Woutine Pauw Email: [email protected] Leibniz Institute for Agricultural Engineering Potsdam-Bornim e.V. Department of Livestock Engineering Project title: Identifying Thresholds of Heat Stress of Dairy Cows in Naturally Ventilated Barns in different Climate Extremes Supervisors: Univ.-Prof. Dr. Thomas Amon, Prof. Thomas Banhazi Project description: The climatic environment of dairy cows influences their welfare. If welfare is significantly impaired, the milk production of the animal is reduced. From ethical as well as from economic perspective it is evident to ensure climate conditions within the cow comfortable zone. To design optimal climate control for dairy barns, animal preferences should be further investigated. Under hot environmental conditions, cows might react by an increased heart frequency, respiration frequency, heat distribution and body temperature and by decreased activity. Goal is to define the exact conditions under which dairy cows get into heat stress. To achieve this goal, a large dataset is created on basis of experiments, to analyze the relationship between weather data (such as temperature, humidity and wind speed) with animal data (such as age and milk yield). Indicators tested are various, ranging from heart and respiration frequency, to heart variability, activity and heat radiation. First step is to recognize the physical and behavioral reaction of dairy cows to heat stress; second step is to test the individual sensitivity of cows to environmental conditions.