Energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another according to the Law of Conservation of Energy. So what does this concept have to do with corn silage?
In a nut shell, it’s the fact that the energy is in the plant in different states. Through tassel, corn is simply a tall grass. Like any grass, it’s full of sugars and fermentable fiber. As the plant reproduces and fosters the growth of seeds, the plant starts to convert these sugars and energy to starch in the seed. It is finding the perfect balance between the natural plant sugars, the right plant maturity to have fermentable fiber and not wood, or unusable fiber, so to have the entire plant be a usable energy load for milk and butterfat production - That makes corn silage a dynamic feed source. An informative graphic on kernel fill and milk line is available here in the Priority Quality Corn Silage Blog.
In a 2020 corn silage harvest study done in Kentucky, Priority looked at the varying forms of energy the plants delivered at different stages of milk line/kernel fill and plant moisture levels compared to different chopping heights from the ground. The outcome truly illustrates an abundance of sugar and fermentable fiber in the plant prior to kernel fill, with a tremendous loss in these items as the seed hardens and starch fills. An overview on these findings and summary points is available here. Richard V. Breunig, President and Founder of Priority also talks through these findings and his insights from the KY study in When to Harvest Corn Silage.