TY JOUR TI Experience in the use of polymerase chain reaction in the diagnosis of bovine leukemia virus and its effectiveness at different stages of health activities KW leukemia virus KW cattle KW cows KW PCR diagnostics KW immunological tolerance KW virus transmission KW virus types. JO Agrarian Bulletin of the AU Bezborodova, N.A. AU Petropavlovskiy, M.V. AU Romanova, A.S. AU Lysov, A.V. AU Kozhukhovskaya, V.V. PY 2019 IS 191 PB Ural State Agrarian University