Serologic profile of avian leukosis virus subgroup-J, Mycoplasma gallisepticum and Mycoplasma synoviae in broiler grandparent flocks of Iran.

Avian Leukosis Virus Subgroup-J (ALV-J), Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) are important pathogens in chickens that cause severe economical losses in poultry industry throughout the world. Seven broiler grandparent flocks of Iran (six broiler strains) were sampled randomly at the ages of 8-63 wk (100 samples from each flock) for antibody detection to ALV-J, MG, and MS by ELISA. One sample ( ۠۠0.9%) of flock F was antibody positive to MG. About the MS, there were 2 (2.1%), 2 (2.1%), 2 (2.1%), 8 (8.7%), 4 (4.3%), 9 (9.8%) and 2 (2.1%) positive samples from those collected from flocks A, B, C, D, E, F and G, respectively. However, in all flocks tested, the mean S/P ratio was < 0.5 and thus all flocks as recommended by the manufacturer were antibody negative to MG and MS. All plasma samples collected from flocks A, B and D were negative for ALV-J antibody. However, there were 2 (2.9%), 39 (51%), 5 (6.6%) positive samples from those collected from flocks C, E, and F, respectively. Only the flock E was antibody positive to ALV-J (according to the manufacturers instructions), because in other flocks the mean S/P ratios were < 0.6. The findings of this study showed that one of the broiler grandparent flocks in Iran exposed to the ALV-J virus.