Drought Could Make Corn Dangerous for Livestock
August 17, 2012

Drought conditions that have gripped many parts of the country could increase the potential for rising nitrate levels in forages. 
That means producers need to take extra care to test corn they feed to their livestock to ensure that nitrate levels aren't at levels high enough to sicken or kill the animal, said Bruce Clevenger, an Ohio State University Extension educator. 
Drought stress increases nitrate in forages because plants are unable to go through normal photosynthesis, Clevenger said. Under normal growing conditions, nitrate is quickly converted to nitrite, then to ammonia, and finally into plant proteins and other compounds. But when plant growth is slowed or stopped, nitrate can accumulate in the plant. Samples testing less than 0.44 percent nitrate on a dry basis is considered safe to feed. 
Producers who find elevated nitrate levels in their fields may be able to take steps that would allow them to still be able to use the corn for feed, Clevenger said. Hay, straw, corn silage with lower nitrate levels, and byproducts can be used to dilute the feed so nitrate levels are below the toxic level in the livestock feed ration. 
Reprinted in part from Farm and Dairy