Revista Chilena de Historia Natural 84 (2): 263-268, 2011
RESEARCH ARTICLE
Comparison between circadian motor activity in pony and
horse
In this study we investigated the influence of body mass on the daily rhythm of
total motor activity in ponies and horses. Six clinically healthy Shetland pony breed with a body mass of 180 ± 30 kg and
six healthy horses Sella Italiana breed with a body mass of 530 ± 20 kg were used. Animals were equipped with actigraphy-
based data loggers, Actiwatch-Mini® to record total activity. The application of two way ANOVA showed a highly significant
effect of time of day and body mass on motor activity. Cosinor analysis identified the periodic parameters and their
acrophases during the two days of monitoring. Mesor and amplitude were statistically higher in horses than in ponies and
no statistically significant differences was found about acrophases and robustness. In conclusion we suppose that the
difference in the amount of total motor activity, in animals that differ in breed, as pony and horse, may lie in physical
differences.
Key words:
body mass,
daily rhythm, Equus caballus, locomotor activity
