Better Pork - December 2006

Features

Can ultrasound grading benefit the pork industry?

Yes, says Dr. Bob McKay, a researcher for the Manitoba Pork Council who has been looking into it for eight years. No, say Canadian packers, who do not feel the extra accuracy justifies the cost

by KATE PROCTER

Who cares if pork carcasses are graded accurately? Packers seem to agree that it doesn’t matter and more accurate carcass evaluation won’t change producers’ bottom lines.

But one researcher who has studied the issue for almost a decade argues that producers are getting the raw end of the deal and that more accurate measurements would benefit the industry. “We want accurate grading and no one seems to give a darn about doing it,” says Dr. Bob McKay, who has been researching carcass grading using ultrasound for the past eight years for the Swine Research and Development Corporation, a subsidiary of the Manitoba Pork Council.

Packers in Canada are currently using 20-year-old technology to grade carcasses. Ultrasound, a more accurate grading method, is available and used in packing plants in the United States, but Canadian packers are reluctant to embrace it. They argue that the high costs associated with the technology do not justify the improvement in results obtained by conducting carcass evaluation with ultrasound.

According to McKay, ultrasound provides much more accurate information to producers and, in turn, could be used by breeders to improve market hog genetics. Packers only use grading information for paying producers, so they do not care if the information is accurate, he adds.

“Do we care if we don’t grade every pig right?” asks Dan Cohoe, hog procurement manager at Quality Meat Packers. There is only so much money to go around, he argues, so even if grading accuracy improved, it would not increase what producers are paid, so it is irrelevant. Expecting precision on every pig is not realistic, he says.

“The aggregate values of large groups are what you care about and the current system is pretty good at that,” says Cohoe. While the present system may not grade every individual carcass with exact accuracy, over the hundreds of carcasses graded from each producer, the end result is the same. One carcass might have the muscle and back fat correlation too low, while the next one might be a bit high, so they all balance out in the end, he says.

“I don’t understand what would be gained by doing it,” says Cohoe. He says the issue has been debated for years and adds that Ontario pork producers are facing many more pressing problems than how their carcasses are graded and he does not think a change in grading will make a difference to their bottom line in the long run.

McKay hears this argument all the time. “It is a crock,” he says. “You would think they would want the most accurate information possible.” Breeding stock producers should care if inaccurate carcass data comes back, he adds.

Ultrasound differs from the current probe used in packing plants today in several ways. Most plants in Canada use a Destron or Hennesey probe, both of which are based on fibre-optic technology developed 20 years ago. The probe is inserted between the third and fourth rib, measuring fat and muscle depth. Those measurements are then plugged into a formula that was devised by using actual dissected carcasses to estimate lean yield.

McKay points out that the equation used to calculate lean yield was developed in 1990 and has not been updated to reflect changes in genetics over the years. “If we haven’t made any progress in 16 years, we’re in deep trouble,” he says.

Ultrasound, on the other hand, has no mechanical parts that go into the meat, so there is no chance of injecting contaminants as the probe passes from the outer layer of the carcass to the inner. It also does no damage to the meat, and the actual loin area is measured instead of loin depth. While the loin area is measured using ultrasound, other muscles are estimated using a correlation equation.

Automated software has been developed to do all the analysis, ensuring that there are no errors in interpretation of results. The images taken by ultrasound are also stored in order. They can then be checked if there are questions with the grader to ensure that he is getting good images.

McKay says that probes are prone to errors because they can be inserted between the wrong ribs, resulting in a “partial error.” Moreover, if they are not inserted perfectly perpendicular to the carcass, the reading will be inaccurate.

A big part of the debate has to do with cost. In an industry that gets squeezed from every side, no one wants to take on extra cost if it can’t be justified. Producers and packers share the cost of grading equally. “The federal government has no say in it anymore. They have abdicated all responsibility for grading,” says McKay, who argues that the cost issue is a minor one in the big picture. “For a plant that processes 90 000 animals per week, a quarter of a million dollars is peanuts in the grand scheme of things,” he notes.

But how much does one of these systems cost? It is not easy to get a good answer. “Cost varies on a case by case basis,” says Bon Wanner, general manager for Animal Ultrasound Technologies, based in Texas where ultrasound is used extensively in the beef sector.

Equipment could be leased and paid for on a per animal basis or purchased outright, Wanner explains. Part of what makes the equipment so expensive is that all the components must be top-notch. It must produce results that are repeatable time after time and be able to stand up in the harsh environment of the meat processing plant. Equipment used today is the same as that used in human medicine, Wanner notes, and the cost is not changing much. He says packers and producers must decide what the data is worth and ask if they are really getting the information that they want.

“It is not that more information wouldn’t be better,” says Bill Ballantyne Director of Technical Service, Maple Leaf Pork. But a retrofit on a plant that costs half a million dollars or more is not going to be very popular with producers. “Producers are not going to be very enthusiastic about sharing those costs,” he adds.
Cost associated with the technology varies so much because it is not just a matter of simply bringing in a new piece of equipment. In a new plant designed for ultrasound technology, costs would be lower than in an existing plant that requires a retrofit, Ballantyne explains.

Tyson has used ultrasound in their plants in the United States to measure fat depth, muscle depth, loin muscle area and the entire lean yield of the carcass, points out Wanner. The technology has helped the company get the carcasses they want -- “they don’t make money on fat, they make money on lean,” he says.
But Cohoe argues against Wanner’s statement that lean is worth more than fat. Many packers actually pay less for ultra lean carcasses, he says because “nobody wants to buy that stuff.” It is all about customer preference and there are also some physical issues with super-lean carcasses, he adds.

The dilemma in Canada, says Wanner, is that the technology is not supported at the government level and that, globally, people do not pay much to obtain accurate data. “The hardest thing to change is a meat cutter’s mind,” he says. “When it comes to grading, a ruler was good enough for many years.”

“Processors and producers are happy with the current system,” adds Dan Bazinet, general manager for the Ontario Pork Grading Authority (OPGA). Ontario Pork established the OPGA in 1996 and it serves as a third party responsible for grading pork, taking direction from a board of directors composed of producers and people from the packing industry. The OPGA currently grades market hogs in federally inspected plants as well as overseeing and auditing all provincially inspected plants.

Bazinet cites a study conducted ten years ago in Burlington which found that the cost associated with ultrasound grading was not justified by any improvements in accuracy. He says that grading technicians must produce accurate results or face decertification. Technicians are audited and four specific parameters are evaluated. Graders obtaining less than 95 per cent accuracy are retrained or decertified, explains Bazinet.
Ultrasound technology has been embraced for use on live animals because it is not invasive, but that does not seem to be an issue when dealing with carcasses, says Wanner. The incision made by the probe is very small and does not result in lost value to the carcass, packers argue.

Frank Wood, hog procurement manager for Conestoga Meat Packers, concurs. Damage done by the probe has not been an issue, he says. While there is always a risk of contamination, they have not had any problems with it.

Ballantyne agrees that this is just not an issue to packers. “We’re in the raw product business,” he says. He believes that if customers were asked whether they would prefer a piece of meat that had not been probed over one that had, many would probably choose the meat that had not been probed. But if they were asked how much more would they pay for an unprobed piece, it becomes a different issue.

Bazinet also accepts that grading probes have not caused meat quality problems in Canadian packing plants. There is currently no requirement from Hazard Analysis Critical Control Points (HACCP) to sanitize the probe between every carcass, but if a problem developed, they could certainly adopt that step in the process, he says. The incision made by the probe is very small and almost invisible, does not damage the prime cut and results in no extra costs to producers or processors, says Bazinet.

While he has not seen research proving that ultrasound is better or worse than the system currently used, Wood is planning to do some preliminary research into alternative technologies in the spring. He says the probe presently being used may not be 100 per cent accurate, but it is consistent. Before switching, Wood would have to be convinced that ultrasound would be fast enough, reliable, cost effective and easy to service. As far as speed is concerned, Wanner says that ultrasound can evaluate an animal every three and a half seconds, while the fastest probe takes seven to eight seconds per animal.

But Cohoe still argues that a lot more energy is being spent on the issue than is warranted. “There is a belief that there is a direct relationship between lean yield and value, but it is not that straightforward,” he says. There are many uses for raw material in a packing plant and packers are looking at many more things than just fat. To a processor, one carcass that has 61 per cent lean is not necessarily worth more or less than a carcass with 62 per cent lean.

Cohoe is also not convinced that more accurate grading will result in more uniform pigs. The information has to go back to the producers and get translated to the breeders so that breeding decisions can be made based on the information. A change in genetics that can be seen at the packing end takes years, he says. Not only would the grading need to be more accurate, the correlation between grading and genetics would also have to be improved.

It is impossible to produce everything exactly the same in a biological system, Cohoe argues. There will always be genetic variation, no matter how information is obtained. “There is variation in what comes off the farm in weight and in lean yield,” he says. Ballantyne notes that hogs being produced in Canada now are already very uniform compared to what they were 25 years ago.

While Cohoe is generally negative about ultrasound technology, he admits that it could be useful in some cases. From a biosecurity standpoint, “we would prefer not to be sticking things into meat,” he says, although he has not heard of any issues arising from doing it.

From a theoretical point of view, it may have some uses, says Cohoe, but this does not include paying producers. While ultrasound could be used internally in the slaughter house to sort carcasses based on different end uses, there are not many plants that are set up to do this, he adds. If the technology could be improved to identify marbling in the meat, then it might be more useful.

Only demand from processors or producers would result in a second look at comparing the two grading technologies, says Bazinet. He does not expect further enquiry because both producers and packers are happy with the current system. BP