الفهرس 
Acknowledgement &DedicationOnly 14 pages are availabe for public view
 |  | from | 147 |  |  |
| | | from | 147 | | |
Abstract
Avian influenza (AI) is a serious viral disease that threatens the health of birds and the economy and leads to severe losses. Therefore, health control is done through proper cleansing and vaccinations and effective biosecurity. This study dealt with a discussion of bird flu, its causes, health and economic risks, its presence within the farms, and the factors that predisposed to increase this huge health problem. This study was conducted in ten poultry farms of different production systems (deep litter, battery / cage) and different types (broiler and layers). Using a cross-sectional study, the collected samples of birds were as follows: Cloacal and tracheal swabs, lung and liver, but environmental samples were taken from: water fecal and feed samples The samples were subjected to serological examination, real time PCR, and sensitivity test for three types of disinfectants in the laboratory. The results of this study were compared with previous studies on avian influenza viruses in poultry farms and the results were attributed to sound scientific reasons. The results were summarized as follows: groups of different isolates of H5 and H9 were identified from tracheal, cloacal swabs, organs, water and fecal samples. The presence of the virus was found to be higher in the deep litter than in the battery/cage system and in bird samples than in environmental samples. Biosecurity applied in farms, season and system of housing used in farms were thought to be the most important risk factors incriminated in AI occurrence. To sum it up: to keep the farmer from the risk of bird flu the farms must be disinfected continuously.