Pork production and marketing have undergone constant and relentless changes for the last 25 years. These changes have accelerated the last 10 years, producing greater changes and challenges for the 21st century pork industry.
The constant question that begs an answer is: "What will we need to know to remain competitive 10 years from now? 20 years?" Certainly, information we believe to be factual today will be disproved as we dig deeper to understand production drivers and meat quality parameters.
In 1990, it is unlikely that anyone would have predicted that pork packers would discount very lean, muscular hogs and incorporate meat quality traits such as color and ultimate pH into market hog procurement programs. Likewise, no one could have predicted the packer demand for higher meat quality to support "case ready," fresh pork marketing programs. Nor would anyone have predicted a traditional hog show would provide the format for delivering the most current, extensive meat quality genetic information to breeders and geneticists.
If we turn back the calendar just a decade, we find pork producers who were finally being paid very large premiums for very lean market hogs. This came after 30 years of talking about and promoting the development of the "meat-type hog." From about 1990, desirable market weights were getting progressively heavier. Large genetic companies were promoting the use of the stress or halothane gene as a "quick fix" to increase carcass lean percent. Terminal crossbreeding programs were replacing rotational crossbreeding programs as the most popular genetic systems in commercial herds. Management protocols for terminal crossbreeding systems included three site-production and artificial insemination. Meat quality was rarely discussed or thought important. It was difficult to differentiate the trends from the fads.
This was the environment that the sponsors of the National Barrow Show (NBS) faced in 1990 as they sought to develop new programs to support production of high quality pork products. The NBS has been a major breeding stock and commercial market hog event since 1946. Sponsored annually in Austin, MN, by the National Association of Swine Records (NASR) and Hormel Foods, it has been a popular meeting place for breeders and producers. Its three-day format encourages those attending to exchange new information and new philosophies.
New Format Sought NBS sponsors felt the value of the single production barrow contest, started in 1976, had about run its course. A committee of purebred breeders, commercial producers, geneticists and packers was formed to develop a new program to retain the value of the NBS to the pork industry.
After several committee meetings, the suggested programs varied from a national, on-farm derby barrow contest to a strictly designed sire progeny production test program. Committee member Lauren Christian, an Iowa State University geneticist, had spent his career working with the genetics of pork quality, first with stress (halothane) gene research in the 1970s, then later by observing the Swedish and Danish meat quality programs while on a research leave to Sweden in 1988. His counsel to the committee was that pork quality was going to become very important for consumer demand, and there was little genetic information available for use by U.S. breeders.
The National Pork Producers Council (NPPC) had just finished three years of Pork Challenge Tests, which included loin quality measures in crossbred market hogs. Great variation between breeds and genetic lines was identified. Producer leadership at NPPC was particularly interested in identifying loin quality measures to support their checkoff-funded "Pork. The Other White Meat" promotion efforts.
In the fall of 1990, a joint agreement of NASR, Hormel Foods, NPPC and the Minnesota Pork Producers Association produced the NBS Sire Progeny Test program. The first pigs were placed on test in the spring of 1991. A second test was conducted in the fall of 1991; thereafter only spring tests have been run.
The sire progeny test program is designed to provide genetic tools for swine breeders to improve meat quality. These tools include breed differences, sex differences, heritability estimates, plus genetic correlations for growth, carcass, fresh meat quality and cooked meat quality traits.
A timely development was the 1991 discovery of a DNA test for stress or halothane genotype. This new test could separate all three genotypes (normal, monomutant and dimutant). The NBS Sire Progeny Tests became the first program to use this test on all pigs and so produced estimates of the meat quality changes caused by each halothane genotype.
The National Pork Board (NPB) supported the meat quality evaluations with checkoff grants while purebred breeders and Hormel Foods organized and supported the production tests. All pigs were production tested at the Minnesota Swine Testing Station, New Ulm, from 1991-1994 and at the Northeast Iowa Swine Testing Station, New Hampton, from 1995-1999. Charles Christians, University of Minnesota swine specialist, led a leg soundness scoring committee that evaluated each pig each year.
Test Protocols Test protocols and invitations to participate were sent to purebred breeders and breeding companies in November 1990. Protocols are:
1) An entry consisted of eight pure line pigs with the same sire representing at least three litters. No more than four gilts/entry.
2) Three generations of ancestry documented for each test pig.
3) Pigs must weigh 35-60 lb. at entry; uniformity of pig size recommended.
4) Pigs started growth evaluation when sire group averaged 70 lb.
5) Leg soundness scoring conducted after pigs weigh 175 lb.
6) Pigs will be slaughtered at 250 lb.
7) Measurements of hot carcass weight and chilled carcass backfat thickness, loin muscle area and length.
8) Loin ribbed at 10th rib and given color score, marbling score, firmness score, Minolta reflectance, Hunter color L score and ultimate pH.
9) A three-rib section of loin (10-12 rib) removed from the carcass and taken to the Iowa State University Meats Laboratory. Lauren Christian led this group.
10) The 10th rib chop is used for total lipid extraction (intramuscular fat percent) and water-holding capacity measurement.
11) The 11th and 12th chops are sent to the Iowa State University Food Science Laboratory for cooking to 158 degrees F. Chops were evaluated for cooking loss, Instron probe tenderness and sensory panel scores of juiciness, tenderness, chewiness and flavor. Iowa State meat specialists Ken Prusa and Chris Fedler led this group.
Whole hams were shipped to the Texas A & M University Meat Laboratory in 1996 and 1997. These hams were separated into fat, lean and bone. Measures of Minolta reflectance, Hunter color L score and water-holding capacity were gathered on fresh and cooked inside, outside and knuckle ham muscles. These three muscles were injected with a brine solution, tumbled and cooked to get cooking yields and slicing yields. Samples of each muscle were used for total lipid extraction. Rhonda Miller led this group.
Loin chops from the 1994 and 1997 NBS tests were used in Consumer Preference Pilot Studies to test those evaluation protocols.
Data analysis of the 10-test results is done by P. Jeff Berger of Iowa State University and Rodney Goodwin, NPPC. Results of this extensive data collection and analysis give all swine breeders and geneticists the necessary tools to design meat quality improvement programs. These include breed differences, sex differences, halothane genotype differences, heritabilities and genetic correlations. The additional information necessary to design profitable meat quality programs is to know the relative economic values of growth, carcass and meat quality traits. Results of the checkoff funded Consumer Preference Studies give unique economic information to breeders.
Genetic Tools Swine breeders in the U.S. have current genetic tools to use. The NBS test results reported in 1994 and 1996 have supported Berkshire and Duroc premium niche marketing and reduced halothane gene use in the industry. Indeed, pork producer leadership at the 1996 Pork Forum resolved to eliminate the halothane gene from the U.S. pig population to improve meat quality. The NBS test results and results of similar programs have helped develop strategies to support case-ready marketing and increase export acceptance of U.S. pork.
The results provide a database with performance records of more than 500 sire groups to guide breeders. Since 1991, 236 breeders - some with 20 sows, some with 5,000 sows - have participated in this program.
The ongoing success of the NBS Sire Progeny Tests is due to strong leadership and vision by a team of industry leaders in 1990. All the members of this team committed funding and capable talents to ensure this program's success for all pork producers.