Diagnosis of Avian Leukosis Virus subgroup J in asymptomatic commercial layers using qPCR

Avian Leukosis Virus (ALV), one of the dangerous retroviruses threatens the poultry industry, is oncogenic and can easily transmit. Over the past three decades, the poultry industry has been significantly affected by subgroup J (ALV-J) in particular, known for its ability to spread both horizontally and vertically. The fact that a commercial vaccine has not yet been developed against ALV increases the risk potential. For these reasons, positive cases should be identified to control ALV infections and minimize infection. A prompt and accurate diagnosis is vital to detecting infected birds. For this purpose, sampling was performed in total 153 blood samples from 14 different asymptomatic commercial layer farm located in Afyonkarahisar, T?rkiye. Herein, the presence, density and prevalence of ALV-J strain and whether it has an oncogenic effect was investigated by qPCR and western blot for the first time in T?rkiye. The average contamination rate of ALV-J was calculated as 70.91% over all samples. However, p27 antigen that is the most abundant polypeptide encoded by the gag gene of ALV could not be detected. High prevalence of ALV-J suggests that ALV strains can be found asymptomatically without showing any symptoms.