Efeito do ambiente térmico do Litoral Paraibano sobre respostas fisiológicas de equinos.

Abstract

The present paper aims to evaluate the thermal environment effect of the coast of Paraíba, in the city of João Pessoa – PB, over the behavior of the physiological responses of acclimatized horses of the Military Police Cavalry – Coronel Calixto Regiment, subjected to different thermal stress conditions, as well as their thermoregulatory performance and ability to adapt during the dry period. 12 crossbred horses aged between 7 and 15 years old, with light and dark coats, healthy and active in their respective functions, were used. The physiological variables measured were heart rate (FC), respiratory rate (FR), rectal temperature (TR) and surface temperature (TS), the last one stand as the average of the surface temperature of the forehead, neck, withers, arms, central point of the ribs, abdomen, rump and leg. The physiological responses obtained were subjected to the tests: ITC (heat tolerance index) and CA (adaptability coefficient). The environmental variables collected and evaluated were air temperature (TA), black globe temperature (TGN), relative humidity (UR), dew point temperature (TPO). The statistical design was completely randomized and the analyzes made included the effect of shifts, when in an exclusive condition of shading and effect of the thermal stress conditions in the measurement times of the parameter. It was possible to observe that the physiological values were influenced, mainly by radiation and air temperature. The horses showed an increase in respiratory rate and managed to keep the rest of physiological parametres within the normal range for the species. The thermal environment of the dry period of the coast of Paraíba interfered in the homeothermia of the evaluated horses, causing, at times, a decrease in the heat dissipation in sensitive form, but this was compensated by the heat dissipation in the latent form, not being harmful to the ideal internal temperature for the species.