Bin run corn is not soybeans-corn is a hybrid, if you plant the kernels it reverts to the parent lines(I was told). I have seen it tried, plants were unbelievably UNeven, looked like weeds planted in rows. Cobs were small to non-existant.

Better to just plant low-priced seed. Many smaller companies sell silage blends made up of leftover/excess/not variety pure seed that will grow OK and yield decent but have ear-to-ear variability in moisture. The past couple years, this stuff was selling for $70 or less per bag. Another option would be open-pollinated, there's a few guys sell that too. Or go with the "leafy" silage corns(Jung's HDS, Mycogen TMF, etc).

Remember, yield is yield, whether it is being harvested mechanically or by animals. 200 bu corn is still 2x as much feed as 100 bu corn. Standability and drydown would be lower priorities for animal-harvesting.