Heterosis and EPDs for Crossbreeding
Nebraska researcher looks at across-breed expected progeny differences and heterosis for calving ease.
by Nicole Lane, Angus Journal® intern
BILOXI, Miss. (June 10, 2015) — Commercial producers are often encouraged to capitalize on the genetic strengths of different breeds to optimize their cow herd. This can be a difficult task when expected progeny differences (EPDs) from the different breeds don’t match up and across-breed adjustment factors aren’t always available for some of the economically valued traits.
At the Beef Improvement Federation (BIF) Annual Convention in Biloxi, Miss., June 11, Matt Spangler of the University of Nebraska shared his research on across-breed calving ease EPD adjustment factors. The goal of his work was to learn how to create an across-breed EPD for calving ease direct (CED) and calving ease maternal (CEM).
Matt Spangler suggested that an updated delivery model be required for EBVs for calving difficulty and other traits that don’t fall on a normal distribution pattern to expand the number of across-breed EPDs that can be made available to producers.
“Currently we have this information for birth weight, but birth weight is an indicator trait, not an economically relevant trait,” Spangler said. “Calving ease is an economically relevant trait, so we would like to be able to develop adjustment factors to tackle that.”
Spangler studied this by evaluating breed-specific heterosis for the seven commonly used beef breeds in the United States (Angus, Hereford, Red Angus, Charolais, Gelbvieh, Simmental, Limousin) and the composite MARC III (¼ Angus, ¼ Hereford, ¼ Pinzagauer, ¼ Red Poll). By creating a population of animals that represented these breeds and frequent crosses, Spangler collected data to provide a heterosis summary.
This type of data can be used to estimate the effect a trait will have in specific cross-breeding scenarios. He concluded that heterosis still exists, use of biological type in breeding systems is warranted, and we need to revisit breed-specific heterosis again.
When attempting to compare calving ease EPDs across breeds, Spangler described it as comparing apples and oranges. This is due to the different models that breed Associations use to provide birth weight EPDs. When scaling differences between breeds the variety of models makes creating an EPD or estimated breeding value (EBV) nearly impossible.
Spangler suggested that an updated delivery model be required for EBVs for calving difficulty and other traits that don’t fall on a normal distribution pattern to expand the number of across-breed EPDs that can be made available to producers.
The 2015 BIF Annual Convention was hosted by Mississippi State University and the Mississippi Extension Service June 9-12 at the Beau Rivage Casino and Hotel in Biloxi. The Angus Journal and LiveAuctions.tv provide comprehensive online coverage of the event at www.BIFconference.com. Visit the Newsroom for summaries, proceedings, PowerPoints and audio of the sessions; the Awards page for announcements of award winners; and the Photos page for galleries of photos from the tour stops.
Editor’s Note: This summary was written under contract or by staff of the Angus Journal®. Through an agreement with the Beef Improvement Federation, we are encouraging reprinting of the articles to those who will adhere to the reprint guidelines available on this site. Please review those guidelines or contact Shauna Rose Hermel, editor, at 816-383-5270. PowerPoints are posted with permission of the presenter and may not be reproduced in whole or in part without the express permission of the presenter.
The Angus Journal's coverage of the event is made possible through collaboration with BIF and sponsorship of LiveAuctions.tv. For questions about this site, or to notify us of broken links, click here. Look for additional coverage in the Angus Journal, the Angus Beef Bulletin, the Angus Journal Daily, the Angus Beef Bulletin EXTRA and Angus TV.
