The leading natural cause of death in beef and dairy cattle is Bovine Respiratory Disease (BRD), a combination of viral and bacterial infections. The disease causes losses of more than a million animals and $692 million annually to dairy and beef farmers.
To tackle the disease, USDA funded a multi-institutional research program to search for a proven genetic link that helps identify and predict resistance to the disease. The team included Texas A&M University, Colorado State University, University of California - Davis, Washington State University, University of Missouri, New Mexico State University, and others.
Scientists took samples from several thousand healthy and sick calves and then tested the DNA to find variations between the animals. Finding and tying genetic markers to the actual gene that is causing the variation helps breeders to incorporate the information into the estimated breeding value of cattle.
The process is beginning to yield results with dairy cattle, which tend to have more genetic uniformity. It is more complicated for beef cattle, since there is a wider range of breeds and crossbreeds. Researchers are sequencing the entire genome of 60 beef animals to identify the genetic link to the BRD causal mutation.
By identifying resistant animals through their genetic profile, breeders can reduce the prevalence of the disease and death in cattle, reduce antibiotic use, and improve ranchers’ bottom lines.