Lignification of cell walls is the major factor controlling the digestibility of forage grasses. Thus far, from QTL analysis, about 15 locations involved in cell-wall lignification or digestibility have been identified in the maize genome, many of which colocalise with QTLs involved in corn borer susceptibility. Genetic diversity for enhancing cell-wall digestibility in maize must be identified in novel germplasm, but genetic engineering is also a relevant way both to design specific cell-wall characteristics for improved digestibility and to identify genes involved in these traits for further discovery of alleles of interest in grass germplasm.