Jembrana disease virus (JDV) is a newly recognised bovine lentivirus causing an acute disease syndrome in Bali cattle (Bos javanicus) in Indonesia. We evaluated the effect of JDV infection on the antibody response to chicken ovalbumin (cOVA) and Brucella abortus Strain 19 in Bali cattle. In infected cattle the IgG and IgM response to cOVA was suppressed and delayed and the IgG response to B. abortus Strain 19 was delayed. The results indicate that the humoral immune response is suppressed and delayed in JDV infected cattle.