OMAHA (DTN) -- Agricultural producers are encouraged to test the nitrate levels in their forage, according to a South Dakota State University (SDSU) Extension news release.

Producers who suspect elevated nitrate levels or who receive high strip-test readings should consult a veterinarian, field specialist, or certified forage testing laboratory for assistance interpreting results and developing safe feeding strategies.

Environmental conditions including drought stress, frost, cloudy weather, hail damage or heavy nitrogen fertilization can increase accumulation in plants. Because nitrate toxicity can lead to reduced performance, illness or death in livestock, testing forage before feeding is an important management practice, according to Parker Witt, SDSU Extension Crop-Livestock Systems field specialist.

High nitrate levels in hay and forage can pose serious health risks in livestock, particularly pregnant animals and ruminants such as cattle. Nitrate test strips can give producers a quick, low-cost screening tool to estimate the nitrate levels in their hay and forage.

"Don't let a preventable nitrate issue turn valuable forage into a costly liability," Witt said.

"Free nitrate testing through SDSU Extension helps forage producers preserve feed value, and livestock owners make informed management decisions before animal health, forage utilization or profitability are affected."

Nitrate testing is available at the SDSU Extension regional centers in Aberdeen, Lemmon, Mitchell, Pierre, Rapid City, Sioux Falls, Watertown and Winner; Berg Agricultural Hall and Raven Precision Agriculture Center on the SDSU campus in Brookings; and at the Bennett County, Butte County, Clay County, Fall River County and Haakon County offices.

For a free, how-to guide on using nitrate test strips, visit the SDSU Extension page: https://extension.sdstate.edu/….

SYMPTOMS OF NITRATE POISONING

If forage contains too much nitrate, plants cannot complete the nitrogen conversion (nitrates to amino acids and other proteins) and nitrate levels build up in the plants, according to a report titled "Nitrates and Prussic Acid in Forage: Sampling, Testing and Management Strategies" from Texas A&M AgriLife Extension (https://agrilife.org/…).

High levels of nitrate can be fatal for livestock, especially cattle. Nitrite is absorbed directly into the bloodstream through the rumen wall, where it combines with hemoglobin to form methemoglobin. Hemoglobin carries oxygen in the blood, but methemoglobin does not, according to the Texas A&M AgriLife report.

The formation of methemoglobin can cause an animal to die from asphyxiation, or a lack of oxygen. The animal's blood turns brown instead of the normal bright red.

Monogastrics (horses, mules, swine, etc.) are less sensitive to nitrate toxicity than ruminants (cattle, sheep, goats, etc.). An animal's conditioning affects its ability to assimilate or tolerate nitrates, so Texas A&M AgriLife Extension recommends producers consult their veterinarian before feeding forage that contains nitrates.

ADDITIONAL RESOURCES

Montana State University had a report on what method to use in forage nitrate testing. The report can be found at https://extension-store.montana.edu/….

University of Georgia Extension's Forage Team also had a detailed report about testing for nitrates in forage. The report can be found at https://site.extension.uga.edu/….

Russ Quinn can be reached at Russ.Quinn@dtn.com

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