Fig. 1

Time-course of M. bovis positive samples from four anatomic sites (nares, eyes, ear canal, vagina) or combinations thereof over 10 sampling days (birth [0* ≤ 9 days of age] to 15 months of age) in all calves from Farm A (N = 72) and Farm B (N = 72) that were comingled at a heifer rearing facility. The graph shows the overall dominance of nasal positives and their apparent importance in transmission