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Gradual Dietary Transitions The equine gastrointestinal tract relies on a highly specialised microbial population adapted to the current diet. Abrupt feed changes disrupt microbial equilibrium, potentially causing hindgut acidosis, colic, or laminitis.
• Dietary transitions should occur over a minimum of 7 – 14 days, incrementally adjusting the ratio of old to new feed.
• This allows cellulolytic and amylolytic bacterial populations to adapt without producing excessive lactate or endotoxins.
• Monitor faecal consistency, appetite, and behaviour throughout the transition period as indicators of gastrointestinal tolerance.
Carbohydrate Management Carbohydrates are an essential component of the equine diet. Plant matter comprises both structural carbohydrates( SC) the cellulose and hemicellulose of cell walls, fermented in the hindgut to produce volatile fatty acids and non-structural carbohydrates( NSC), which are hydrolysed to simple sugars in the foregut and readily absorbed into the bloodstream.
• Prior to modern pasture improvement, native grasses were inherently low in NSC and less readily available, resulting in lower glycaemic loads and greater foraging effort.
• Excessive NSC intake overwhelms hindgut buffering capacity, causing rapid fermentation, lactic acid accumulation, and subsequent disruption of cellulolytic microbial populations.
• Dysbiosis from hindgut acidosis triggers bacterial die-off, endotoxin release, and increased intestinal permeability key precursors to laminitis.
• Chronic hyperinsulinaemia from sustained high-NSC diets is implicated in Equine Metabolic Syndrome( EMS), insulin resistance( IR), and obesity.
Exclusion of Synthetic Additives The equine digestive system evolved to process whole-plant material without exposure to synthetic compounds. Many commercial feeds contain artificial preservatives, flavourings, binders, and colourants that offer no nutritional value and may compromise gastrointestinal integrity.
• Synthetic antioxidants are used to extend shelf life but have been associated with oxidative stress and hepatic burden in sensitive individuals.
• Artificial sweeteners and molasses-based palatants mask poor-quality ingredients while contributing to glycaemic dysregulation and altered feeding behaviour.
• Calcium propionate and other mould inhibitors may disrupt hindgut microbial populations when consumed regularly.
• Best practice: Select feeds with transparent ingredient declarations, minimal processing, and no synthetic additives prioritising bioavailable, whole-food nutrient sources.
AQHA 2026 NOVEMBER / DECEMBER ISSUE