AAA Identifies New Genetic Condition


According to a letter sent out to Angus breeders by the American Angus Association, their Board of Directors has now voted unanimously to recognize “Developmental Duplication,” or DD, as a genetic condition.  Inherited as a simple recessive, Dr. Jonathan E. Beever explains that the majority of calves exhibiting this trait are born with additional limbs.  This typically is a duplication of the front legs and originating from the neck and shoulder region.  With the exception of mortality and calving difficulty, calves with DD often thrive.


This picture, from Flock and Herd, shows DD, formerly called polymelia, expression in an Angus calf.


Newly-adopted policy by the Board determines that producers are not mandated to test potential DD carriers as a precondition of continued or prospective registration.  Instead, the letter states that they’ll assume members will follow sound breeding decisions and make strategic use of DNA testing in dealing with this genetic condition.  


This change in policy represents an evolution in the Angus Association’s approach to genetic defects since the discovery of arthrogryposis multiplex (curly calf) and neuropathic hydrocephalus (water head) in 2008.  Phil Trowbridge, President of the American Angus Association, explains that shift in mindset in Wednesday’s letter.


CLICK HERE for more information on DD from Dr. Jonathan Beever including a list of preliminary test results for 1,099 Angus bulls.




© Northern Ag Network 

Haylie Shipp




Notify of
Inline Feedbacks
View all comments
Would love your thoughts, please comment.x