Forages that contain a high level of nitrates can pose a health risk to livestock. However, it's also important to consider the amount of nitrates that cows consume from water.

"You need to be extremely careful when both feed and water sources contain nitrates," says Bill Mahanna, global nutritional sciences general manager with Pioneer Hi-Bred International, Inc. "A level of 300 milligrams of nitrate nitrogen per pound of live weight per 24 hours is often fatal to ruminants," he adds.