Economic Impact on Herd Level of Three Categories of Lameness Causing Disorders Estimated Through Simulation

The stochastic, mechanistic and dynamic simulation model Simherd was used to quantify the economic impact of three (aggregations of) diseases causing lameness.
In this simulation study, these three modeled disorders were Digital Dermatitis (DD), Interdigital Phlegmon (IP) and Hoof Horn Disorders (HHD). Parameters on risk factors and effects of the three disorders were retrieved from literature review.
Cow specific risk of each lameness disorder was calculated at each timestep in the simulation by a logistic regression model and an incidence of the disorders was triggered stochastically. The simulation was run with prices, treatment costs and management strategies representative for Danish dairy farms in 2007.
A pair wise comparison was made between each of three scenarios and one default scenario (default). In the latter, risks parameters for all three disorders were set to represent first-case incidence of 10, 3 and 18 cases per 100 cow-years of DD, IP and HHD, respectively. In the other three scenarios the risks for DD, IP and HHD was doubled. Compared to a gross margin per cow-year in the default scenario of €2231, margin decreased with ...