You can feed it a few days after ensiling it, says Mike Hutjens, University of Illinois extension dairy nutritionist. But corn silage quality is optimal if the crop is stored in a bunker, upright silo or bag for three to four months. Feeding it three to four weeks after ensiling is better than feeding it a week after, he adds. For more on the subject, read "Slow-Cooked Silage" in the September issue of Hay & Forage Grower.