Samples of serum of 376 lactating cows were analyzed for research of antibodies against the virus of the bovine viral diarrhoea virus, through the test of indirect ELISA. The study was accomplished in 10 dairy herds located in the South region of the State of Minas Gerais and Northeast region of the State of São Paulo, between the months of march and june of 2000. In all the herds were found reactor animals and the occurrence in the two regions was proportionally similar. In the South region of the State of Minas Gerais the occurrence was 57,56% and in the Northeast region of the State of São Paulo was 56,49%. Also were analyzed the characteristics of the properties and of the flocks and the largest occurrences were found in the simplest flocks and in properties less technicality.
Bovine Viral Diarrhoea; Serum; ELISA; Antibodies