Improving the digestibility of forage maize through plant breeding is important for optimizing the efficiency of ruminant rations. This can be achieved in part by improving the digestibility of stem tissue, a genetically complex and diverse trait that changes during the growing season (Boon et al. 2012). The aim of this study was compared maize hybrids of the early maturity group (FAO 230­260) and the moderately early group (FAO 290-340), while comparing also the influence of endosperm type (dent or flint kernel and intermediate values for these), according to the chemical composition, ensilability, and especially in vivo total tract digestibility of silage.