IFNG and infection: This study evaluated immune responses to tuberculin and DIVA peptide cocktails (ESAT-6, CFP10, and Rv3615c) in IFN-γ and skin tests in 67 BCG-vaccinated and 67 unvaccinated controls prior to exposure and in 65 unvaccinated and 62 BCG-vaccinated cattle after one year of exposure to natural infection.