Soon corn silage harvest will begin across Michigan. Corn silage is a great feed for ruminants, like cattle, providing energy and fiber to keep them healthy and growing or milking. However, under some weather conditions, quality issues can arise as a result of fungal infection of ears, resulting in the production of mycotoxins. Contamination of animal feed by mycotoxins such as deoxynivalenol (DON or commonly known as VOM) has been on the rise in Michigan and other northern US production regions over the last few growing seasons.

Mycotoxins are secondary metabolites produced by specific fungal species (such as Fusarium graminearum that produces VOM). A combination of optimal (cool and wet) weather conditions favorable to fungal infection and hybrid susceptibility can result in ear rot infection and associated pre-harvest mycotoxin contamination. Moreover, feeding by western bean cutworm and other ear feeding insects has been observed in conventional and even some Bt hybrids can contribute to ear rot and mycotoxin accumulation.

Some mycotoxins can cause lost milk production, poor reproductive performance, sickness or even death of animals. In sufficient concentrations in the diet, mycotoxins can have a serious economic impact on farms. Interaction of mycotoxins with other factors make it difficult to determine safe levels for individual mycotoxins.

While some farmers may feed a “binder” to tie up the toxin in the animal’s digestive tract, this is not always effective and is only a treatment after the animal has already ingested toxins. Since there are few ways to overcome problems once mycotoxins are present in corn, prevention of mycotoxin accumulation in the field is essential. Mycotoxin accumulation in a bunker silo will not decrease or be eliminated after the corn silage fermentation process is completed. Management practices that can be used to minimize mycotoxin production in a corn field include: hybrid selection including insect protection package, fungicide application, scouting and spraying for ear feeding insects, crop rotation, tillage, planting density, and harvest timing.

Michigan State University is conducting research to determine the effects of management practices on mycotoxin development in corn. The goal is to investigate the relative impacts of agronomic practices, bird and insect damage, and weather conditions across Michigan on mycotoxin contamination and overall corn silage quality. Michigan corn farmers are invited to be a part of this research.

Farmers can submit corn silage samples for free testing of 26 different mycotoxins. Samples, of approximately one pound, should be collected from various locations in the same field and then either dried or frozen soon after collection. A data sheet is available to record information about the location, crop practices and corn crop. This information must be completed before samples will be analyzed.

Funding for this project are provided by the Michigan Alliance for Animal Agriculture, Project GREEEN and The Michigan Milk Producers Association. Farmers that are interested in participating should contact Michigan State University Extension Educators Phil Durst (989-387-5346), Phil Kaatz (810-338-5242) or Martin Mangual (787-378-1720).

The mycotoxin analysis results will be communicated back to the farmer so that any needed feeding rate adjustments can be made. This 2-year project aims to advance the knowledge of predicting when and where mycotoxins will be a problem and better enable farmers to reduce their risk.