A new genetic disorder called Arthrogryposis Multiplex (AM), also known as Curly Calf Syndrome, has been identified in Angus cattle.  This disorder can cause calves to be born with twisted spines and curled up legs, which is why the generic term for the genetic defect is Curly Calf. 

Curly Calf is a lethal genetic abnormality that is caused by a recessive inheritance.  What this means is that both the sire and the dam have to be carriers of the gene in order for it to express itself.  According to the American Angus Association, it appears that the genetic abnormality comes from a bull by the name of GAR Precision 1680.  At least most of the calves that have been born with this problem have 1680 on both sides of the pedigree.  However, the exact source of where the genetic abnormality originated is unknown.

If there is any good news in this situation it is that the genetic problem is a recessive inheritance.  As was indicated earlier, both the cow and the bull have to be carriers.  If  a bull and a cow are mated and both are carriers, there is a 25% chance that the calf will have Curly Calf and be born dead.  There is a 50% chance that the offspring will be carriers of the recessive gene but not exhibit the symptoms and there is a 25% chance that the calf will be born and not be a carrier.

So what should you do if you are a commercial producer that has been using Angus genetics in your herd?  According to Dr. John Hall, University of Idaho Extension Beef Specialist at the Nancy M. Cummings Research and Extension Center in Salmon, producers need to implement a strategy for managing their genetics.  Dr. Hall recommends that producers continue a planned crossbreeding program.  He recommends that producers continue to use Angus genetics in the crossbreeding program. 

Dr. Hall also recommends that producers need to pay more attention to the pedigree of their cows and bulls.  If Precision 1680 is in the pedigree of the cows or heifers you have on the ranch, there is no need to cull them from the herd.  However, producers will need to mate them to bulls that do not have Precision in the pedigree.  Dr. Hall does not recommend that commercial producers test their herd for the AM gene when a commercial test becomes available.  He indicated that Angus breeders will soon be able to provide bulls that are tested for the AM gene.  Purchasing AM free bulls will eliminate the problem.

The American Angus Association and US Angus breeders have done a great job in the last few months of trying to inform the industry about this disorder and identifying possible carriers of the defect.  Producers do not need to panic at this time.  The best advice is to adopt the strategies outlined by Dr. Hall and stay informed on this topic.