# Cooling Effectiveness of the Sustainable Cooling Solution for Cattle: Case Study in Poland
## 4 Discussion
### Behavioral Observations  
High THI values clearly affect the productivity, physiology, and behavior of cows [29; 35; 39]. However, the physiological response is characterized by high individual variability, which results from genetic differences, different milk yields, body size, and hair structure [39; 40; 41; 42]. Additionally, the nutritional factor and precise supplementation can alleviate hyperthermia, improve nutritional status, and modulate immune parameters [43]. Moreover, under conditions of an increased THI, cows having the opportunity to cool down show great variation in their cooling needs due to their different responses to the heat load [39]. Milk yield is of great importance here [39]. Future research will include the use of cooling mattresses in cattle breeding. For that reason, behavior was another aspect taken into account for cows' welfare evaluation. Heat-stressed cows have been reported to increase their standing time to enable more intensive heat dissipation via radiation and convective air movement from the skin through an enlarged heat transfer area [44; 45]. The bouts number of lying and standing may vary depending on considered time, environmental conditions, bedding type, and individual behavioral patterns. For example, [PERSON] and [PERSON] [46] reported an average of 14.4 of lying bouts on rubber mats for a 24 h time period.  
According to Table 2, for both days of observation all cows spend most of their time standing, which indicates their high environmentally based need for cooling. Although the lying time of CowCM on the third day was the lowest (with \(p<0.05\)) recorded during the conducted experiment, it was comparable to the one reported by [PERSON] et al. [47] for a similar observation time. [PERSON] et al. [44] reported a reduction in the average lying time from 10.9 to 7.9 h/day due to high ambient temperatures. A similar environmental correlation was observed in the presented study, in which an increase in THI among experimental days probably caused a skin temperature increase [29] and a greater need for convective heat dissipation, which was especially visible for CowS. The reaction of CowCM could suggest that an increased peripheral circulation influenced [29] cows' susceptibility to direct contact with the cold surface, making the standing position preferable. However, future studies with higher water temperature setpoints need to be carried out to verify this thesis. Furthermore, the experiment was conducted when the prolongated high outdoor temperature was recorded when the last day of the experiment coincided with the second day of the three-day-long heat wave (c.f. Figure 5). Lying behavior could be also an effect of prolongated exposure to a high thermal load. An inverse relation in lying behavior was observed for CowM. However, the relatively short duration of the experiment, as well as the individual behavioral patterns and habits of each animal, make these data difficult to interpret precisely. Therefore, behavioral observations need to be extended for a longer experimental period.  
Point observations showing individual behaviors that are known as stereotypes and social behaviors were also under observation, as a developed indicator of the animal's welfare (Table 2). The two common behaviors were detected in the experiment: grooming and self-grooming. Grooming is a positive indicator, which testifies to strengthened social relations in the herd, and it was the most frequently recorded behavior. Self-grooming is a natural behavior, which can also increase, triggered by stressors or environmental factors [48]. Furthermore, stereotyped and aggressive behaviors, including chain shaking and kicking, which would be associated with a reduction in animal welfare, were not observed in the experiment.