Hordes of viruses and bacteria pose the threat of disease to cattle. Brucella abortus, for example, causes bovine brucellosis (BB), which causes abortions, threatens fertility, lowers milk yields and weakens calves. Vaccination is a primary means of preventing BB, but the currently used vaccine has drawbacks. Agricultural Research Service (ARS) researchers are testing an improved, genetically modified vaccine. ARS efforts to combat infectious bovine rhinotracheitis and other cattle diseases are ...