Fig. 5From: Comparison of a mycobacterial phage assay to detect viable Mycobacterium avium subspecies paratuberculosis with standard diagnostic modalities in cattle with naturally infected Johne diseaseWhen Control animals are stratified by ages 1–3 (53%; 9/17). and 4–12 (47%; 8/17) years, the younger Control animals have significantly fewer plaques (25 ± 16) than the older animals (308 ± 134: Mean ± SEM: p = 0.04; unpaired two tailed t-test.)Back to article page