Hay made from small grains can poison cattle, warns Bruce Andersen, University of Nebraska forage specialist.

Nitrate levels can be dangerously high, even if rainfall has been normal, he says.

“Drought might be a major factor influencing nitrate content, but other factors also are important,” says Anderson.

These include fertilization, cutting height, maturity at harvest, drying conditions and the type of small grain made into hay. Oats have high nitrate levels most frequently, but wheat, rye and triticale also can be hazardous.

Symptoms of nitrate poisoning include brownish-colored blood, difficult and rapid breathing, muscle tremors, low tolerance to exercise, lack of coordination, diarrhea and frequent urination.

The best way to make sure feed is safe for cattle is to have it tested, says Anderson. Take core samples from at least a dozen bales and send a composite sample to a lab.

“Don’t risk cattle losses by assuming your hay is safe,” says Anderson. “Test to be sure.”