In the video below, the parade of tractors going around and around looks like they are building the pile in layers and compacting it as is done with the bunker storage of silage. Some research indicates that corn can indeed be stored like silage if the kernels are cracked into pieces varying between 5% and 95% of a whole kernel. The different sizes allows the corn to be packed tightly to remove oxygen from the pile. The pile will then be covered with plastic and tires like other silage is stored to keep moisture and oxygen out of the stored product. In addition to bunkers, other silage storage technologies such as traditional silos and long plastic bags can also be used.
(Writing a posting on silage is on my todo list. In the meantime, here are three videos that show how plastic bags can now be used to store silage: setting up the bag, filling the bag, switching to another bag. Update: a video showing how a used bag can be picked up as round bales.)
This partially ground corn can be mixed with other products such as distillers grains to make feed for beef and dairy cattle. Since distillers grains are one of the waste products from ethanol production, they are relatively cheap.
An advantage of using high-moisture corn is that it can be harvested as soon as the seed has matured while the stalk is still strong. This reduces loss in the field. It also extends the harvest window so that a combine can pay for itself quicker by harvesting wet corn for this market and then dry corn for the traditional markets. One of the references I read said high-moisture corn was being trucked from farms as far away as 60 miles.
In this Nebraska operation, the trucks dump into piles at one end of the bunker. Two front loaders are used to feed two mill rollers. The output of the mill rollers will then be piled and compacted by the "parade" of tractors. Notice that the front loaders use an oversize bucket because grain is easier to "dig" than dirt.
Some of the cuts were rather long, I found myself skipping ahead several times.
He evidently got permission to get up close and personal to get scenes for this video.