ENZOOTIC BOVINE LEUKOSIS - EXPERIMENTAL I NDUCTION WITH 2 SOURCES OF VIRUS

A group of nine Holstein Friesian calves, 9 months of age, belonging t o the same herd, and not showing antibody gp 51 in two serologic contr ol tests were used. Three of them were inoculated with 100 mu l of hep arinized blood obtained from the one dairy cow positive to antibody gp 51. These animals produced antibody gp 51, detected by ELISA, 30 days post inoculation and by IDAG 60 days after. Besides, the lymphocytes obtained from calves induced syncytia in cocultures with foetal lamb k idney cells (RFD) from day 120 of inoculation. Three calves inoculated with 100 mu l of supernatant of RFD cultures infected with the BLV di d not generate antibody anti gp 51 during the 365 days of the experien ce. Of the three animals in the control group, one of them produced th e natural infection and developed antibody anti gp 51 120 days after t he start of the assay. The control group grazed together with the inoc ulated animals in the same pasture, isolated from other animals, and h ad a similar management. The possibility of natural infection in the e xperimental model used is discussed.