Table 4.

Serological responses and lesion scores of cull cows infected with M. avium subsp. paratuberculosis

GroupMedian (range) of serological response (S/P %)aLesion score (range)b
Distal ileum and ileocecal valveMesenteric and ileocecal lymph nodesCombined tissues
Control1.3 (0.4–32.1)3.5 (2–7)0 (0–0)3.5 (2–7)
Nonlesioned/M. avium subsp. paratuberculosis infected0.3 (0–4.2)4.5 (2–8)0 (0–0)4.5 (2–8)
Moderately lesioned243.6 (139.8–290.6)15 (10–19)5 (3–10)20 (13–27)
Severely lesioned259.5 (180.4–338.0)22 (20–24)12 (8–12)34 (29–36)
  • a S/P percentage = 100 × [sample optical density at 450 nm (OD450) − negative-control OD450]/[positive-control OD450 − negative-control OD450].

  • b Maximum score of 24 for distal ileum and ileocecal valve, 12 for mesenteric and ileocecal lymph nodes, and 36 for the combination of the four tissues.