Science predicts quality of cattle
Ultrasound isn't just for helping parents decide whether to buy pink or blue baby clothes.
Now it's helping cattlemen provide better steaks. It's giving them a look at beef cuts long before their animals head for the stockyard.
"The success of beef producers depends on their ability to provide high- quality, consistent end- products to consumers," said Dean Pringle, University of Georgia animal scientist.
Many management practices help farmers improve beef quality. But ultrasound is one of their most effective means. It has been around since the 1950s, Pringle said, but farmers have embraced fully it in the last five to 10 years.
"Real-time ultrasound can be used to measure various carcass traits in live animals," he said. "You can measure an animal's intramuscular fat percentage in the ribeye and, from that, predict its marbling score and USDA quality grade."
Ultrasound can give farmers estimates of the ribeye area, back fat, rump fat and the percentage of intramuscular fat in the ribeye. The process is harmless to the animal, he said.
After placing a probe on the animal's back, sound waves penetrate its tissues. They then reflect off the boundaries between hide, fat and muscle layers.
"As the sound waves reflect back, a cross-sectional image is created (and) displayed on a computer monitor," Pringle said. "Ribeye area and back fat are measured between the animal's 12th and 13th ribs. These traits are highly related to the retail product yield."
As the fat measurements increase, they have a negative effect on the yield of beef cuts. An increase in the ribeye area, though, creates a positive effect, he said.
By enabling farmers to predict meat quality, ultrasound is helping them select their best breeding stock. Before ultrasound, cattlemen evaluated a sire's carcass merit by studying the carcass quality of the animal's offspring.
Ultrasound can give farmers enough data on their bulls and heifers to decide rightly when to cull cattle from their herds.
"Culling decisions need to be based on a combination of reproduction, growth and end-product," he said. "Ultrasound offers a means to accurately measure the latter."
Ultrasound carcass traits are considered highly inheritable, he said. "So now selection of bulls and replacement heifers can be based on these traits," he said, "and producers can bring about genetic change in their calves."