A note on calculating the benefit from replacing one breed by another

Abstract

ABSTRACTFormulae are derived to calculate the genetic merit of a commercial population during replacement of one breed by another, based on the rates of genetic change in the old and new breeds, the initial difference between the breeds, the lag between the first use of replacement stock and the appearance of their genes in commercial progeny and the effect of replacement on the old breed improvement scheme. By comparing the merit of the population with and without replacement the value of a change in breed can be assessed. The method is illustrated with an example from pig breeding.