Dynamic stochastic model of robotic milking of dairy cows

A dynamic stochastic simulation model was built to study the functioning of an automatic milking system and the labor planning of a farmer. The components of the model are formulated, being the milking robot, the cow selection units, the milking units, the cows and the farmer. The model assumptions are described in the paper. Most parameters of the standard situations are estimated from studies on commercial farms. The model can simulate two working methods with automatic milking systems, automatic milking with a computer-controlled cow traffic and voluntary visits of cows to the milking unit, and automatic milking with a human-controlled cow traffic and forced visits of cows to the milking unit in fixed periods of the day. Important features are the inclusion of robot failures, the availability of the farmer to the system and the ability to combine automatic milking with pasturing of cows. Effects of unscheduled downtimes of the milking robot on the quality of the milking process can be studied. Tests of the accuracy of the model against results with automatic milking applied on a commercial farm suggest an accuracy of within 5%.