Figure 2.

Single intradermal comparative tuberculin testing (SICTT) responses in vaccinated and control calves with visible (VL) and non‐visible lesions (NVL) The calves were tested with SICTT at the fourth (a), eighth (b) and 12th (c) month post‐exposure to infected herd. The means of change in skin thickness following SICTT were significantly greater (unpaired t test with Welch's correction) in control calves with VL than in control calves with NVL at eighth (p = .002) and 12th (p = .002) month post‐exposure to infected herd. However, although the mean of change in skin thickness after SICTT was greater in vaccinated calves with VL than in vaccinated calves with NVL at all the months tested, the differences were not significant at any of the months