الفهرس 
DiclazurilOnly 14 pages are availabe for public view
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Abstract
Cecal coccidiosis is one of the most important parasitic disease affecting poultry . It causes
severe economic losses due to the deteriorated birds performance .
Cecal Coccidiosis became as an increasing problem and most poultry producers blame on the absence
of an ideal control program . This gave the research in cecal coccidiosis an essential trend to
cover some points about the ideal methods in the prevention and control of this disease .
This study was carried out to compare between the most recent ionophore anticoccidial, semduramcin
and the most recent chemical anticoccidial, diclazuril. Half the recommended and the recommended
use level of both drugs were used. Double the recommended dose was also tried to predict if there
were any improvements in the control of coccidiosis and the possible adverse effects.
In the present work two hundreds and ten mixed sex one day old Hubbard chicks wePe divided into 3
main groups. The first one was used as a control group and divided in 2 subgroups each contains 15
chicks. All were fed on ordinary ration free from any anticoccidial drugs allover the experiment
(56 days) .
The first subgroup was kept non infected and served as the negative control. The second subgroup
was infected with 50000 oocysts of E.tenella
at 21 days of age and considered as a positi ve control group. These two subgroups were considered
as a control for the prophylactic and therapeutic experiments.
The second main group was divided into 6 subgroups, 15 chicks each. It was used for studying the
efficacy of the prophylactic half - recommended, recommended and double recommended dose of
diclazuril or semduramici n. The drugs were given from day- I old till the day-42 of age followed
by 2 weeks of withdrawal. Infection was carried out at day -21 of age with 50000 sporulated oocysts
of E.tenella for each chick.
The third main group was subdivided into 6 subgroups. It was used for studying the therapeutic
effect of diclazuril and semduramicin. All fed on ordinary ration free from any anticoccidial drug
and infected at day - 21 of age with 50000 sporulated oocysts of E.tenella for each chick then fed
on a ration supplemented with half - recommended, recommended and the double recommended dose of
diclazuril or semduramicin. At 42- days of age all drugs were withdrawn from the chicken feeds for
2 weeks.
The comparison between the different treatments are based on clinical signs, lesion scores, oocyst
counts, birds performance, some hematological and biochemi<::al parameters and histopathological
examination.
The obtained resu lts are summerised as Follows:
I-Clin ical signs
The infected non-treated group showed the typical sign of coccidiosis including depression, loss of
appetite and bloody droppings one-week post infection. A variable degree of illness was recorded
until the end of experiment.
The medication of semduramicin or diclazuril at all dose levels improved the clinical sign. The
chickens given double therapeutic doses of semduramicin showed depression and inapeatence, which
was more marked at the 6th week of age.
2-Lesion scoring
The infected non-treated group showed the highest lesion score. The lesion scores were improved by
the different treatments. The lesion scores were neerly zero in chickens given prophylactic double
recommended doses of either diclazuril or semduramicin.
3- Oocyst count
The infected non treated group showed the highest oocyst count. Diclazuril and semduramicin at all
dose levels showed significant decrease in oocysts count. The oocysts shedding stopped in chickens
given prophylactic double recommended doses of either diclazuril or semduramicin on the 13th
day post infection and in chickens given
prophylactic recommended doses of either diclazuril or semduramicin at day-14 post infection
.
4-Ch ickens performa nce
The infected non treated group showed significant decrease in body weight, weight gain, feed
consumption and improved feed conversion rate throughout the experiment.
Chickens fed on diets containing diclazuril at all dose levels showed significant increases in body
weight, weight gain, feed consumption and improved FCR.
The resul ts obtained suggested that semduramicin has a growth suppressing effect. Significant
improvements in performance parameters were recorded after withdrawal of semduramicin from the
chicken feeds.The growth suppressing effect of semduramicin given at double the recommended
dose was permenant and no significant improvement in performance of chickens after the withdrawal
of the drug from chicken feeds.
5-Hematological examina tion
The infected non treated group showed significant decrease in RBCs, hemoglobin % and PCV throughout
the experiment.
Significant improvements in the measured hematological parameters were recorded in chickens fed on
prophylactic doses of diclazuril, prophylactic semduramici n at it’s approved use levels and
therapeutic 2 ppm diclazuril .
The infected non treated group showed significant increase in total leucocytic count. The total
leucocytic count of the chickens given prophylactic 50 ppm semduramicin showed low total leucocytic
count that semduramicin might has a suppressive effect on leucocytic production at high doses .
6-Biochemical examina tion
The infected non treated group displayed an increased activity of serum AST, ALT, and AP.The levels
of total serum proteins, albumin and globulins were significantly decreased while the serum levels
of urea, uric acid were significantly increased.
The activity of serum AST, ALT and AP were decreased by all treatments except in chickens given
prophylactic double recommended doses of semduramicin, there were significant increase specially
at 42-days of age.
The serum total protein , albumin and globulins were increased by all treatments but were
significant in the groups given prophylactic 1 or 2 ppm diclazuril, 25 ppm semduramicin and the
therapeutic 2 ppm diclazuril. Chickens given prophylactic double recommended doses of
semduramicin
showed significant decrease in serum total protein , albumin and globulins specially at 42-days
of age.
The infected non treated group displayed a significant decrease in serum sodium and potassium
levels throughout the experiment. The level of these electrolytes was increased by treatment with
diclazuril while sermduramici n treated groups showed a dose and time dependent decrease in serum
sodium and potassium. These levels were improved following the withdrawal of sermduramicin from
chicken feed.
7-Histopa thological exam ination .
Pathological examination of the infected non treated group revealed the presence of different
stages of E.tenella in the wall of cecum . These stages were not recorded in cecal section derived
from chickens fed on prophylactic doses of the test drugs . A small number were present
in section from chickens fed on the therapeutic doses and many of them appear degenerated .
In liver, there was congestion , hemorrhage and degeneration of hepatocytes in the infected non
treated group, with a lesser degree m chickens fed on therapeutic doses of the test drugs . In
chickens fed on prophylactic doses , the liver was nearly normal but in chickens given the
prophylactic double recommended doses of semduramicin there was liver necrosis and focal
aggregation of mononuclear cells . In the chickens given the prophylactic double recommended doses
of diclazuril there was hypercellularity and vaculation in the lining epithelium of bile ductioles
prophylactic double recommended doses of semduramicin there was hypercell ularity of renal
glomeruli and degeneration of the lining epithelium of renal tubules.
In heart, significant pathological changes were in the chickens given the prophylactic double
recommended doses of semduramicin there were subendocardial and intermyofi brillar aggregation of
mononuclear cells and degeneration of cardiac muscles.
In skeletal muscle, significant pathological changes were in chickens given the prophylactic double
recommended doses of semduramici n these were intermyofibri l!ar edema and myocytes degeneration .