Relationships between racing times of Standardbreds and v4 and v200

• Published in: Journal of animal science Vol. 88; no. 3; pp. 950 - 954
• Main Author: Lindner, A. E
• Format: Journal Article
• Language: English
• Published: Champaign, IL Am Soc Animal Sci 01.03.2010; American Society of Animal Science
• Subjects: Animal productions; Animals; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Heart Rate - physiology; Horses - physiology; Lactates - blood; Physical Conditioning, Animal; Running - physiology; Terrestrial animal productions; Time Factors; Vertebrates; Heart rate; Lactates; Vertebrata; Mammalia; race record; Horse; Race; exercise; Perissodactyla; lactate; Ungulata; Blood
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/jas.2009-2241

The objective of the study was to examine the validity of v(4) [velocity run under the defined conditions inducing 4 mmol/L of blood lactate concentration ([LA])] and v(200) (velocity run under the defined conditions inducing a heart rate of 200 beats/min) to differentiate performance level among Standardbred racehorses. For this purpose, 19 Standardbred trotting racehorses with differing racing time records in 2 training yards were submitted to a standardized exercise test to determine their v(4) and v(200) (6 horses of one yard only). The test consisted of 4 or more consecutive intervals depending on when the blood [LA] of a horse increased above 4 mmol/L. Speed and time trotted in each interval as well as time between consecutive intervals were the same for horses of a training yard. The blood [LA] measured after each interval was plotted exponentially against running speed to derive v(4) from the blood lactate-running speed relationship, and the mean heart rate during the intervals was plotted linearly against running speed to derive v(200) from the heart rate-running speed relationship. The correlation coefficient between v(4) and the racing time record was 0.77 and 0.75 for horses in racing yard A and B, respectively. There was no correlation between v(200) and the racing time record. Therefore, v(4) is a valid indicator of performance level of Standardbred trotting racehorses; however, v(200) may not be or to a lesser extent.