Comparison of Heritability Estimates from Daughter-Dam Regression and Paternal Half-Sib Correlation

Abstract

Analysis of 60,000 pairs of daughter and dam first-lactation records expressed as deviations from herd-mate averages for five breeds yielded markedly different heritability estimates from daughter-dam regression than from paternal half-sib correlation. These results suggest that 18% of the within-herd variation is due to genetic maternal effects. The same records analyzed as mature equivalent records and not as deviations but by a sire by herd model did not show this difference. Confounding between year and sire effects probably biased the intra-class correlation estimates upward in the latter analysis, since year effects were not included in the statistical model. © 1965, American Dairy Science Association. All rights reserved.