A recently completed study of the accuracy of USDA Feeder Cattle Grade Standards revealed the system works like it is intended, with graders placing frame scores on feeder cattle to estimate the live weight of a fed steer or heifer when it reaches 0.50 inches of fat.
“The first conclusion to be drawn from the study is the USDA frame score is very predictive of bodyweight,” says feedlot specialist and associate professor Chris Reinhardt of Kansas State University Extension. “What is essentially a subjective score on a feeder calf by a human is actually statistically accurate 80 to 90 percent of the time. We were very pleasantly surprised by that.”
The study was conducted by Reinhardt and Darrell Busby, coordinator of the Tri-County Steer Carcass Futurity Cooperative, operating out of the Iowa State University Outreach Armstrong Research Farm near Lewis, Iowa. Initiated by the USDA, it compares actual carcass data from 23,057 head of beef cattle harvested between 2002 and 2011 with USDA Feeder Cattle Grades of those animals.
“We studied full carcass data and feedlot growth information collected by the Futurity and compared it to the Feeder Grade frame and muscle scores,” Busby says. The cattle in the database come from 16 states — two-thirds from the southeastern United States and one-third from the Midwest. The largest groups were from Georgia, Iowa, Missouri, Virginia, Indiana and Kentucky. Seventy-two percent were steers and 28 percent heifers, harvested at 375 to 525 days of age. Final weights in the study were adjusted to 0.50 inches of back fat for consistent comparisons.
Results of the study cement the USDA graders’ role in the beef cattle marketing system.
“It’s a language, and if you can understand that language, you can talk fluently within the industry,” says Corbitt Wall, officer in charge of the USDA’s St. Joseph, Mo., Voluntary Market News Office. He emphasizes the need for keeping the language relevant. “We’re always looking for the opportunity to see if feeder cattle graders are doing a good job of predicting what will be.”
The data speak
“The data show the grading formula and system do work,” Busby says. “The graders do a good job. But small-frame animals are not being identified as accurately as the rest of the population. Perhaps we need to take a closer look at how those smaller-framed animals are being classified.”
The study shows accuracy is high — over 90 percent — for the vast majority of animals, which fall between the middle of medium-frame to the middle of large-frame categories, but accuracy drastically decreases for those outlier animals, especially small-frame cattle.
“What this says is we are good at doing what we do the most,” Reinhardt says. “The system is good with the vast majority of the animals. But where there are only a small number of representative animals, such as extremely small- or extremely large-frame animals, the system is not so good at anticipating the outcome.”
Breaking the data down according to frame-score categories, the accuracy remains fairly high. The frame-score system is designed to use a projected weight of 1,250 pounds as a breaking point between a medium and a large steer. The actual data show the breaking point within the study was 1,240 pounds. Likewise, for heifers, a break point of 1,150 pounds compared to an actual data break of 1,145 pounds.
“And, again, there’s just a shot-gun blast at the bottom of the graph where the relatively small number of small-frame animals results in inaccurate prediction of final bodyweight,” Reinhardt points out. The USDA system calls for the break from small to medium frame at 1,100 pounds for a steer, whereas the data shows the break at 1,175 pounds.
Over the course of the study, Reinhardt and Busby met with graders to get their reaction to the data. The graders back up the theory that minority populations are simply not as familiar and, therefore, are assessed with less accuracy.
“Experience matters,” Reinhardt says. “Those who have been graders for a long time, who have been in the feedlot and packing plant, are probably better tuned to the end product and thus have an advantage in accuracy.”
While assessing the data, Reinhardt and Busby took the opportunity to look at other aspects of the data set. They found USDA muscle scores were accurate at identifying heavier-muscled cattle. Also, from a performance standpoint, more highly muscled cattle and larger-frame cattle had greater average daily gains. The USDA frame scores are not intended to translate into carcass quality grades, and the data show little correlation between frame or muscle score and marbling score.
“The bottom line here is frame score is remarkably accurate at predicting final weight for the bulk of the animals,” Reinhardt says, “but the relationship between frame and muscle score and feedlot performance is less precise.”
“My first response is the typical researcher’s response: More research is needed,” Reinhardt says. “Cattle are different now; they’re coming through larger.” In this study, only 10.4 percent of the cattle received a beta agonist, whereas today, the industry is feeding cattle to 0.60 inches of fat, using more aggressive implant and beta-agonist strategies.
He cites a Journal of Animal Science article (2011 National Beef Quality Audit: In-plant survey of targeted carcass characteristics related to quality, quantity, value, and marketing of fed steers and heifers, M. C. Moore, et al. (2012) J ANIM SCI 90:5143-5151), which puts the average carcass weight of steers harvested in 2011 at 823 pounds, which translates to about 1,285 pounds of live weight if the cattle have a 63.5 percent dress. The size of the smallest large-frame steer in the USDA Frame Score Standards is 1,250 pounds.
He says he would like to study a more recently harvested cattle population in order to get what he believes would be a more relevant picture of today’s beef animals. Wall also sees the value in that. “Better genetics and changing production methods are taking cattle to higher weights,” Wall says.
Wall fears tight budgets will inhibit the USDA’s quest to utilize studies like this one to assess the system’s accuracy and make the necessary adjustments that keep it working for producers. “Doing this type of study is becoming more rare,” Wall says. “The cattle-feeding business is based off averages and those averages have to be relevant and accurate. Producers have to be able to look at the grade standards in the market report and see the type of cattle they raise, and what cattle they want to purchase to feed out or retain for replacements.”
It’s a system that works, according to Busby, because the USDA has taken the time to hire and train graders to do a good job assessing frame and muscle scores and making accurate predictions.
“For many years, USDA frame and muscle scores have provided a service to the beef industry to compare similar cattle from different regions across the country,” Busby says, “and the Feeder Cattle Grading System, because of its accuracy, still has value because it’s uniform across the country. The typical cow-calf producer can use the frame and muscle scores to see how his feeder calves are valued. A medium-frame muscle score one is the same whether or not he’s in a state with a cattle-feeding industry. And the feedlot can adjust its final weight based on the implant and beta-agonist strategy. It puts everybody on the same page.”
Sidebar: Tri-County Steer Carcass Futurity
For 31 years, the Tri-County Steer Carcass Futurity (TCSCF) Cooperative has gathered growth, genetic and carcass information on beef production.
“Our original premise was to determine the most profitable animal in the feedlot,” says retired Iowa State University Extension beef specialist Darrell Busby. That’s still the goal.
TCSCF is governed by a 10-member board of cow-calf producers and allied industry representatives, coordinated by Busby. The effort includes more than 900 cow-calf producers, Extension staff from 23 states and 18 cooperating feedlots in southwest Iowa, all keeping detailed data on their cow herds and production outcomes.
Regarding USDA’s familiarity with the program, “We sought them out for this study because of their large existing database of carcass information,” says Corbitt Wall, officer in charge of the USDA’s St. Joseph, Mo., Voluntary Market News Office.
The Futurity includes beef from 23 states, primarily in the Midwest and Southeast, and Manitoba, Canada.
Through the years, the Futurity has studied the benefits of genetic improvements and management practices on the profitability of beef.
“Cow-calf producers have used data we collected and reported back to them to produce cattle that are healthier, calmer, gain faster, gain more efficiently and produce high-quality carcasses that result in higher profits for their cow herd,” Busby says.
TCSCF is based at the Iowa State University Outreach Armstrong Research Farm near Lewis, Iowa. The Iowa Beef Center at ISU is one of TCSCF’s many trusted partners.
More information on TCSCF can be found at TCSCF.com.