Nitrate poisoning in cattle is a growing threat across southeastern states battling drought. An animal scientist with the Alabama Cooperative Extension System says drought is increasing the chance for livestock forages to develop elevated nitrate levels.
Dr. Kim Mullenix says that nitrates can accumulate in forages when plants are stressed by low soil moisture, high temperatures or low humidity.
“Producers should check their forages’ nitrate levels,” said Mullenix. “Nitrates can build up to toxic levels in bermudagrass or summer annual grasses when nitrogen has been applied and drought conditions limit the forage’s regrowth.”
Some commonly grown forage crops in Alabama that are known for their potential for accumulation of toxic levels of nitrates are sorghum, corn, sudangrass, sorghum-sudan hybrids, soybeans, fescue, pearlmillet, and bermudagrass.
Mullenix said that forages and feeds with high nitrate levels can poison cattle and other livestock.
“Cattle may exhibit labored breathing, muscle tremors and a staggering gait,” she said. “Nitrate toxicity usually results in death within a short period of time, but if prompt action is taken, death can be prevented.
Mullenix said livestock producers should have forages’ nitrate levels tested.
“Nitrate levels can be determined through our Extension Feed and Forage Testing Program. Extension animal science agents can advise producers on how to take a good sample.”
Go to www.aces.edu for a listing of county Extension coordinators and regional Extension agents. Learn more about sampling different forages and the testing process at http://www.aces.edu/go/523. Watch the Extension video, How to Pull a Hay Sample (http://www.aces.edu/go/647 ) on how to properly collect a representative forage sample.
Nitrate Toxicity: Points to Remember:
· Test forages and hay grown under drought conditions for elevated nitrate levels.
· Nitrates in stored forages degrade little with time.
· Bermudagrass and summer annual grasses are more likely than other forages to contain toxic levels of nitrates.
· Nitrate levels can be determined through the Alabama Cooperative Extension System Feed and Forage Testing Program.
· Use of large round bales or hay stack systems increases the danger of nitrate toxicity because in these situations cattle have unlimited access to the hay and overconsumption may result.
· Feeding nonprotein nitrogen with hay containing high nitrate levels increases the likelihood of nitrate poisoning.
· Danger of potentially toxic hay can be reduced by feeding other nitrate-free feeds along with the potentially toxic material.
· There is a wide variation in toxicity level, and these differences can be attributed, in part, to rate of ingestion.
· If administered quickly, it is possible to treat for nitrate poisoning. In cases of suspected toxicity, contact a veterinarian immediately.