Epsilon Archive for Student Projects

Abstract

Bits of different varieties are hypothesized to have been used for horses for at least 4000 of the 6000
years of domestication. However, the focus of previous studies regarding bits have mainly been on
physical injuries caused by pressure points, effects of different shapes and their influence on the
horse. Limited focus has been put on the temperature of the bit and its impact, although this aspect
affects many horses daily. The present study aimed to investigate and compare horses’ responses of
both facial expressions and body language when being bridled with warm respective cold bits.

The study was performed in April in Sweden with an air temperature of 5°C. It was performed
on ten Icelandic horses and behaviours were divided into positive and negative expressions. Facial
expressions and posture of the head were analyzed as proportion of time, while body languages and
full eye blinks were analyzed as frequencies of observation occasions.

The results suggested that the horses, on average, seemed to prefer warm bits of 35°C, roughly
equivalent with the temperature of their mouth, over cold bits with a temperature of 6°C. This was
reflected in a higher proportion of time correlated with positive behaviours when being bridled with
a warm bit compared to a cold bit. The results also suggested that a cold bit was perceived as more
uncomfortable than not being bridled, while a warm bit, and its connection to perceived discomfort
between being bridled and not, was less clear. The effect of the bit temperature needs further
investigation in future studies.

Based on present study, one could speculate that horses might accept or like warmer bits more
than cold bits. This could potentially affect initial responses to training and handling as evasive
behaviours could be eliminated.