Abstract
Recently, animal food industry has shown an increasing interest in Direct-Fed Microbials (DFM) to keep the concept of safe food supply at the consumer level. In the absence of suitable growth stimulant after banning the use of antibiotics in animal feed, a positive manipulation of rumen microbes has become the field research for entrepreneurs and research scientists. Direct-fed microbials is a term reserved for naturally occurring live microbes that can be supplemented orally to produce a beneficial health response in the host animal. A number of genera of live microorganisms including; bacteria, yeast and fungi are frequently used in different combination feed as DFM for domestic ruminants. It has been documented that these live culture of microbes improve ruminant productivity, milk production, immunity, digestibility of feed, counter infectious pathogens and protect health. Possible attempts have also been undertaken to justify the mechanism of these microbes. This review tries to summarize the effect of supplementation of DFM on the production, immune response, fermentation pattern and safeguarding health. The discussed concepts and advances concerning to DFM implementation will be useful not only for the researchers, animal owners, feed manufacturers, pharmacists, pharmaceutical companies, stake holders but will also boost the economic gains and profits by promoting the ruminant health and production through feed modification.