As soybeans are combined, cows sometimes are put out on the residues to graze. Some bean residues are even baled. But how good is this feed?
"We're all familiar with the usefulness of grazing corn stalks, but I see more and more residue from soybean fields grazed every year," says Bruce Anderson, University of Nebraska-Lincoln forage specialist. And cows seem to like licking up what's left behind after combining."
But Anderson says he's concerned that some folks may think their cows are getting more from those bean residues than what truly is there.
"The problem is a matter of perception," he says. "When most of us think of soybeans, we think high protein. So we expect bean residues will be a high protein feed, too. Unfortunately, the opposite is true; soybean residue is very low in protein."
Soybean stems and pods contain only about 4 to 6% crude protein, well below the 7 to 8% needed for minimum support of a dry beef cow. "And even though leaves can be up to 12% protein, it's only around one-third digestible, so that's not much help. In fact, protein digestibility is low in all bean residues."
Energy is even worse, according to Anderson. Total digestible nutrients average between 35 and 45% for leaves, stems, and pods. This is even lower than wheat straw. Unless cows fed soybean residues also find and eat quite a few beans, cows fed only bean residue can lose weight and condition very quickly.
"This doesn't mean soybean residues are worthless for grazing or even baled. They can be a good extender of much higher quality hay or silage. But, cattle must be fed quite a bit of higher energy and protein feeds to make up for these deficiencies in soybean residues.
"Don't be misled into thinking bean residues are as good or better than corn stalks. Otherwise, you and your cows will suffer the consequences."