Answer provided by Mike Hutjens, extension dairy specialist at the University of Illinois.
Q: With wind damage, heavy rain, frost potential, and cool weather, what should we be watching for in feed quality?
A: Each weather factor effects bring new challenges and can be additive to one another. Wind has flattened corn fields, resulting in damage to immature plants. Heavy rain can delay harvest and increase the risk of mold and mycotoxin developing in corn silage, corn grain, and fuzzy cottonseed. Cool weather will delay maturity and encourage mold growth, possibly leading to mycotoxins under wet conditions. An early frost can result in harvesting immature crops.
Waiting for the corn to reach optimal dry matter for ensiling and fermentation is ideal, but delays can allow for mold growth and additional dry matter loss in the field. Start harvesting to minimize these losses and risks, especially if corn silage is stored in bags, bunkers, and/or piles to lower seepage compared to tower silos. Harvest corn plants when the crop reaches 30 to 35 percent dry matter (may require several days to dry down). Soybean silage must be harvested to minimize leaf loss.
Harvesting at optimal dry matter for silage is ideal, but as corn silage advances in maturity, plant/kernel processing and shorter chop length can improve packing and nutrient availability.
Feed quality should be monitored for mycotoxin levels. Add mycotoxin binders to rations if needed.
Use of inoculants can improve fermentation time, silage pH, and volatile fatty acid profiles.