A Field Study of Oxygen Consumption and Estimated Energy Expenditure in the Exercising Horse

Abstract

Hanak J., P. Jahn, R. Kabe‰, M. Sedlinska, Z. Iert, J. Mezerova, O. Chvatal: A Field Study of Oxygen Consumption and Estimated Energy Expenditure in the Exercising Horse. Acta Vet. Brno 2001, 70: 133-139. The major goal of this study was to estimate the aerobic and anaerobic contribution to energy expenditure in the running warmblood horse under field conditions. The oxygen consumption (VO 2 ) in 12 saddle horses was determined at rest, walk, trot, and canter and in 6 horses at gallop. In the 10 min immediately following exercise the relative oxygen debt (RD-VO2) was measured. The horses were exercised by riders in the various gaits at speeds representing 15, 30, 50 and 70% of the their individual maximum speed (Vmax). The distances covered were 3000 m in each walk, trot and canter and 1500 m in gallop. VO 2 and RD-VO 2 m and energy expenditure (J.kg.min-1) using the oxygen caloric equivalent of the measured respiratory quotient (RQ) were studied for possible relations to the speed. The proportion of anaerobic energy expenditure (%E anaer.) to the total energy production was also investigated. A linear relation between speed and aerobic energy expenditure (E) and a quadratic relation between speed and anaerobic energy expenditure (RD-E) and total energy expenditure (TE) was found. The %E anaer. was 1.21 ± 0.40 at a speed of 15% V max , 3.40 ± 0.38 at 30% V max , 18.58 ± 2.05 at 50% V max , and 29.47 ± 1.17 at 70% V max . Post-exercise oxygen uptake appears a suitable measure for the major part of the oxygen debt (relative oxygen debt) and could be considered as an indicator of anaerobically released energy. For this reason it may also be an indicator of the anaerobic capacity of the horse at a standard or maximal exercise.