Farm Talk


July 3, 2012

Test forage to avoid nitrate toxicity

Parsons, Kansas — Hot dry summer weather brings about heat and drought stress on summer annuals, wherein stressed plants such as the forage sorghums can occasionally accumulate dangerous concentrations of nitrates for cattle grazing them.

“These high nitrate plants, either standing in the field or fed as hay, can cause abortion in pregnant cattle, and even animal death if consumed in great enough quantities,” said Bob Leadford, Garvin County Extension director and agricultural educator.

Nitrates do not dissipate from sun-cured hay, in contrast to prussic acid; therefore, once the hay is cut the nitrate levels remain constant.

“It’s always a good idea to test hay fields before they are cut, so that the producer knows what he or she has in terms of a safe food resource for livestock,” Leadford said. “Feel free to stop by your local OSU Cooperative Extension county office for testing details.”

Testing the forage before cutting gives the producer an additional option of waiting and allowing for the nitrate to lower in concentration before harvesting the hay. The major sources of nitrate toxicity in Oklahoma will be summer annual sorghum-type plants, including sudan hybrids, sorgo-sudans, sorghum-sudans, millets and Johnsongrass.

Leadford said an excellent resource listing plants that may accumulate nitrates is Oklahoma State University Extension fact sheet PSS-2903, “Nitrate Toxicity in Livestock,” available through the county office or online at http://osufacts.o via the Internet.

“Be aware that drought-stressed corn plants were tested last summer in north central Oklahoma and were reported to test well above the 10,000 parts per million nitrate concentration that is considered potentially lethal to cattle,” said Glenn Selk, OSU Cooperative Extension emeritus animal scientist.

While the risk of poisoning cannot be totally eliminated, OSU’s Division of Agricultural Sciences and Natural Resources recommends the following management techniques to reduce the risk of nitrate toxicity in livestock:

Test the crop before harvesting it. If the crop tested has an elevated concentration of nitrates, the producer still has the option of waiting for normal plant metabolism to bring the concentration back to a safe level.

“It is not possible to estimate nitrate content just by looking at the field,” Selk said.

Raise the cutter bar when harvesting the hay. Nitrates are in greatest concentration in the lower stem.

“Raising the cutter bar may reduce the tonnage, but cutting more tons of a toxic material has no particular value,” Leadford said.

Know the extent of nitrate accumulation in the hay and the levels that are dangerous to different classes of cattle, such as pregnant cows, open cows or stocker steers.

“If a producer has any doubt about the quality of the hay, send a forage sample to a reputable laboratory for analysis, to get an estimate of the nitrate concentration,” Selk said. “This will provide the producer with guidelines as to the extent of dilution that may be necessary to more safely feed the hay.”

Allow cattle to become adapted to nitrate in the hay. By feeding small amounts of the forage sorghum along with other feeds such as grass hay or grains, cattle begin to adapt to the nitrates in the feed and develop a capability to consume the nitrate with less danger.

“Time and again there is some producer who cut hay when nitrate levels were high and then used the hay as part of a winter feeding program and had problems at that time,” Leadford said. “Avoid the temptation of feeding the high-nitrate forage for the first time after a snow or ice storm. The cattle will not have adapted to the nitrates; they will be stressed and hungry and often will consume unusually large amounts of the forage.”

Leadford and Selk recommend producers make reviewing OSU Extension fact sheet PSS-2903 part of their normal management plan before cutting and feeding any summer annual hay.£


Text Only
  • To store corn or not to store corn, that is the question

    The majority of annually produced crops such as corn obviously have to be stored. For corn producers, the question at harvest time will be who will store the portion of the crop which has not yet been sold?

    July 29, 2014

  • Scientists complete chromosome based draft of wheat genome

    Several Kansas State University researchers were essential in helping scientists assemble a draft of a genetic blueprint of bread wheat, also known as common wheat. The food plant is grown on more than 531 million acres around the world and produces nearly 700 million tons of food each year.
    The International Wheat Genome Sequencing Consortium, which also includes faculty at Kansas State University, recently published a chromosome-based draft sequence of wheat's genetic code, which is called a genome. "A chromosome-based draft sequence of the hexaploid bread wheat genome" is one of four papers about the wheat genome that appear in the journal Science.

    July 22, 2014

  • Drought & poor wheat harvest in Kan. has effects on nat’l economy

    The Kansas wheat harvest may be one of the worst on record — and the loss doesn't just hurt Kansas, according to a Kansas State University expert.

    July 15, 2014

  • Watch for corn leaf diseases

    In general, corn in southeast Kansas looks about as healthy as any reasonable producer might hope.

    July 1, 2014

  • Consider wind when applying herbicides

    Jill Scheidt, agronomy specialist with University of Missouri Extension in Barton County, scouted fields west of Lockwood on June 18 for the crop scouting program.

    June 24, 2014

  • WheatTour-007.jpg SW Mo. wheat tour yields nutrient tips

    Laying down nitrogen on the wheat fields is quite possibly one of the most complex and critical operations facing producers.

    June 17, 2014 3 Photos

  • Corn planting nears completion, early condition good

    With corn planting nearly complete and emergence keeping pace with the five-year average, the U.S. Department of Agriculture released its first forecast for the condition of the 2014 U.S. corn crop.

    June 10, 2014

  • Harvesting short wheat

    In many areas of Kansas, prolonged drought has resulted in short wheat and thin stands. Harvesting wheat in these situations can be a challenge.

    June 3, 2014

  • Controlling large weeds in Roundup Ready soybeans

    Controlling large weeds is often considerably more difficult than controlling smal-ler weeds. The following are some suggestions for controlling larger troublesome weeds in soybeans.

    May 28, 2014

  • aflatoxin-corn.jpg Aflatoxin risk looms large for corn growers

    To diversify their farms and tap into high demand for one of agriculture’s most profitable crops, dryland farmers more familiar with growing wheat and milo are eager to try their hand at corn.

    May 21, 2014 1 Photo

Hyperlocal Search
Premier Guide
Find a business

Walking Fingers
Maps, Menus, Store hours, Coupons, and more...
Premier Guide
Seasonal Content