Impact analysis of cow skin cleaning methods on heat stress

In this study, three types of skin cleaning: dry, wet, and wet cleaning with special cleaning agents were compared. It was conducted on six Holstein cows using a special climate camera. The methodology consisted of registration of skin temperature and pulse rate of cows under the temperature of 25 °С to 35 °C, relative humidity from 50% to 75%, and airspeed from 0.5 to 2.0 m s-1 using different methods of skin cleaning. The study was conducted over four days: before and after skin cleaning with different methods. The skin temperature was recorded in three areas using a pyrometer and thermal camera. It was determined that by temperature increasing from 25 °С to 35 °С and relative humidity from 50 % to 75 %, the skin temperature was increased by 14.3% using dry cleaning, by 11.8% using wet cleaning, while by 11.6 % using wet cleaning with a special cleaning agent. After wet cleaning, the pulse rate in animals decreased to 9.5%, and after wet cleaning with a special cleaning agent, it was 10.7% higher than before skin cleaning. Also, the pulse rate decreased after the wet cleaning by 9.5% and after wet cleaning with a special cleaning agent by 10.7%, which allowed about reducing the influence of heat stress with skin cleaning under higher temperatures and relative humidity. Moreover, an increase of the airspeed directed at the animal from 0.5 m s-1 to 2.0 m s-1 reduced the increase in skin temperature during dry cleaning to 12.0%, during wet cleaning up to 8.4%, and during wet cleaning with special cleaning agents up to 8.1%. Experiments proved that the researched skin cleaning methods decreased the elevation in body surface temperature, increased heat transfer and sweat evaporation, upraised heat exchange between cows and the environment, and reduced the impact of heat stress. The most effective methods of decreasing heat stress are wet cleaning and wet cleaning with special cleaning methods compared with dry cleaning methods.