Excessive rain and late-season corn diseases have made the 2016 corn harvest a bit of a challenge in the upper Midwest.
“Despite extremely wet conditions, on average plants grew aggressively earlier in the season and appear to be maturing through the rainy month,” said John Goeser, Rock River Laboratory’s animal nutrition, research, and innovation director. “Typically, Rock River Laboratory observes freshly chopped whole-plant corn moisture decreasing in samples throughout the harvest season. This year, we have observed moisture content trending down at a seemingly faster pace, suggesting either advanced maturity or a disease-pressured crop.”
Goeser said that harvesting the crop at the correct dry matter content, or approximately 35 percent on average, depending on silo type, is critical for effective ensiling and preservation to feed-out this year.
With the exception of fields that were planted late, or in regions that experienced hail damage, flooding or soggy conditions too wet to harvest, corn silage yield output has largely already been determined. These late-planted or damaged areas will likely experience substantial yield tonnage losses, among other issues.
“Relative to yield, the corn plant’s health and cleanliness are of equal or greater concern,” says Goeser. “Epiphytic [meaning natural and wild] mold and yeast measures on standing or fresh plants within the Midwest are typically in the 1,000,000’s,” explains Goeser (Lin et al., 1992; Rock River Laboratory unpublished data). “We’ve recognized increasing mold counts in both fresh and fermented feed and total mixed ration samples the past five years and this trend will undoubtedly continue.”
Aggressive (low pH) ensiling will help suppress these anti-nutritional microbes, but with fungal disease showing up earlier this year and substantial rain through harvest, the Midwest will likely be dealing with mold challenges.
In addition to recognizing these harvest challenges and the potential resulting effects on the crop, Goeser recommends aggressive management through simple steps that producers and their harvest team can take to optimize the crop at hand, with the following points:
1. Harvest at the appropriate plant or grain maturity and whole-plant dry matter content to optimize fermentation and preserve nutrients.
2. Avoid tracking mud onto chopped corn where possible.
3. Use a research-backed forage preservative, preferably one with mold and yeast controlling abilities.
4. Cover the bunker or pile between chopping days if rain stops the harvest.
5. Seal the silo to the best of your abilities, including tops, edges, walls and ends.
6. Visually assess the crop and feel for heating within the first few days when opening the silo to feed out. Monitor animal performance closely.
High moisture or dry corn crops
1. Monitor grain maturity and moisture content.
2. Process the corn accordingly with dry matter at harvest. For corn wetter than 30 percent dry matter, a coarser grind can be tolerated. For corn drier than 25 percent dry matter, slower and less fermentation can be expected. Grinding must be finer and uniform.
3. Consider mold and yeast control strategies similar to those described above.
4. Aggressively ferment or dry this challenged crop adequately in order to stabilize the grain.