Although heat detection makes a relevant contribution to good reproduction performance of dairy cattle, available studies on the economic evaluations of automatic heat detection systems are limited. Therefore, the objective of this article is to provide an economic evaluation of using automatic heat detection. The effect of different heat detection rates on gross margin is modelled with SimHerd (SimHerd A/S, Denmark). The analysis considers all additional investment costs in automatic heat detection. The economic evaluation is carried out on the assumption of two different herds of Simmental cattle with milk production levels of 7000 and 9000 kg and herd sizes of 70 and 210 cows, respectively. Furthermore, we distinguish between two investment scenarios: In scenario 1, only cows are equipped with automatic heat detection, while scenario 2 assumes that cows and heifers are equipped with automatic heat detection. Because some variables are relatively uncertain (heat detection rates; time for heat control), they are modelled with triangle distributions using the Monte Carlo method in @RISK (Palisade Corporation software, Ithaca NY USA). This makes it possible to model a probability distribution for the net returns of investment in automatic heat detection.  

The simulation results show that the net return of investing in an automatic heat detection system ranges in all scenarios from -33 to +111 € per cow and year, with mean values of +6 to +35 € per cow and year. In general, the net return is independent of the milk production level assumed. A comparison amongst all scenarios shows higher net returns for bigger herd sizes, due to fixed cost degression effects. Considering all scenarios, the probability of a positive net return of using an automatic heat detection system is 82 %. The economic advantage or disadvantage depends strongly on the current fertility management of a dairy farm without automatic heat detection. Additionally equipping heifers with the system has a strong positive effect on the economy of automatic heat detection systems, due to the resulting reduction in the age at first calving.