Thermoregulatory responses and adaptability of Anglo-nubian goats maintained in thermoneutral temperature and under heat stress

Abstract

This study aimed to evaluate the physiological responses and adaptability of Anglo-Nubian goat breeds by Ibéria and Benezra tests, maintained in bioclimatic chamber under different temperatures: 20, 24, 28 and 32 °C, where temperature and air relative humidity and black globe humidity index (BGHI) were measured. The design was completely randomized with four treatments and six replicates. With the increase of temperature and the BGHI, increased the surface temperature, the cardiac and respiratory frequency, and the thermal gradient, the rectal temperature remained within normal limits. The adaptability tests indicated that animals in the temperatures of 28 and 32 °C had the physiological parameters altered to maintain the warm-blooded, which BGHI values corresponding were 78.21 and 82.55 respectively, characterizing a warning and danger situation.