M. SUNGIRAI ET AL.
434
3.4. Relative Risk
The relative risk of infection with coccidiosis was calcu-
lated and found to be 100%.
(1.5) riskin exposedgroup100
riskinnon exposedgroup
4. Discussion
Aloe managed to reduce oocyst levels to minimum levels
but the results were not comparable to that of ESB3. Re-
sults obtained by [2] showed that treatment with 0.8 g of
Aloe Excelsa ground powder in drinking water signifi-
cantly reduced oocyst numbers. In his he showed that
differences in oocyst counts proved A. excelsa juice to be
as effective as ESB3 in controlling coccidiosis. However,
their results also showed that the Aloe drug although ef-
fective, had a lower curative value as compared to that
shown by the ESB3 drug. This is similar to this case,
where A. chabaudii gel was not as efficient in its control
as compared to ESB3. The most possible reason for this
could be that, the concentration levels of Aloe used in
this experiment were not enough to conclude that A.
chabaudii leaf gel could not reach an oocyst reduction
level like that observed for ESB3. This implies that, since
the reduction in oocysts with increase in Aloe juice con-
centration was not exhausted to the threshold level, fur-
ther increasing the Aloe concentration could possibly
have increased oocyst reduction in the broilers.
Another reason why Aloe was proved not to be as ef-
fective as ESB3, though it reduced oocyst numbers, is
due to the differences in the mode of action towards coc-
cidian oocysts control between the two agents. ESB3 is a
coccidiocidal drug meaning it actually kills disease agents
by inhibiting protein synthesis within their systems and
thus kill the microbes. This is different from Aloe juice’s
mode of action which is more coccidiostatical, meaning,
it arrests the intra and extra cellular growth of the disease
agent though development may resume after drug with-
drawal. This is supported by work done by [8] which
looked at the protective effects of Aloe vera based diets
in Eimeria maxima, in which Aloe treatment proved suc-
cessful. The study discussed that Aloe was able to control
coccidiosis due to the chemistry of its gel. The chemistry
of Aloe juice comprises of a class of organic chemicals
known as 1.8 dihydroxyanthraquinone derivatives includ-
ing Aloe emodin, aloetic acid and isobarbaloin [9]. These
chemical constituencies in the Aloe juice act as laxative
agents by interacting with the gastrointestinal mucosa
and inducing bowel motility and allowing for quick dis-
charging of coccidia lodged in fecal matter.
Though effective, ESB3 was not able to reduce the
number of oocysts to zero to show complete disease con-
trol. This could be explained by the issue of emergence
of drug resistant Eimeria strains due to the continued use
of ESB3 to control coccidiosis as it is the most available
anticoccidial. As explained by [10], there has been a
concern in the rise of ionophore and sulphonamide resis-
tant strains of coccidia in many broiler production sys-
tems of the world and much research is being done to
investigate such problems.
[4] also found out that there were significant decreases
in oocyst counts by increasing Aloe concentration in a
related study, same way with what was observed in this
study. However lesion score results from this study
showed differences from what was obtained by [8] as
there were no differences in the range of the number of
birds that had lesion scores for all treatment only with
ESB3 showing significant lesion score control. This can
be due to differences in the pathogenicity that occur be-
tween Eimeria strains. Since this experiment was based
on a mixed Eimeria strain exposure, it could be that there
was an uneven distribution between the most virulent and
less virulent strains of Eimeria during the time of infec-
tion as the eight species known to infect poultry are not
known to be equally important. For instance, E. mitis is
very pathogenic, but doesn’t necessarily result in lesions
as compared to E. acervulina and E. maxima [11]. In
another experiment involving using A. secu ndiflora gel
as anticoccidial, [12] observed that Aloe treated birds had
a glyco protein Aloe layer, lining the intestinal lumen of
the gastro intestinal tract. This layer prevented the ad-
herence and invasion of the intestinal lining by mature
oocysts such that the birds had less clinical lesions.
Lesion score results showed no significant differences
in terms of the number of birds infected between A. cha-
baudii gel treated groups, which is different from what
was shown with the oocyst count results. [11] explains
this by stating that there is weak correlation between le-
sion scores and oocysts per gram (OPG) meaning that
increase in lesions is not directly linked to amount of
oocyst per gram fecal matter and vice versa. According
to [13], Eimeria have a high morbidity, resilience and
incidence may occur due to transferring by animals, in-
sects, dust, contaminated feed, water and equipment.
This probably explains the incidence of disease in the
prospective cohort analysis of this study proving the im-
portance of coccidiosis as a disease in poultry production.
The uninfected birds which received no treatment were
housed in the same run as with all the other treatments
thus mature oocyst could have possibly been transferred
to these birds.
5. Conclusion
Coccidiosis has been shown to be a disease of economic
importance under poor habitat, health and nutrition. This
thus implies that there is a need to control cases upon
incidence, and proper management should be effected to
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