Estimation of Actual and Ideal Bodyweight Using Morphometric Measurements and Owner Guessed Bodyweight of Adult Draft and Warmblood Horses

Abstract

Bodyweight (BW) estimation equations have not been developed for draft and warmblood horses. The objectives were to develop BW estimation equations using morphometric measurements for draft and warmblood horses and investigate horse owner's ability to estimate BW. Morphometric measurements were collected on adult (≥3 years), nonpregnant, draft (n = 138), and warmblood (n = 89) horses. Personnel measured wither height, body length (BL) from the point of the shoulder to the point of the buttock (BL wrap), BL from the point of the shoulder to a line perpendicular to the point of the buttock (BL straight), neck circumference, girth circumference, body condition, and BW using a livestock scale. Equations for the estimation of BW were developed using linear regression. For estimated BW, the model was fit using all individuals and all morphometric measurements, except BL wrap. For ideal BW, the model was fit using individuals with a body condition score of 5, BL straight, and height. Bodyweight (kg) was estimated by taking [girth (cm)1.528 × BL straight (cm)0.574 × height (cm)0.246 × neck (cm)0.261]/1,181 (draft) or 1,209 (warmblood)] (R2 = 0.96; root mean square error [rMSE] = 28 kg). This was an improvement over the previous BW estimation equation (R2 = 0.94; rMSE = 34 kg). Ideal BW (kg) was estimated by {[4.92 × BL straight (cm)] + [4.64 × height (cm)] − 951 (draft) or 1,016 (WB)} (R2 = 0.90; rMSE = 33 kg). Owners accurately estimated horse BW (R2 = 0.87). Morphometric measurements were used to develop BW-related equations for draft and warmblood horses.