Genetics, environment and bovine respiratory disease.

The heritability estimates for resistance and/or susceptibility to bovine respiratory disease (BRD) are small, suggesting response to direct selection will be slow. The number of mammalian genetic markers associated with resistance to specific pathogens or improved immunity is increasing and will provide additional information for developing selection criteria for producing animals with an innate resistance to BRD. Environmental and management factors play significant roles in the prevalence of BRD and must be considered in a holistic approach to reducing BRD. Although no single solution for preventing BRD is likely to be discovered in the immediate future, the long-term outlook appears very promising.