I would think cows would be the better choice. My dad brought some cows in from the sandhills of NE that did not know what corn was. It did not take long for them to find out. A cow would be walking along, stop, stick her nose in the snow, and pull out an ear of corn and start chewing. In the late 40's and 50's, my dad raised Funks corn. It would make abut 100 bpa and about 20 bushels would fall on the groung. The cows would fertilize as they were picking up the corn on the ground.
If you are worried about volunteer corn next year, plant liberty link corn.