Department of Animal Science
First Advisor
Lena M. Luck
Date of this Version
5-2017
Abstract
Monitoring horse activity continually is a valuable aid for horse caretakers to provide recommendations to help users meet their goals and improve overall horse health. Activity trackers commonly use an accelerometer to determine steps and exercise intensity. The activity level capabilities using a 3-axis accelerometer were tested in three locations on the horse. The objectives were to determine which location results in the most accurate step count, threshold values for each gait and to identify correlations between the thresholds and horse characteristics. Twenty-four horses wore three identical smartphone accelerometers, one in each of three locations: right side of the head attached to a halter, right front leg, and right back leg attached to a boot slightly above the fetlock. Acceleration data was collected as the horses performed each gait (walk, trot, canter) for one minute. The accelerometer output was compared to step count and exercise intensity as determined from video recordings. MATLAB was used to process the acceleration data using a Fourier transform to calculate step frequency and total step count for each trial. Threshold values to delineate between gaits were determined by the maximum and minimum acceleration values observed during each gait for all horses in the study. Additionally, threshold values for the average frequency (cycles per second) were identified for each gait. The results revealed a significant difference (p=0.02) between all three sensor locations and the video analysis. While all the sensors significantly underestimated the step count, the front leg location was the most accurate with no significant difference between calculated steps and video analysis at the walk. Analysis of step frequency allowed for the definition of distinct step frequency ranges for walk, trot, and canter. The height of the horse significantly interacted with step frequency for the canter only. An equine activity monitor using an accelerometer yields more accurate step counts when placed on the front leg of the horse for future energy expenditure estimates, though horse height needs to be considered for the canter.
Advisor: Lena M. Luck
Comments
A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Animal Science, Under the Supervision of Professor Lena M. Luck. Lincoln, Nebraska: May, 2017
Copyright (c) 2017 Carol J. Thompson