Investigations on merging breeds in genetic conservation schemes.
Genetic diversity within livestock species is threatened by extinction of breeds and by genetic drift; the need to conserve genetic diversity by conservation schemes is widely accepted. To maintain the between-breed diversity, breeds are usually kept separately in live conservation schemes. However, in some cases it might be very difficult or even impossible to conserve a highly endangered breed in a closed population. If this breed is important for diversity, it might be beneficial to merge it with one or more breeds to conserve a part of the diversity that is contributed by this breed. The present study introduces a general framework that may enable one to decide when it is beneficial to form a synthetic breed that includes highly endangered breeds to maximize conserved diversity and when to keep the breeds separate. Expected future diversities were estimated using a kinship-based diversity measure together with extinction probabilities of the breeds. Using a small hypothetical data set, the pattern of diversity and its 2 components, within-breed and between-breed diversity, were analyzed in detail when forming a synthetic breed. The suggested approach was applied to a data set of 13 central European red and yellow cattle breeds. The results suggested forming a synthetic breed by combining a nonendangered breed with 1 of the 2 highly endangered breeds, which would result in a slight increase in conserved diversity.
Bennewitz
J
J
Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Box 1432, As, Norway. jorn.bennewitz@umb.no
Simianer
H
H
Meuwissen
T H E
TH
D000818:Animals; D001947:Breeding / Q000379:methods*; D002417:Cattle / Q000235:genetics*; D003247:Conservation of Natural Resources; D003433:Crosses, Genetic; D005260:Female; D005787:Gene Frequency; D040961:Genetic Drift; D014644:Genetic Variation; D008297:Male; D008957:Models, Genetic