotoxigenic E. coli
(ETEC) and gastrointestinal parasites (GP) caused 11.8% of
the diarrhoea, while mixed infection of E. coli strains
which agglutinated Ox RBC caused 9.8% of the diarrhoea.
While the combination of GP and E.coli strains contributed
23.5%; and E. coli strains alone contributed 5.9% of the
diarrhoea. The freguencies of enterotoxins identified were
ST (8.1%), and LT, (3.3%) from diarrhoeic calves while the
freguencies of verocytotoxins were 3.3% and 9.8% from
diarrhoeic and non-diarrhoeic calves respectively. The
property of E. coli to haemagglutinate Ox RBC (16.4%) was of
significant finding in diarrhoeic calves.
A total of 17 lambs were used for experimental
reproduction of enteric colibacillosis. The lambs were
divided into 3 groups of 3, 4, and 10 lambs each. The first
3 lambs were in group one which served as blank control
lambs that were administered 5.0ml of sterile Brain Heart
Infusion Broth; 4 lambs in group two were positive control
lambs that were administered 5.0ml of Brain Heart Infusion
Broth containing about 3 x 108 E. coli organism/ml, while 10
lambs in group three were experimental lambs that were
Abstract viii
administered 5.0ml of Brain Heart Infusion broth containing
about 3 x 108 E. coli organisms/ml. The average pack cell
volume, protein levels, temperature (°C), pulse and
respiratory rates were recorded before and after infection.
From group one, lamb 01 developed mild non-smelly pasty
diarrhoea probably due to change in feed. From group two,
lambs 04 and 07 had severe smelly and pasty diarrhoea and
latter died (50% case fatality rate) suggesting that the E.
coli strain used was enterotoxigenic in lambs. From group
three 5 lambs developed severe smelly and pasty diarrhoea
and case fatality rate was 80%. Experimental infection of
lambs suggested that the E. coli strain from diarrhoeic calf
in Zaria was enterotoxigenic in lambs. Cross infections can
easily occur between lambs and calves kept together. The
average values of temperature, pulse and respiratory rates
were not significantly different between groups before or
after infections suggesting non-involvement of circulatory
system.
In conclusion further studies are needed to evaluate
the roles of viruses, parasites, bacteria and management
practices on the prevalence of calf diarrhoea in Zaria.
Experimental infections of calves with single and multiple
combinations of common enteric pathogens is suggested to
determine experimentally any correlation between the nature
of diarrhoea and enteric pathogens. This information will
be helpful in making a clinical diagnosis of diarrhoea in
calves.
Description
A Thesis Submitted to Ahmadu Bello University in Partial
Fulfilment for the Degree of Doctor of Philosophy.
Department of Veterinary Surgery and Medicine
Ahmadu Bello University
Zaria, Nigeria
MARCH, 1994
Keywords
EPIDEMIOLOGIC,, BACTERIOLOGIC,, COLIBACILLOSIS,, CATTLE,, ZARIA