The voluntary NYS Paratuberculosis Eradication and Certification Program was started in 1985 and during 1990 had an active enrollment of 85 dairy and 15 beef farms. The program emphasizes cooperation between the herd owner, herd veterinarian, and the NYS Diagnostic Laboratory. Through biannual fecal culture testing and implementation of practical management procedures to prevent continued spread of infection, effective control programs can be designed to accommodate herds with widely varying degrees of infection. Participating herds are certified "Paratuberculosis-free" by the NYS Department of Agriculture and Markets after three consecutive negative herd tests. Owners of several severely infected herds (over 10% prevalence by fecal culture) who have actively pursued a testing and management program for 3-5 years have significantly reduced the prevalence of Johne's disease in their herds and made large improvements in overall herd productivity.