Trade patterns for animal movements of a specific industry are complex to study because they include many stakeholders, farming sites that are spread heterogeneously over the country, and the flow of animals between the farming sites is very dynamic.Two aspects of this complex situation are of special interest for predicting the outcome of an epidemic and for managing the epidemic during such a crisis: the degree of heterogeneity in animal movement and the dynamics of the flow of animals between farms. The movements of cattle and swine were investigated under the conceptual framework networks and analysed using graph theory. The farms of Denmark were considered to constitute the nodes of a network and the links were the animal movements. In this framework, each farm had a sub-network of other premises to which it was linked. A premise was a farm, an abattoir or a market. If no movements of animal were registered then the network was constituted by only that farm. Otherwise, the network of the farmwas linked by the movements on and off the other premises where the animals had resided. This approach allowed illustration and analysis of the four organisational levels of outputs from these registers: the animal, the movements of animals between twofarms, the specific farm network and the overall industry network.
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