Adel Feizi, Mansour Khakpour, Hossein Nikpiran, Kamrouz Kaboli, Amid Reza Jeyrani Moggadam, Peyman Bijanzad and Hossein Hosseini
Mycoplasma gallisepticum (MG) is one of the most important diseases in Iranian poultry industry and all over the world. Mortality, poor weight gain and increasing of feed conversion ratio (FCR) were seen in MG infected flocks. In this study, 11 broiler breeder farms located in northwest of Iran were investigated during 2011-2012. Three of these farms infected with Mycoplasma gallisepticum during study, the clinical signs and lesions were evaluated. Results showed that in farms infected with Mycoplasma gallisepticum, severe conjunctivitis, lungs and trachea hyperemia, and sever airsacculitis with caseous exudates were obvious. It can be concluded that MG in broiler breeder farms have potency of great economical losses, and it's clinical signs and gross lesions in infected birds were very severe and it could decline broiler breeders performance.