Nitrates in Forages

Drought Conditions Can Lead to Nitrate Poisoning in Cattle

As much of the South moves into dry conditions, pastures will begin to accumulate nitrates, creating a life-threatening condition for some cattle.

It's time for cattle producers to start checking nitrate levels in pasture forages again.

Kim Mullenix, animal scientist with Alabama Cooperative Extension System, said drought has increased the chance for livestock forages to develop elevated nitrate levels. This can lead to nitrate poisoning in cattle.

"Nitrates can build up to toxic levels in bermudagrass or summer annual grasses when nitrogen has been applied and drought conditions limit the forages regrowth," she explained.

Commonly grown forages known for their potential to accumulate toxic nitrate levels include sorghum, corn, sudangrass, sorghum-sudan hybrids, soybeans, fescue, pearl millet and bermudagrass. Testing of growing forages, as well as any hay produced under drought conditions, is recommended. Mullenix recommended producers contact their local Extension agent if they need help with the process of sampling and/or testing forages or hay.

Symptoms of nitrate poisoning can appear suddenly in cattle and death can occur in as little as one hour.

"Cattle may exhibit labored breathing, muscle tremors and a staggering gait," Mullenix reported. "Nitrate toxicity usually results in death within a short period of time, but if prompt action is taken death can be prevented."

If nitrate poisoning is suspected, contact a veterinarian at the first sign of trouble, making a point to handle cattle as little and as quietly as possible. If caught in time, affected animals can often be treated.