Effects of Diet and Weight Gain on Body Condition Scoring in Thoroughbred Geldings
Authors: Suagee Jessica K., Burk Amy O., Quinn Rachael W., Petersen Erin D., Hartsock Thomas G., Douglass Larry W.
Journal: Journal of Equine Veterinary Science
Summary
# Editorial Summary Obesity in horses, like in humans, may be preceded by low-grade inflammation, yet the mechanisms driving this response in equines remain poorly characterised. Fifteen mature Thoroughbred geldings were fed either a conventional high non-structural carbohydrate (NSC) concentrate or an iso-energetic fat and fibre-based alternative for 32 weeks whilst gaining approximately 89 kg (from 519 to 608 kg bodyweight) and increasing body condition score from 4.3 to 6.9. Serum tumour necrosis factor-α (TNF), a key inflammatory cytokine, was measured at four-weekly intervals and revealed that horses consuming the conventional diet maintained significantly elevated TNF concentrations throughout the study, whilst the fat and fibre-fed group showed suppressed TNF levels from week 12 onwards—a differential that persisted despite similar weight gains between groups. Notably, TNF concentrations did not correlate linearly with body condition changes in either group, suggesting the inflammatory response was driven by diet composition rather than adiposity itself. These findings have important implications for practitioners managing weight gain or performance in horses, indicating that NSC-rich concentrates may initiate systemic inflammation independent of condition scoring; however, further research into longer-term maintenance diets and clinical metabolic outcomes is warranted before reformulating feeding protocols.
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Practical Takeaways
- •When weight gain is necessary (rehabilitation, sales prep), consider fat and fibre-based supplements over high-starch concentrates to minimise systemic inflammation and associated metabolic stress
- •Body condition score alone does not predict inflammatory state—diet quality matters; two horses at the same BCS may have different inflammatory profiles depending on what they're eating
- •High-NSC commercial concentrates may trigger metabolic inflammation in Thoroughbreds even before obesity develops, suggesting diet choice is important for metabolic health prevention
Key Findings
- •High non-structural carbohydrate (NSC) diet promoted increased serum TNF (inflammatory marker) compared to fat-based diet despite similar weight gain in both groups
- •Fat-based diet feeding for 12 weeks decreased circulating TNF concentrations, an effect largely maintained throughout the 32-week study
- •No linear correlation found between serum TNF concentration and body condition score as horses increased from BCS 4 to 7
- •Diet composition influenced systemic inflammation independent of weight gain, suggesting NSC may promote low-grade inflammation even during weight gain phase