Abstract: Understanding animal social structures is imperative when it comes to the care, housing and handling of large herd animals. Knowing how hierarchies are structured, along with environmental and physiological aspects that may affect them, will allow owners and breeders to house and care for their animals. The aim of my study was to better understand two methods used to assess dominance hierarchies in horses, Equus caballus, and to predict which method would be more useful for owners housing domestic horses. I designed an experiment where I compared a structured method, the paired feeding test, with behavioral observations from the horses’ natural setting. I hypothesized that the structured method would not conclude the same dominance hierarchy as the natural observations. I also hypothesized that traits of the horses, such as size or age, would correlate with the hierarchy ranking within a herd. A herd of six individual horses from a small ranch east of Platteville, Colorado was used to test the two methods. I found that the two methods measured different hierarchies. The paired feeding test showed no correlations to any of the physical measurements, as well as did not provide a hierarchy that was similar to the natural dominance observations of the horses. Natural observations established a more linear hierarchy and had significant correlations with weight and overall body size. The results indicate that the paired feeding test may not be a valid method for establishing dominance hierarchies within domestic horses housed in a small range.
I recommend use of natural observations over paired feeding tests for ranchers, breeders or owners trying to understand the dominance hierarchies among their herds.