Monitoring of major infectious diseases of broiler flocks in Iran: ۲۰۱۶-۲۰۱۸

۲۶۰ broiler flocks with ۱۷.۰۰۰.۰۰۰ capacity have been monitored in a period of ۳ years (۲۰۱۶-۲۰۱۹) in Iran with focus on Gilan province due to integrated nature of poultry sector in this area. In order to analyze base lines and performances, flocks with mortality more than ۵% were omitted from current study (finally, data of ۱۸۴ broiler flocks with ۱۲.۰۰۰.۰۰۰ capacity were analyzed). Serological data include Elisa of infectious bronchitis (IB) and infectious bursal disease (IBD),Hemagglutination inhibition (HI) test for avian influenza (AI) and Newcastle disease (ND) as well as flock performance data (European production efficiency factor (EPEF), slaughter average body weight and age, first week and total mortality, FCR and etc) in slaughter age have been collected during the study period. Concerning almost various vaccination regimes: Our findings showed that flocks which received ۶ doses of ND live vaccine did not have significantly higher HI titer in comparison with flocks which received ۴ and ۵ live ND vaccine (P>۰.۰۵). Also, the HI titer of ND in spring and autumn was significantly higher than in summer (P<۰.۰۵).Flocks which received AI inactivated vaccine showed a higher average HI titer in comparison with others. Although very low HI titerswere expectedin flocks which did not receive AI inactivated vaccine, the average HI titer in these flocks were ۲.۶۲ ± ۱.۶۳.There was no significant difference in IB Elisa titer between flocks which received ۲ IB live vaccines (two serotypes) with flocks that received ۳ and ۵ live IB vaccines (P>۰.۰۵). EPEF was significantly higher in flocks which received ۲ live IB vaccines in comparison with other groups (P<۰.۰۵).Regarding to IBD, there were no sign of clinical Gumboro in monitored flocks. All flocks received one dose of live immune-complex IBD vaccine in hatchery. The average IBD titer in slaughter age was ۵۲۷۱ ± ۲۵۴۴.In conclusion the current study will discuss the outcome of different vaccination regimes applied for controlling major broiler infectious diseases