Molecular survey of avian oncogenic viral diseases in commercial layers in Namakkal region of South India Gowthaman V.*, Murthy T.R. Gopala Krishna, Sakthipriya M., Udhayavel S., Kumar G. Suresh, Senthilvel K. Poultry Disease Diagnosis and Surveillance Laboratory, Veterinary College and Research InstituteCampus, Tamil Nadu Veterinary and Animal Sciences University, Namakkal-637002, Tamil Nadu, India *Corresponding author Email: vetgowth@yahoo.co.uk
Online Published on 15 January, 2024. Abstract The present study was carried out in Namakkal region of South India from 45 commercial layer flocks suspected for oncogenic diseases. Necropsy examination was carried out and pooled tissue samples showing lymphoid tumours were collected for diagnostic studies. Viral DNA from affected tissues was extracted and screened for Marek’s Disease Virus (MDV), avian lymphoid leucosis virus (LLV) subtype A and reticulo-endotheliosis Virus (REV) infections by Polymerase Chain Reaction (PCR). The rate of mortality in the affected flocks ranged between 0.3% to 12% in HVT+SB1 vaccinated flocks and almost 60% in HVT alone vaccinated flocks. The age of the infected flocks ranged between 8 weeks to older birds of 82 weeks of age. The highest prevalence and mortality were reported during early laying to peak stage of production (20-40 weeks). The affected birds were weak and emaciated, had pale and shrunken combs. Postmortem examination revealed debility, focal/ multifocal to diffused lymphomatous enlargement of liver, spleen, and kidney. Lymphomas were also found in other visceral organs. PCR screening revealed all the tumor samples found positive for either MDV (44.44%) or LLV or both (86%) and negative for REV. Top Keywords Avian oncogenic viral diseases, Co-infections, Epidemiology, Molecular prevalence. Top |