Technical Keynote Session 5
Managing Genetic Defects
A proactive approach — rather than a reactive one — needs to be taken by the beef industry as it responds to emerging genetic defects that are being identified. That was the message University of Illinois animal scientist Jonathan Beever shared as he addressed attendees at the Beef Improvement Federation (BIF) symposium in Sacremento, Calif.
Beever has been the lead researcher in assisting the beef industry in identifying recent genetic defects, including arthrogryposis multiplex (AM), neuropathic hydrocephalus (NH), fawn calf syndrome (FCS) and others.
Because most genetic defects are recessive, both parents have to be carriers in order for the defect to be expressed. But to prevent the spread of the defect through the beef population, some form of management is needed. Beever emphasized that with today’s technology, specifically DNA-testing tools, these genetic nonconformers can be identified and managed among sires and cow herds. And, Beever said, by taking a proactive approach toward genetic defects, beef producers can reduce losses and increase their potential profit margins.
Beever told beef producers in the audience that when dealing with a potential genetic defect carrier in cow herd populations they have options:
- 1. Ignore it. Of this, Beever said producers then run the risk of seeing the defect come back in populations years later.
- 2. Completely eliminate the genetic source. Beever cautioned that there are also problems with this choice, including the fact that pedigrees can be wrong, you may miss an individual with that pedigree, and removing this gene pool from the population may be contradictory to breed improvement.
- 3. Find outcross genetics or, in other words, breed away from the gene pool with the defect. Beever said this choice isn’t practical for seedstock breeders, but could be a potential option for commercial operations, particularly if they produce a terminal cross.
- 4. Accurately identify the carriers through genetic testing and then utilize breeding management. Beever called this the most responsible choice. “Genetic testing is a tool that allows beef producers to manage these problems. They are highly accurate and are becoming more cost-effective,” he said.
Beever added that how producers develop their response to genetic defects within the beef industry will also be influenced by their place in the production system. He said seedstock breeders should be especially proactive.
“Most of the responsibility falls on you to manage your herd as best you can so these genetic defects don’t trickle out into commercial populations,” he told seedstock breeders in attendance.
For commercial cattlemen producing replacement females, Beever encouraged testing those females for the identified genetic defects in order to minimize calf losses.
On the other hand, commercial breeders producing calves for terminal programs have little or no risk with passing the genetic defect to other cow populations. Thus, Beever suggests that those commercial producers just make sure they are using a sire that is negative for the defects. He suggests it may be worth paying a premium for sires that have been tested and proven to be “free” of genetic defects.
Beever acknowledged there is a cost to cattle producers for genetic testing, but he said he believes that investment can be made up by the reduction in calves lost to genetic defects had you not tested. Beever suggested that one cost-effective strategy for some producers is to test those animals with the most influence on your herd — sires and herd matriarchs — and then test replacement females annually.
Beever concluded by saying, “If we are going to be serious about this (dealing with genetic defects), it is going to require investment. Genetic defect research should be viewed as a preventative investment.”
He encouraged producers to get educated about the existing defects and the DNA-testing tools available. As well, Beever called for a change in the psychology of reporting defects, saying that rather than hide or ignore the issues, breeders must be willing to report these cases for the future good of their breed and the beef industry as a whole.
Beever clarified that he and his colleagues only work on genetic defect issues that are brought to them. Looking to the future, he said, “We must have a proactive and positive attitude toward defect surveillance and standardized reporting.”
Editor’s Note: This summary was written under contract or by staff of Angus Productions Inc. (API). To request reprint rights 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 41st BIF Research Symposium and Annual Meeting was hosted by the California Beef Cattle Improvement Association and the California Cattlemen's Association. For more information, visit www.bifconference.com or www.calcattlemen.org/bif2009.html.
