title: Impact of the use of cryobank samples in a selected cattle breed: a simulation study.
abstract: BACKGROUND
  High selection pressure on domestic cattle has led to an undesirable increase in inbreeding, as well as to the deterioration of some functional traits which are indirectly selected. Semen stored in a cryobank may be a useful way to redirect selection or limit the loss of genetic diversity in a selected breed. The purpose of this study was to analyse the efficiency of current cryobank sampling methods, by investigating the benefits of using cryopreserved semen in a selection scheme several generations after the semen was collected.
  
  
  METHODS
  The theoretical impact of using cryopreserved semen in a selection scheme of a dairy cattle breed was investigated by simulating various scenarios involving two negatively correlated traits and a change in genetic variability of the breed.
  
  
  RESULTS
  Our results indicate that using cryopreserved semen to redirect selection will have an impact on negatively selected traits only if it is combined with major changes in selection objectives or practices. If the purpose is to increase genetic diversity in the breed, it can be a viable option.
  
  
  CONCLUSIONS
  Using cryopreserved semen to redirect selection or to improve genetic diversity should be carried out with caution, by considering the pros and cons of prospective changes in genetic diversity and the value of the selected traits. However, the use of genomic information should lead to more interesting perspectives to choose which animals to store in a cryobank and to increase the value of cryobank collections for selected breeds.
authors: AgroParisTech, UMR 1313 Génétique Animale et Biologie Intégrative, 16 rue Claude Bernard, 75231 Paris 05, France. gregoire.leroy@agroparistech.fr
authors: Grégoire
authors: G
authors: Leroy
authors: Coralie
authors: C
authors: Danchin-Burge
authors: Etienne
authors: E
authors: Verrier
mesh_terms: D000465:Algorithms; D000818:Animals; D001947:Breeding; D002417:Cattle / Q000235:genetics*; D003198:Computer Simulation; D005260:Female; D014644:Genetic Variation; D008297:Male; D008957:Models, Genetic; D012641:Selection, Genetic; D013074:Sperm Banks