Résumé
Avian leukosis viruses [ALVs] cause different types of tumours in poultry and can affect the health and egg production of the birds. To investigate the presence of the virus in chicken layer flocks in Shiraz, 222 egg albumen from local layer breeder [25 eggs], local layer grand parent [30 eggs], broiler breeder [60 eggs], commercial layer [46 eggs] and broiler grand parent [61 eggs] were tested by antigen-capture enzyme-linked immunosorbent assay [AC-ELISA]. The results showed that 3.33, 76 and 80% of commercial broiler breeder, local layer breeder and local layer grand parent were positive, respectively. Thirty-five albumen samples were randomly selected and tested by RT-PCR using PU1/PU2 and PA1/PA2 primer sets. The samples with ELISA S/P ratio equal or more than 0.17 were positive by RT-PCR using PA1/PA2 primers. This is the first report of the presence of the ALV in egg albumin samples of chicken layer flocks in Shiraz