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.