Diet digestibility by total faecal collection and insoluble acid ash in horses at maintenance fed S. cerevisiae

The aim of the trial was to evaluate the effect of the administration of live yeast to mature horses fed at maintenance by total faecal collection and Acid Insoluble Ash (AIA) methods. Six mares were used in a two-period crossover design with two treatments on the basis of body weight (544±14 kg) and age (15.3±3.9 years): Control (CTR) fed a basal diet, Treatment (LY) fed a basal diet and 2 g/head/d of live yeast (S. cerevisiae 4.6¥1010 CFU/day). The trial consisted of two different periods named period 1 (P1) and period 2 (P2) of 35 days each, including 14 days adaptation period to the diet, 18 days of supplementation with the test material, and 3 days of faecal collection. Each horse was fed 2.50% of body weight at a 70:30 forage:concentrate ratio. Obtained results evidenced a positive effect of live yeast on dry matter (63.94% vs 59.37%; P=0.03), and ADF (35.04% vs. 24.30%; P=0.03) digestibility, while higher organic matter (66.10% vs 61.60%; P=0.04) and NDF (42.20% vs 35.90%; P=0.04) digestion rates in LY animals found with the use of AIA as marker were not confirmed by total collection technique, although detected values with both methods were comparable. The administration of S. cerevisiae to mature horses resulted in increased digestibility of some constituents of the administered diet that mainly include the fibre fractions such as NDF and ADF.