Horse Preferences for Insolation, Shade or Mist Curtain in the Paddock under Heat Conditions: Cardiac and Behavioural Response Analysis

Abstract

The horse’s welfare and, consequently, the emotional arousal may be connected with stressful environmental conditions. This study aimed to determine whether horses show behavioural or physiological symptoms of thermal discomfort and if their behaviour and cardiac parameters are related to freely chosen insolated (IS), shaded (SH), or water sprayed (with a mist curtain (MC)) areas in a paddock under heat conditions (29–32 °C, 42.0 ± 1.5% humidity). Twelve adult horses freely moving in the paddock were studied during a 45 min solitary turnout. Six cardiac variables, locomotor, and non-locomotor activities as well as rectal temperature before and after the test were monitored with regard to the area of staying. Horses did not show clear preferences regarding the time spent in IS, SH, and MC, although preferences of particular horses differed considerably. When staying under IS and MC conditions, the horses showed a higher level of relaxation compared to SH. Horses did not exhibit symptoms of thermal discomfort while staying in the sun. Free choice between the three areas differing in environmental conditions could be a crucial factor in maintaining body temperature as well as emotional arousal at similar levels. Thus, the provision of a shade and mist curtain in paddocks seems to be reasonable.

Behavioural responses of Konik Polski horses to natural, familiar sound of thunderstorm, and unfamiliar similar-sounding sounds of volcanic eruption and sea storms

“…However, it was not observed that the horses expected the sound signal that they had heard on the previous day of the experiment. Varied behaviour of the horses during their stay in the paddock was also noted by Janczarek et al [ 24 ]. As Morris [ 25 ] points out, one of the reasons for this variation is the mood of the animals which may change on a daily basis.…”

Effect of Cooling Blanket on the Heat Stress of Horses in Hot and Humid Environments

“…On the other hand, Bilgili et al [ 24 ], reported that cutaneous and respiratory evaporative heat loss contributed approximately 90% and 10%, respectively, to total evaporative heat loss in humans. These two studies, as well as others [ 7 , 8 ], demonstrate that horses and humans have comparable thermal regulation. Due to the similarities in thermal regulation between horses and humans, the ice vest could be used to provide heat protection for horses.…”

“…Heat stress due to either climate or exercise, or both, has been shown to increase the risk of heat stroke in horses [ 6 ]. Horses have a high metabolic rate but a small surface area for heat dissipation, as described by Janczarek et al [ 7 ]. As a result, horses must be actively cooled, even more so in hot environments.…”

“…As a result, horses must be actively cooled, even more so in hot environments. Studies of heat in horses often focus on the effects of exercise and in the paddock [ 6 , 7 , 8 , 9 ]. However, there are few reports on the stall where horses spend the majority of their lives.…”

“…Humans frequently use fans and air conditioners as heat protection devices [ 14 , 15 ]. In the case of horses, mist curtains, fans, and cold ice water poured over the horse’s body are used to reduce heat stress [ 7 , 8 , 16 ]. However, it is not appropriate to use water in the stall, as it is widely believed that water causes horses to slip, they injure themselves, and if a horse spends a long time in the stall with its hoof wet, bacteria and fungus will develop on the hoof, making it unsanitary and in fact, the insanitary condition of it can cause hoof disease such as white line disease and thrush [ 17 , 18 ].…”