Study Reports Supplementing Cattle on Forage Doesn’t Compromise Meat Quality
by Loretta Sorenson
Kansas State University (KSU) researchers found that beef producers can combine forage with a shortened, high-concentrate finishing feeding period utilizing dried distillers grains with solubles (DDGS) without compromising carcass or meat quality traits.
The study design included supplementation at zero or one percent of body weight with DDGS on a dry matter basis fed once per day. Crossbred steers were divided into three groups, on 75, 100 or 125 feeding days. Each group consisted of four different pens of steers. All animals had access to fresh, clean water. Animal performance measurements taken during the finishing phase included average daily gain, dry matter intake, and gain-to-feed ratio.
Among the researchers, KSU Assistant Professor/Meat Scientist, Terry A. Houser Ph.D, says the 2008 high corn prices caused beef producers to ask if marbling, yield grade and carcass yield would be affected if grazing resources were combined with DDGS. The Cattlemen’s Beef Board funded the study.
“At the time the study was funded, corn prices were in the $7 range,” Houser says.
KSU Beef Cow-Calf Nutrition and Management Specialist, K. C. Olson, also assisted with the research. He says cost of gain for cattle on grass continues to be an economical element of beef production.
“We have a lot of high quality forage in Kansas from May 1 through about July 15,” Olson says. “The quality of that forage drops sharply after that point. Animals raised on range or pasture resources need some form of supplemental nutrition. This study demonstrates that distiller grains can be selected as that supplement for late season pasture cattle.”
Average daily gains for steers fed 75, 100 and 125 days respectively were 3.42, 3.52 and 3.37. Gain to feed ratio, respectively, was 0.125, 0.128 and 0.120.
Hot carcass weight averages were 704.7, 758.6 and 820.9. Dressing percentages averaged 60.5, 61.7 and 62.0. Yield grades were 2.1, 2.1 and 2.4. Ribeye area in inches was 13.05, 13.71 and 14.13. Protein composition of the carcass in each group averaged 17.0, 16.5 and 16.0.
Juiciness and beef flavor intensity for all three groups averaged 5.6. Overall tenderness was at 6.3, 6.3 and 6.1 respectively
“Ribeye area of the steers in this study actually increased,” Houser says. “In sensory evaluation tests and shear force values we found similar marbling and values in each group. There were no negative impacts from the feeding plan in any of the three groups.”
A higher prevalence of yellow fat was found on cattle fed for 75 days compared to the other two groups. Increasing days on feed decreased carcass protein and carcass moisture percentages while increasing carcass fat percentage.
Professor Jim Drouillard, Ph.D. and faculty coordinator for KSU Beef Cattle Research Center notes that, if there was any downside to the finishing plan, it was the fact that the cattle were somewhat less efficient coming into the feedyard because they were heavier than average due to the forage resource segment of the study.
“I think most feedyards would give up a little efficiency in performance as a trade off for the economics of the finishing plan,” Drouillard says.
Olson was surprised that the rate of gain the steers demonstrated even late in the grazing period. Drouillard says the control group, receiving only a forage diet, saw some weight loss at the season’s end.
“The cost of DDGS to obtain that gain at the finish was relatively small,” Olson says. “From a management standpoint, this is an uncomplicated growing system. No mixing ingredients, cattle select the forage they want and a single ingredient supplement is delivered to them at one percent of bodyweight. The system may work well on range or pasture under dry or droughty conditions when forage production is abnormally low. Some studies show that feeding DDGS at one percent of body weight (10 pounds of DDGS to a 1,000 pound animal) allowed stocking rates to be increased by 20 percent without overtaxing the forage base.”
The study concluded that producers can place heavy yearling stocker cattle on high-concentrate diets for a minimum of 75 days with minimal changes to performance, efficiency and sensory traits. Heavy yearling stocker cattle should be fed a minimum of 100 days to optimize marbling score and white external fat color.