Kansas State University researchers are reporting findings of a study in which they tested the effects of varying levels of fumonisin-infected corn on the growth performance of nursery pigs. They say their work will help to increase the safety of feeding corn, as well as heighten swine producer’s awareness of testing the quality of grain after harvest.
“Testing the corn after harvest is important, especially when we have had wet harvest conditions,” says Mike Tokach, a swine nutritionist with K-State Research and Extension. “That becomes even more important if the wet harvest follows a period of drought.”
Fumonisin is a kind of mycotoxin that is more likely to develop in corn under those weather conditions. Mycotoxins are toxic chemicals that are naturally produced in certain types of fungi, usually in certain crops. K-State’s work with 20- to 60-pound nursery pigs showed a decrease in the animals’ performance when their diets contain more than 30 parts per million (ppm) of fumonisin.
“Up to 10 ppm, corn can be fed without impacts on pig performance,” Tokach says. “Up to 20 ppm, the corn can be fed for short periods, such as five weeks, without reducing pig performance.”
Johnson Rao, a K-State graduate research assistant who helped conduct the study, says levels of 30 ppm or higher should never be fed to pigs without a mitigation strategy. “Based on our data, when a producer has a load of corn with high levels of fumonisin contamination, they should dilute it to a safe range for swine feed production,” he says.
Tokach added that producers who receive corn that tests high for fumonisn can also contact a nutritionist or K-State experts for guidance. “There are products that can be used to lessen the impact of some mycotoxins,” he says. “But it’s important to seek professional guidance.”
High levels of fumonisin in corn were reported in Kansas and the Midwest in 2018 when the early portion of the growing season was hot and dry, followed by heavy rains late in the growing season. While the conditions were less ideal for fumonisin this year, the toxin still can be present.
Tokach noted that fumonisin does not make food products unsafe for consumers. “The meat is safe to eat,” he says. “The concern we have is for animal health and performance.”
K-State’s study will be presented during the university’s annual Swine Day, which is taking place in Manhattan on Nov. 21. Registration for that event costs $25 through Nov. 12, $50 afterward. Students can attend Swine Day for free if they pre-register.