Feed Troubles May Be Lurking

If going directly from monsoon season to the middle of winter weren’t bad enough, it appears that Wisconsin’s dairy and livestock producers may need to keep their eyes open for something lurking in their feeds: mycotoxins.

For those not familiar with the term, mycotoxins are stable toxic compounds produced by some molds that can accumulate in both the corn grain and the stalk. When eaten, these compounds can lead to a variety of health hazards in livestock and humans, including suppressed intakes, a pronounced drop in milk production, and abortions or other reproductive issues.

This fall’s excess precipitation—further delaying an already late harvest—along with warm days and cool nights, have set the stage for near-perfect growing conditions for several molds in the corn crop. According to several Landmark agronomists, this year’s biggest offenders appear to be Gibberella/Fusarium and Diplodia ear rot, as well as Gibberella and Anthracnose stalk rot.

In terms of potential mycotoxin production, the pink-colored Gibberella/Fusarium molds are likely to cause the biggest issues. These are the molds responsible for vomitoxin (deoxynivalenol or DON), zearalonone, T-2, and fumonisin. In the feed and grain industry, we often use vomitoxin testing as a marker to judge the severity of a mycotoxin issue in the feed.

To be clear, the presence of these molds does not automatically result in high levels of mycotoxins. However, early testing of this year’s corn crop at our grain facilities is showing some instances of highly elevated levels of vomitoxin. Rock River Laboratory in Whitewater also reported elevated vomitoxin levels in some TMR samples from both the Midwest and eastern United States. The graph below is from their October 18, 2019 “Data Distillations” report.

Landmark is working hard to ensure safe feed production for our customers. As a precaution, all loads of corn entering the Landmark Animal Nutrition facilities are being tested prior to dumping to ensure the inventory for feed production remains below 2.0 ppm vomitoxin. Since corn byproducts also tend to concentrate the mycotoxin levels, we’re in regular communication with suppliers regarding their testing and labeling of products. Additionally, in order to preserve the integrity of the marketable corn, Landmark Grain locations are monitoring vomitoxin levels each day. In some cases, we are testing individual loads as well, depending on the overall levels coming into that location.

It’s important to remember that vomitoxin levels alone may not give producers a clear-cut answer on what to expect regarding reduced performance. In many cases, vomitoxin levels do serve as a guide for the overall level of concern we should be taking regarding other mycotoxins. Cattle generally tend to be less susceptible than monogastrics such as swine and poultry. That said, depending on the levels and combinations of mycotoxins in the total diet, serious economic loss can also occur in dairy cattle.

As you begin distributing this year’s feedstuffs to your herd, keep an eye on feed intakes, milk production, overall herd health, and reproductive performance. If you have questions or concerns, be sure to address those with our nutritionist and veterinarian. In many cases, we can provide options to minimize the effects.

And as you wrap up this fall’s harvest and field work, be sure to bring up any mycotoxin concerns with your agronomist. They can help you select more Gibberella-resistant varieties, determine proper crop rotation and nutrient management, and schedule fungicide applications.