Corn Silage Update 2020:
Mycotoxin risk going into 2021

The 2020 corn crop grew and matured under a variety of conditions from near ideal, to increased heat, to drought, to windstorms and hail events. How did these conditions influence the risk of mycotoxins in dairy TMRs?

Extreme events during corn growth can increase plant stress and the incidence of molds that can produce mycotoxins.

For 2020, the first 288 corn silage samples submitted to the Alltech Analytical Services Lab showed an average of 5.4 mycotoxins per sample with 99% of the samples containing 2 or more mycotoxins.

The greatest risk to dairy cows is coming from DON (deoxynivalenol, also known as vomitoxin or VOM) with Fusaric Acid and T-2/HT-2 also being present at lower risk levels. Figure 1 shows that the risk level of DON has increased in recent years. As the crop remains in the field, exposed to increased environmental pressure, the risk level of DON increases.

Also, field dry down typically increases dry matter (DM), which can result in a drier than expected silage that does not pack as well. The lack of density allows greater oxygen penetration that can result in higher levels of Penicillium mycotoxins.

For 2020 silage, the increase was already trending up, Figure 2, and will need to be closely monitored during 2021 winter and spring feed out.

Figure 1. Trend in DON level in corn silage August – October 2020

Figure 2. Trend in Penicillium level in corn silage August – October 2020

The average mycotoxin risk for 2020 corn silage closely matches the risk in the corn silage from 2016, when hot and dry growing conditions also impacted the crop and caused higher risk TMRs when fed in 2017. This serves as a warning for those feeding 2020 corn silage to be diligent and test mycotoxin levels going into 2021.

Mycotoxins in dairy feeds can cause reduced feed intake, damage to gut integrity, and poor fertility. Alltech 37+® testing means mycotoxins cannot hide in 2020 corn silage.

For more on Alltech 37+® testing, including a brief video of the procedure, click here.

For more on the mycotoxin threat in dairy and other ruminant feeds, click here.