Quantization
of Plasma D-xylose Concentration Following of Vaccination
against Coccidiosis and Experimental Subclinical Coccidiosis
Induced By Eimeria maxima in Broilers
Shojaei, S.Sh.R*, Nodeh,H.**, Teshfam,
M**, Rahbari ,S.***Bokaie, S****
*Department of Parasitology, Faculty of Veterinary
Medicine, Islamic Azad University, Karaj Campus, Karaj,
IRAN, vetparasitologist@yahoo.com
**Department of Physiology and Pharmacology, Faculty
of Veterinary Medicine, University of Tehran
***Department of Parasitology, Faculty of Veterinary
Medicine, University of Tehran
****Department of Food Hygiene, Faculty of Veterinary
Medicine, University of Tehran
Coccidiosis,
particularly its subclinical form, which usually is
not being promptly and correctly diagnosed, causes
economic losses in broiler production. Each year,
a significant amount of money is spent in its chemical
prevention, but this is not always effective due to
several causes, such as management problems, drug
resistance, etc. The use of vaccination for the prevention
of coccidiosis has been recently proposed, and different
vaccines have been evaluated and compared. The intestinal
D-xylose absorption test is a suitable method for
studying intestinal mal-absorption in humans and animals,
such as poultry. The main aim of this study was to
evaluate the effects of vaccination against coccidiosis
on the absorptive index by using the intestinal absorption
test in broilers. A total number of 60 healthy Arbor
Acres one-day-old broilers was purchased and equally
divided into 6 experimental groups as follows: Group
1 –negative control with no vaccine and no challenge
by E. maxima; Group 2 – 15-day-old birds were
challenged with a suspension containing 50,000 sporulated
oocysts of E. maxima, but no vaccinated; Group 3 –
vaccinated at 4 days of age with Iracocc (a non-attenuated
live vaccine) and not challenged; Group 4 –
vaccinated at 4 days of age with Livacox T (a live
attenuated vaccine) and not challenged; Group5 vaccinated
with Livacox T and challenged with E. maxima; Group
6 – vaccinated with Iracocc and challenged with
E. maxima. Seven days after challenge (at 21 days
of age), 5 chicks were randomly chosen from each group,
and after being submitted to 12 hour fasting, each
chick received a solution of D-xylose at 5% by stomach
tube. Blood samples were taken 30, 60, and 90 minutes
after D-xylose administration, using heparinized microhematocrite
tubes. Plasma D-xylose concentration was determined
using the Modified Ebert’s Methods (Goodwin,
1984). The obtained results showed that the lowest
plasma concentration of D-xylose belonged to the challenged
group. However, no significant difference was observed
between the negative control group and all vaccinated
groups, including the group that was vaccinated and
challenged with E. maxima. The results of this experiment
indicate that concentration of plasma D-xylose in
vaccinated broilers was not significantly reduced
in comparison with normal broilers. On the other hand,
it was shown that this concentration was significantly
higher in all vaccinated groups as compared to the
group that was challenged, but was not vaccinated.
No significant difference was found between group
4 (vaccinated with Livacox and not challenged) and
group 5 (vaccinated with Livacox and challenged) or
group 2 (challenged and not vaccinated). The same
results were obtained for the Iracocc-vaccinated groups.
Therefore, it seems that both vaccines are not efficient,
and that it is possible to use intestinal D-xylose
absorption test to evaluate anticoccidial vaccines,
in addition to parasitological and immunological evaluation.
In fact, we recommend the use of these physiological
experiments to better evaluate anti-coccidial vaccines,
and we believe that this method can be used for evaluating
broilers flocks in which subclinical coccidiosis is
suspected.