Fig 5.

Secretory IgA in the intestinal contents of M. avium subsp. paratuberculosis-infected (grey bars) and uninfected (white bars) compartments collected from mid-jejunal (A) and terminal small intestinal (B) segments. Secretory IgA levels were measured using an IgA-specific ELISA with intestinal contents diluted 1:50. Intestinal samples were assayed from calves 6, 7, and 10, for which there was no evidence of M. avium subsp. paratuberculosis infection in the PBS injected compartments. Data presented are mean A₄₉₀ values and error bars represent SEM.