With the 2014 harvest just on the horizon, many swine and poultry producers are finding the last of the 2013 grains being used in feed are of substantially lower quality. Even when stored in the best conditions, grains never improve quality during the storage period. Grain quality is either maintained or lost, taking with it the farm’s net returns.

Corn, a key ingredient of swine and poultry diets, may represent close to 60 percent of the total feed. Nutritionally, it can make up 65 percent of the energy, 24 percent of the protein, 14 percent of the lysine and 24 percent of the methionine+ cysteine in a broiler’s diet.

“The quality of the grains stored depends on many different aspects, and it starts in the field by choosing the hybrid to be planted, density of plants, tillage management and weather conditions,” said Guilherme Bromfman, Alltech’s North American mycotoxin management manager. “Post-harvest there are also key factors such as air management, insect control, moisture of grains, rodents, molds and weather conditions during storage.”

According to Bromfman, it is imperative that grains are stored under 13 percent moisture, however even if dried to that level, there is a risk for moisture absorption as the hygroscopic equilibrium of the corn fluctuates based on temperature and relative humidity. The movement of the moisture inside the silos generates “hot spots,” small areas with higher moisture and an increased incidence of molds that, through respiratory process, elevates the temperature.

“When a higher mold incidence occurs, there are two key challenges: first is the reduction of nutritional values and the other is a higher frequency of mycotoxins,” Bromfman said.

For both poultry and swine, mycotoxins can reduce weight gain, increase feed conversion and shrink net returns per animal. Bromfman advises producers to be aware of these specific mycotoxin symptoms in each species:


Type B Trichothecenes (DON):

  • At chronic low levels, DON compromises immune functions and absorption of nutrients, and increases incidences of gut diseases such as coccidiosis, necrotic enteritis, colibacillosis and salmonellosis.
  • At subchronic levels, the toxin reduces weight gain and feed efficiency and causes digestive disorders, abnormal feathering and immune suppression.
  • Acute toxicity can result in reduced feed intake, weight gain, digestive disorders, abnormal feathering and immune suppression. The toxin can also cause muscle bruising, which can downgrade carcass quality.


  • At low levels, Fumonsin impacts the intestinal system, lowers immunity by altering cytokine profiles, and increases mortality and morbidity.
  • Moderate levels can decrease feed intake, weight gain and immunity. It affects gut integrity, which leads to increased intestinal diseases and compromises feed digestibility and the ability to absorb nutrients.
  • Acute toxicity decreases feed intake and performance and affects gut integrity, leading to increased intestinal diseases and compromises in nutrient absorption.


Type B Trichothecenes (DON):

  • Long term exposure of low levels of DON results in lower feed efficiency and immunity.
  • Moderate risk levels of DON reduce feed intake and efficiency, and cause pigs to be lethargic. DON can also have a strong impact on gut health, causing damage to the intestine and reducing nutrient utilization.
  • At high risk levels, the toxin can alter brain neurochemistry, leading to a severe decrease in feed intake, lethargy and vomiting. Together, these can result in weight loss. DON also causes damage to internal organs such as the intestines and liver, causing lesions and hemorrhages.

“As we get closer to this time of the year when the last corn in the silos is used in the diets, it is crucial to have a complete mycotoxin management program in place,” Bromfman said. “Alltech’s broad detection mycotoxin laboratory analyzes feed contamination and manages potential risks in the feed mill and in production houses to minimize the impact low quality grain can have on livestock and poultry performance and profitability.”