Influence of diet and yeast supplement on in vitro ruminal characteristics

Abstract

The effect of Yea-Sacc supplement on the level of rumen fermentation products in dependence on the diet has been investigated in the Rusitec fermentation apparatus. The solid and liquid components of the rumen contents of sheep fed a diet consisting of 80% meadow hay and 20% ground barley were used as an inoculum. Three experiments were carried out in which four fermentation vessels were each fed Diet 1 (80% meadow hay and 20% barley), Diet 2 (50% hay and 50% barley) and Diet 3 (65% hay, 20% barley and 15% treated beech sawdust). The yeast culture Yea-Sacc 1026 contained 10 8 live cells of Saccharomyces cerevisiae per gram and was added to two fermentation vessels every day at an amount of 0.5 g 1 −1. Results showed that the Yea-Sacc supplement increased the digestibility of hemicellulose with Diets 1 and 2. The digestibilities of other parameters were not affected. With Diet 3 digestibility of dry matter, neutral detergent fibre, hemicellulose and cellulose were significantly lowered. Microbial proteosynthesis increased with Diets 1 and 3. No significant differences were found in the pH, ammonia N and gas production values. The volatile fatty acid production was variable. From the results it followed that the Yea-Sacc additive significantly influenced some aspects of rumen fermentation in vitro, which appeared to be dependent on the nature of the diet used.