Design and testing of a sweat meter for the cutaneous evaporation determination in cattle

ABSTRACT

The physiological processes of adaptation respond to autonomic mechanisms. Ruminants are known to regulate heat by sweating, among other mechanisms. Bos taurus cattleusually do not compensate well for exposure to high temperatures. In the tropics, sweating is the most important way for ruminants to lose heat. The objective of this research was to design and validate a non-invasive external mean to determine sweat production in Colombian Creole cattle. In a research center located in the Colombian eastern plains at4°05'N and 73°34'E, at 330 m ASL, a simple, lightweight, operational, safe, and easy-to-use device was designed to collect sweat from bovine Planum nasolabiale in 15 lactatingcows of Colombian Creole breeds. Besides, blood samples were collected and physiological constants were determinedand analyzed the relationship of this parameter with physiological measurements and heat indices. The measurement device designed and tested has proven to beefficient for sweating collection in cattle; however, the quantity of sweat collected could not reflect in a trustworthy way the overall animal response to the environmentalconditions. In contrast, the heat load index was more related to evapotranspiration and sweat production than the humiditytemperature index, indicating that a high heat load may lead to a major need for triggering high-level regulatory physiologic mechanisms like sweat production to compensate the rise of core temperature.