Black-globe temperature effect on short-term heat stress of dairy ewes housed under hot weather conditions

Under abnormally hot summer conditions, black-globe temperature directly affected the thermal behaviour of the Chios and the Karagouniko breed. The dairy ewes had respiration rates (breaths/min) above normal, whereas their body temperature (°C) was not affected. The two breeds seek shade during sun presence and cooled-off at the outside lot during night. As a result their minimum and maximum respiration rate values were strongly associated to minimum and maximum black-globe temperature values. As heat ensued towards noon the apparent short-term heat stress of the Chios ewes was milder than that of the Karagouniko ewes as indicated by the significantly lower respiration rate.