Effect of live yeast (Saccharomyces cerevisiae) administration on apparent digestibility of horses

Six mares were divided into two groups of three subjects each in a crossover design on the basis of body weight and age: Control(C)fedabasaldiet,Treatment(T)fedabasaldietand2 Control (C) fed a basal diet, Treatment (T) fed a basal diet and 2 2 g/head/d of live yeast ((S. cerevisiae 4.6x1010 CFU/day).Theexperimentaldesignwasdividedintotwo ).Theexperimentaldesignwasdividedintotwo . The experimental design was divided into two periods named period 1 and period 2 respectively of 35d each, and consisting of 3 different phases. Dur- ing each period all animals were subject to an adaptation phase of 14d (phase1); during phase 2 (18d) and phase 3 live yeast was administered (T) or not (C). Phase 3 consisted in a three days individual fecal collection period all the groups, in order to determine dry matter, organic matter, crude protein, crude fat, NDF and ADF apparent digestion rates using acid insoluble ash (AIA) as internal marker (Bergero et al., 2005). Results obtained evidenced as the administration of S. cerevisiae to mature horses resulted in increased digestibility of dry matter, organic matter, NDF, and ADF.