STUDY OF PHYSIOLOGICAL RESPONSES OF EQUINES WITHOUT DEFINED BREED AND QUARTER HORSE TO THE CLIMATIC CONDITIONS OF TERESINA, PIAUÍ

Abstract

This study was developed to evaluate the adaptability of without defined breed and Quarter Horses to the thermal conditions of Teresina, using physiological parameters using tolerance tests and heat dissipation. The measures of rectal temperature and heart and respiratory rates were collected in March and October. These months represents, respectively, the rainy period and the hot and dry period in the area studied. The response of each genetic group was evaluated using physiological parameters and adaptations indexes (Ibéria, Benezra and Rainysby tests). In each herd the experimental design was completely randomized and the statistical model included the effect of period of the year and/or schedule of measurement of the parameter. The thermal environment in the area during the dry period of the year hinders the homoeothermic maintenance in the animals, limiting the physical activities with horses. The physiological parameters suffered with an increase of the environmental temperature. The Quarter Horses were shown to be adapted to the environmental conditions, with small alterations in the rectal temperature caused by increment of the temperature. The hot thermal environment during the dry period of the year interfered in the homoeothermic behavior of the Without Defined Breed animals.

KEY WORDS: Adaptation, indexes, rectal temperature, respiratory rate, thermal environment.