Predicting cattle grazing behavior on rangeland using accelerometers

Authors: SPRINKLE, JAMES - University Of Idaho; SAGERS, JOSEPH - University Of Idaho; HALL, JOHN - University Of Idaho; ELLISON, MELINDA - University Of Idaho; YELICH, JOEL - University Of Idaho; BRENNAN, JAMESON - South Dakota State University; Taylor, Joshua - Bret; LAMB, JAMES - Furst-Mcness Company

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/13/2020
Publication Date: 5/1/2021
Citation: Sprinkle, J., Sagers, J., Hall, J., Ellison, M., Yelich, J., Brennan, J., Taylor, J.B., Lamb, J. 2021. Predicting cattle grazing behavior on rangeland using accelerometers. Rangeland Ecology and Management. 76:157-170. https://doi.org/10.1016/j.rama.2020.10.001.
DOI: https://doi.org/10.1016/j.rama.2020.10.001

Interpretive Summary: An accelerometer is a tool that measures acceleration. It is used in many kinds of machines and equipment, the most familiar being automobiles, boats, and aircraft. It can be designed to measure acceleration along one (e.g., forward-backward), two (e.g., left-right and forward-backward), or even three axes (e.g., left-right, forward-backward, up-down). Recently, researchers have proposed and initially tested the three-axis accelerometer as a tool for measuring and describing the daily activity of grazing cattle. Accordingly, we set out to evaluate the utility of using three-axis accelerometers to estimate the daily activity of different types of cattle that were grazing in a sagebrush steppe ecosystem. By using this advanced technology, we were able to discover how daily activity patterns of grazing cows were altered by the grazing system, climate, animal-efficiency type, and supplements fed. Based on the results, we suggest that an individual cow’s accelerometer data should be paired with in-the-field observations of the cow, so that proper accelerometer calibrations can be performed to increase measurement precision.

Technical Abstract: The objective was to determine if 3-axis accelerometers could be used to predict daily activity for cattle grazing rangeland. There were 48 Hereford × Angus 2-yr-old low- or high-residual feed intake (LRFI or HRFI) cows used in this 2-yr trial. Cattle grazed in 4 pasture treatments consisting of continuously grazed, control (CCON); continuously grazed, supplemented (CTRT); rotationally grazed, control (RCON); and rotationally grazed, supplemented pastures (RTRT). Three LRFI- and 3 HRFI-collared cows in each treatment had accelerometers mounted for 29 d in 2016 and 45 d in 2017, beginning mid-October. Grazing time (GT), resting time (RT), and walking time (WLK) were obtained on each cow by direct observation over 3 d each year and compared to accelerometer predicted behavior. In 2016, 1.6% of the days were rejected for halter mounted accelerometers and 3.6% were rejected in 2017 for collar mounted accelerometers. The GT and RT were more accurately predicted than was WLK with the percentage error of predicted against observed data being 11.94% for RT, 13.51% for GT, and 30.13% for WLK in 2017. Less observation data were available in 2016, but when considering other sampling periods for the same cows and halters, the error rate was 15.1% for RT, 19.3% for GT, and 52.6% for WLK. The accelerometers successfully identified patterns of grazing behavior and differentiated between climatic, grazing system, supplementation status, and RFI classification influences upon GT, RT, and WLK. In a more moderate climate year, HRFI cattle appeared to rest less (P < 0.08) and walk more (P < 0.07) than LRFI cattle. Similar patterns were observed for cattle in the CCON vs CTRT treatments, with supplemented cattle resting more (P < 0.05) and walking less (P < 0.05). Accelerometers appear to be effective in determining mechanistic adaptations in grazing behavior by beef cattle on range.