Evaluation of the Thuringian Bovine Johne’s Disease Control Program—A Case Study

SIMPLE SUMMARY: Paratuberculosis, or Johne’s Disease, occurs worldwide, causing a granulomatous enteritis in ruminants. Control programs, which operate mainly on a voluntary basis, have been established in several regions. In Thuringia, a federal state of Germany, a voluntary control program was firstly established in 2003 and revised in 2008 and 2015. This study aimed at evaluating the results achieved in voluntary Johne’s Disease control in Thuringia between 2015 and 2020. By the end of 2020, a total of 67 dairy herds with approximately 33,000 dairy cows and 87 suckler herds keeping approximately 6000 cows of beef breeds were enrolled, representing 35% or 16% of the population, respectively. In affected herds, the program focused on prevalence reduction by hygienic measures to break the infection cycle, annual testing for the detection of animals shedding the infectious agent and culling of these animals. A certification pathway was established based on a testing period of 3 years without positive results, and 58 herds were certified as ‘non-suspect’ with respect to Johne’s Disease. Analyzing the annual calf mortality rate in enrolled dairy farms revealed that herds that had been certified as ‘non-suspect’ regarding Johne’s Disease had a lower calf mortality rate than herds that were not enrolled in the program. ABSTRACT: The Thuringian Johne’s Disease (JD) Control Program provides a voluntary approach to JD control in Thuringia, a federal state of Germany. The program has three objectives: reduce the level of infection when present; reduce the spread of JD to uninfected herds; and facilitate the certification and protection of herds that are non-suspect with respect to JD. The program offers pathways for the management of affected herds and for certification of herds with continuing negative tests. After the control stage (CS), a certification stage of at least 3 consecutive years with continuing negative results in the annual whole-herd test has to be passed until a herd can be certified as ‘non-suspect’ with respect to JD. This study focused on calf mortality in relation to JD herd status. In a longitudinal study, the association of annual calf mortality rate of a total of 93 dairy herds (13 ‘non-suspect’; 26 in control stage; 54 not enrolled) over 10 consecutive years with JD herd status was investigated using a generalized mixed linear model with repeated measures. Non-suspect herds had a lower calf mortality rate compared with other farms. We conclude that establishing JD control measures lowers the calf mortality rate.