At their recent meeting, the Holstein Association USA board of directors voted to declare Brachyspina as an undesirable recessive trait in the Holstein breed, and approved the recording of testing results on Holstein Association USA pedigrees and other performance products. Brachyspina is expressed when an animal is homozygous for the undesirable allele, meaning that two carrier animals have been mated. Holsteins that are known carriers will be labeled with the code BY, and tested non-carriers will be labeled TY.

“It’s our belief that labeling the carriers of Brachyspina will give breeders the information they need to dramatically reduce the frequency of the undesirable recessive allele in the Holstein breed. In the interim, top genetic animals, identified with BY, can still be used with some attention given to the pedigree of the potential mate,” said Dr. Tom Lawlor, Holstein Association USA director of research and development.

It is estimated that approximately 6 percent of Holstein cattle carry the gene for Brachyspina, which can cause embryonic death, stillbirth or other physical deformities. In a random mating population, it’s estimated that 1 out of 1,000 matings would result in early embryonic death and an increase in days open. PD

—From Holstein Association USA, Inc. news release