Within-herd phenotypic, genetic and environmental trend lines for beef cattle breeders

Computational procedures were developed to compute within-herd phenotypic, genetic and environmental trend lines on a breed-wide basis by using best linear unbiased estimates of fixed effects and predictors of random sire and dam genetic effects. Procedures were demonstrated by using weaning weight performance records from 20 herds participating in the American Angus Herd Improvement Program. Current evaluation procedures used by several beef breed associations make it possible to provide such information to breeders on a routine basis, along with within-herd breeding values. The within-herd genetic trends are relative to the national genetic evaluation base. Procedures are summarized in addition to presentation of within-herd trend lines for four of the 20 herds, demonstrating the utility of such information to breeders, along with a discussion of several alternative presentation formats.