Nitrate a concern in drought-damaged corn fed to livestock

Drought-damaged corn plants, especially those heavily fertilized with nitrogen, can accumulate nitrate, making them dangerous for animals to consume, according to Tim Evans, an associate professor of veterinary pathobiology and toxicology section head at the Veterinary Medical Diagnostic Laboratory at the University of Missouri College of Veterinary Medicine.
In normal conditions, corn crops typically absorb nitrate into only the lower 12–18 inches of the stalk, which does not have to be fed to animals. However, during severe drought conditions, high concentrations of nitrate can accumulate in the upper portions of the stalk, which cattle and other livestock often eat, said Evans. "Eating plants with too much nitrate can cause damage to red blood cells, resulting in lethargy, miscarriage and even sudden death,” he said.

Farmers should test the nitrate levels of their crops and pastures before allowing their animals to eat any of the plants. “Missouri farmers should definitely contact their local MU Extension offices for help in the preliminary stages of testing the nitrate concentrations in their crops,” said Evans. “MU Extension workers have their boots on the ground all across the state and are truly a valuable resource for farmers who are worried about their crops and livestock.”