An adequate duration of time for fermentation is often cited as a critical management tool for silages. The first reason is to allow the fermentation process to stabilize the forage as feeding unstable forage can lead to disruptions in animal feeding patterns and health. In the case of hay crop silage, this is the main consideration, and therefore guidelines often suggest that feed-out can begin after approximately four weeks in storage. With corn silage,there is another consideration,as fermentation plays a role in improving starch digestibility. While evidence is not consistent that fiber digestibility changes during fermentation, numerous studies have documented improved starch digestibility as fermentation time increases. Current guidelines suggest waiting a minimum of three to four months before feeding out corn silage, although additional gains can be realized even past this point. Data from this study are consistent with the current understanding of the topic.