April 30, 2023

Dr. Willy Horne

Standards and Specifications Division

USDA, AMS, LP

1400 Independence Avenue, S.W.

Washington, DC 20250-0254

Willy.Horne@usda.gov

Dear Dr. Horne:

I am writing this letter in response to the notice, “United States Department of Agriculture, 

Agricultural Marketing Service Proposes Revisions to the Procedures related to Red Meat 

Instrument Grading” (January 4, 2023). Beef carcass grading has been the focus of my 

academic and professional career now for 25 years and I have been involved in the evolution 

and implementation of beef carcass instrument grading in the U.S. through several different 

roles and organizations. With that experience I appreciate, firstly, the need to update 

procedures as the beef industry and technology evolve, secondly, the challenge finding the 

correct elements and language to improve a program with industry acceptance. I hope that I 

can provide some comments that might be helpful in that process and ultimately help the 

industry take advantage of new innovations in beef carcass grading technology.

While I do find it advantageous to have a single instrument approval document instead of 

multiple documents like in the past, I believe the new requirement of having an instrument 

simultaneously pass the approval criteria for marbling score, ribeye area, fat thickness, and final 

yield grades is unnecessary and will be detrimental to the development of new technologies. 

With the recent advancements in vision Artificial Intelligence, I believe it will be much easier to 

develop operator-less vision systems and cell phone-based systems to predict marbling scores 

with much more accuracy and precision than current systems. However, I believe the time 

needed to develop those systems for ribeye area, fat thickness, and final yield grades to be 

relatively more difficult. Since marbling scores have a much higher impact on the beef industry

in regards to value, I believe forcing such technologies to need to be approved to measure all 

factors instead of one at a time will deter or greatly lengthen the development cycle and 

lengthen the time at which a company could begin to recover development costs which will 

ultimately disincentive innovation. For small beef processors not to have access to cheaper, 

more portable cell phone-based technology to assess marbling scores because that technology 

has not been approved for factors could keep that segment of the industry at a disadvantage. 

Lastly, since most beef processors in the U.S. only use approved instruments for determining 

marbling scores it seems like this requirement is not aligned with current industry adoption.
Along the same reasoning, I believe the increased requirement for Ribeye Area measurement 

to 95% of the measurements within 1.0 square inch instead of 1.5 square inches is overly 

restrictive and will ultimately deter other companies from trying to develop a better technology

for the industry. From my perspective there little to no benefit from increasing this 

requirement as it has little impact on increasing the accuracy of yield grade due to the small

effect ribeye area has on final yield grade compared to fat thickness. Also if there were 

branded programs that were concerned about the ability of currently approved instruments to 

accurately measure ribeye area then they would have adjusted their ribeye area specifications 

accordingly. The impact of the angle of ribbing and variation of this process has more impact 

on a carcass’s ribeye area than the accuracy of an instrument’s measurement at these 

tolerances. For example, Steiner et al. (Journal of Animal Science, 2003. 81-), a study published 

with USDA AMS, found that there was 0.3 square inches of difference in ribeye area between 

sides of the same carcass. If USDA AMS has since collected data that differs from this, then 

they should make the effort to publish such information.

In everyday application of traditional grading within beef processing plants current procedures 

allow for a processor to hold carcasses and re-present them to up to six different graders. In all 

practical purposes this means that the carcass receives the highest assigned quality grade of the 

six different graders that are in that plant for that day. I mention this because while I agree that 

using an average of a gold standard panel is an acceptable method to evaluate the ability of an 

instrument system to effectively measure differences in marbling between carcasses, it doesn’t 

provide the actual grade lines that exist in the industry to calibrate an instrument to. I believe 

that is the major reason an adjustment to increase the instrument marbling scores was 

necessary for industry adoption when instruments were first approved for determining 

marbling score. This discrepancy or gap (between the average of a gold standard panel and line 

grades), although I agree it may be tough to figure out, is a topic that absolutely needs to be 

addressed as part of these revisions to procedures. Without a method to address this 

discrepancy or gap, any comparison made from an average marbling score from a gold standard 

panel to the existing instruments is invalid. One method to approximate the gap would be to 

take the maximum of the individual gold standard panel marbling scores as the official instead 

of the average of the gold standard panel. With that said, if this approach were to be used, a 

panel of five graders would be more representative of every day in-plant practice than using a 

panel of three graders although it is important to remember that the variation that exists 

among line graders is greater than those graders selected to be part of the gold standard panel. 

Assessing the variability between graders is as important as determining the average of graders 

for marbling scores and that is why the five-member panel should be utilized instead of the 

three-member panel. If this discrepancy or gap is not addressed, I believe that there will be a 
major disadvantage to any new or improved instruments that gain approval, and it will keep 

them from being implemented in the industry.

Finally, I’m glad to see QAD 516 draft procedures as I believe some constant process monitoring 

will add strength to the overall grading process. I suggest that before publishing the final 

requirements however, that USDA AMS work with the industry to conduct multiple examples of 

each of the steps and share the results and discuss them with the industry in order to build 

trust in that process and to get a better understanding if the comparison criteria is appropriate

before they are finalized. 

I appreciate the opportunity to comment and if I can provide further clarification or insight, I 

would be happy to.

Sincerely,

Derek Vote, Ph.D.

DerekVote@gmail.com

970-373-6261