Genetic and economic evaluation of genetic improvement schemes in pigs ndash; I. Methodology with an application to a three-way crossbreeding scheme

摘要

A method is presented for evaluating selection strategies for a three-way cross in pigs. Multitrait selection isconsidered. The criteria of evaluation are the annual genetic gains in the breeding objeetive and its componenttraits, and the profit which is the net present value of return from investment in the scheme.Selection in the sire line (Pietrain) contributes higher returns than selection in the dam lines. Meat percentage isthe dominant trait in the sire line and has the highest impact on the breeding objective. The sire line ischaracterised by a negligible economic weight for the reproduction trait and has higher weights than dam linesfor growth and carcass traits. The higher discounted economic values of these traits for Pietrain compared tothose for dam lines deviate considerably from the equal weighting often applied in practical breedingprogrammes.