Studies on the Epidemiology of Respiratory Diseases in Chicken Farms with Relation to Biosecurity and Vaccination Regimes Adopted

Abstract

The main objective of this study is to investigate the prevalence of avian respiratory pathogens especially AIV, IBV, vNDV and MG in six Egyptian governorates with relation to biosecurity level in some flocks as well as trials to isolate some viruses. Moreover, some respiratory viruses are selected for their molecular identification to monitor the genetic variations of the circulating viruses. Also, investigate pathogenesis of Egyptian local vNDV isolate related to genotype VII in chickens. To achieve this target. Trachea and lung tissues were collected from different chicken farms suffering from respiratory diseases problem in different localities in Egypt to screen respiratory pathogens involved in occurrence of that disease as well as trials to isolate some viruses. Moreover, the molecular characterization of some respiratory pathogens was applied and application of experimental infection of chickens with vNDV isolate. Main steps: 1) Trachea and lung tissues of a total of 70 chicken flocks (66 broiler flocks, 3-layer flocks, 1 breeder flock) (10 samples per flock), suffering from respiratory diseases problem were collected under hygienic conditions between November 2018 and April 2019 from six Egyptian governorates including (Beni-Suef, Fayoum, Minia, Giza, Sharqia and Qalubia) then these samples were subjected to nucleic acid extraction (DNA&RNA) and screened by real-Time RT-PCR for detection of AIV, IBV, NDV, and MG.