Mixed Model Methodology for Farm and Ranch Beef Cattle Testing Programs

TLDR

Mixed‑model methods can efficiently use beef cattle performance data, but high computational demands have limited their routine use. The study demonstrates applying mixed‑model procedures to weaning weight and postweaning gain records to estimate breeding values for weaning weight (direct and maternal) and yearling weight. The authors simplify computation by using an equivalent model that greatly reduces the number of equations needed. The procedures offer advantages for genetic evaluation programs.

Abstract

Although mixed model methods for multiple traits offer a means for efficient utilization of beef cattle performance test data, excessive computational requirements have precluded routine application. This paper describes how these procedures can be applied to weaning weight and postweaning gain records to estimate breeding values for weaning weight (direct and maternal) and yearling weight. Computational simplifications are emphasized. These include the use of an equivalent model which allows a great reduction in the number of equations that need to be solved. Advantages of these procedures for a genetic evaluation program are discussed.