Effects of Saccharomyces Cerevisiae on Nutrient Digestibility in Mature Horses Fed Diets with High and Low Concentrate to Hay Ratios

Abstract

The objective of this study was to determine the effects of Saccharomyces cerevisiae on nutrient digestibility in mature geldings being fed either a high concentrate (70:30) or high forage (30:70) diet. Eight mature, sedentary geldings were fed four treatments consisting of a) high concentrate without yeast (HC); b) high concentrate with yeast (HCY); c) high forage without yeast (HF); and d) high forage with yeast (HFY). Samples were analyzed for dry matter, NDF, ADF, fat, gross energy and minerals. The resulting digestibilities and balances were calculated. There was no significant effect of yeast culture across parameters. However, there was a significant diet effect. Gross energy intakes were higher for the HF diets due to level of intake. Energy excreted from the feces was higher on the HF diets, however, significantly more energy was excreted in the urine from the HC diets. Therefore, DE and ME values were not significantly different.