Rejected Soybeans Can Feed Beef Cattle — With Strict Limits

Mature beef cows should eat no more than 2 to 3 pounds of whole soybeans per day, and total dietary fat must stay below 5% of the ration. Those are the core numbers in new University of Missouri Extension guidance for producers feeding soybeans rejected at the point of sale.

Missouri farmers this season are confronting a practical question: what to do with loads of beans refused for moisture, weather damage or other quality defects. Feeding them to beef cattle is a workable option, but only with testing and tight ration discipline, Extension specialists said.

Eric Bailey, University of Missouri Extension beef nutrition specialist, said rejected soybeans may have substantially different nutrient concentrations than normal soybeans. The reasons for rejection — moisture, weather damage, other quality faults — translate directly into feed value that can swing from load to load.

Whole soybeans are, on paper, a strong feed. They supply both protein and energy in one package. But Gene Schmitz, MU Extension livestock specialist, said producers should compare their cost against other grain and grain byproduct options before adding beans to a ration. The goal is the most economical way to meet the herd's nutritional needs, not simply to dispose of a rejected load.

What are the rules for feeding rejected soybeans?

MU Extension's guidance comes down to eight points:

• Test before feeding. Rejected beans vary in nutrient content. Test for protein, fat and dry matter. Check for mold and mycotoxins when conditions warrant.
• Never feed chemically treated beans. Seed-treated soybeans or any beans treated with products not approved for livestock feed are off-limits. If a load's treatment history is unknown, keep it out of the ration and consult an Extension livestock specialist.
• Limit feeding rates. Mature cows: no more than 2 to 3 pounds daily. Weaned calves, stockers and replacement heifers: 1 to 2 pounds.
• Protect rumen function. Whole soybeans run 18% to 20% fat. Excess dietary fat cuts fiber digestibility and drags down animal performance, so total ration fat must not exceed 5%.
• Keep whole soybeans out of creep feeds. Raw soybeans carry a trypsin inhibitor that interferes with protein digestion. Nursing calves — especially those two to three months old and under roughly 300 pounds — are vulnerable because their rumens are not fully developed.
• Do not combine whole soybeans with urea-based supplements. Urea-containing protein supplements, protein tubs, liquid supplements and other nonprotein nitrogen sources can react with raw beans to release potentially toxic levels of ammonia.
• Consult a nutritionist. Safe inclusion rates depend on the class of cattle being fed and everything else in the ration.

Why the urea warning matters most

The ammonia risk is the sharpest edge in the guidance. A producer who tops up a protein tub while feeding whole soybeans could poison stock without any visible warning in the beans themselves. The combination, not either component alone, creates the hazard.

The fat ceiling carries its own logic. At 18% to 20% fat, whole soybeans push a ration toward the 5% limit quickly; roughly 25 pounds of beans in a ration would supply enough fat on their own to reach it. That arithmetic is why the daily caps sit where they do.

The creep-feed restriction turns on calf physiology. A 300-pound calf at two to three months has an underdeveloped rumen and limited capacity to overcome the trypsin inhibitor in raw beans, making what is safe for a cow a liability for her nursing calf.

Producers weighing a rejected load should test first, price the beans against corn and byproducts second, and build the ration third. Farmers with questions can contact Gene Schmitz through MU Extension or the Pettis County MU Extension Center at 660-827-0591 before the beans enter the bunk.