Recent flooding and persistent rainfall across portions of Nebraska created challenges for corn growers and cattle producers. Field conditions have led to questions regarding the feeding quality of corn grain, mycotoxins, and mold presence, and the value of corn residue for grazing cattle. Instances of grain sprouting on ears, moldy grain, and mycotoxin positive grain, have been reported this fall. While these concerns deserve attention, the key is understanding the actual risks, testing when necessary, and making informed management decisions. 

Kernels Sprouting on Ear

One of the more unusual observations this fall has been kernels sprouting while still attached to the ear, which is called vivipary. Unfortunately, extended rainfall, high humidity, and delayed dry down created conditions that caused kernels to germinate before being harvested. 

Not all hybrids have been affected equally, however. Producers frequently report greater issues in hybrids with more erect ears, which retain moisture under excessive moisture conditions. In many fields, sprouting is most severe at the base of the ear where water trickles down and accumulates. 

While sprouted kernels certainly look alarming, small amounts of sprouting do not result in major losses in feeding value of grain. The greater concern is the storage life, harvest losses, and an increased potential for ear and cob rot to develop. In other words, grain may require more attentive management but should not automatically be considered an unsalvageable crop.

Mold ≠ Mycotoxins and Vice Versa 

Mold and mycotoxins are not synonymous. Feed may contain mold without mycotoxins, and mycotoxins may be present without visible mold. The presence of one does not necessarily indicate the presence of the other.

Weather damaged grain that contains acceptable concentrations of mycotoxins may still be a valuable feed resource for livestock. Because tolerance to mycotoxins varies among animal species and classes, particularly between cattle and the more sensitive swine and poultry, grain should be tested before feeding. Laboratory analysis can help determine which livestock are appropriate recipients and whether feeding limitations or inclusion rate restrictions are warranted.

Laboratory testing is the only reliable way to determine risk. If grain, ensiled corn, or residue quality is of question, collect a representative sample and submit it for analysis before making feeding decisions. Moldy grain may still have feeding value, while visually clean grain may warrant caution if field or storage conditions favored mycotoxin development.

Utilizing Damaged Grain

Weather damaged grain may be able to be marketed in multiple ways, such as dry grain for livestock feed or processing markets, or sold as discounted grain. The most common impacts include reduced stability in storage, lower palatability, and market discounts. In general, low mold counts are considered a minimal concern, moderate mold counts warrant caution, and very high mold counts may require dilution or need to avoid feeding altogether. However, mold counts alone do not determine whether mycotoxins are present.

Impacts on Corn Residue Grazing

Grain quality concerns have received most of the attention, but residue quality may also be affected. Tar spot and other fungal diseases, combined with prolonged moisture and warm fall temperatures, accelerated decomposition of residue in affected areas.

Leaves and husks are typically the most digestible and preferred portions of corn residue. Increased weathering and fungal activity may reduce both residue quantity and quality prior to grazing. Producers should evaluate fields individually and recognize that stocking rates and supplementation needs may differ from a typical year.

Summary

The challenges of this growing season emphasize the importance of evaluating feed resources carefully and making decisions based on facts rather than assumptions. Sprouted ears, mold, and residue deterioration warrant attention, but they do not automatically eliminate the value of grain or grazing resources. Careful evaluation and testing can help producers make informed harvest, marketing, and feeding decisions. If you have further questions about grain quality, mycotoxins, feed testing, or corn residue grazing, please contact me at my office (402-624-8007) or by email (cbiehler2@unl.edu).

Additional Resources

• UNL Extension Circular EC3069, “Sampling and Testing Feed for Mycotoxins”
• UNL Extension Circular EC3066, “Use of Mycotoxin-Contaminated Feed for Animals”
• Pasture and Forage Minute: Considerations for Grazing Corn Residue, “Cornstalk Quality After Weathering”
• Corn Stalk Grazing Toolbox: Multiple resources