For this study, we collected sera from 255 cows and 2 bulls in the period from 2004 to 2009, with six-month intervals, a dairy cattle farm in the municipality of Buriti dos Lopes, in the state of Piauí. By the microscopic agglutination test (MAT), we found the following serovars of leptospira: Hardjobovis, Hardjoprajitno (Norma), Hardjoprajitno (WHO). For the control of leptospirosis, a vaccine containing the same serovars that were found infecting the herd was tested. The results showed that in dairy cattle in the basin of Parnaiba, state of Piauí, leptospirosis occurs with a predominance of serovar Hardjobovis. The use of a vaccine containing the most prevalent serovars in the herd applied every six months during the course of five years was important to reduce antibody titers and reproductive problems in cattle.
dairy cattle; immunotherapy; serovars of leptospira; vaccine; reproductive problems