Mycotoxins in corn and corn byproducts – even at low levels – can damage the poultry gut and predispose chickens to necrotic enteritis, revealed new research from the U.S. Department of Agriculture (USDA) Agricultural Research Service’s (ARS) National Poultry Research Center.
“We are very concerned about gut health in the poultry industry. The intestinal tract is the first site of contact for mycotoxins, and intestinal epithelial cells are the first target cells exposed to the highest concentration of mycotoxins,” explained Revathi Shanmugasundaram, research biologist at the National Poultry Research Center.
“These gut microbiome profile shifts can be responsible for the onset of certain infectious diseases, like subclinical necrotic enteritis in poultry flocks.”
FDA regulates mycotoxin levels in poultry feed
The use of mycotoxins in the feed of poultry and other livestock is allowed at low levels by the Food and Drug Administration (FDA).
“Mycotoxins are chemical compounds, called metabolites, that are produced by fungi and are toxic to animals, including humans,” Shanmugasundaram said. “For example, fungi can grow and produce a range of mycotoxins that contaminate corn, including aflatoxins, trichothecenes, fumonisins, and zearalenone. These toxins each have their risks depending on the level of contamination and the animal species that consumes the contaminated food or feed.”
There are screening tools to determine the level of mycotoxins in poultry feed, however the test results can sometimes be misleading when several mycotoxins are present. According to Shanmugasundaram, 92% of poultry feed samples analyzed in 2021 contained more than one mycotoxin.
“With corn being an integral part of poultry feed in the USA, economic loss due to aflatoxins, fumonisins, and deoxynivalenol is estimated to be USD $900 million per year,” she added.
Necrotic enteritis, mycotoxin link
The research showed that fumonisins and deoxynivalenol in poultry feed negatively impacted the body weight gain and feed conversion ratio (FCR), as well as the morphology of the small intestine.
The toxins also significantly increased incidence of necrotic enteritis in broilers. Necrotic enteritis is an acute infection in poultry caused by the bacteria Clostridium perfingens. Sudden changes in feed formulation, such as the addition of high levels of fish meal or wheat, can disturb the intestinal microflora, leaving the gut vulnerable to infection.
“The level of fumonisins and deoxynivalenol in the experimental diets of the current study was much lower than the FDA tolerance levels,” said Shanmugasundaram.
“Our findings identified the mechanism through which fumonisins and deoxynivalenol synergistically affect chickens and predicted the specific thresholds of fumonisins and deoxynivalenol toxins when present together.”
