The term probiotic is generic and all-encompassing, to include microbial cultures, extracts & enzyme preparations. As such, the Office of Regulatory Affairs of the Food & Drug Administration (FDA, 2003 ), as well as the Association of American Feed Control Officials (AAFCO, 1999 ), have recommended the term direct-fed microbials (DFM) be used to describe feed products that contain a source of live, naturally occurring microorganisms. Feeding DFM generally results in a 2.5 to 5% increase in average daily gain and an approximate 2% improvement in feed efficiency in feedlot cattle. DFM promotes the absorption & digestion of feedstuff, growth and development. Improve the meat quality and intestinal tract condition, temper the bacteria balance, increase immune function & anti-virus ability of the organism. Increase egg laying rate and poultry fertility rate.