Associative Effects between Forages and Concentrates on In Vitro Fermentation of Working Equine Diets.
Authors: Gandarillas Mónica, Keim Juan Pablo, Gapp Elisa María
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Prediction of nutrient availability in equine diets requires understanding how forage and concentrate ingredients interact during hindgut fermentation, yet most nutritional tables rely on ingredient values determined in isolation rather than as mixed diets. Gandarillas and colleagues used in vitro fermentation models to measure gas production and volatile fatty acid (VFA) profiles from combinations of typical high-performance equine forages (alfalfa hay, timothy hay, oat straw) paired with common concentrates, examining whether the fermentation outputs differed significantly from simple ingredient summation. The researchers identified notable associative effects—situations where the combined mixture fermented differently than predicted from individual component values—with particular implications for VFA ratios and overall energy yield depending on forage type and concentrate inclusion level. These findings suggest that current dietary energy calculations, which sum ingredient values without accounting for fermentative interactions, may substantially misestimate the actual postgastric nutrition available to working horses. For practitioners formulating diets for performance horses, the work underscores that forage-concentrate ratios and specific ingredient pairings warrant closer scrutiny, as standard feeding tables may not accurately reflect the metabolically available energy from typical mixed rations.
Read the full abstract on PubMed
Practical Takeaways
- •Forage-concentrate combinations produce different fermentation outcomes than expected from feeding individual ingredients separately—diet formulation should account for these synergistic effects
- •Working horse diets should be evaluated as complete mixtures rather than summed individual components to accurately predict energy availability and hindgut health
- •When designing performance horse rations, consider that gas production and VFA profiles from actual mixed diets may differ substantially from theoretical calculations
Key Findings
- •Gas production and volatile fatty acid concentration from forage-concentrate mixtures differ from predicted values based on individual ingredient fermentation
- •Associative effects between different forages and concentrates significantly influence postgastric nutritive value in equine diets
- •In vitro fermentation patterns of traditional high-performance horse diet combinations were quantified for nutritional evaluation