A. Example of interpolation. Blue squares represent the original data (whenever it is available). Dashed blue line is the interpolation and red squares represent the new “samples” in the new time points (every 180 days). B. Schematic timeframe of positive and negative fecal data for one cow. “−” and “+” indicate negative and positive samples, respectively. In this example, there are two negative and two positive samples. The cow is susceptible (X) until the first negative sampling point, latent (H) between the first negative sampling and the first positive sampling, late shedding (Y1) between the first positive sampling and the second negative sampling and non-shedding infected (Y2) between the last negative sampling and its death.