Genetic Conditions Update- DD

IBBA Executive Vice President Dr. Tommy Perkins discusses the genetic condition Developmental Duplication, referred to as “DD”, and the impact the defect has on the Brangus breed as well as the beef cattle industry. Perkins also provides IBBA’s response to handling the defect. Visit http://www.GoBrangus.com for more information.

Brangus Board Approves Genetic Disorder Testing Policy

SAN ANTONIO, TX – The discussion of genetic defects has been ongoing in the Angus breed and others for the past five years or more. Most recently, Brangus and other breeds have joined in on this debate with the discovery of the genetic disorder called developmental duplication (DD).

It is important to note that DD testing, to date, has rendered a very low occurrence of the condition in our Brangus population. Ultimately, members will be able to manage this condition and others with a sound DNA testing policy and a well thought out breeding program. Therefore, the International Brangus Breeders Association (IBBA) Board of Directors has adopted a new genetic disorder testing policy to aid breeders and members in this process. The policy is summarized below:

1. The Executive Vice-President will contact Zoetis and at least one other genomic company to form an agreement for genetic testing of all genetic conditions that could impact Brangus cattle. The agreement will:

  • Allow IBBA members to order test kits (blood cards, hair cards, purple top tubes, tissue cards, etc. and all paper work) directly from the genomic companies’ websites (and linked from the IBBA website).
  • Allow for direct shipment of DNA samples from individual IBBA members to the genomics company.
  • Allow all test results to be sent from the genomics company directly to the IBBA office and copied to the member submitting the samples for testing.
  • Require the genomics company to send all results on a timely basis to IBBA staff for daily entry into the database.
  • Require the notation of current genetic condition status in the IBBA system as is currently done with known Angus issues in the pedigrees in our database.

2. The IBBA staff will perform a query of the database to determine pedigrees with potential genetic condition carrier animals linked to known Angus and Brangus carrier animals for Developmental Duplication (DD), Arthrogryposis Multiplex (AM), Neuropathic Hydrocephalus (NH), Contractural Arachnodactyly (CA), Osteopetrosis (OS), and other known genetic conditions with available DNA tests.

3. The top 50 to 100 Brangus, Red Brangus, Ultrablack and/or Ultrared candidate sires and/or dams for the above mentioned genetic conditions will be identified and tested for such conditions. Owners of the selected animal(s) will pay for the genetic testing of their animal(s). If a candidate animal is owned by a non-IBBA member, IBBA will pay for the test(s).

4. All DNA tested animals and potential carrier animals will have notation included in the IBBA database using the following protocol:

  • The phrase “potential carrier” will refer to a genetic defect mutation (DD, AM, NH, CA and OS) and is used to refer to animals that are deemed impacted animals due to confirmed carriers of such genetic defects in their pedigree.
  • All recorded animals with impacted genetics shall remain recorded (registered, certified, appendix, Ultrablack, Ultrared, etc).
  • All progeny of identified carrier animals can be recorded without submitting to DNA testing if they do not become an AI sire or donor dam.
  • All animals used as an AI sire or donor dam that have been identified as a potential carrier (impacted genetics) for any defect will be required to be tested for such defect.
  • All animals with impacted animal pedigrees will have the below notation on each recording certificate, listed on individual animal detail page on IBBA website, and be required to have same notation in any sale catalog, printed material, electronic information, etc. where animal has name, number, pedigree, part of pedigree, picture, etc.

This animal has one or more ancestors genetically tested and identified to carry the genetic condition Developmental Duplication (DD) (or fill in the blank for other genetic conditions).

  • Once an animal with impacted genetics is tested for DD, AM, NH, CA or OS, the above mentioned notation will be deleted from the recording certificates, animal detail page on IBBA website, any and all other areas of former notation, and replaced as follows depending upon tested status:

Genetic Condition Status Designation Codes. 

DDPC, AMPC, NHPC, CAPC & OSPC Animal that hasn’t been tested for the genetic condition but has known carriers in pedigree
DDF, AMF, NHF, CAF & OSF Animal tested FREE of the genetic condition
DDC, AMC, NHC, CAC & OSC Animal tested as a CARRIER (one copy of the defective allele)
DDA, AMA, NHA, CAA & OSA animal tested as AFFECTED and carrying two copies of the defective allele

 

  • Any animal that will be used as an AI sire or donor dam with known impacted genetics will require testing and then identified with above notation regardless of tested and known free pedigrees.
  • Any animal that has been previously tested of other known genetic conditions will have those notations listed beside animals recorded name/registration number.
  • Any animal tested as a carrier animal or affected animal can be retested at a second lab to confirm first test results.

5.  The above mentioned policies go into effect for IBBA membership beginning February 1, 2014. In the meantime IBBA urges all public sales to initiate testing policies so that potential buyers and new members can be made aware of impacted genetics in the sale offerings.

6.  An effort to educate and inform the membership on various genetic conditions will be initiated and incorporated in the Brangus Journal and IBBA website.

 

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