Fig. 7.

Plasma tryptophan levels are decreased in clinically diseased sheep compared to in control animals and M. avium subsp. paratuberculosis-exposed subclinical cases. Results for individual animals are shown, with the median of each group indicated by a horizontal bar. Plasma was collected from experimentally exposed sheep at 15 months postexposure. Clinically diseased sheep were identified in the 2-month period following sampling and necropsies performed to confirm disease status. Unexposed controls, n = 10; exposed (subclinical) cases, n = 13; clinically diseased cases, n = 6. For significant differences, “a” indicates a P of <0.00001 in comparisons with the unexposed control group and “b” indicates a P of <0.0005 in comparisons with the exposed (subclinical) group.