Estimating Digestible Energy Requirements of Three-day-event Horses Using KER ClockIt Sport Smartphone Application
Joe D. Pagan1, Kathleen O’Neill1, Natalie Ireland1 and Mike Davies2
1Kentucky Equine Research, Versailles, Kentucky, USA; 2ClockItEQ, Ltd., Perth, Western Australia
This study estimated digestible energy (DE) requirements of three-day-event horses during training in the early stages of the 2015 American eventing season using a novel smartphone application (KER ClockItTM Sport; Kentucky Equine Research, Versailles, KY). Heart rate (HR), session duration, and distance traveled were measured in 26 eventers representing 5 different levels of competition. The horses included 5 Advanced (including 3* and 4*), 5 Intermediate (including 2*), 7 Preliminary (including 1*), 5 Training, and 4 Novice level horses of Thoroughbred, Warmblood, and other sport-horse bloodlines. A Bluetooth-equipped heart-rate monitor (Polar H7; Polar Electro Inc., Lake Success, NY) was used to measure and transmit HR data to the application. Velocities were divided into 5 ranges corresponding to the most common gait at each speed. During each training session, time and average HR at each gait were calculated. These data were used to calculate energy expenditure using a regression equation that estimated oxygen consumption from HR. Weekly energy expenditures were calculated for each horse, and DE requirements were estimated based on maintenance DE requirements and previously determined efficiencies of utilization of DE for exercise. DE requirements were expressed as percentages of maintenance DE. DE requirements for horses training at Novice, Training, Preliminary, Intermediate, and Advanced levels averaged 124%, 131%, 145%, 158%, and 148% of maintenance, respectively (Table 1). DE requirements (% maintenance) were highly correlated with both total distance (km) trained per week (DE % = 1.337 X km traveled/wk) + 96.7)(R2=.98) and total time (hr) spent training per week (DE % = 13.46 X hr exercise/wk) + 86.0)(R2=.95). HR and duration of exercise can be used to estimate DE requirements for different disciplines. These equations can then be used to estimate DE requirements for individual horses by monitoring their weekly activity with the KER ClockItTM Sport smartphone application.
Table 1. DE (% maintenance) required, distance (km/week), and time (hr/week) of exercise in different levels of event horses.
| Novice | Training | Preliminary | Intermediate | Advanced | |||||||
| DE (% maintenance) | 123.5 ± 3.1a | 131 ± 2.8a | 145.3 ± 3.7a,b | 158 ± 9.8b | 147.8 ± 6.7a,b | ||||||
| Distance (km/wk) | 18.92 ± 1.9a | 27.92 ± 2.4a,b | 36.43 ± 2.1b,c | 45.8 ± 2.3c | 37.1 ± 1.7c | ||||||
| Time (hr/week) | 1.31 ± 0.23 a | 3.59 ± 0.26 a,b | 4.39 ± 0.28b | 5.07 ± 0.26b,c | 4.81 ± 0.13b,c | ||||||
| a,b,c values with unlike superscripts are different | |||||||||||