Assessing intrastate cattle shipments from interstate data and expert opinion

Live animal shipments are a potential route for transmitting animal diseases between holdings and are crucial when modeling spread of infectious diseases. Yet, complete contact networks are not available in all countries, including the United States. Here, we considered a 10% sample of Interstate Certificate of Veterinary Inspections from one year (2009). We focused on distance dependence in contacts and investigated how different functional forms affect estimates of unobserved intrastate shipments. To further enhance our predictions, we included responses from an expert elicitation survey about the proportion of shipments moving intrastate. We used hierarchical Bayesian modeling to estimate parameters describing the kernel and effects of expert data. We considered three functional forms of spatial kernels and the inclusion or exclusion of expert data. The resulting six models were ranked by WAIC and DIC and evaluated through within- and out-of-sample validation. We showed that predicti...