Measuring Activity-Rest Condition by Using Two Different Accelerometer Devices in Trained and Retired Horses

To advance technological applications in animal welfare assessment, this study evaluated resting activity as a component of total locomotor activity (TLA) in horses using two different accelerometer devices: a collar-mounted device containing a single-axis accelerometer that records physical movement, and a three axes accelerometer that classifies the measured physical activity into nine different activities. Ten clinically healthy Italian saddle horses were enrolled in the study and divided into two groups on the basis of their lifestyle. Group A consisted of regularly trained horses housed continuously in boxes, Group B comprised retired horses turned out in paddocks during the day and stabled in boxes at night. TLA was simultaneously monitored for 48 consecutive hours using both devices, in each horse. Two-way ANOVA applied to the one-axis and three-axis data showed a significant effect of group (p < 0.0001) and day in group A (p < 0.0001), with higher intensity values during day 1 compared to day 2 (p < 0.0001). A significantly greater amount of time spent in the "Lying/sitting rest" (recumbency) position was observed in group A (3.37 h ± 1.19 h) compared to group B (1.88 h ± 0.06 h), in both days of monitoring (p < 0.0001). A greater amount of time spent in the "Lying/sitting rest" (recumbency) position was observed during day 1 (4.16 h) compared to day 2 (2.58 h), in group A (p < 0.0001). Both devices detect the same qualitative pattern of group and day differences. Different amounts of activity were observed in trained and retired horses, with more rest periods in trained than in retired horses.