PART 1 : GRADING OVERVIEW AND THE CONCEPT OF RED MEAT YIELD
By Ty E . Lawrence , Ph . D ., Caviness Davis Distinguished Chair in Meat Science , West Texas A & M University
This is the first in a series of three articles examining the purpose and origin of the beef carcass Yield Grade , the pros and cons of the tool that determines the product measurement , and how the evolution of cattle type and management may require a fresh look at the accuracy of the current tool . This article series , on behalf of the Red Meat Yield Round Table , aims to raise awareness of current carcass yield assessments and make advancements more accessible to producers who select higher-value cattle and receive accurate recognition for true carcass yield . Introduction to Grading
The U . S . beef industry has benefited from a voluntary beef grading service since May 1927 . Grading of beef allows for differentiation of carcass quality and yield in the value transaction between producers and processors . Grading also ensures uniform marketing and promotes market differentiation of subprimal and retail cuts . Initially , beef carcass grading was based solely upon quality — originally estimated from outward carcass finish ( and later via marbling ) and maturity to estimate “ how good ” a carcass is . Later in 1965 , grading standards were amended to also categorize carcasses based on lean meat yield — an estimate of “ how much ” of the carcass will become boneless closely trimmed round , loin , rib and chuck . Beef quality grades are well understood across industry segments ; likewise , customers both domestic and international seek specific quality grades to meet their palatability expectations . Today in contrast , nearly 60 years since their inception , yield grades are poorly understood by industry participants , and consumers have no knowledge of their existence . Evolution of Grading Standards
Interest in lean yield measurement was a focus of scientific investigation during the 1950s . Landmark data used to develop the USDA Yield Grade ( YG ) was presented in 1960 — an equation using 12th rib-fat depth , percentage of kidney-pelvic-heart fat , hot carcass weight , and ribeye surface area was developed from 162 carcasses . After a brief trial period , yield grading was put into effect on June 1 , 1965 .
Since its introduction , quality grading has continually evolved and has been amended / updated 15 times to reflect the latest science and to improve beef marketability . Updates to quality grading standards have included modernization of terms , methodology changes and modification of standards . However , yield grading is fundamentally stagnant , aside from the allowance of camera grading technology to determine individual parameters and calculate the YG , no meaningful change has occurred since origination six decades ago .
Beef grades were established to be discerned and subjectively applied by experienced , knowledgeable beef experts . Nevertheless , industry frustration with the inconsistent application led to the development of an electrical instrument grading system that became a reality in September 2009 . Cameragrading instruments are currently approved to assess marbling score , subcutaneous fat depth , ribeye area and lean color . Camera-derived YG is calculated from the hot carcass weight , subcutaneous fat depth , ribeye area and either actual , algorithmpredicted or assumed constant percentage of kidney-pelvic-heart fat . Today , approximately 78 % of fed cattle are graded using camera technology . Concept of Red Meat Yield
Lean meat yield evaluation allows processors to estimate and , therefore , value carcasses based on component values of muscle subprimals , trim fat and bone . In the current market , boneless subprimals are valued ($/ cwt ) approximately 175 % of the whole carcass whereas trim fat and bone are valued approximately 19 % and 2 % of the whole carcass value , respectively . This valuebased approach results in premiums for carcasses with a greater proportion of lean subprimals and discounts for carcasses with excess backfat or are lightly muscled and have a disproportionate amount of bone . The maximum premium offered for a YG 1 carcass currently equals $ 8 / cwt whereas a YG 5 carcass may be penalized up to $ 25 / cwt . Producers may sell cattle on value-based marketing systems whereby each animal is eligible for premiums and / or discounts . Alternatively , they may market cattle against a threshold , which compares each lot of cattle to a rolling plant average per cattle type . The threshold method of carcass valuation allows a discount to become a premium when cattle grade better than the plant average and a premium to become a discount when cattle grade worse than the plant average .
The current industry standard is value-based grid marketing where each individual animal is valued . A robust and reliable YG estimation system is paramount to determine true carcass value . Scientific investigations comparing YG to actual red meat yield are often disappointing and demonstrate that 0 % to 50 % of the variation in red meat yield can be accounted for . In other words , 100 % to 50 % of the variation in red meat yield is accounted for by factors not used in the YG equation . When YG was developed , the industry was dominated by two breeds that had been selected for small-framed early-maturing traits which are not representative of the genetic diversity raised and fed today . Furthermore , contemporary cattle are fed longer and to ever-increasing weights using the latest in growth enhancement technology to maximize growth and favorably alter the composition of gain . The population of cattle from which the YG equation was derived had an average hot carcass weight of approximately 600 lbs . Vast improvements in genetic selection and growth technologies have led to hot carcass weight gains exceeding 5 lbs annually . Soon , hot carcasses will average 1,000 lbs — the approximate live weight of the animals originally used to develop the YG equation . The relationship between hot carcass weight and ribeye area is assumed to be linear . However , multiple scientists have demonstrated the relationship is curvilinear . As carcass weights continue to increase , the distribution of yield grades will shift to an ever-increasing percentage of “ fatter ” carcasses because they are unable to maintain the expected ribeye area size .
Our beef carcass yield estimation system was developed from a small population of cattle of a biological type no longer existing . Today , it is applied to predict the lean meat yield of increasingly variable and larger carcasses . Beef industry leadership has concluded that the status quo is no longer acceptable , and YG standards are long overdue for an improvement . www . NCBA . org NATIONAL CATTLEMEN 11