Brachyspina - undesirable recessive trait in holsteins
Holstein Association USA board of directors recently voted to declare Brachyspina as an undesirable recessive trait in the Holstein breed.
April 6, 2011 - Author: Kathy Lee, Michigan State University Extension
Holstein Association USA recently announced that its board of directors voted to declare Brachyspina as an undesirable recessive trait in the Holstein breed. Testing results for the trait will be recorded on Holstein Association USA pedigrees and other performance products.
Brachyspina is a single gene recessive trait, which can cause embryonic death, stillbirth, or other physical deformities. It is characterized by a shortened spinal cord, long legs, and abnormal organs in calves. Approximately 6% of Holstein cattle are estimated to carry the gene for Brachyspina. Holstein Association USA has indicated that in a random mating population, one out of 1,000 matings would be predicted to result in early embryonic death, and therefore, an increase in days open.
Both parents must be carriers of the gene for Brachyspina to produce an affected calf, which would occur 25% of the time, on average, when carrier parents are mated. Known carriers will be designated by the code BY, and animals tested as non-carriers will be labeled TY.
Currently a marker test is used to identify carriers of the Brachyspina gene. With this marker test, a carrier of Brachyspina can be determined with 95% reliability. In the future, bulls that are carriers likely will not enter progeny test programs.
The Brachyspina syndrome was first described in 2006 by Danish researchers at the University of Copenhagen.