This growing season presented a wide variety of challenges for corn silage growers and producers across the Midwest. Delayed planting, cooler temperatures and a lack of sunlight dramatically slowed growing degree days. In addition, heavy rainfall throughout the season and into harvest has presented another layer of challenges.
    Corn silage often receives praise for the consistency it brings to a dairy ration. But with the multiple variables listed above, many producers may see significant variation across their fields. For many, corn silage harvest is in full swing or already completed. For others, it has yet to begin.

Harvesting immature corn silage
    Harvesting and feeding immature corn silage is a likely potential for many producers this fall. As harvest is delayed, the risk for frost becomes more likely. Do everything you can to harvest corn silage at the right dry matter content. The target range for harvest is 30 to 38%, depending on the storage structure. If immature corn silage is harvested with less than 30% dry matter, kernel processing may not be needed. In addition, you may need to extend chop length beyond your normal target.
    After a frost, immature corn silage will most likely be too wet to harvest and may need to stand in the field for several days for further drying. The leaves will brown and give the appearance of rapid dry down. However, since most of the moisture is in the stalk and ear, the plant will look drier than it actually is. Use whole plant dry matter to determine when to harvest. Milk line is not a good indicator of harvest time with immature or frosted corn silage.

Feeding immature or frosted corn silage
    Immature corn silage is higher in crude protein, sugar and neutral detergent fiber (NDF), and lower in starch than mature corn silage. NDF digestibility is often higher with immature corn silage, but environmental conditions at different phases of plant growth can influence these results. Energy value of immature corn will typically be 80 to 95% of the normal maturity corn silage. If you are challenged with feeding immature corn silage, work closely with your nutritionist at adjust for these differences.

Corn silage harvest is ready, but the fields are not
    Recent rains on already saturated fields have created conditions where fields are simply impassible. By the time equipment will carry, silage dry matter may be above our target range. If you are faced with chopping corn silage above 40% dry matter, it is recommended to reduce chop length for better fermentation and packing. Roll gap clearance will likely need to be tightened to ensure maximum kernel processing.
    Adding water to silage that is too dry is not very effective due to the large quantity needed to have an impact. If you have the option to blend immature corn with this high-dry-matter corn silage, this can help. At least try to position your wettest forage on the top layer of the pile or bunker. In a few cases, the option to shift from corn silage to snaplage or earlage may be a partial solution when dealing with muddy fields.

Remember the basics
    Regardless of the harvest challenges you may face, always employ the best harvest management practices possible. My August column listed several options for maximizing packing density. With the excessive moisture comes greater potential for molds and mycotoxins. A well-researched bacterial inoculant will enhance fermentation and improve dry matter recovery. Covering piles and bunkers with a proven oxygen barrier plastic will further reduce the potential for spoilage in the top several feet of forage. Most importantly, keep safety at the forefront of your harvest goals.
    Barry Visser is a nutritionist for Vita Plus.