Animals don't like the taste of raw, whole soybeans, right? Don't tell that to the steers in Monty Kerley's feeding trials.
Kerley is a University of Missouri animal science researcher. He found that steers not only eat whole beans as part of the finishing ration, they also produce higher-grading carcasses than animals fed more conventional high-concentrate diets.
With funding from the Missouri Soybean Merchandising Council (MSMC), Kerley and graduate student Gene Felton bought 800-lb Angus crossbred steers, then divided them into four feedlot groups. One group received no whole soybeans; the others were fed rations with 8%, 16% or 24% whole beans.
All rations were balanced for 15.25% protein, using soybean oil meal, whole soybeans or both. All cattle were fed to 1,250 lbs and slaughtered, then carcass data were collected.
"We found no differences among the groups in average daily gain, total gain, carcass weight or yield grade," Kerley reports. "However, we did see a trend toward a better carcass quality grade as the amount of whole soybeans in the diet increased."
The reason: Whole soybeans are 18-20% fat, a concentrated source of energy. According to Kerley, fat yields 2.25 times more energy than starch, pound for pound. Other research has shown that feeding fat can have a positive effect on carcass quality.
"With whole beans, one ingredient provides both fat and protein," he adds. "Whole soybeans average 38-40% protein."
Here's how the steers graded: Zero beans - 45% low Choice, 55% Select. 8% beans - 10% mid-Choice, 30% low Choice, 60% Select. 16% beans - 17% mid-Choice, 44% low Choice, 39% Select. 24% beans - 5% high Choice, 5% mid-Choice, 45% low Choice, 45% Select.
While feed conversion efficiency varied little among the four groups, cost of gain was slightly higher with cattle fed bigger fractions of whole beans.
"That was due primarily to the price relationship of whole soybeans and soybean oil meal at the time we did the trial," says Kerley. "Beans were $6.25/bu; soybean meal was $185.70/ton. This ratio puts soybeans at a greater disadvantage than usual.
"But feeding beans to cattle provides a marketing option for both soybean growers and cattle feeders. When soybeans are priced low in comparison with other sources of protein, feeding them may be a way to earn more profit on the crop."
He plans another soybean feeding trial, but this time will start cattle on feed at lighter weights.
"With cattle started lighter and fed longer, an even greater difference in quality grades may occur with steers fed higher levels of whole beans," he reasons. "And there may be even more potential for soybeans fed to beef cows. Spring-calving cows typically need energy in winter and early spring to be in shape to rebreed."
Chris Zumbrunnen, University of Missouri extension livestock specialist, agrees. He plans to test the soybeans-fed-to-cows idea next spring.
"We want to set up a controlled trial with cows fed the same energy and protein levels, but from different sources," he says. "We believe the unsaturated fat in whole soybeans helps stimulate cows to cycle and rebreed."
Zumbrunnen will begin feeding soybeans to one group of cows 60 days before calving; a second group, 30 days before calving; and a third group, at the time of calving.
"We'll continue feeding the cows through the breeding season. My only concern is that feeding whole soybeans for a longer period may cause the fetus to grow too big for calving ease."