Characterizing dietary and exercise management practices and inflammatory biomarkers in a population of recreationally managed horses in Pennsylvania.

Overview

• This study investigated how different dietary and exercise management practices affect inflammatory biomarkers, specifically acute phase proteins (APPs), in recreational horses in Pennsylvania.
• The goal was to understand relationships between feed types, exercise intensity, and levels of inflammation to better manage horse health.

Background

• Horses evolved as slow-moving grazers over millions of years, primarily consuming forage like grass and hay.
• Domestication introduced diets higher in grains and concentrates to support performance and athleticism.
• Such dietary shifts, coupled with varying exercise regimens, might increase risk for chronic inflammation.
• Inflammation in horses can be detected by measuring acute phase proteins (APPs) like serum amyloid A (SAA), C-reactive protein (CRP), and haptoglobin (Hp) in blood plasma.

Objective

• To characterize the relationship between dietary/exercise management practices and inflammation markers (APPs) in horses managed recreationally.

Methods

• A total of 144 horses from Pennsylvania were studied.
• Data collected included body condition scores, blood samples for APP measurement, and surveys on how horses were managed diet-wise and exercise-wise.
• Measured biomarkers included plasma levels of:
  • Serum Amyloid A (SAA)
  • C-reactive protein (CRP)
  • Haptoglobin (Hp)
• Exercise intensity classifications were based on 2007 National Research Council guidelines, categorized as light, moderate, or heavy.
• Statistical analyses used were the Kruskal-Wallis test and post-hoc Dunn’s test, with significance set at P ≤ 0.05, to evaluate differences in APP levels across groups.

Results

• Exercise Intensity and Serum Amyloid A (SAA):
  • SAA concentrations showed a significant increase as exercise intensity rose from light to moderate to heavy.
  • Reported median values in mg/L were approximately:
    • Light exercise: 0.727
    • Moderate exercise: 0.918
    • Heavy exercise: 1.597
  • This indicates more intense exercise correlates with higher systemic inflammation markers.
• Dietary Factors and Other APPs:
  • Horses offered cereal grains had significantly lower levels of haptoglobin (Hp) compared to those not offered grains.
  • Horses fed hay had significantly lower C-reactive protein (CRP) levels than those not fed hay.
  • These findings suggest that the type of feed influences distinct inflammatory biomarkers differently.
• Diet Quantity and Exercise:
  • Horses that were exercised consumed more concentrate feed (median 1.05 kg/day) than non-exercised horses (0.15 kg/day).
  • Total recorded diet weights were also higher in exercised horses (median 3.0 kg/day) compared to non-exercised horses (1.80 kg/day).
  • This likely reflects increased energy demands from exercise.

Conclusions

• Both dietary and exercise management practices are associated with changes in inflammatory biomarkers in recreationally managed horses.
• Higher exercise intensity correlates with increased serum amyloid A, indicating greater acute phase inflammatory response.
• The type of diet, particularly the inclusion of hay or grains, influences levels of other acute phase proteins like CRP and Hp.
• These findings emphasize the importance of carefully considering diet and exercise when managing equine health to minimize risk of chronic inflammation.
• Further research may be needed to explore causal pathways and long-term health impacts.