High Nitrates Detected in Forages

Sorghum-related plants, like cane, sudangrass, shattercane, and milo can be highly toxic during certain growing conditions.
( Troy Walz, University of Nebraska )

High level of nitrates have been detected in forages this year in South Dakota and other states.  Depending on where you live, it could be due to weather conditions, fertilizer, previous crop, or a combination. Regardless of the situation or where you are located, it is advised to have your forages tested for nitrates this year. Asking your neighbor, if he or she has high nitrates, is no indication of what your forage will be. Likewise, there is variation amongst fields that sit side by side.

Common forages that accumulate nitrates include: oats, wheat, millet, sudangrass, sorghum, corn, orchardgrass, tall fescue and weeds (i.e. kochia, pigweed, lambsquarters, ragweed). Another concern are cover crops. Several of the cover crop mixtures include the plants listed above. In addition most cover crops include brassicas (turnips, radishes, rapeseed) that can also accumulate nitrates.

If forages are too high in nitrates, abortion and or death could occur. Death may occur within 1 hour, or in the usual case, 3 to 4 hours after the onset of difficult breathing. An analysis of your forages, will prevent you from having these wrecks.

Several laboratories perform nitrate testing. Depending on lab, up to $20/sample. One abortion will pay for a lot of testing. Taking a representative sample is important regardless if it is standing forage or bales. When sampling from a standing crop, collect plants from all parts of the field, the good and bad areas. Do not sample from just one end of the field or the most convenient. If the hay is in a bale, a hay probe needs to be used to collect cores. For the proper method of sampling, view Proper Sampling of Hay and Forages or contact a SDSU Extension expert.

If an analysis indicates nitrates are present, most forages can be incorporated into your feeding program by blending with feedstuff that are low in nitrates. When nitrates get above 2000 ppm nitrate nitrogen, it should not be fed to pregnant animals, regardless if you were going to blend.

Nitrate poisoning can be prevented by testing and incorporating into the ration properly. For additional information on Nitrate Poisoning visit iGrow Beef.

View the Feed & Water Testing Laboratories publication for a complete listing of laboratories.