When Distillers Grains With Solubles are used in moderate amounts in cattle finishing diets, beef quality grades get a boost.
Chris Calkins, University of Nebraska meat scientist, says feeding WDGS in amounts up to 30 to 40 % increases marbling scores.
At national animal science meetings last summer, Calkins presented a meta-analysis of studies that looked at WDGS feed effects. Larry Corah and Mark McCully of Certified Angus Beef LCC (CAB) cited that presentation in a recent research review of factors responsible for a spike in beef quality grades. Through July 2009, 60.1% of cattle in the nation's harvest mix were grading USDA Choice, a 7.5-percentage-point leap in just two years.
An abrupt departure from the 30-year decline in grades, the recent turnaround may be partly explained by judicious use of WDGS.
"Marbling increases, but if you get the levels too high it starts to trail off," Calkins says. The data he presented showed a marbling score of 518 for animals fed no WDGS. The score increased 14 to 15 points, up to 533, for animals fed WDGS at 20% to 30% on a dry-matter (DM) basis.
Calkins says the marbling score increase is probably related to fat content of the feedstuffs.
"When you make ethanol from corn you've basically driven off about two-thirds of the components," he says, noting that both ethanol and CO2 are produced from the starch that comprises two-thirds of corn grain. "So everything else is concentrated by about threefold. That includes the fat content."
This higher-fat diet promotes marbling development. Theoretically, it can increase external fat as well, but Calkins says that's a fairly small shift.
To read "Quality Grade: What is driving the recent upswing?" in its entirety, visit www.cabpartners.com/news/research/index.php.