Technical Abstract: Johne's disease is a chronic, debilitating intestinal disorder in cattle, sheep and wild ruminants, characterized by diarrhea, weight loss and death. Animals usually become infected when they are young by ingesting feces or milk containing the causative bacteria. However, clinical signs of disease do not usually present themselves until the animals reach 3 to 5 years of age or even older. During this time the animal is infected and may be shedding the organism in its feces without showing any clinical signs of disease. In addition to reduced production by these animals, they also present a potential infective threat to the rest of the herd. Johne’s disease is difficult to diagnose and therefore to control. Control measures for paratuberculosis include management at the herd level to reduce exposure of neonates to contaminated manure or milk. Vaccination is another management tool that is becoming more widely used. Studies reported herein have yielded results that have helped to improve our understanding of the epidemiology of transmission of MAP to youngstock and adult animals, as well as identify useful management strategies for controlling this costly disease.