Body Condition Scoring System Benefits for Horses and Owners

Body condition score (BCS) is a numerical scoring system from 1 to 9, with 1 indicating extremely emaciated and 9 indicating extremely fat. It is based on the visual and palpable appraisal of the amount of fat covering on the body at certain locations, such as the ribs, tailhead, withers, neck, behind the shoulder, and along the back (Henneke et al.) (Figure 1). This evaluation tool can help horse owners, breeders, and managers maintain proper nutrition practices in order to most effectively keep horses at peak performance and optimum health.

Horses that are too thin may have performance and reproductive problems. An adequate amount of body fat is necessary for females to achieve normal reproductive processes. For example, proper body condition following parturition is beneficial for achieving a quick pregnancy in the mare. Studies have concluded that females that are too thin as a result of inadequate nutrition may suffer from reproductive inefficiencies, such as longer interovulatory intervals, decreased pregnancy rates, and decreased ovarian activity (Dunn et al. 1969; Rutter and Randel 1983; Richards et al. 1986).

While providing a cheaper feed source may seem reasonable to the underlying economy of some horse owners, the result may be a lower-quality horse with lower energy. For example, if you are maintaining your horse at a BCS 4 and trying to use the horse in an athletic setting, you may not see the same performance as you would if the horse had greater body fat. In addition, a broodmare maintained at a BCS 4 may have a harder time breeding because of interovualory interval lengthening; she will struggle even more as the BCS falls below 4 if she is lactating, which will reduce the potential for a foal the next year.

While low BCS is certainly a problem, it is important to note that high BCS may pose problems, too. Overfeeding is associated with insulin-resistant horses that may not do well on high-starch feeds, or horses that may be too “hot” (too energetic and hard to handle). Reproductive problems are not typically seen in horses with high amounts of body fat. Overfeeding mares in a BCS of 9 during gestation did not adversely affect postpartum reproductive performance (Kubiak et al. 1989). Additionally, fleshy-conditioned (BCS 7) mares are not prone to demonstrate subfertility as compared to mares in moderate condition (BCS 5) (Cavinder et al. 2009).

On a practical note, it requires more energy, thus more overall feed, to achieve a high level of adiposity, so you will have to spend more money to achieve a higher BCS. If the overall benefit of maintaining horses in moderate condition (BCS 5 to 6) is not significant, then spending more money to maintain horses in a fat condition (BCS 7 to 9) may prove wasteful.

The BCS system is a useful tool for horse owners that will help effectively evaluate the nutritional status of all horses. However, assigning a BCS to a horse is subjective and not foolproof. One way to avoid as much error as possible when assigning a BCS is to use your hands to feel the areas of the horse outlined in Figure 1. Additionally, reading the definitions of each BCS will improve accuracy of the scores assigned to the horse. Also note that the definition of each score does not fit all horses. Horses are individuals, and variation may exist on fat deposition from horse to horse. This is one reason that some people use half-points when scoring (5½, 6½, etc.).

So how do you change the BCS of your horse? The simple answer is to increase or decrease the digestible energy of the diet the horse is eating. The complex part is determining how much to increase or decrease. Research is currently being conducted that will provide horse owners with an exact method to alter BCS in their horses (Cordero et al. 2013). Until then, horse owners should start by increasing or decreasing horses’ diets gradually and assessing body condition every 3–4 weeks until the desired results are seen.

References

Cavinder, C. A., M. M. Vogelsang, P. G. Gibbs, D. W. Forrest, and D. G. Schmitz. 2009. Variances in reproductive efficiency of mares in fat and moderate body conditions following parturition. Prof. Anim. Sci. 25:250-255.

Cordero, V. V., C. A. Cavinder, L. O. Tedeschi, D. H. Sigler, M. M. Vogelsang, and C. E. Arnold. 2013. The development and evaluation of a mathematical model to predict digestible energy intake of broodmares based on body condition changes. J. Anim. Sci. 91:2159-2177.

Henneke, D. R., G. D. Potter, J. L. Kreider, and B. F. Yeates. 1983. Relationship between condition score, physical measurements, and body fat percentage in mares. Equine Vet. J. 15(4):371-372.

Kubiak, J. R., J. W. Evans, G. D. Potter, P. G. Harms, and W. L. Jenkins. 1989. Postpartum reproductive performance in the multiparous mare fed to obesity. Theriogenology 32 (1):27-36.

Richards, M. W., J. C. Spitzer, and M. B. Warner. 1986. Effect of varying levels of postpartum nutrition and body condition at calving on subsequent reproductive performance in beef cattle. J. Anim. Sci. 62:300-306.

Rutter, L. M., and R. D. Randel. 1983. Postpartum nutrient intake and body condition: Effect on pituitary function and onset of estrus in beef cattle. J. Anim. Sci. 58: 265-273.

Publication 2947 (POD-04-19)

By Dr. Clay Cavinder, Professor, Animal and Dairy Sciences.