Seroprevalence of Mycoplasma gallisepticum infection in Iranian north-west broiler breeder farms.

Mycoplasma gallisepticum (MG) is one of the most im portant diseases in Iranian poultry industry and al l over the world. Mortality, poor weight gain and increasing oconversion ratio (FCR) were seen in MG infec ted flocks. In this study, 11 broiler breeder farms located in northwest of Iran were investigated during 2011-201 2. The prevalence of Mycoplasma gallisepticum was studied by ELISA test, and the clinical signs and lesions w ere evaluated in all farms. Our results indicated that the prevalence of MG in broiler breeder farms was 3 3.3% during study period. Also in farms infected with MG, sever e conjunctivitis, lungs and trachea hyperemia, and sever airsacculitis with caseous exudates were obvious. I t can be concluded that MG in broiler breeder farms have potency of great economical losses, and it's clinic al signs and gross lesions in infected birds were v ery severe and it could decline broiler breeders performance. And als o because of controlling of MG in Iran the prevalen ce of MG was lower in comparison to previous years.