A mold on corn has caused the deaths of some livestock in Dickinson County.
A mycotoxin called fumonisin has been causing adverse health and death loss in swine and horses in north-central Kansas over the past several weeks. Several reports have come from the areas of northern Dickinson county, southern Clay County and eastern Ottawa County, according to a news release from the K-State Research and Extension Service
Dr. Mike Whitehair, an Abilene veterinarian specializing in large animals, said at his retirement reception Saturday that fumonisim has shown up in Dickinson County and has led to deaths.
He said the mold is toxic mainly to horses, swine and rabbits.
“In basic terms, it’s a mold,” Whitehair said. “This mold gets a chance to propagate in plants, especially those that have endured the stress of the spring when things were quite dry.”
Dry and wet
at wrong times
A green plant would not allow the mold to grow and adhere to the kernels of corn, he said.
“What complicates it is that when the harvest comes along, especially this year, we had some moisture, and that moisture activated the mold to become even more prevalent in the plant,” he said.
Whitehair said livestock producers should be aware and recognize that conditions are “ripe for this having a better chance of occurring.”
“If we flipped it around and had a wet spring and dry fall we wouldn’t have this conversation,” he said.
Test for toxicity
Whitehair said corn should be tested for toxicity.
He said the corn can be blended with other feed and be less toxic.
“But if the tests are out of sight, the only option is to destroy the feed that is collected,” Whitehair said.
The Kansas Department of Agriculture – Division of Animal Health has warned that corn producers and those feeding corn to livestock, with fall harvest still taking place in this part of the state and livestock being transitioned to concentrate diets, need to be aware of the potential for fumonisin in their corn.
Question of quality
Experts are encouraging close attention be paid to grain quality and condition during harvest and while in storage.
Those with horses and livestock should have a discussion with their local feed retailer to make sure their source of corn is safe.
Fumonisin is a mycotoxin produced by strains of Fusarium molds that are associated with ear rots and stalk rots in corn. These are both seed-borne and soil-borne pathogens that can develop under a wide range of environmental conditions.
In-field conditions that favor the disease are hot, dry conditions during midseason followed by cool and moist conditions during pollination and kernel formation. Insect or hail damage to ears can create entry wounds and insects can transport the fungus.
Warm, wet weather at harvest also facilitates the disease.
Fumonisin can also develop after harvest if grain storage conditions are not monitored. Optimal mold growth can commence if grain moisture content is between 18 percent and 23 percent. Producers with on-farm storage and commercial grain facilities can reduce the chances of fungal growth and fumonisin production by keeping moisture levels below 16-18 percent.
Affected kernels may appear purple, tan, or brown and have visible white or salmon-colored mold, which is a smoking gun for fumonisin contamination. This sort of appearance is typical for the Fusarium species but, just because you have Fusarium does not mean you have fumonisin. However, it is a very good indication that testing needs to be done.
May appear normal
On the contrary, the suspect corn in the recent toxicity cases did not appear to be discolored or abnormal at all. So, a simple visual inspection may not tell you if there is fumonisin present at a concentration of concern.
The only way to determine the concentration of fumonisin that is contained in corn is to have it analyzed either with ELISA or a chemistry method through a qualified laboratory.
Fumonisin has few effects on most animals and the vulnerability ranges vary greatly. Research shows that horses and rabbits are the most sensitive while poultry, mink and feeder cattle are the least susceptible. Fumonisin concentrations of concern are greater than 1 parts per million in equine diets and greater than 10 ppm in swine diets. The fumonisin concentration of concern for cattle is unknown, but studies indicate levels from 30 to 90 ppm are safe.
As a point of reference, some of the corn that has been analyzed in the north-central Kansas cases have had fumonisin concentrations greater than 100 ppm and as high as 700 ppm.
For questions or more information about fumonisin or other mycotoxins, contact your local Extension Office, veterinarian or the Kansas State Veterinary Diagnostic Lab at (866) 512-5650.