Thesis (M.Sc.) - Cairo University - Faculty of Veterinary Medicine - Department of Veterinary Hygiene and Management

The current work was established to assess the impact of indoor air quality IAQ (climate elements Ta.C, RH %, AV m/sec. and ammonia ppm) and microbial load (ML) on humeral immune response (HIR) against infectious bronchitis vaccine and the vaccination index (VI) in cool and non-cool seasons in commercial broiler farms. An established questionnaire was used for recoding management, biosecurity indicators and level (BSL), vaccination programs and history of respiratory symptoms during cool and non-cool seasons. Onsite measures for IAQ (Climate elements, ammonia) ,collecting air samples for evaluation bacteria and fungi loads (BL&FL) ,blood samples for measuring HIR (ELISA kit) and target organs samples for identifying IBV gene using PCR and sequencing .Results reveled that, both of Ta.C and AVm/sec. revealed a high significant difference in mean values between cool& non cool seasons. In non-cool seasons the indoor climate elements revealed significant correlations between each other basically RH% with both Ta.C and AV m/sec. Also significant correlations were clarified the impact of indoor RH% and AV m/se .on broiler HIR. Cool seasons showed lower Ta.C, RH% and AV m/ sec with higher ammonia compared with non-cool seasons. The decreased HIR in cool seasons was associated with lower Ta.C, RH% and Av m/sec. but increased ammonia compared with non-cool seasons. The lowest CV % was in 20%of farms with the highest HIR. The lowest VI was associated with the highest coefficient of variance (CV%) and the lowest HIR were recorded in 33.3% of farms. The means differences of IAML revealed highly significant differences between all seasons

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