YeaVita R is a safe and efficient Saccharomyces cerevisiae strain from rumen, which does not contain any carrier and has more than 20 billion viable strains per gram. YeaVita R maintains a good anaerobic environment in rumen by consuming oxygen, so as to increase the three key microorganisms in rumen, especially the fibrinolytic bacteria, and improve the digestion and absorption of nutrients. Yeavita R can also promote lactic acid utilization and effectively prevent rumen dysfunction and acidosis caused by lactic acid accumulation.