Embedded sensor technology for real time determination of animal lying time

Lameness in dairy animals poses an immediate and significant animal welfare and economic concern. A new sensor has been developed to monitor and record the lying patterns of dairy cows in order to benefit the study of lameness. The sensor utilizes an embedded accelerometer to measure the orientation of the hind leg of an animal based on the relative direction of the gravitational field. A microcontroller with nano-watt power technology facilitates sensor sampling, data recording and time stamping, and interfacing with external hardware systems. The interrupt triggered firmware protocol enabled low power consumption and made efficient use of microcontroller's resources. A single measurement axis, oriented with the vertical position of the animal's hind leg, was found to be sufficient in determining lying activity. In repetitive testing on three unique Holstein dairy cows, the layometer sensor recorded 100% of the lying events and had a total difference in lying time of 2.2% when compared to a human observer. It was also shown that unique sensors provided a statistically similar response when applied to the same test animal. The technology presented within this publication is protected under international patent application PCT/US2008/059234.