The National Johne's Demonstration Herd Project (NJDDHP) in the United States was initiated to evaluate the long-term feasibility and effectiveness of management-related practices designed to control Johne's disease on dairy and beef cattle operations. The NJDDHP was started in 2003, but a few States had demonstration herds prior to the start of the National Project. The NJDDHP includes 67 dairy herds and 21 beef herds in 17 states. Adult populations in these herds range from 35 to more than 4,000 animals. All enrolled herds began with culture-confirmed Mycobacterium avium subspecies paratuberculosis (MAP) on the operation. Sufficient time since the start of the NJDDHP has now elapsed such that Johne's testing information on cattle born since the beginning of the project are becoming available. Using a generalized estimating equations approach to adjust for effects of herd and after adjustment for cow age, odds for fecal shedding at moderate to high levels were significantly less in the third year of the project compared to the first year (3^rd Year OR=0.73 95% CI 0.56,0.96). Compared with the first year, significant differences were also noted for both dairy and beef herds by ELISA test results (Dairy: 2^nd Year OR=0.80, 95% CI 0.65,0.97; 3^rd Year OR=0.75 95% CI 0.62,0.91 Beef: 2^nd Year OR=0.85, 95% CI 0.59,1.25; 3^rd Year OR=0.36, 95% CI 0.24,0.55). These results to date suggest that herd prevalence has decreased since the beginning of the project.