Open the catalog from your favorite genetics supplier and what do you see? Outside of the pretty pictures, you see numbers. Lots and lots of numbers.
Connecting the dots between the pretty picture (an indication of the bull's phenotype) and the numbers (an indication of his genotype) has become more challenging of late, what with the recent explosion of genotypic information now available.
However, there's a research effort underway to make the game of genetic hopscotch a little more comprehensible. And the idea behind it has a name — phenomics.
The goal, ultimately, is to develop a way to combine information from multiple sources to come up with a selection tool that producers are familiar with, says geneticist Denny Crews, Colorado State University. That tool, of course, is EPDs (Expected Progeny Difference).
Peruse the data in the above-mentioned genetics wish books and you see a traditional EPD report and, presented separately, some kind of genotypic score. EPDs have values that give you an idea of the score's predictability and accuracy. Genotypic scores don't.
“My approach to phenomics,” says Crews, who first coined the term as it applies to beef cattle, “has been looking for ways to combine those pieces of information and still report it in a classical EPD-style report with an accuracy value.”
Both the Beef Improvement Federation (BIF) and the National Beef Cattle Evaluation Consortium (NBCEC) have adopted the idea of adding accuracy values to gene-assisted evaluation and marrying those figures with an EPD-type score as a long-term goal. But it's going to take some intensive research to get there, says Mark Enns, Colorado State University associate professor of animal science.
The beauty of gene markers is they give the industry a way to look at some economically important traits that are very difficult to measure. From Enns' perspective, then, the phenomics concept opens a whole new realm of possibility.
“There are some things we haven't produced EPDs for that we probably need to,” he says, such as feed intake, maintenance energy in cows, health attributes and bull fertility, to name a few. These traits are very hard to derive phenotypic measures on in a commercial setting. But if researchers can find ways to measure those traits, match those phenotypic indicators with genetic markers and then develop an EPD-like score useful to commercial cattlemen, the industry stands to gain in significant ways.
Clearly, this is more than just measuring cow size. “We need to go deeper into what's going on physiologically, and try to understand some of the mechanisms,” Enns says. “All 1,100-lb. cows of body condition score 5 don't have the same maintenance requirements. So how do we break that down in order to give breeders a tool to help make selection decisions that produce a female adapted to her range environments?”
Research is ongoing at several universities and in the private sector to achieve this goal; and at least one breed association, the American Simmental Association, has developed a marker-assisted EPD for tenderness. Other breed associations are developing similar marker-assisted EPDs. But it will take some time before EPD-type gene marker figures are widely available.
“The timeline, of course, is the thing nobody knows for sure,” Crews says. “Obviously it will come on line at various rates of speed, but it's the only logical way, as far as I'm concerned, to make optimal use of this explosion of genomics interest.”