English

Abstract

Sweat is important in thermoregulation, helping to dissipate heat in the body by evaporation in hot conditions in dairy cows. The purpose of this study was to evaluate the variation of sweat fatty acid compositions in summer conditions in Jersey and Holstein dairy cattle for their potential thermoregulatory roles in animal health protection. Temperature, relative humidity and Temperature-Humidity Index (THI) values were calculated for the intensity of stress in the indoor environment. The chemical compounds of sweat were determined by gas chromatography device and inter-breeds differences were revealed. As a result of analyzes, a total of 23 fatty acids were detected in both breeds. It was understood that there were 15 fatty acids in the Jersey breed. Palmitic acid was detected at a rate of 27.72 % in Holstein cows and 25.16 % in jersey cows that may be due to a higher rate of fatty acid release from muscle tissue, so that it may be less resistant than the jersey breed in heat stress conditions. It can be said that palmitic acid can be an indicator for heat stress conditions. ∑SFA and ∑PUFA contents of the sweat of Holstein cows were lower than those of Jersey breeds while ∑MUFA content was higher than those of Jersey breeds. The high expulsion of ∑SFA and ∑PUFA in the sweat of the Jersey cows can provide the function of delaying the body's dehydration by forming a hydrolipid film on the skin surface in hot conditions