“The National Animal Health Monitoring System Dairy 2007 study indicates that 68.1 percent of U.S. dairy operations are infected with Mycobacterium avium subspecies paratuberculosis (MAP), the organism that causes Johne’s disease” (https://johnes.org/handouts/files/CostofJD_IDEXX%20booklet.pdf). “Johne’s disease is a contagious, chronic and usually fatal infection of cattle that causes a thickening of the intestines.” This disease also prevents the absorption of nutrients and all ruminates can be infected. Johne’s disease is a herd problem because mothers can easily pass it to nursing young. But the real question is; how did the mother become infected to begin with? “Johne’s spreads primarily through ingestion of feed or water contaminated by manure from infected animals” (www.in.gov). With this knowledge…show more content… Symptoms rarely begin to show before two or more years from the infection date.
Stage one is silent and non- detectable for the most part.
Stage two the cattle appear healthy, but they are passing the disease to the environment through their manure.
Stage three includes visible symptoms: “watery diarrhea, weight loss, and a drop-in feed efficiency and milk production” (www.in.gov). These visible symptoms are a cause of the cattle’s immune system fighting the disease. Special cells take up the bacteria into the ileum, which is located in the small intestines. The body responds by preventing any further damage by creating a thick protective barrier of mucus all around the intestinal lining. Nutrients will have a near impossible chance of being absorbed which causes the eventual diarrhea, in addition, this contributes to the weight loss despite appearing and eating well (https://www.aphis.usda.gov/publications/animal_health/content/printable_version/faq_johnes_disease08.pdf).
Stage four is the end of the process and usually results in the animal looking extremely