Abstract
The aim of this study was to determine the effects of heat stress on the thermoregulation in Aardi goat. The present study was conducted for 35 days in summer and 35 days in winter. Ambient temperature (Ta), relative humidity (RH) inside the pens were recorded continuously every 6 hours (4 time/day) and temperature humidity Index (THI) was calculated. Ten healthy Aardi does, aged 67 months were used. The experiment started in summer, followed by winter (control). The thermoregulation of animals under heat stress was evaluated every five days for 35 days in summer (n=8) and in winter (n=8) from 10:00-11:00 am. Measurements, including skin temperature (T-skin), coat temperature (T-coat), rectal temperature (T-rectal), vaginal temperature (T-vaginal), heart rate (HR), respiratory rate (RR), were recorded. In addition, triiodothyronine (T3), thyroxin (T4) and Cortisol serum concentration were calculated. The results revealed that Ta, THI, T-Coat, T-skin, T-Vaginal, T-Rectal, HR, RR and serum cortisol concentration values were significantly (P<0.0001) higher in summer than in winter, while average RI-I, T3 and T4 were significantly (P<0.0001) lower in summer than in winter. In conclusion, Aardi goats are exposed to heat stress during the summer season in Saudi Arabia and are adopted to its environment, which might explain its survivability and potential as a milk and meat-producing animal.