Heat Adaptability of Growing Bedouin Goats in Egypt

Abstract

Thirty four growing male goats were used. An attempt to assess a useful heat tolerance index using some physiological and biochemical changes due to solar radiation exposure was carried out. The changes in body temperature, haemoglobin, haematocrit, total body water, triiodothyronine and cortisol did not correlate with body gain decrease due to heat stress. Therefore, it can not be used to predict heat adaptability in this study.
During the hot-humid summer (temperature humidity index = 80.7. +/- 8.9°) daily body and solids gain, dry matter intake, thyroid, liver and kidney functions were reduced. However, total body water, water intake, rectal temperature and respiratory rate were increased. Treatment of heat stressed goats by chilled drinking water significally improved daily body and solids gain and reduced the effects of heat stress on thermal and water balances and thyroid, liver and kidney functions. Tap water sprinkling significantly failed to alleviate bad effects of heat stress.