Optimisation of livestock routing on farms

Abstract

A grass-based livestock farm will typically be partitioned into a set of fields which may not be contiguous. The livestock in question will be distributed among these fields plus a set of buildings. This distribution will change over time as a result of livestock being routed between different locations. This change in distribution is not a random process. It is instead planned by the farmer to satisfy a set of constraints while minimising workload. The set of constraints in question are designed to maximise the performance of the farm and, in many cases, will be large.In this work, we refer to the above planning problem as the Livestock Routing Problem (LRP). We propose modelling the LRP as an integer program, which is a specific type of mathematical optimisation problem. Our model is general in nature whereby many farming activities can be incorporated. These activities include rotational grazing, silage production and livestock breeding.In our analysis we consider many different instances of the LRP and attempt to solve these instances using an off-the-shelf integer program solver. In most cases, an optimal or close to optimal solution is found in reasonable time. These results demonstrate that the proposed methods could be used within a decision support system for livestock farmers and, in turn, reduce the workload associated with the routing of livestock.