The present document describes a technique aiming at detecting antibodies specific of smooth Brucella species (B. abortus, B. melitensis and B. suis) in bovine milk from the bulk tank by the Milk Ring-Test (MRT).

In lactating cattle, the MRT can be used for screening herds for brucellosis. In large herds (> 100 lactating cows), the sensitivity of the test becomes less reliable.

False-positive reactions may occur in cattle vaccinated less than 4 months prior to testing, in samples containing abnormal milk (such as colostrum) or in cases of mastitis.