A general procedure for predicting rates of inbreeding in populations undergoing mass selection

P. Bijma, J.A.M. Van Arendonk, John Woolliams

Research output: Contribution to journalArticlepeer-review


Predictions of rates of inbreeding (Delta F), based on the concept of long-term genetic contributions assuming the infinitesimal model, are developed for populations with discrete or overlapping generations undergoing mass selection. Phenotypes of individuals are assumed to be recorded prior to reproductive age and to remain constant over time. The prediction method accounts for inheritance of selective advantage both within and between age classes and for changing selection intensities with age. Terms corresponding to previous methods that assume constant selection intensity with age are identified. Predictions are accurate (relative errors less than or equal to 8%), except for cases with extreme selection intensities in females in combination with high heritability. With overlapping generations Delta F reaches a maximum when parents are equally distributed over age classes, which is mainly due to selection of the same individuals in consecutive years. Delta F/year decreases much more slowly compared to Delta F/generation as the number of younger individuals increases, whereas the decrease is more similar as the number of older individuals increases. The minimum Delta F (per year or per generation) is obtained when most parents were in the later age classes, which is mainly due to an increased number of parents per generation. With overlapping generations, the relationship between heritability; and Delta F is dependent on the age structure of the population.
Original languageUndefined/Unknown
Pages (from-to)1865-1877
Number of pages13
Issue number4
Publication statusPublished - 2000


  • overlapping generations effective size breeding programs index selection families

Cite this