Silage can be defined as product formed when forage with adequate moisture content is stored anaerobically, being at the risk of spoilage by aerobic microorganisms. The ultimate goals of the ensiling process are: (1) to retain as much as possible of the original nutrients and dry-matter (DM) through an efficient lactic acid fermentation; and (2) to have a stable product throughout the phases of storage and feed-out. Unfortunately, losses inevitably occur during the ensiling process: from the time of the harvest in the field, through plant respiration and microbial fermentation, effluent production, and exposure to air during storage and feed-out. Furthermore, the level of management has a major impact on the magnitude of these potential losses since some of these losses are avoidable.