Abstract:

Selecting animals for breeding based on their selection index should maximize the genetic merit of a population in future generations. Selection index theory assumes traditionally that the vector with breeding values of an animal is a sufficient statistic from which the optimum selection index can be calculated. It is, however, intuitively obvious that selecting outcross animals for breeding can increase the genetic variance in future generations, and can thus accelerate future genetic progress. This calls the traditional assumption into question. It is shown that the optimum selection index for the additive model depends not only on the breeding values, but also on the allele contents of major QTLs, and on the kinship of the individual with the population.