The National Johne's Demonstration Herd Project (NJDDHP) in the United States was initiated to evaluate the long-term feasibility and effectiveness of management practices to control Johne's disease on dairy and beef cattle operations. The NJDDHP started in 2003 and includes approximately 90 beef and dairy operations in 17 states. All herds began with culture-confirmed Mycobacterium avium subspecies paratuberculosis(MAP) on the operation, and all herd owners agreed to make efforts to control exposure of young cattle to adult cow fecal contamination. A Cox Proportional Hazards model was used to evaluate incidence of fecal shedding while adjusting for effects of herd. Cows were divided into 3 cohorts: -2 = cows born 13-24 months prior to program participation, -1 = cows born 1-12 months prior to program participation, and 0 = cows born 0-11 months after beginning the program. Results to date indicate that after three years of follow-up, dairy cattle born since the beginning of the project had a significantly decreased risk of being fecal culture positive and of fecal shedding at moderate to high levels compared to cattle born 2 years prior to the start of the project (Fecal-culture positive: Cohort -1: HR 0.61, p=0.08; Cohort 0: HR 0.49, p<0.02; Fecal shedding at moderate-to-high levels: Cohort -1: HR 0.77, p=0.36; Cohort 0: HR 0.49, p=0.02) . In beef herds, there was not a significant decrease in risk, but there are fewer enrolled beef herds. These results suggest that management efforts initiated since the beginning of the project were effective in reducing incidence MAP. However, further analysis is needed to identify those efforts that have the greatest effect on incidence.