About 6.4% of the ~87 million acres of corn harvested in the U.S were dedicated to silage production in 2010. Of those, approximately 750,000 acres were located in Wisconsin, the largest silage producing state in the U.S. (USDA, 2010). Maize silage is produced by ensiling the whole plant harvested a few weeks prior to physiological maturity. The starch from the grains and the complex carbohydrates in the cell walls are the primary sources of energy for the complex community of anaerobic microbes that reside in the gastrointestinal tract of ruminant animals (Van Soest, 1994; Coors and Lauer, 2001). Substantial improvements in forage digestibility have been achieved through traditional breeding in maize (Frey et al, 2004; Gustafson et al, 2010) as well as through the incorporation of large mutations such as the brown midrib3 (Sattler et al., 2010).