A throughout evaluation of the Lely Astronaut automatic milking system’s health report

Abstract

In 2016, Lely introduced a health report; an extension of the earlier udder health report that was part of the management system (Time for Cows, T4C). The health report enables the farmer to be able to detect more diseases than just mastitis with the Lely Astronaut. The overall goal of this study is to evaluate the performance of the health report from the management system T4C from the Lely Astronaut. To get this insight, the positive and negative predictive value has been calculated, the number of false positives has been determined and the use of the health report by farmers has been examined. Six farms around Utrecht that use a Lely Astronaut were visited three to four times for the study. During the first visit, a questionnaire was taken to get an impression of the farm. Each visit the farmer was interviewed about the attentions on the health report that day. After this interview, the student examined the cows that were on the health report that day with the aid of two flowcharts. The student also visually assessed with the aid of a flowchart the health of five cows randomly selected per AMS that were not on the health report. A total of 41 attentions were examined on the health reports. In this study, a value of 90% was found for the positive predictive value and a value of 89% was found for the negative predictive value. Furthermore, a percentage of 10% false positives has been found. Farmers checked once a week to three times a day the health report and it appeared that on average 56% of all attentions are checked by the farmers. The most important reason to check a cow on the report is when the attention for increased conductivity or mastitis attention is on the report. It can be concluded that the health report of T4C van Lely has been improved compared to the udder health report of T4C. The positive predictive value has increased compared to previous findings and farmers are checking more attentions than before. However, cows are still missing on the report and for this reason the report is mainly used for the detection of mastitis. It is a challenge for Lely to improve the detection models drawn wider than mastitis with the aim of missing fewer cows on the health report.