Evaluation of Yeast Supplementation with Urea-Molasses in Rice Straw-Based Diets on in vitro Ruminal Fermentation

The effects of yeast supplementation on in vitro fermentation characteristics of rice straw and urea-molasses diets in Indonesian swamp buffalo were examined; five doses of yeast (0, 2.5, 5.0, 7.5 and 10 g/head/d) were tested. The results indicated that yeast supplementation increased dry and organic matter, neutral detergent fiber (NDF), cellulose and hemicellulose degradability, ammonia-nitrogen and total volatile fatty acid concentration and decreased the ruminal pH but had no effect on acid detergent fiber (ADF) degradability or cellulolytic bacterial or protozoan populations. Supplementation with yeast supported ruminal fermentation of urea-molasses and rice straw-based diets, with 5.0 g yeast/head/d showing the greatest response for most variables tested.