Auditory enrichment on facial and physiological responses of Pantaneiro geldings and mares under short-term stress.

The study investigates how different types of music affect the stress levels of Pantaneiro horses when they’re socially isolated or movement-restricted. It suggests that playing music, especially classical and country pieces, may help lower stress responses in these horses.

Key Objectives of the Research

• The researchers were interested in understanding how auditory stimulation could influence stress responses in Pantaneiro horses. The horses were put under conditions of social isolation and movement restriction, context in which stress levels are typically elevated.

Methodology

• The study involved eight Pantaneiro horses, with four mares (female horses) participating in the first experiment and four geldings (castrated male horses) in the second.
• Both experiments followed a 4×4 Latin square design, a statistical method used in experiments to minimize the influence of extraneous factors.
• Each group of horses was exposed to different types of music – classical, country, and new age – and a control group was maintained without any music.
• During each 24-minute session when the horses were in the restraining stock (a device that keeps them in a fixed position), various physiological parameters and facial expressions were measured. These included heart rate, respiratory rate, eye closure, blink and half blink, ear rotation, nostril dilation, and others.

Findings

• In the first experiment with mares, the researchers noticed a significant drop in heart rate when classical and country music were played. The mares also showed increased body and auricular (ear) temperatures under classical music, and reduced frequency of certain facial expressions.
• In the second experiment with geldings, there was a significant increase in ocular (eye) temperature during the country and control treatments, and a higher frequency of ears-forward expression under country music. The geldings showed less pronounced responses to music compared to mares, indicating a possible preference for new age music.
• Notably, the researchers found that playing Beethoven’s 9th Symphony (classical genre) and Hank Williams Jr.’s “Ramblin’ In My Shoes” (country genre) led to reduced stress in mares. However, the specific songs might not have the same effects in a broader population of horses.

Study Implications

• The study indicates that auditory stimuli, particularly certain genres of music, can be effective in alleviating stress in Pantaneiro horses. This could be beneficial during situations of social isolation or when movement is restricted.
• While the study is limited in its sample size and the specific horse breed, its findings suggest that further research could be useful in understanding how to better manage the stress levels of horses in different situations.