# Cooling Effectiveness of the Sustainable Cooling Solution for Cattle: Case Study in Poland
## 1 Introduction
[15], as the first study on this topic to the authors' knowledge, observed that a cow lying on a waterbed could give off its heat. The chilled water temperature setpoint of 10 \({}^{\circ}\)C was tested and the data from the experiment were used to create a model of heat loss by conduction. [PERSON] et al. [16] evaluated the use of a heat exchanger supplied by chilled water at a temperature of 7 \({}^{\circ}\)C, located under 25 cm of animal bedding as part of a cooling system for dairy cows under controlled environmental conditions. They observed a decrease in core body temperature, respiratory rate, and skin temperature, pointing out that the cooled cows consumed more dry feed and produced more milk. [PERSON] et al. [17; 18] studied a conductive cooling system for heat-stressed lactating dairy cattle. The observation of the animals during experiments using the two different temperature setpoints of 10 \({}^{\circ}\)C and 4.5 \({}^{\circ}\)C was carried out. The influence of the thickness and type of bedding on the value of the heat flux was also determined. The aforementioned studies indicate that work related to conduction cooling is still at an early stage and requires further development. The usefulness of the proposed solution is visible also in cows' time spent in a lying position, whose range is between 8 and 16 h a day [19]. Furthermore, conduction cooling is a precision cooling system for cattle, delivering cooling exactly where it is needed. [PERSON] et al. [20] summarized the existing precision cooling technologies and pointed out that this area still requires more research and work. Sustainability in the dairy, livestock, and agricultural sectors is now an ongoing topic in research in an era of global warming. A Canadian study [21] comprehensively focused on sustainability strategies, ways to reduce greenhouse gas emissions, and ways to manage the barn and its resources while maintaining animal welfare. Moreover, new sustainable cooling solutions are constantly being developed that could be used in the livestock sector in the future. These include earth pipe cooling [22] or the direct-contact air, gravel, ground heat exchanger [23]. The main aim of our study was to confirm the cooling effectiveness of the proposed conductive cooling solution based on the example of experiments carried out in Poland. Subsequently, the introduction of a new sustainable cooling solution based on thermal conduction, as a potential for implementation in the dairy sector, was the parallel (equivalent) goal. The innovation of the solution uses a unique geometry that allows a uniform distribution of chilled water temperature inside the mattress, which was analyzed by Computational Fluid Dynamics-based simulations [24]. The final aim of this experiment was to prove the potential of the proposed conductive cooling system in heat stress mitigation. Following that goal, we put forward the research question: whether changing the supply of chilled water temperature of the cooling water mattress twice a day would be sufficient to affect the rumen temperature of the cow and its behavioral response in the conditions of diurnal air periodical temperature increase.