الفهرس 
AcknowledgmentOnly 14 pages are availabe for public view
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Abstract
The present work was carried out to evaluate some vaccination programs
adopted in the field against infectious bursal disease ( IBD ) in broiler farms in
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Alexandria, Bohira and Kafr-El-Sheikh governorates. The investigation covered 95
broiler flocks in the 3 governorates In addition , laboratory evaluation of seven
common vaccination programs with different commercial vaccines similar to those
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used in the field was performed.
The field evalution revealed the following results:
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1- The field programs were based on using: (a) - One up to three field doses of live
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intermediate vaccine (s) given via drinking water and eye at the age between 8 and
4;
26 days ( program B ) adopted on 45 farms; :444•
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(b) - Inactivated vaccine given S / C or I / M early in life (day 1 - 2 using partial dose
f 3/5111 or 4/5111 field dose or full field dose on day (5-13), followed by 2-4 field doses
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of live intermediate vaccine (s) given via drinking water at 7-26 days of age
program(A) adopted on 28 farms and ; (c) -Program (C) using one field dose of live
intermediate plus vaccine (s) given via drinking water at 8 to 14 days alone adopted
on 21 farms , or given at 16 days and precceded by a field dose of intermediate
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vaccine at 8 days adopted on a single farm .
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2- Thirty four ( over 35%) out of 95 investgated farms which adopted any one of the
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above mentioned vaccination programs suffered from IBD outbreaks , the 4 4.
majority of which (about 76%)occurred on the 3rd and 4111 weeks of age probably
as a result of early and heavy exposure to infection with IBD field viruses before
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expected satisfactory vaccinal immunity would have enough time to develop after
being interfered with high levels of maternal antibodies during the first 2 weeks of .4.4
life . Suboptimal managment and biosecurity observed on the majority of the
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