Butt profile: Weapons of Mass Discounting, or legitimate carcase sorting tool?

Jon Condon, 20/08/2013


An episode during the recent Brisbane Show’s commercial cattle competitions has rekindled a 25-year debate about the use of butt shape as a yield sorting tool in meatworks grid payment systems based on the industry’s AusMeat language.

What appeared to be an unusually large number of cattle competing in Brisbane’s large 100-day grainfed competition this month received substantial price discounts – as per the processor, JBS’s normal grid pricing structures – after being assigned D butt shapes as part of the killfloor assessment process.

Of 478 cattle entered in the grainfed performance class, 33 carcases, or 7 percent, received a D butt shape assignment. Four of the seven Shorthorn carcases from the pen which won the competition’s carcase quality division were in fact discounted on the basis of butt shape.

Given that these were ‘competition standard’ cattle from a broad assortment of breeds which excelled as a group in feedlot weightgain, chiller assessment and MSA-based carcase quality criteria, it was perhaps not surprising that exhibitors’ hackles were raised when grid payments were made.

Supporting the view of butt profile critics that the measurement has little predictive value in yield assessment was the finding that the 33 entries awarded a D but shape produced an average estimated lean meat yield of 59.6pc. A random sample of 34 C-butt entries fared worse, averaging 59.2pc ELMY.  To be fair, though, fat depth on the D-butt cattle ranged from 5-25mm, and they appeared to carry less fat, on average, than most C-butt entries. Fatness is also a major contributor to boning room yield.  

As will be described in a separate item published on Beef Central later today, concerns have been raised about the application of butt shape as a yield-predicting carcase sorting and payment tool off and on for much of the past 25 years.

For decades producers have levelled accusations at processors that the criteria’s primary use was as a ‘Weapon of Mass Discounting,” rather than any practical commercial value as a yield predictor.

Frequent stories over the years have told of large mobs of slaughter cattle being divided and sold two ways, only for starkly different butt shape assessments – and grid payments – to come back on kill sheets.

The key question in all this is: Are such episodes deliberate attempts by processors to secure their kill more cheaply through ‘vigorous’ application of butt discounts, or is it simply variability caused by the highly subjective nature of the assessment, carried out by AusMeat-accredited graders across the country?

As former CRC meat science head, Professor John Thompson, will suggest in more detail in a follow-up article tomorrow, butt shape has little or nothing to contribute as an indicator of carcase yield.

“AusMeat never had the evidence to support its adoption in the first place,” Prof Thompson said.

Even before the CRC was formed, he and fellow meat scientist Dr Drewe Ferguson showed as part of their early R&D work supporting the development of VIAscan, that butt profile had “absolutely no value” as a yield indicator.

Queensland domestic processor Terry Nolan, who is widely regarded for his meat science and carcase composition knowledge, said while a loose correlation may exist between butt shape and yield, it should not be looked at in isolation, but in connection with fat and bone.

“An E-butt dairy cow for example might yield only 58-60pc boning room dressing percentage, while a D-butt might be mid-60s, C’s 70+ and A’s high 70s. It’s probably wrong to suggest there’s no correlation at all, but it cannot be used in isolation,” he said.

“While it’s a crude measure, I believe butt profile still provides an indicator of yield, and has a legitimate place in the AusMeat language,” Mr Nolan said.

“But how that AusMeat language is used is up to the commercial parties. At no stage did AusMeat say that discounts or premiums have to be attached to butt shape results. It’s commercial parties that have taken it on board, but there would be plenty of boning rooms out there that would have clear evidence of yield differences between different butt shape groups. In simple terms, there’s no doubt that an A or B butt will yield better than a D or E,” he said.

He suggested that one of the reasons why butt shape had not aroused more attention recently was that the industry was now much more focussed on eating quality, rather than yield outcomes.

“I think some industry members are all-too-ready to jump onto something like butt shape as a discount tool, when really some of these attributes are designed to be nothing more than a communication mechanism in kill sheets back to the producer. If I wanted to buy a certain sort of animal to improve our boning room yield, I could go back to Nolans’ suppliers and encourage them to breed more B-butt cattle, and less D-butts. It’s a language, designed to help communicate a feedback message from processor to producer,” he said.

“Simply banning butt shape from the AusMeat language would be like removing words from the English dictionary because you don’t like them.” 

The justification for the assessment of butt shape was that it added to the yield predictability of a carcase, beyond what can be achieved with simple carcase weight/fat thickness/eye muscle area equations.

“But more and more, with the advent of MSA where eye muscle area assessment is compulsory, there is perhaps greater emphasis now on EMA rather than butt shape,” Nr Nolan said.

“The process has transitioned over the years from no yield consideration, to a description using a butt shape silhouette, which then morphed into a multi-dimensional muscle-score type view, and on to today where EMA is the predominant yield indicator – plus, perhaps, a bit of butt shape.”

What has confounded a number of senior beef industry stakeholders spoken to by Beef Central about the Brisbane show outcome was that it is said to be ‘highly unusual’ to see any sort of significant numbers of D-butts to occur in grainfed cattle at all.    

In the case of Nolan Meats, killing domestic weight cattle only, the plant can often do an entire run of 60-70 day yearling steers and heifers without seeing a single D-butt shape recorded.


Subjectivity biggest challenge

One of the critical points about butt shape assessment is that it is easily the most subjective measurement taken by an AusMeat-accredited meatworks grader.

A widely respected senior livestock buyer who has bought cattle across eastern Australia for one of the nation’s largest processors for 25 years, told Beef Central that the primary issue surrounding butt shape was the consistency of application of the assessment by the graders, because it its subjectivity.

Looking at the AusMeat example carcase images published with this story, there is no question that only a fine line exists between a C and a D butt shape, when applied in silhouette. E-butts are largely a separate issue, being confined primarily to a few dairy steers, rather than beef animals, where their bone structure has a big bearing on yield potential.

The former livestock buyer spoken to by Beef Central said it was this inconsistency in grading performance that sowed the seeds of the notion among some producers that some processors were deliberately and methodically downgrading carcases to D-butts, to reduce livestock costs.

“I never saw any evidence of it over the 25 years I worked in the industry,” he said.

He pointed out however, that while grid price discounts also applied for overweight (making it impossible to get three rumps into the carton, for example) or under-fat (chiller burn risk on the butt cuts, making them unsuitable to pack), in all likelihood a D-butt shape carcase was still going to end up in the same carton as beef from A-C butts.

“To me, P8 fat depth remains a far better recognition of yield than butt shape,” he said. “There’s a really strong correlation between boning room yield and P8 fat – at least for animals up to 30mm of cover,” he said.

“In my opinion this episode with the Brisbane show cattle was a grading consistency problem, not an attempt by the processor to rip-off producers on price. Therefore it becomes an AusMeat problem, in addressing the lack of consistency between plants, and perhaps even between shifts in the same plant.”

“To suggest that a processor would try to pull such a price-discounting stunt during Brisbane show is ridiculous – why would they attract attention to themselves in the biggest public showcase of slaughter cattle in Australia?”  

“What AusMeat needs to work towards is a yield indicator that is more objective, and more reliable. If not, just use eye-muscle area and fat cover and leave it at that.”

To add to industry and producer confusion over butt shape, different processors exercise different payment/grid policies so far as the measurement is concerned. Here are three examples from grids from the nation’s largest processors:

  • Teys Australia (all plants): The company says while D/E butt shape discounts are listed on grids, the discount is not activated unless the carcase first fails to meet minimum fat requirements. A carcase meeting the minimum requirement for fat depth (6mm in the case of 0-2 tooth cattle, 8mm for 4-tooth and over steer), does not attract butt shape discounts, even for D/E. For cattle that fail to meet the minimum fat requirement, butt shape penalties apply for D-E in steers, and E's in cows below 3mm of fat. Yearling steers below 6mm of fat with a D or E butt shape are discounted 25c/kg. Teys said it had adopted the policy because the butt shape assessment on the kill floor was extremely subjective, and was ‘very, very hard’ to deliver with any consistency.   
  • Nippon Meat Packers Australia (Oakey, Borthwicks Mackay, Wingham): Policies vary a little from plant to plant. Oakey does not apply butt shape discounts at all, on grain or grassfed. Wingham’s grids all run from A-D butts as acceptable, with E's (mostly dairy) discounted 20c/kg across the board. Borthwicks is a little different, being similar to Teys, in not applying butt shape for cattle 7mm and above on carcases 280kg or better. Steer 6mm or less are regarded as secondary ox, attracting a 10c/kg discount; if they are D-butts as well, they attract no further discount. All E butts go into a manufacturing grade and price. Essentially Borthwicks is saying that if the carcase has acceptable fat cover, butt shape is irrelevant.
  • JBS Australia (Northern division): Grids show optimum price on ox is for butts A-C for 0-4 tooth, with D-E butts discounted 20c/kg. In 6-tooth and older, A-D are accepted, with E discounted 10c. On yearlings 0-2 tooth, both grain and grass, A-C is the premium, with D attracting a 10c/kg discount. Cows grids are all A-D no discount, with discounts applied to E butts only. EU grassfed discounts on D-E butts 45c/kg.

Tomorrow on Beef Central: Is there a better solution for yield assessment/payment?



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  1. Monique Lobegeier, 29/04/2023

    Is there any breeds that have higher percentage of B class rumps?

    Hi Monique. Not sure what you mean when you refer to ‘B class’ rumps. There’s nothing in the AusMeat language around that term. Like most other primals, export rumps are generally segmented by their AusMeat cipher – YG (yearling 0-2 tooth), Y (young, four-tooth max), S (Steer, six-teeth max) etc. Grainfed carries the pre-cipher (GF) – thus, GFYG = Grainfed Yearling etc. We are certainly not aware of export rumps from Indicus cattle being discriminated against, beyond the AusMeat dentition-based ciphers they carry. Domestically, MSA index figures apply to the entire carcase. Of course, what meat companies choose to prescribe in terms of criteria, beyond AusMeat and MSA, is up to them. Editor

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