Heat tolerance in Brazilian sheep: Physiological and blood parameters

• Published in: Tropical animal health and production Vol. 41; no. 1; pp. 95 - 101
• Main Authors: McManus, Concepta, Paludo, Giane Regina, Louvandini, Helder, Gugel, Rosilene, Sasaki, Luiz Cláudio Bastos, Paiva, Samuel Rezende
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 2009; Springer Nature B.V
• Subjects: Adaptation, Physiological - physiology; Animals; Biomedical and Life Sciences; Blood Chemical Analysis - veterinary; Body Temperature Regulation - genetics; Body Temperature Regulation - physiology; Brazil; Climate effects; Climatic conditions; Crosses, Genetic; Female; Heart Rate; Heat tolerance; Hematologic Tests - veterinary; Life Sciences; Original Paper; Physiology; Respiration; Sheep - blood; Sheep - genetics; Sheep - physiology; Skin Pigmentation - genetics; Skin Pigmentation - physiology; Stress, Physiological - genetics; Stress, Physiological - physiology; Tropical Climate; Veterinary Medicine/Veterinary Science; Wool; Zoology; Brazil; Farm animal genetic resources; Physiological parameters; Temperature; Hematological parameters; Stress
• ISSN: 0049-4747; 1573-7438
• DOI: 10.1007/s11250-008-9162-1

Thirty Santa Ines adult, non-lactating, non-pregnant ewes, ten with a brown coat, ten black coated and ten white coated, as well as ten Bergamasca and ten of mixed breed were used to evaluate the effect of climate on physiological and blood parameters in sheep. Two sample collections were taken (6  am and 2  pm ) on six days. Sweating rate (SR), heart (HR) and breathing rates (BR), complete hemogram, rectal (RT) and skin temperatures (ST) were measured. Variance analyses were carried out using SAS®. In general, there were significant differences between animals due to skin type, time and day of collection. White coated animals showed lower HR, BR and RT, with afternoon parameters higher than morning. Correlations between HR, BR, RT, SR and ST were medium and positive. Correlations between physiological and blood traits were in general negative and medium. Packed Cell Volume (PCV), total plasma proteins, red blood cell count and hemoglobin concentration had high positive correlations between each other. The first two autovectors explained 49% of variation between traits. White coated Santa Ines animals were shown to be better adapted to climatic conditions in Central Brazil and wool sheep more affected by heat.