Co-Authors:
Israel, C., Department of Genetics, Hebrew University of Jerusalem, Jerusalem 91904, Israel
Weller, J.I., Institute of Animal Sciences, A.R.O., Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Abstract:
Two markers bracketing a quantitative gene with a substitution effect of 0.5 or 0.3 phenotypic standard deviations with recombination frequencies of 0.1 and 0.2 with the quantitative gene were simulated. Ten simulated populations with 20 sires heterozygous for both markers with varying numbers of daughters were analyzed for each combination of gene effect and allele frequency. Sire quantitative gene genotype was determined by the regression of the daughter genetic evaluations on their paternal markers. Sires were determined to be heterozygous by an F-test of the model to residual sum of squares. Three values for probability of type I error were simulated: 0.05, 0.1 and 0.20. Marker allele effects were then included in an animal model analysis of the simulated populations. The algorithm of Whittaker et al. [Heredity 77 (1996) 23] was used to estimate gene effects and location. Estimates for both effect and location of the quantitative gene were nearly unbiased. Cow genetic evaluations were always more accurate by the model proposed than by a standard animal model. The increase of genetic gain due to marker-assisted selection of young sires, as compared to dam selection was between 2% and 15%. Type I error rate did not appreciably affect selection decisions. © 2003 Elsevier B.V. All rights reserved.