Variance component and heritability estimates of early growth traits in the Elsenburg Dormer sheep stud

Author: J.B. van Wyk, G.J. Erasmus and K.V. Konstantinov
Year: 1993
Issue: 3
Volume: 23
Page: 72 - 76

Records of the Elsenburg stud where the Dormer sheep breed originated in 1941, were analysed from 1941 to 1990 to investigate non-genetic factors contributing to early growth traits. The fixed effects, identified as having a significant (P < 0.01) effect on birth weight, weaning weight, average daily gain and Kleiber ratio, were year-season, age of dam, sex, birth status and level of inbreeding. Although some significant interactions were found, they were subsequently ignored owing to their very small effects. A model best describing the data, which can be used for further analyses, is constructed and discussed. It is advocated that the uniqueness of each population and situation necessitates such an analysis in each specific case.


Keywords: Dormer sheep, heritability, maternal effect, REML, variance components
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