By Connor Biehler
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.
Source : unl.edu