Sports fans compare teams by power rankings. Now the beef industry has a statistical ranking system, too.
"Instead of teams, we have animals," said Keith Bertrand, a University of Georgia animal scientist who helped develop the ranking system. "It's a way for breeders to compare animals and find out what bull has the potential to pass the best characteristics on to offspring. Bulls with the best numbers will be more popular for breeding purposes."
Consumers are the real winners in this new process because the models help breeders select which steers are most likely to yield lean, tasty, well-marbled steaks.
Using high-powered computers Bertrand, and other animal and dairy scientists in the UGA College of Agricultural and Environmental, analyze and evaluate millions of animal records to generate rankings. The rankings are then used to develop models that predict possible outcomes for the beef industry.
"Our models are similar to weather forecast models," said Bertrand. "We try to predict the future."
Livestock breeders can compare values for 15 genetically linked characteristics, such as those that indicate greater growth potential, leaner meat and other qualities important to growers and/or consumers. The bovine matchmaking models predict which bulls will produce future generations with the desired traits.
"Producers realize this information means money, and they use genetic evaluation to buy and sell bulls," Bertrand said.
The system, which evaluates 14 breeds of cattle in the United States and Canada, is being expanded to include Central and South American stock. The international ranking system will eventually replace the U.S. National Beef Cattle Genetic Evaluation System, Bertrand said.
Once a prize bull with desired genetic traits is selected, a breeder can simply arrange to buy the bull's germplasm - either in the form of semen or fertilized eggs. If properly stored, semen for artificial insemination has a "shelf life" of two to three decades.
Collecting genetic data on cattle is expensive and time consuming, especially when taking before and after measurements of animals destined for supermarket shelves.
The UGA scientists pioneered beef cattle evaluations using ultrasound, a less expensive alternative to other methods. Their work has been funded by UGA Agricultural Experiment Stations, the cattle industry, breed associations and the USDA.
The team has found that ultrasound provides reliable measurements of the amount of fat around the muscle, the size of the ribeye and even the extent of marbling. In fact, research has shown that ultrasound measurements are equal to and in some cases better than similar measurements obtained by USDA graders.
"By measuring yearling bulls and cows with ultrasound, we can help breeders select for improvements in steers and heifers before they get to the slaughterhouse," Bertrand said.
But neither scientists nor ultrasound can predict tenderness, which results from a combination of age, breed, genetics and muscle characteristics.
"Tender is a hard quality to measure," Bertrand said. "What does tenderness look like?"
UGA scientists are now working on methods to measure tenderness. Research strongly indicates there are bloodlines in each breed that can provide tender beef. "Our goal is to find them," he said. "Some day we may be able to use a blood test to see if animals carry the genetic characteristics of tenderness."
(Photo 1. S. Bauer, USDA-ARS, Photo 2. J. Purdy, UGA CAES.)
(Judy Purdy is a marketing and outreach specialist with the University of Georgia College of Agricultural and Environmental Sciences.)