ABSTRACT
The key to understanding and indeed manipulating ruminant production is the rumen as microbial fermentation in the rumen plays a central role in the ability of ruminants to utilize fibrous substrates (Hobson and Stewart, 1997). Microbial biomass produced in the rumen and the resultant fermentation end products provide the host animal with a substantial proportion of the nutrients required to produce meat and milk and directly affect product quality but also result in the production of methane, an important greenhouse gas (GHG), and the loss of excess nitrogen in excreta (Steinfeld et al., 2006). The manipulation of rumen fermentation to maximize efficiency of feed utilization to increase ruminant productivity continues to be of great interest commercially. In simple terms, manipulation of rumen fermentation aims to minimize fermentation processes that are inefficient or deleterious to the host while maximizing the beneficial aspects of rumen fermentation.
