Seroprevalence of Mycoplasma gallisepticum infectionin commercial layer farms in Alborz and Qazvinprovinces

Mycoplasma gallisepticum is associated with signifcant economic losses in domestic poultry, caused suboptimalegg production in layers. This survey was carried out to determine the seroprevalence of Mycoplasma gallisepticum infection in commercial layer farms in Alborz and Qazvin provinces for primary evaluation of usage of liveMg vaccine in commercial layer flocks. A total of 2050 serum samples were collected from 41 commercial layerflocks (50 samples from each farm) mostly over 40-week-old. Sera were tested by Serum Plate Agglutination(SPA) method using commercial Mg antigen (Noblis MG®, Intervet Co, Holland). Positive reactions retested bySPA on 1:8 dilution and the farms with more than 10% positive reactions were considered positive serologically.The result showed that in the Alborz province, only one out of 21 (4.8%) farms were positive and the rest (95.2%)were negative; also, 51 out of 1050 (4.86% ) sera were positive, 991 out of 1050 (94.38%) were negative and 8out of 1050 (0.76%) were doubtful. In Qazvin province, 3 out of 20 (15%) farms were positive and 17 out of 20(85%) were negative; also, 74 out of 1000 (7.4%) sera were positive, 46 out of 1000 (4.6%) were doubtful and880 out of 1000 (88%) were negative. As seroprevalence of Mg infection in these two provinces which are veryimportant areas in poultry production in Iran were low,so it seems that using live vaccine against Mg needs morestudies. However, molecular identifcation should be used for completing this fnding and biosecurity notices arevery important for controlling of Mg.