Relative Efficiencies of Heritability Estimates Based on Regression of Offspring on Parent

Abstract

Consideration of the source and magnitude of the correlation ([rho]) between the deviations from regression associated with progeny of the same dam was based on a theoretical additive genetic model. It was found that [rho]= o, if and only if, h2 = O or 1. Conversely [rho] >O for O >l and reaches a maximum value of .067 when h2= .586. The effect of [rho] on the variance of heritability estimates based on offspring - parent regression was examined in five generations of a poultry population with unequal numbers of progeny per dam. Method 1 (phenotypic mean of progeny on the parent phenotype) consistently yielded the largest standard errors of the heritability estimates. Method 2 (the parents record repeated for each progeny record) and method 3 (the Kempthorne-Tanden weighted regression technique) were approximately equal in efficiency for these data.