General Session II
Implementation of Genomic-Enhanced EPDs
COLUMBIA, Mo. (June 30, 2010) — The American Angus Association (AAA) is the first breed organization to provide a suite of genomic-enhanced expected progeny difference (EPD) values as a tool for genetic selection. During the 2010 Beef Improvement Federation (BIF) research symposium in Columbia, Mo., Association Director of Research Sally Northcutt talked about the development of genomic-enhanced EPDs and the opportunities they offer beef cattle producers.
Sally NorthcuttNorthcutt explained how results of DNA testing for genes associated with specific traits, using the Igenity® Profile for Angus are combined with available individual, pedigree and progeny data used to calculate traditional national cattle evaluation (NCE) EPDs. Northcutt said the addition of genomic profile information provides more thorough characterization of economically important traits and improved accuracy on young animals.
“In September 2009 [the Association] began accepting DNA samples submitted by breeders,” said Northcutt, explaining how samples were then sent to Igenity for creation of the genomic profiles for each animal represented. “In October 2009,” she added, “the first genomic-enhanced EPDs for carcass traits were released.”
The predictions for carcass traits (carcass weight, marbling score, ribeye area and fat thickness) incorporate harvest records, ultrasound scans, and genomic results. According to Northcutt, the beauty of using the genomic data as an indicator trait is that even very young animals can have carcass trait EPDs prior to ultrasound scanning. Unlike the phenotypic data, the genomic result requires no contemporaries to enter the genetic evaluation. A genomic profile from animals of any age can be incorporated. If a calf is later scanned as a yearling and eventually accumulates progeny data, each new piece of information may be added to carcass evaluation.
For animals that already have traditional EPDs for carcass traits, the genomic results still have impact. EPDs may move up, down or stay the same, and the accuracies increase on animals having little or no progeny data. Genomic-enhanced EPDs essentially bypass “interim” EPDs based solely on pedigree data.
“A full national cattle evaluation is conducted weekly, and breeders can access updated genomic-enhanced EPDs every Friday morning. Angus dollar value indexes ($Values) are also updated on-the-fly,” Northcutt stated.
She said the main advantages are the ability to provide more accurate predictions of genetic merit and do it more rapidly. Carcass genomic profile results are incorporated into EPDs without a six-month wait for biannual evaluations. Northcutt said producers are asking when weekly computation and release of genomic-enhanced EPDs for other traits will occur.
“We’re working on it,” she stated. “And we’re working on a predictor of feed efficiency. Through collaborators helping collect feed intake data, we're working to create a ‘residual average daily gain EPD,’ which eventually would be incorporated into a $Feedlot selection index.”
The American Angus Association genomic-enhanced NCE EPDs are available at www.angus.org/Animal/EpdPedSearch.aspx.
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