by Wes Ishmael

Sometimes you chase the wrong rabbit.

Beef cattle seedstock and commercial producers included ribeye area in their selection decisions over decades because it is the only muscle measurement included in USDA’s yield grade equation. Yield grade, of course, is supposed to describe differences in the percentage of closely trimmed, boneless retail cuts.

Turns out, ribeye area explains less than 5% of the variation in actual subprimal yield, according to Dale Woerner, Cargill endowed professor in sustainable meat science at Texas Tech University.

“There is not enough muscle in the carcass for what the ribeye tells us. Therein really lies the problem,” Woerner says. “Ribeye area is a very poor indicator of muscle in carcasses, particularly in dairy-beef type cattle, which represent about 23.5% of the total feedlot mix.”

Broke and busted
Sometimes you chase the wrong rabbit for a long time.

Woerner explains the yield grade equation itself only explains about a third of the variation in subprimal yield for native cattle.

Charlie Murphy developed the original yield grade equation in 1958, according to Woerner. Murphy published his work in 1960; USDA adopted it in 1962. The formula is based on 1958-model cattle, and literally a handful of them at that.

Ty Lawrence, Caviness Davis Distinguished Chair in Meat Science at West Texas A&M University, provided historical perspective at the 2016 Beef Improvement Federation (BIF) Annual Research Symposium.

“The era in which the yield grade was developed was dominated by small-framed, early maturing cattle, which were primarily purebred Herefords. In contrast, the current fed beef population is a kaleidoscope of genetic diversity that is medium and large in frame; the greatest population of purebred animals is now represented by the Holstein breed,” according to the BIF proceedings. “Moreover, cattle feeding technology including growth promoting implants and beta-adrenergic agonists offer cattle feeders the opportunity to maximize growth and manipulate composition of gain.”

“Yield grade is broken because the individual factors don’t tell us what we want it to,” Woerner explains. “We utilize ribeye area as the single indicator of muscling, in proportion to weight, in the yield grade equation. So, when your indicator of lean red meat yield doesn’t work, then how can you expect an equation that was created to predict red meat yield to work?”

The problem, long understood, has deepened over time through genetic selection and management.

From a genetic standpoint, Woerner wonders, “Did we create this by only selecting for ribeye area, allowing for round muscling and shoulder muscling and total animal muscling to drift apart? I think, yes. With single-trait selection, irrespective of true muscling, not only did we allow for this to happen, but we probably made it happen, and we made it happen pretty quick.”

In terms of management, Woerner points out economic signals continue to encourage feeding cattle to heavier weights. Annual average fed cattle finished weights and carcass weights accelerated in recent years as cattle feeders added significantly more days to the finishing period. Historically low cattle numbers explain part of the shift — slowing turnover while trying to maintain pen occupancy rates — as does relatively marginal penalties for excessive weight.

As cattle age and weight increase, Woerner explains fat increases more than muscle, leading to a disproportionate increase in fat as part of carcass composition. While carcass quality has increased over time, due in part to feeding cattle longer, so have the number of Yield Grade 4 and 5 (less valuable) carcasses.

Woerner points out muscle is more efficient to produce than fat. Increased muscularity improves feed efficiency. In an era of societal concern about squandering resources, he says needlessly putting more fat on finished cattle is also a sustainability problem.

New measures
“The system used today is based on the premise of premiums awarded to carcasses with higher lean proportions, while discounts are applied to those with excess fat or bone. However, as modern cattle differ significantly from those of the past, the ability of the yield grade system to accurately predict red meat yield has declined,” says Jessica Lancaster, National Cattlemen’s Beef Association (NCBA) senior director of product quality research. “This misalignment signals the need for a science-based approach that better reflects modern cattle.”

This need led researchers like Woerner and Lawrence to focus on how to improve assessing red meat yield. The same quest is why the NCBA, on behalf of the beef checkoff, established the Red Meat Yield (RMY) working group several years ago, guiding necessary checkoff-funded research.

“The goal of the working group is to look at the scientific foundation of how we quantify red meat yield and to determine if there was a need to contribute to the science,” Lancaster explains. “We’re currently looking at if carcass computed tomography (CT) can be used as a biological reference standard for determining compositional attributes of fed beef carcasses and validating future measurement and predictive technologies.”

Currently the RMY working group and researchers are about 75% finished with CT-scanning about 600 head of fed cattle that are representative of the harvest mix, conducting a traditional cutout and yield test of each carcass and comparing the results. It is the largest commercially available study ever conducted.

“We’re hoping to have all of the scientific data needed in the next couple of years to hand off to industry partners,” Lancaster says.

The study represents a herculean step toward likely reality.

“With CT, we can actually measure carcass composition. So, this is no longer a prediction tool; it’s an actual measurement,” Woerner explains. “From this data, we can tell you how much muscle, fat and bone are in the carcass and how much marbling is in the muscles. We would use this on every carcass, but it doesn’t operate fast enough.”

Without sauntering into the scientific weeds, and painting with the broadest of brushes, the notion is to collect CT scans on a representative sample of cattle populations that can be used to train predictive technologies which can assess carcasses at packing house chain speeds. In other words, accurately assess red meat yield of every carcass flowing through a packing plant.

“If we can measure red meat yield accurately, we know there is a really strong relationship between true red meat yield and true value,” Woerner says. In fact, he explains the relationship is 89%, when comparing value to actual red meat yield.

Emerging technologies such as three-dimensional (3D) imaging and radar are demonstrating such accuracy. For instance, 3D digital imagery has been used to explain more than 90% of the variation in saleable red meat yield.

Unsurprisingly, Woerner notes major packers have been collecting data from CT and other technologies in their investigation of the potential. Moreover, he says some breed associations are working aggressively to understand these new technologies, how total red meat yield might be measured and valued in the future, and how to identify genetic differences and possible selection tools.

The American Hereford Association (AHA), for instance, invested in CT scans for a portion of the latest steers harvested from its National Reference Sire Program. Shane Bedwell, AHA chief operations officer and director of breed improvement, explains the live animals were scanned with radar technology and assigned phenotypic scores before harvest. This data will also contribute to the RMY working group project.

“Our participation ensures Hereford genetics are included in the population of cattle that will be used to train the predictive technologies,” Bedwell explains. “It also puts us at the forefront of developing genetic selection tools for Hereford breeders and their commercial customers.”

Sooner than you think
“I believe we’ll see these technologies in use for transactional purposes within the next 3-5 years,” Woerner says. “As soon as packers have the opportunity to implement it, they will move forward sooner rather than later.”

When that day comes, logic suggests packers will apply new premiums and discounts based on red meat yield — in place of the current ones based on yield grades — no different than how they reward and penalize carcass quality, which has long been accurately measurable with camera grading technology.

Speaking of which, expect the industry’s intent focus on carcass quality to continue when it can also more accurately assess and value differences in red meat yield. Cattle producers fought too long and hard regaining consumer demand with improved eating satisfaction by ensuring the majority of carcasses grade Choice and higher.

“Marbling will and should remain important,” Woerner says. “We cannot, as an industry, afford to lose eating quality. It is our advantage compared to competing proteins. It is also the original form of stored energy for the maternal side of the equation.”

So, premium Choice and Prime will likely remain the quality targets, while the highest-value carcasses will also be leaner and heavier muscled.

Gearing up for the revolution
Given the bovine biologic cycle and slow generational interval, if red meat yield premiums and carcasses become reality in the next 3-5 years, as Woerner believes, then the clock is beginning to tick with more urgency.

“Cattle being harvested today were bred 27 months ago,” he says. “We’re already making breeding decisions that may be valued in a new system.”

Although the day might come when producers have predictive technologies to assess red meat yield differences chute-side, an astute eye goes a long way. No one can peer beneath the hide with the naked eye, but many can see differences in muscle shape, thickness and volume.

“Pay attention to muscle, round shape, the hind quarter and forequarters while maintaining ribeye area and marbling score,” Woerner says. “It’s really not much more complicated than that.”

As Bedwell says, the challenge, as always, comes with selecting for improved red meat yield while also maintaining balanced selection for other economically relative traits.

“Maintain quality grade without excessive backfat, pay attention to muscle, watch for antagonisms and keep focus on balanced multi-trait selection,” Bedwell says.

In the meantime, Lancaster notes the RMY working group and NCBA continue to provide significant producer education so producers can be prepared for the likely industry transition.

Transformation
“I dare say the biggest improvement that will be made by accurately assessing red meat yield is the fact that we’ll be able to accurately assess and breed livestock using genetics and genomics that are actually higher in red meat yield, not just with larger ribeyes,” Woerner says.

Accurate red meat yield assessment is the next step in the value-based evolution. Producers asked for and received the opportunity to market fed cattle based on individual differences rather than receive an average price which subsidizes inferior performers and penalizes superior ones. Most fed cattle today are sold via alternative marketing arrangements, including marketing grids, because they have proven to return more dollars to producers while increasing the availability of higher-quality beef that consumers demand. Accurate red meat yield assessment will further differentiate value.

“The RMY working group has always had the producer’s interest in mind in terms of how they can be better rewarded for carcass composition,” Lancaster says.

Woerner believes identifying and rewarding true red meat yield will bring an industry paradigm shift.

“I would expect cattle to look and perform differently than they do today once the systems are in place and operational,” he says. “I would expect it to completely transform the look of the cattle.”

Woerner points out cattle producers have already demonstrated their ability to transform cattle in a relatively short period of time. Think of the frame race in the 1970s and the current ongoing shift in carcass quality. Progress can be even more rapid today with genomic and genetic tools, including advanced reproductive technology.

“If the premium for red meat yield is large enough, I think the greatest thing that will come out of this for Hereford is more industry emphasis on crossbreeding,” Bedwell says. “When you factor in cow-calf producers’ maternal considerations, the need for crossbreeding will be even more important because terminal sires for red meat yield will not produce the type of daughters that thrive on the range.”