Buffering capacity and fecal pH in healthy horses submitted to experimental enteral nutrition

Abstract

This study set out to determine the impacts of a commercial equine enteral nutrition product on fecal pH, buffering capacity (BC) and physical examination variables. Eight healthy horses were randomly allocated to one of two simultaneous experimental groups in a 4×4 Latin square design. Horses were submitted to 12 hours of solid fasting, then fed increasing doses of the test product via nasogastric tube, as follows: 0% (pure water), 50%, 75% and 100% of the daily recommended dose. Test product doses were diluted in water (1:3) and delivered by bolus feeding. Fecal samples were taken directly from the rectal ampulla prior to (T0) and within 3, 6, 12, 24, 36 and 48 hours of product administration (T3, T6, T12, T24, T36 and T48 respectively). Within 24 to 36 hours of product administration, fecal pH was near 6 (p = 0.01). However, dose variation had no effect on pH. Product dose and sample collection time had a significant impact (p = 0.00) on buffering capacity at pH 6. The more dramatic drop in pH occurred within 24 to 36 hours of product administration, except in horses receiving the 0% dose (water). At pH 5, buffering capacity was affected by dose but not by sample collection time. Soft fecal consistency, increased intestinal motility and fat droplets in fecal samples were noted in most horses. Fecal pH and buffering capacity assessment are indirect tests. Still, results obtained from these tests were deemed useful for detection of intestinal changes, particularly when combined with physical examination. The product had an impact on faecal pH, buffering capacity and intestinal motility, therefore, it is recommended that the formulation be revised.