Milestones in beef cattle genetic evaluation.

National beef cattle genetic evaluation programs have evolved in the United States over the last 35 yr to create important tools that are part of sustainable breeding programs. The history of national beef cattle genetic evaluation programs has lessons to offer the next generation of researchers as new approaches in molecular genetics and decision support are developed. Through a series of complex and intricate pressures from technology and organizational challenges, national cattle evaluation programs continue to grow in importance and impact. Development of enabling technologies and the interface of the disciplines of computer science, numerical methods, statistics, and quantitative genetics have created an example of how academics, government, and industry can work together to create more effective solutions to technical problems. The advent of mixed model procedures was complemented by a series of breakthrough discoveries that made what was previously considered intractable a reality. The creation of modern genetic evaluation procedures has followed a path characterized by a steady and constant approach to identification and solution for each technical problem encountered. At its core, the driving force for the evolution has been the need to constantly improve the accuracy of the predictions of genetic merit for breeding stock, especially young animals. Sensible approaches, such as the principle of economically relevant traits, were developed that created the rules to be followed as the programs grew. However, the current systems are far from complete or perfect. Modern genetic evaluation programs have a long way to go, and a great deal of improvement in the accuracy of prediction is still possible. But the greatest challenge remains: the need to understand that genetic predictions are only parameters for decision support procedures and not an end in themselves.