الفهرس | Only 14 pages are availabe for public view |
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 p.4.4. 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 ‘4.4. used in the field was performed. The field evalution revealed the following results: 4.4. 1- The field programs were based on using: (a) - One up to three field doses of live .4.4. 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• .4.4. (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 .4.4. 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 4.4. vaccine at 8 days adopted on a single farm . ‘.4.4 2- Thirty four ( over 35%) out of 95 investgated farms which adopted any one of the 4.4. 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 .4.4 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 L.4. |