Author: Kristine Piccart (ILVO) - December 22, 2017
On November 30, the Flemish 4D4F partners ILVO, Liba and Lactis organized a workshop on the profitability of automatic heat detection. The event started off with a brief overview of how to detect heat in dairy cattle, and the available automated systems on the market. Before the start of the event, the dairy farmers were asked to share some of their farm’s fertility KPI’s (anonymously).
Of all 40 participating dairy farms, the median herd size was 120 lactatings cows. The average calving interval was 402 days and the average age at first calving was 24,3 months. Perhaps surprisingly, the farms with more than 120 cows had an on average shorter calving interval (396 days) than the smaller farms (407 days).
The next speaker, professor Geert Opsomer (Ghent University), adressed the most important fertility KPI’s for dairy cattle. He stated that it all starts with a correct identification of the dairy cow. Visual identification of the bulling cows gets increasingly more difficult as the herd becomes larger. Based on his experience, he estimates that around 12% of all cows that are inseminated, are not actually in heat. Activity meters can improve the heat detection rate, which can be estimated by dividing 21 (=the average estrus cycle length) by the average estrus interval on farm, and multiplying that number with 100. Farmers should strive for a heat detection rate of at least 60%. If the rate drops below 60%, that means that there is still some room for improvement, and that automated heat detection might be a good option.
After lunch, Niels Rutten (dairy farmer & technology specialist), demonstrated an online tool for calculating the return on investment for actvity meters and pedometers. The calculation tool was based on the work he did as a PhD candidate at Wageningen University. Using the tool, Niels Rutten illustrated that the sensitivity of the sensor is more important than the specificity, meaning that it’s more costly to miss one heat event than to inseminate a cow that’s not in heat. The herd size does not have a significant impact on the cost-benefit analysis. In most cases, activity meters are shown to be a good investment in the long run.
Finally, the family Guns – Van Den Broeck shared their experience with activity meters during a guided tour throughout their farm. In 2015, the family had three milking robots installed. For them, it was a sensible choice to include activity meters in their new farm set-up. Monitoring the rumination proved to be an added value.