Producer question: Genetic selection for pork quality still holds many unknowns. How soon may it become a major selection consideration, and what can or should I do now?
Baas’ response: Today, economics and productivity are major considerations when you chose genetic lines. Marketing trends have increasingly influenced genetic trends. For example, here are some marketing trends that have played a role in genetics:
- Emphasis on lean.
- Optimum weight ranges.
- Larger animal lots.
- Regularly scheduled animal shipments.
These trends influence packer profitability and have resulted in lean-value pricing. They also have influenced your genetic selection for leanness. Pork quality traits are next in line for a premium or discount, and they will affect genetic selection.
One potential problem in selecting for pork quality traits is that pH, one of the best quality indicators, and leanness tend to run inversely. The relationship is not exact, but leaner pigs may not be the best pork quality animals.
Another obstacle in selecting for meat quality is the fact that genetic traits vary in their ability to be incorporated into your genetic program. Carcass traits are easy to change because they are highly heritable, which has helped speed the transition to a lean hog. Reproductive traits are harder to change and can negatively impact carcass merit. The heritability of pork quality traits is still to be determined, as well as their impact on other traits.
There are a few guidelines for including a genetic trait in your selection program.
- It must be measurable.
- It must be under genetic control.
- It must not be genetically related to other traits in a negative manner.
- It must have an economical impact on commercial producers.
To make genetic gains, the optimal situation is a terminal crossbreeding system, where the sire provides half of the desired traits and dam provides the other half. That sounds simple enough. But to see any actual improvement, you need accurate evaluation at the seedstock level. The National Pork Producers Council has done several studies to provide the data to help you evaluate genetics, including the Terminal-Line Sire Study, the Quality-Lean-Growth Modeling Project and the Maternal-Line Project.
These studies can provide some of the tools you need. However, there are large breed and genetic line differences when it comes to pork quality – enough to change the performance rankings when you take meat quality into account.
Bottomline, selecting for quality still holds many unknown variables. Also, until there are price premiums – or discounts – for pork quality, there will be no rush to select genetics for quality. So, genetic selection for quality on a large scale may still be a few years away, but getting a jump on the next genetic trend might be something you should consider.
Tom Baas is a swine geneticist at Iowa State University in Ames, Iowa.