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Physiological, metabolic and biochemical responses of horses competing in the speed and endurance phase of a CCI**** 3‐day‐event
Author(s) -
MARLIN D. J.,
HARRIS PATRICIA A.,
SCHROTER R. C.,
HARRIS R. C.,
ROBERTS C. A.,
SCOTT C. M.,
ORME C. E.,
DUNNETT M.,
DYSON SUE J.,
BARRELET F.,
WILLIAMS B.,
MARR CELIA M.,
CASAS I.
Publication year - 1995
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/j.2042-3306.1995.tb05006.x
Subject(s) - horse , heart rate , zoology , wet bulb globe temperature , medicine , mathematics , biology , blood pressure , heat stress , paleontology
Summary The present study was undertaken to investigate physiological, metabolic, haematological and biochemical changes in horses competing in the Speed and Endurance test of a Concours Complet International (CCI) **** 3‐day‐event held under FEI rules. A total of 28 horses competing in the Burghley Horse Trials Speed and Endurance test were selected to be monitored: 11 horses in 1993 and 17 horses in 1994. Of the 28 horses selected, 17 completed the Speed and Endurance test and went on to complete the showjumping test. Mean ± s.d. shade temperature and relative humidity, black globe temperature and wind speed were 13 ± 1 and 20 ± 2°C, 54 ± 3 and 55 ± 10%, 17 ± 2 and 29 ± 4°C and 2.7 ± 0.7 and 1.2 ± 0.3 m/s, for 1993 and 1994, respectively. Mean heart rate during Phases A, B and D was not significantly different between years, but mean heart rate during Phases C and X was significantly higher in 1994. Mean (± s.d.) heart rate on Phases B and D for all horses in both 1993 and 1994 was 198 ± 8 and 188 ± 11 beats/min, respectively. Mean heart rate during Phase D showed a poor correlation with mean speed (r=0.412). Total mean (± s.d.) weight loss from the start of Phase A to the end of Phase D was 15.5 ± 6.1 kg in 1993 and 16.5 ± 5 kg in 1994 and did not differ significantly between years. Following 14–18 h completion of Phase D , mean bodyweight was not significantly different from that at the start of Phase A in either year. Mean rectal temperature at the end of Phase D was 41 ± 0.6°C and 41.1 ± 0.6°C in 1993 and 1994, respectively (P>0.05). Both the lowest (39.7°C) and highest (41.8°C) rectal temperatures were recorded at the end of Phase D in 1994. Plasma lactate concentrations at the end of Phase D were 8.5–38.5 mmol/1. The highest lactate concentration also coincided with the highest plasma glucose concentration (11.4 mmol/1) as well as the joint fastest time in either year, although overall lactate showed only weak correlations with mean speed on Phase D (r=0.12, 1993; r=0.58, 1994). While the Speed and Endurance test at CCI**** level run in a temperate climate presents a considerable challenge to the fitness and ability of the horses competing, the metabolic and physiological changes are not extreme. The majority of horses that finish the test appear to undergo a rapid and considerable degree of recovery and are able to present sound at the final inspection, take part in the showjumping test and complete the competition.