In contrast, genomic screening offers immediate feedback. Technicians can take a sample of blood or hair from a newborn calf, extract the DNA, and have an almost instant prediction of how she’ll perform in the herd. This is done by scanning the calf’s genetic code for the presence of certain markers, snips of DNA that are associated with various important traits. Roughly $150 will pay for a scan of 50,000 genetic markers. A new, slightly more expensive version will look at almost 800,000 markers.
“It’s not as accurate (as progeny testing)—not yet,” says Weigel. “We’re in this transition period, starting to move away from the progeny testing to the DNA testing. But decisions based on the DNA test results are taking a greater and greater role.”
Much of the industry’s excitement about genomic screening has focused on having a new way to spot the same traits measured by progeny testing—like a cow’s potential for producing milk, butterfat and protein. But genomics promises a much richer lode of data. Over time, it will make it possible to predict traits that are too difficult or expensive to measure on the thousands of commercial farms that supply data to the progeny testing system, such as genetic predisposition to infertility, or resistance to disease, or how efficiently a cow converts feed into milk.
“To measure feed intake on an individual animal basis you need a lot of labor and specialized equipment. We couldn’t measure it on hundreds of thousands of animals. It would be prohibitively expensive,” says Weigel. “But you can do it on a few thousand cows in research herds and then DNA-test those animals. If it works as we hope, we’d` be able to take specialized traits and put them in a national breeding program.”
Identifying specialized traits could lead to specialized cows. For example, producers who feed their cattle on pasture might be able to select cows that are really good at converting grass to milk. “In the past all you could do is try to select different sire families whose daughters seem to have done better on grass than on total mixed rations,” says Weigel. “You didn’t really know what you were selecting. But now you could test individual animals and target them for grazing, target them for confinement, target them for producing cheese, or for a certain kind of cheese. ”
“It’s far fetched today,” says Weigel. “But not that far fetched. We can imagine being able to do it.”