Complex Vertebral Malformation (CVM)


CVM is a genetic defect that first was identified in Denmark in 2000. The first peer-reviewed scientific article summarizing this genetic defect appeared in the July 2001 issue of The Journal of Veterinary Diagnostic Investigation. In August 2001, Danish researchers announced that they had discovered the gene that causes CVM.

Since then Danish researchers now have licensed several laboratories to conduct a diagnostic test that identifies whether an animal has the actual gene that can cause CVM. Between September 2001 and March 2002, Select Sires conducted CVM testing through Van Haeringen Laboratories, the laboratory in The Netherlands that is licensed to conduct CVM testing. Since March 2002, all CMV testing conducted by Select Sires has been through ImmGen Inc., College Station, Texas.

Economic Impact of CVM

To calculate the impact of CVM, we can make these assumptions:

  • Based on research to date, it appears that when a fetus is CVM-affected, it results in abortion in about 75 percent of the cases and a stillborn calf 25 percent of the time.

  • The gene frequency for CVM is about seven percent.

  • Approximately four percent of the pregnancies created by randomly mating a CVM-carrier bull to the current cow population would be affected with CVM.

Based on these assumptions, to recoup the losses from increased abortions and stillborn calves, the worst-case scenario is that each remaining daughter of a CVM-carrier bull will need to generate about $75 more during her lifetime if the CVM-carrier bull is used randomly throughout the herd. This is a significant cost, but it can be overcome by leveraging advantages in other selection traits and by avoiding matings in which there are carriers on both sides of the pedigree. By maintaining pedigree information and using a mating program like Select Mating Service™ (SMS™) to avoid inbreeding, producers can reduce the incidence of CVM in their herds.

™Select Mating Service and SMS are trademarks of Select Sires Inc.