ABSTRACT
Maternal selection for optimum productivity in diverse environments is a formidable challenge for beef-cattle seed stock producers. Optimum productivity in a cow can be defined as consistent efficient production of a product of economic value. Crossbreeding systems in the commercial industry correctly use terminal sires on maternal cow herds. Many of the traditional maternal female seed stock sources that were available at the beginning of the performance movement have been incorporated into terminal sire upgrading and crossbreeding programs. The goal of beef improvement has been to help seed stock producers develop maximum potential for growth —which results in an increase in size without an upper limit. Cows of different sizes can possess inherent traits that make them efficient producers. Factors that increase cow size but are negative to optimum reproduction are: slower sexual maturity, irregular calving, and excessive supplementary feeding. Maternal analyses = total efficiency generates meaningful selection criteria and management assistance from a minimum number of weights and measurements.
