Heat tolerance of goats and woolless sheep in Sobral Brazil

Abstract

Breeds of goat (Canindé, Anglo-Nubian, Bhuj) and of woolless sheep Morada Nova and Santa Inés were used in the tropical Northeast Brazil to compare their rectal temperatures and respiratory rates before and after exercise and thereafter upto one hour to evaluate tolerance to environmental heat. Results showed that initial body temperature was not different among the five breeds and after exercise it rose by 1.25°C to 1.95°C in breeds. There was no species difference in rise to body temperature. After exercise, most rapid recovery was made by Bhuj and Canindé goats. Recovery was slower in Anglo-Nubian and the two sheep breeds. Initial respiratory rate appeared to be high in Anglo-Nubian in comparison to other breeds of sheep and goats. After exercise, sheep breeds showed smaller rise in respiratory rate than goats. This may explain the faster rate of recovery of body temperature by Bhuj and Canindé which had distinctly higher post-exercise respiratory rates. The respiratory rate of Anglo-Nubian had returned to pre-exercise level within 15 minutes of termination of exercise and it was only in case of Bhuj that the respiratory rate continued to be high at 15 minutes after exercise. Thirty-minutes after exercise all breeds had returned to their normal pre-exercise rates of respiration.