Technical Abstract: The USDA Animal Improvement Programs Laboratory conducts research to discover, test, and implement improved genetic evaluation techniques for economically important traits of dairy cattle. While the dairy industry has been extraordinarily successful in improving genetic merit for yield, that has come at the cost of fitness traits such as udder health and fertility. The antagonistic relationships among these traits demonstrate the danger of single-trait selection programs. Geneticists are now studying ways to improve the health of the national dairy herd. Many challenges must be overcome before useful tools to this end can be provided, including a lack of standardization in disease recording and the absence of a national health database. Careful record-keeping, correct use of culling codes, selection of bulls with desirable PTA for calving ease and net merit, and patience on the part of the industry are needed to help this effort succeed.