128 Gullet size can be predicted using wither body condition score in horses

Abstract

Gullet size provides guidance about saddle fit for horses. However, no information exists evaluating the impact of body condition score (BCS), particularly wither region BCS, on gullet size. The objective was to develop a prediction equation for gullet size in moderate-heavy working adult horses based upon wither region BCS and gullet size. Body condition score and gullet size were evaluated fall of 2021 (n = 23 geldings, n = 1 mare), spring of 2021 (n = 25 geldings, n = 3 mares) and fall of 2022 (n = 25 geldings, n = 5 mares). Body condition score was determined by 2 observers. Gullet size was quantified using a gullet gauge protractor (Easy-Change Gullet System, Saddlery Brands International, AUS) over the wither region. Correlations between BCS, wither region BCS and gullet size were analyzed using Pearson correlation coefficients, and the equation for estimating gullet size used a linear regression model.Gullet sizes were categorized as narrow (0), medium-narrow (1), medium (2), medium-wide (3), and wide (4). Gullet size and BCS was minimally correlated (r = 0.19, P = 0.09, n = 82), whereas gullet size and wither region BCS was moderately correlated (r = 0.44, P = 0.0001, n = 82). Gullet size was estimated using the equation 0.7x – 1.3 (R2 = 0.20; P < 0.01; n = 82), wherein x is the wither region BCS. The equation is most applicable to horses with wither region BCS between 4 and 6, and moderately to heavily exercised. Measurements of ultrasound fat depth, wither height, and shoulder width may provide further precision to the above equation. In summary, measurement of wither region BCS translated well to a determination of gullet size, and thus constitutes a potentially appropriate metric for saddle fit in horses.