Induction of bovine leukemia C-type oncornaviruses.

The data are presented concerning the induction of bovine leukemia with purified and concentrated C-type oncornaviruses isolated from cattle of Latvian Brown breed with persistent lympholeukemia. The calves induced with C-type oncornaviruses were found to have early signs of persistent lympholeukemia. Pathohistological changes suggesting persistent lympholeukemia were observed to precede early clinical and hematological signs of the disease. C-type oncornaviruses were reisolated from blood plasma of calves with experimentally induced lympholeukemia.