Diurnal and Seasonal fluctuations in rectal temperature, respiration and heart rate of pack donkeys in a Tropical Savannah zone.
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Date
2014
Journal Title
Journal ISSN
Volume Title
Publisher
Japanese Society of Equine Science
Abstract
The study was designed to determine diurnal and seasonal changes in basic physiologic
responses of donkeys adapted to the tropical Savannah. The rectal temperature (RT),
respiratory rate (RR) and heart rate (HR) of six male Nubian pack donkeys, and the drybulb
temperature (DBT), relative humidity and heat index of the experimental site were
concurrently recorded hourly, from 06:00 h to 18:00 h (GMT +1), for three days, spread
1 week apart, during the cold-dry (harmattan), hot-dry and humid (rainy) seasons, in an
open grazing field. Values of the physiologic parameters recorded during the morning
(06:00 h–11:00 h) were lower (P<0.001) than those obtained in the afternoon (12:00
h–15:00 h) and evening (16:00 h–18:00 h) hours in all seasons, but the robustness of
the diurnal rhythm differed (P<0.05) between seasons. Many diurnal hourly DBT mean
values recorded during the harmattan and hot-dry seasons fell outside the established
thermoneutral zone for tropically-adapted donkeys, while those obtained during the rainy
season were within the zone, indicating that the dry seasons were more thermally stressful
to the donkeys than the humid season. Overall mean RT dropped (P<0.05) during the
harmattan season. The RR rose, while HR dropped (P<0.001) during the hot-dry season. In
conclusion, daytime and season had profound influence on RT, RR and HR of the donkeys,
therefore, diurnal and seasonal variations should be taken into account during clinical
evaluation before reaching conclusion on health status and fitness for work in donkeys.
Description
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Keywords
clinical evaluation,, fitness,, physiologic parameters,, stress,, thermal load
Citation
16