Use of sensor systems on Dutch dairy farms

A survey was developed to investigate the reasons for investing or not in sensor systems on dairy farms, and to investigate how sensor systems are used in daily cow management. This survey was sent to 1,672 Dutch dairy farmers. The final dataset consisted of 512 dairy farms (response rate of 30.6%); 202 farms indicated that they have one or more sensor systems and 310 farms indicated that they do not have any sensor systems. In total, for 95 dairy farms with oestrus detection sensor systems, information about the average calving interval for the years 2003 to 2013 was available. In addition, for 30 dairy farms with oestrus detection sensor systems for young stock, information about the average first calving age was available for the years 2003 to 2013. The most common sensors on farms with an automatic milking system are sensor systems to measure the colour and electrical conductivity of milk. In total, 41% of farms with an automatic milking system had activity meters/pedometers for dairy cows, and 70% of farms with a conventional milking system and sensor systems also had activity meters/pedometers for dairy cows. The main reasons for investing in activity meters/pedometers for dairy cows were to improve detection, improve the profitability of the farm and to gain insight into the fertility level of the farm. The most important reasons for not investing in sensor systems were economic. Having an oestrus detection sensor system was not linked with the average calving interval of the farm. Furthermore, having an oestrus detection sensor system for young stock was not linked with the average first calving age. These results suggest that the farmers use the same rules on when to start inseminating as without oestrus detection sensor systems, and as a result there is no change in first calving age and calving interval.