The pericarp or outer shell of the Maize corn was intended to protect the Maize germ until germination, but it also restricts bacterial access in the rumen. The role of maize silage and a corn cracker is to break this defence (shell) allowing access to both the soft and hard endosperm. Dent Maize has a soft dent in the top (see above), meaning that the grain is weaker, whereas Flint Maize is covered with a pericarp and hard endosperm layer limiting access. Therefore, in the rumen Dent Maize Silage naturally offers more fermentable starch for the rumen bugs. Most US Maize are Dent varieties, whereas European Maize Growers tend to grow flint varieties, because of its earlier flowering period and tolerance to drought. After the same ensilement procedures as one another Flint Maize starch is more likely to bypass the rumen. Bypass starch will break down in the lower gut but ultimately the Dent starch will offer more fermentable energy which creates more bacteria, which then die and are consumed by the cow as microbial protein. As a result, less supplementary protein like Rape and Soya meal need to be fed, and a big reason why many US dairy rations are now based on 15-16% crude protein. The remaining dent starch will also be broken down in the lower gut, so from a utilisation perspective Dent offers better value for money!
If this sounds of interest to you, please contact Wesley Habershon at firstname.lastname@example.org or your local FCG Office.