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AQHA FEATURE: NUTRITION
Meal Size and Gastric Capacity The equine stomach represents the initial site of enzymatic digestion, with a relatively limited capacity of approximately 8 – 15 litres( varying with body size). Gastric retention time for dry feed ranges from 30 minutes to 12 hours, depending on meal composition and volume.
• The non-glandular( squamous) mucosa of the proximal stomach lacks a protective mucusbicarbonate barrier, rendering it vulnerable to acid exposure.
• Hydrochloric acid is secreted continuously independent of feed intake at a rate of approximately 1.5 L / hour.
• Large, infrequent meals cause acute gastric distension, increasing pressure and splashing acid onto unprotected squamous epithelium.
• Prolonged fasting between meals results in a low gastric pH environment with no feed buffer, promoting Equine Gastric Ulcer Syndrome( EGUS).
• The horse evolved as a trickle feeder, grazing low-energy forage for up to 18 hours per day; digesta moves continuously via peristalsis through the gastrointestinal tract.
• Chewing during grazing stimulates salivary bicarbonate production( the only buffer for gastric acid in the proximal stomach).
• Best practice: Provide small, nutrient-dense meals that encourage chewing, alongside access to hay and pasture at all times.
AUSTRALIAN QUARTER HORSE ASSOCIATION- www. aqha. com. au