## 3 Results and Discussion
### Behavior
In confined systems, dairy cows spent an average of 10 to 12 h lying down per day [28]. In this same period, three to four hours corresponds to the time cows sleep in average periods of three to five minutes [78]. [PERSON] and [PERSON] [48] first observed the behavior of dairy cows housed in compost barns. The authors observed an average total rest time of 12.7 h/day when the THI was less than 72. When the THI was above 72, the cows lay down for 7.9 h/day. In another study, the average daily rest time for cows housed in a free-stall system ranged from 6.6 to 14 h/day. However, as the THI increased (THI above 70), the time spent lying decreased (range: 9-10.5 h/day) [79]. Consequently, the reduction in resting time may result in productivity [80; 81] and welfare problems [15]. Cows subjected to heat stress change their posture; i.e., they reduce their time spent lying down and consequently spend more time standing up. When the THI was above 70, the cows spend less time lying down and increased their time standing [81]. Thus, cows will seek cooler places in the feedlot, such as the feeding corridor, which usually has a cooling system [53]. This change in posture in lactating cow reduces heat absorption through long wave radiation arising from the bedding, facilitating the circulation of cooler air and aiding heat dissipation through convection. However, increased standing time interferes with the longevity of lactating cows. Cows exposed to heat stress showed an 18.6% increase in hood problems [82]; the increase in hood diseases may be related to lameness [83] and hock lesions [84]. As the thermal environment becomes more challenging, the number of steps for lactating cows increases [50]. This behavior in confined systems may be linked to ventilated areas [49] and water demand [50]. In warm regions, water consumption by lactating cows can increase by 10 to 20% during summer [85]. The greater water intake by cattle under heat stress affects the water requirements for evaporative thermolysis and bodily maintenance of dairy cows [86]. [PERSON] et al. [87], when assessing lactating cows housed in free-stall barn, observed that as THI increased (56.3-81.3), cows ingested more water (112.7 kg/d), spent more time at the trough (54.0 min/day), made more visits to the trough (31 visits/day) and participated in more competitive events at the trough (172 competitions/day). Furthermore, the authors also observed that more productive cows presented more competition for the troughs. This behavior can be explained because high-producing cows ingest more water due to milk production. Thus, lactating cows that have access to the drinker 24 h/day can increase milk production by up to 10% [88], as well as the dominance of multiparous and agonistic behaviors (pushing, butting, and chasing) [52]. Although water is an essential thermoregulatory resource for cows, the more frequent the search for ventilated areas, the greater the animal's thermal discomfort; the ventilation system in the confinement system can promote the dissipation of the animal's heat to the environment when the air is colder than the cow's body temperature. Thus, mechanical ventilation in a confined system can effectively reduce dairy cows' body temperature [89]. However, this process takes three to four days to properly balance the bodily heat loss in cows [15]. It is worth noting that housing is not always sufficient to cool cows in hot climatic conditions [32]. In a European study, [PERSON] et al. [90] investigated the relationship between housing structures and the internal microclimate in eight dairy cow confinements. They observed that the housing characteristics affected the internal microclimate, mainly during summer. Another study evaluated the thermal variability in compost barns in southern Brazil. The authors identified that multiporous cows were allocated to the most ventilated housing regions during the afternoon [49]. Thermal heterogeneity in compost barns was also verified by [PERSON] et al. [91].