Abstract:
This study was conducted on 8,527 Holstein Friesian cows born to 242 sires from seven origins
and 1430 dams that calved between 1974 and 2006, archived for 32 years, with the objectives of
evaluating the relationship and inbreeding, the inbreeding effects on the performances, and
proposing the future mating strategy. The relationship among the small herd of Holstein Friesian
dairy cattle at the Holeta Bull Dam farm was estimated by the RelaX2 software package. The traits
considered in this study were birth weight (BWT), age at first calving (AFC), calving interval (CI),
days open (DO), number of services per conception (NSC), lactation milk yield (LMY), lactation
length (LL), and 305 days milk yield (305-dMY). The least squares mean of non-genetic factors
affecting these traits were analyzed by fitting GLM procedures of SAS version 9.3 (2011). The
genetic parameters and breeding values for BWT, reproductive, and milk production traits were
estimated using the ASReml statistical package. The univariate analysis was undertaken for each
trait for estimation of heritability (h 2 ±SE), repeatability (r±SE), and estimated breeding values
(EBV), whereas genetic and phenotypic correlations were estimated using bivariate analysis
