Pork quality used to mean getting production and carcass traits fine-tuned for leanness. Today, pork quality refers more to eating traits valued by the consumer, such as tenderness and juiciness.



Ten years ago, pork was not so lean, but it was tasty and tender. Today pork is much leaner, but it is not always tasty and tender.

What gives? In a way, it's a story of gains and losses for the pork industry. It's a battle to efficiently produce and process a quality product and win the hearts of consumers.

Gains and Losses

The pork industry has gained a stronger basis for improving pork quality, long-term with the terminal line and lean growth modeling studies, says David Meisinger, assistant vice president of pork quality, National Pork Board.

There's been a strong push to select for productivity traits that have greatly reduced genetic variation and improved lean content. There also has been a reduction in pork quality problems associated with the stress gene, says Rodney Goodwin, director of research, National Pork Board.

But while pork gained ground on the production and carcass sides, it apparently has lost ground on the consumer side for eating quality. “It is like a crap-shoot now every time you go to the grocery store because you don't know until you get it home, cook it and eat it whether the product will be a tender piece of pork or not,” declares Meisinger.

“There's no doubt that pork has improved in terms of color and solving pale, soft, exudative (PSE) problems just in the last five years alone,” adds Steven Lonergan, assistant professor of animal science at Iowa State University (ISU), who works in the meat laboratory at ISU. “But there has been a tradeoff. We've also started seeing a greater incidence of variation in eating quality,” he says.

Goodwin notes at least now all the segments of the pork production chain seem to be working in tandem on a goal of improving the four big factors that affect pork eating quality: pH, water-holding capacity, tenderness and juiciness.

Second Pork Quality Audit

To reach the ultimate in pork eating, quality remains much a conundrum. That's because it covers such a vast array of factors from genetic selection and production to handling, slaughtering and processing.

Because so much has changed in pork quality in the last decade and a new sense of direction is needed, a second National Pork Quality Audit is being developed for rollout in early 2003, Meisinger says. The National Pork Board is working jointly with the University of Illinois, Colorado State University and Texas A&M University.

The audit has four phases. Phase one surveys all segments of the pork industry for what participants think are the pork quality problems and costs. That will be supplemented with spot audit checks in packing plants and data on quality measurements taken in plants by genetics companies, explains Meisinger.

In phase two, Texas A & M University scientists will work with a major meat processing company in Houston, TX, to review pork quality problems during processing.

An examination of pork quality at retail and merchandising efforts in grocery stores comprises phase three of the audit. Some 200 stores in eight U.S. cities will be surveyed to learn if there are geographic and chain store differences, Meisinger explains.

Phase four will be formulation and evaluation of the data collected and development of tactics to move forward.

Other Pork Quality Projects

A project funded by the National Pork Board in cooperation with the ISU meats lab looks at how harvest processes affect pork quality, says Lonergan. The big question that has never been publicly probed is what is the impact on pork quality of changing line speeds in a slaughter plant, says Meisinger. Answers will be different for different packers with different facilities.

“But we know that meat is a very dynamic tissue, and it goes through a lot of metabolic processes in the first five to six hours, postmortem, that is changing the structure of those proteins that influence the quality of the product,” Lonergan notes. Altering stunning, sticking and scalding procedures could provide some interesting answers, he says.

It is hoped the trial work at ISU's own plant will help answer some of those questions for packers, says Lonergan. ISU operates a small-scale packing plant in the meat lab complex. The plant is used to slaughter and process about 1,000 hogs/year for various research projects as well as undergraduate teaching and Extension activities, Lonergan says.

The Pork Quality Research Initiative is an effort to develop a device that will read carcasses at line speeds for pork quality. It is privately funded by four packers and four genetics companies and managed by the National Pork Board, Meisinger says. It will likely key on water-holding capacity and color as key indicators of pork quality.

A lot of pork quality studies have been done in the producer and packer sectors, but not on the transportation area, he says.

That's about to change as the National Pork Board begins development of a Trucker Quality Assurance (TQA) program. It will include animal welfare and animal health/biosecurity parameters.

The goal is to have a national workshop in September to launch the program, Meisinger says. Truckers would participate in training sessions and take a test to become certified livestock haulers.

“The whole idea is to raise the level of awareness and make truckers realize that what they do can have an affect on pork quality and other production issues,” Meisinger asserts.

Recent availability of genetic tests has allowed another chance to look at well documented meat quality evaluations.

Frozen DNA from loin samples of 1,600 pigs of eight pure breeds will be used to evaluate processing and eating quality differences due to the stress (Halothane) gene, Napole gene and H-FABP gene markers.

The H-FABP gene markers are claimed to predict intramuscular fat or marbling of loins. This is a joint project of the National Pork Board, Hormel Foods and the National Swine Registry, explains Goodwin.




Targeting Pork Quality Genes

Long-time swine genetics researcher Max Rothschild of Iowa State University (ISU) hopes new research will target specific genes that relate to pork quality.

A year ago, he and his colleagues concluded work that identified localized regions in the genome that might affect pork quality.

The $250,000 project was sponsored by the National Pork Producers Council, Iowa Pork Producers Association, Iowa Purebred Council, Danbred USA, Seeghers, Dekalb Choice Genetics, PIC, Babcock Swine and Shamrock.

“Now we are attempting to move a step further and find the actual genes that are causing affects on pork quality,” says Rothschild, a C.F. Curtis Distinguished Professor of Agriculture and ISU Animal Breeding & Genetics Group Leader. The research is a USDA-funded grant to develop statistical methods to improve predictions of the regions in the pig genome associated with meat quality, he says.

A second study to identify meat quality genes in the pig is sponsored by PIC USA.

Rothschild has found several regions associated with pork quality traits and has identified two genes associated with those traits.

This cooperative project with PIC has turned up additional mutations in the RN or Napole Gene, he says. The original mutation was only linked to the Hampshire breed.

These new mutations in the RN gene are less significant. But the overall economic impact is potentially larger because it includes all breeds, he notes.
Joe Vansickle