Estimating Body Weight in Growing WarmbloodsBy Kentucky Equine Research Staff · November 9, 2015
The perils of owning an overweight or obese horse are widely known, yet overconditioning continues to be a problem throughout the equine industry. Similarly, low body weight in horses is equally concerning because poor condition is an indicator of disease, advanced age, parasite infestations, excessive workload, poor or imbalanced nutrition, and submissiveness in a herd resulting in a horse being excluded from feed.
“The first step to helping your horse achieve and maintain a healthy body weight and condition is having an accurate idea of what he currently weighs and what his target weight is,” advised Kathleen Crandell, Ph.D., an equine nutritionist for Kentucky Equine Research (KER).
Because many farms and veterinarians do not have access to a livestock scale, there are multiple methods of estimating body weight or condition. Examples include the nine-point Henneke scale for body condition and various body-weight equations that take into account measurements, such as girth circumference, height at withers, and body length.
“Nonetheless, there is currently no perfect method of estimating body weight, especially in growing horses,” noted Crandell.
A group of researchers from the Czech Republic* recently took 13 body measurements and measured body mass index and body weight in 524 Warmblood horses ranging in age from 97 to 1,290 days. The researchers found:
- Age is a poor predictor of body weight because of the rapid growth and increase in body weight in the first year;
- The growth curve of a horse is not linear. Instead, the original body “shape” of a growing horse is a standing rectangle (height at withers is greater than body length). By 12-18 months, horses become squarer as body length increases. By four years of age, little growth occurs;
- Of the 15 body measurements, four were most important: heart-girth, sternum height, body length, and front pelvis width;
- Those measurements were used to develop a formula for estimating body weight. That formula was applicable to growing Warmbloods, making it useful in the breeding industry; and
- The equation was more accurate than other formulas for predicting body weight in growing Warmbloods.
“Having an accurate estimation of body weight without the luxury of owning a livestock scale will help ensure young horses are growing at appropriate rates, minimize health issues in adult horses, and avoid over- and underdosing of medications such as anthelmintics and antibiotics,” concluded Crandell. “The proposed formula is easy to use and widely applicable.”
*Čoudková, V., V. Sachello, H. Štěrbová, et al. Bodyweight estimation from linear measures of growing warmblood horses by a formula. Journal of Equine Veterinary Science. In Press.