Northeast Brazilian donkeys have little physiological responses influenced by tropical conditions

ABSTRACT

Ten northeast Brazilian donkeys were used to evaluate the influence of meteorological variables on their physiological responses in tropical conditions. Physiological data included respiratory rate (RR), heart rate (HR), rectal temperature (RT), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and cortisol concentrations. The environment was characterized using the following meteorological variables: air temperature (AT), relative humidity (RH) and wind speed (WS). The variables were organized into time. The performed statistical tests included correlations, multivariate and variance analysis. The RR variable was lower in the period between 7 pm and 10 am associated with a decreased RT in the same period. Differences were not detected within each time group of the day for the HR, cortisol concentrations, SBP, DBP and MAP. The physiological traits of the animals in this study were not affected by the time of the day according to the principal component analysis. Significant results were found in the correlation analysis between the RR physiological variable and the meteorological variables of RH (−0.66) and WS (0.69). Thermoregulation mechanisms exhibit few daily cyclical variations; therefore, the northeast Brazilian donkeys have little physiological responses influenced by environmental factors in the semi-arid region.

KEYWORDS:

• Adaptation
• animal welfare
• body temperature
• Equus asinus
• semi-arid region

Acknowledgments

We thank the Polícia Rodoviária Federal from Brazil for the collection of animals and Luis Bermejo for collaboration in statistical analyzes.

Ethics Committee

All procedures used in this research are in accordance with the ethical standards and have been approved by the Ethics Committee on Animal Use of the Federal University of the Semi-arid Region/Mossoró (nº 22/2013).

Disclosure statement

No potential conflict of interest was reported by the authors.