q
How long has the American Angus Association been aware of developmental duplication, or DD?

a
Grant:
The American Angus Association board of directors voted unanimously in August 2013 to recognize DD as a genetic condition, inherited as a simple recessive gene.

Dr. Jon Beever began his research into DD in Australia in 2011. Until Dr. Beever’s research was completed, however, there was no way to fully understand the condition or its effects.

q
Does the association refute any of the findings from Dr. Beever’s research into DD, or has that research been beneficial to defect identification?

a
Grant:
Dr. Beever’s research has resulted in the identification of several genetic conditions in many breeds of cattle, and having this information available has equipped cattle producers with powerful tools to manage them.

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Keep in mind that genetic conditions affect all breeds of cattle and have been around since the very beginning of the livestock industry.

The advent of DNA technology arguably could be one of the most significant advancements in the history of our business.

The work of Dr. Beever and his colleagues at other universities and private companies is helping all of those who raise cattle to reduce risk in mating decisions and advance more rapid genetic improvement.

q
Since Dr. Beever has suggested that early DD events usually result in embryonic death, rather than affected calves, how does the association suggest producers prevent growth of the defect?

a
Grant:
Researchers continue to evaluate DD and its inheritance. As Dr. Beever recently reported, certain findings suggest phenotypic expression of the condition may be more complex than originally reported.

Based upon current understanding of the condition, the board of directors has established policy that relies on sound management decisions – such as not breeding carriers to carriers – and strategic use of DNA testing.

If you’re a commercial producer, contact your seedstock provider or A.I. company to determine the genetic-condition status of animals within your breeding program.

If you determine you have used carrier, DDC bulls, then simply use DNA tested, DDF bulls – or cattle that are free of the condition in their pedigree – in the future. Remember: in order for DD to be expressed phenotypically, both parents must be carriers for the condition.

If you’re a registered Angus breeder, you can visit AAA login at www.angus.org to generate a list of potential DDP carriers.

While the AAA board policy does not require testing of these animals, Angus breeders can collect a hair or blood sample and submit these to Angus Genetics Inc. (AGI) for analysis.

The DD test is available for $22 per head. If they have existing DNA samples already on file with AGI, they can use these samples to determine DD status.

If you choose not to test potential carriers, you can simply breed these cattle to DNA-tested, DDF cattle – or cattle that are free of the condition in their pedigree – and the condition will never be expressed phenotypically.

q
The Angus Association on Sept. 12 issued a policy update allowing DD-affected animals to remain registered by Angus without a mandatory test. Why was this approach taken?

a
Grant:
The association's early "DNA era" began in 2008 with the development of policies related to first AM and then NH. Those policies were based on the perception that each represented a catastrophic, once-in-a-lifetime event. Both conditions were lethal.

These early policies were premised on the good faith belief that the best way to eliminate the condition and, at the same time, protect the interests of our commercial customers, was to impose some form of testing as a precondition for registration.

Since that time, leading geneticists in the bovine academic community have increasingly observed that all breeds have hundreds of mutations in their genome and that an association's approach to genetic conditions should be adapted to reflect the likelihood that the discovery of such conditions will continue in the future and at a pace accelerated by new scientific tools available at every turn.

Furthermore, since 2008, cattle producers have become much more adept and knowledgeable about managing the impacts of genetic conditions.

When you think about it, the message is really pretty simple: if you think you might have potential carriers, breed them to DNA-tested, DDF cattle or to cattle that are free of the condition in their pedigree.

q
So the display of information related to animals tested for DD will show they are either DD free (DDF), a DD carrier (DDC) or DD affected (DDA)?

a
Grant:
You can also add “DDP” for potential, untested cattle. This designation does not mean they are carriers; it simply communicates that the animal in question possesses cattle in its pedigree that have been designated as either DDC or DDA.

The DDP designation simply provides our members with basic information they need to move forward. They can test to determine the animal’s status.

Or, they can choose to breed this animal to a tested, DDF animal or to cattle that are free of the condition in their pedigree. It’s their choice.

q
What approach should a producer take when a bull or female is determined as a carrier for DD?
  

a
Grant:
That’s up to each producer and their own marketing and management situation. If they determine they have DDC or DDA cattle, then the simplest way to manage the condition is to breed them to DNA-tested, DDF cattle or to cattle that are free of the condition in their pedigree.  

q


So if a bull is a carrier, its future is not compromised?

  

a
Grant:
If a bull is determined DDC, it does not mean it shouldn’t be used. It’s how it’s used that matters.

Some of the leading genetics that the industry has to offer are also DD carriers, and there are many other important attributes like carcass merit, growth and calving ease that ease that carrier cattle bring to the table.

A DDC bull can be bred, for example, to non-carrier cows to improve a number of traits as well as carcass quality – and in this situation, the DD condition will not be expressed phenotypically.

q
Is the Angus Association working with other breed associations to spread information and proper protocols regarding DD?

 
a
Grant:
DD is a condition that affects a number of other breeds, not just Angus. Our job is to equip cattle producers with the DNA tools they need to manage around it and continue to advance the quality and performance of their cattle.

This is something that all breed associations have as goals. And, as genetic providers to the industry, we are working hard to mitigate the downside of genetic conditions but also use advancements in DNA science and technology to equip producers with the tools they need to remain competitive in a worldwide marketplace.

q
With so many resources available for healthy breeding decisions, should producers worry less about genetic defects?

a


Grant:
This is an exciting time to be in the cattle industry – probably one of the most exciting times in history.

Cow herd numbers are at their lowest levels since the early 1950s. At the same time, worldwide demand for quality, U.S. beef continues to rise.

For instance, Certified Angus Beef enjoyed yet another record-setting year in FY 2013, selling more than 868 million pounds of Certified Angus Beef Brand product to markets around the world. That’s a 7 percent increase over last year, and the seventh-consecutive, record-setting year.

We also saw record-high acceptance rates for cattle qualifying for the program at 24.4 percent.

These records wouldn’t have been possible without the commitment of America’s cattle producers using advancements in genetic technologies to improve the quality of their cow herds.

While genetic conditions represent challenges for our industry, we must keep in mind that all living things have them. They are a fact of life if you’re in the livestock industry – always have been and always will be.

What’s different about today is that livestock producers are finally being equipped with the DNA tools they need to manage around them – and improve their cattle like never before.

Finally, keep in mind that the cattle industry is fraught with risks and potential economic losses – everything from disease, dystocia, weather and market fluctuations. Genetic conditions, as a risk for the cattle industry, would rank well down the list among these other risk factors that cattle producers face every day.

The only difference is that – thanks to advancements in DNA technology – we now have powerful tools to reduce those risks in animal breeding and add tremendous economic value at the same time.  end mark