The experiment was carried out to measure effects of thermal stress on the rectal temperature (RT) and respiratory frequency (RF), in animals of Anglo-nubian and Saanen breeds, raised in a tropical humid climate. The goats were divided into three groups, each group consisting of four females from each breed group. Each group was submited to three experimental treatment: treatment A, with a sun protected enclosed area; treatment B, a sun exposed area without covering; and treatment C, area with 50% covered section and 50% sun exposed area, which permitted free circulation of the goats. A Balanced Latin Square design was used. The RT and RF of the goats, in the afternoon periods (l4h00), were higher, than in the morning periods (08h00). The animals kept in the sun presented much higher results, especially in the afternoon periods, than the animals in the other two areas. There were no differences in the RT and RF between groups maintained in the shade or in partially covered area but there were differences in the RT and RF measurements between the two breeds, in the morning periods and in the afternoon periods. Independently of treatment and daily (morning and afternoon) surrounding temperature variation, the average of RT and RF in the Anglo-nubian goats were lower than the Saanen goats, which showed to be more sensitive to thermic stress.
Physiological reactions in goat breeds maintained under shade, sun and partially shaded areas/ Reações fisiológicas de caprinos das raças Anglo-Nubiana e Saanen mantidos à sombra, ao sol e em ambiente parcialmente sombreado