TABLE 2.

Average numbers of tissues positive by culture and histopathology among tissues obtained from calves at necropsy 12 months following oral or intraperitoneal challenge with live Mycobacterium avium subsp. paratuberculosisa

Tissued% Positive tissues for treatment group (unless stated otherwise)
Orali.p.Oral/DXMOral/M
Jejunum + LN (proximal, mid-, and distal)b54254267
Ileum + LN (proximal, mid-, and distal)c17251750
Duodenum + LN50503850
Ileocecal valve501005067
Ileocecal LN2550033
Spleen501005033
Iliac LN75505033
Spiral colon + LN63253850
Transcending colon + LN13132550
Descending colon + LN2501317
Avg no. of positive tissue sites10.38.59.515
Avg no. of tissues with lesions1983115
  • a The total number of tissue sites sampled per calf was 22.

  • b Three sections of the jejunum (proximal, mid-, and distal sections) plus three associated lymph nodes (n = 6) were sampled.

  • c Three sections of the ileum (proximal, mid-, and distal sections) plus one associated lymph node (n = 4) were sampled.

  • d Tissue + LN, the lymph node (LN) associated with that tissue site was also collected (n = 2 tissue sites).