[Passive immunity in calves born of cows that have recovered from foot-and-mouth disease or been vaccinated against it].

It has been found that the antibody titers in the case of passive immunity in calves from cows that have recovered from foot-and-mouth disease or have been vaccinated against it rise immediately following the intake of colostrum. They have been found to reach a peak level, displaying maximal values for a long period of time. Later on the antibody titers decline gradually. Specific antibodies have also been demonstrated at the age of more than two months following birth. Higher values of passive immunity have been established in calves from survivals and from cows that have been vaccinated twice and this is explained by the presence of a higher content of foot-and-mouth disease antibodies in the dams. The importance of passive immunity for the prevention of the disease in growing animals is discussed.