Harvesting and storing high-moisture corn can help producers get a jump on harvest; avoid drying costs; and put up a highly palatable, digestible, nutritious feedstuff.
But, like any fermented feedstuff, its quality can be fragile, and hinges on careful decisions made during harvest and storage. Among them are:
Moisture – The ideal moisture content at harvest is 28-34 percent, according to Warren Rusche, Assistant Professor of Animal Science at South Dakota State University. He said harvesting at dryer levels will result in reduced starch digestibility and increased spoilage risk because there isn’t enough moisture for the crop to ferment properly. Jodie Myers, Forage Specialist with Cargill Animal Nutrition, cautioned that too-high moisture presents another set of challenges. She said levels approaching 40% or higher promote anaerobic instability (heating) at feed-out. As a general guideline, Myers suggested black layer is a good indication of correct harvest stage.
Processing – High-moisture corn that will be stored in a bunker or bag needs to be processed prior to storage by either roller mill, hammer mill, or grinder, advised Myers. Rusche said rolling generally produces fewer fines and thus creates less risk of causing acidosis at feed-out. He also noted whole, unprocessed, high-moisture corn can be stored in oxygen-limiting upright silos.
Packing – As with all ensiled crops, packing is critical to remove oxygen and create an anaerobic environment that is favorable to healthy fermentation. Processing helps facilitate effective packing, and Rusche advised sealing bunkers with plastic to minimize spoilage. If the product is bagged, be sure it is packed tightly as well, and leave enough plastic at the end so a tight seal can be achieved.
Inoculants – Both experts recommend inoculating high-moisture corn, especially if the crop has sustained ear damage or mold growth, and/or is at the lower end of the acceptable moisture range. “Cooler temperatures in the fall can compromise some of the variability of naturally occurring bacteria, and high-moisture corn has lower levels of sugars compared to traditional corn silage to promote rapid fermentation,” advised Rusche. He said inoculants containing Lactobacillus buchneri strains have proven beneficial in promoting fermentation. Myers added L. buchneri also will increase stability at feed-out, thanks to its acetic-acid-raising and yeast-lowering capabilities. The result: feed temperature will remain stable when it is re-exposed to oxygen at feed-out.
Additionally, Rusche suggested considering ensiling high-moisture corn in multiple, smaller bunkers or piles to minimize face surface exposure compared to one larger unit, especially if the product will be fed in the summer.
Above all, he emphasized the importance of being nimble at harvest to capture the best-quality feed store for the year ahead. “Crop conditions can change quickly,” he advised, “so growers need to be prepared to fill storage facilities rapidly or switch fields as conditions change.”
