To obtain a better understanding of disease progression and provide a means of profiling the disease within a herd, three types of diagnostic tests were applied to study herds. Humoral immune response to M. paratuberculosis was evaluated using an absorbed antibody ELISA. Cellular immune response to M. paratuberculosis was evaluated by measuring the release of bovine g-IFN from whole blood cell cultures. Cattle shedding M. paratuberculosis were identified using either culture or the M. paratuberculosis specific DNA probe. Utilization of the two tests to measure immune response gave results which exhibited good sensitivity and specificity and allowed detection of immunologically sensitized animals at both early and late stages of infection. Information from the g-IFN assay can be used in conjunction with the absorbed antibody ELISA and the DNA probe to create a herd profile in less than a week. Monitoring both disease progression and eradication on a herd basis and in individual animals can be performed using a herd profile and repeated testing of the herd.