Crop residues such as cornstalks and sorghum and soybean stubble can be economical sources of nutrients for grazing animals, says Bruce Anderson, University of Nebraska forage specialist.

But crop residue grazing takes planning, says Anderson. First you need to decide how you want to graze. Strip grazing, or fencing off portions of the field for grazing, permits higher stocking rates and provides a more uniform diet. But good-quality feed can be lost to mud or snow cover if animals haven’t grazed all the acres before bad weather.

Grazing whole fields is more common. It allows livestock to eat the best feed before snow or muddy conditions.

Cornstalks should be grazed as soon as possible after harvest because their nutrient value declines the longer they weather, says Anderson. You’ll also need to make sure there isn’t excess grain still in the field because it can cause acidosis and founder.

Supplements such as salt, calcium, phosphorus and vitamin A should be provided at all times during fall grazing. Once cattle consume grain left in the field, extra natural protein supplements also are needed.

Black nightshade can be toxic, Anderson warns. But he says animals seldom eat enough to be affected.

Frost also can cause toxicity, especially in sorghum-related plants such as sudangrass and shattercane, he adds. He recommends waiting three to five days after a freeze before grazing sorghums.

Alfalfa reacts to a hard freeze, too, so wait several days before grazing it. Nitrates can increase, though rarely to a hazardous level. But the risk of bloat can be especially high shortly after a freeze, says Anderson.