Abstract

Identification of the germ plasm resources of domestic cattle is important for future breeding programs because progress in selection for a production trait is dependent upon there being genetic variation for that trait within the population under selection. Relevant genetic variation decreases as a result of selection; genetic variation, in general, decreases whenever the effective population size is reduced. Today genetic variation within breeds is undoubtedly decreasing as a result of both selection for economically important traits and artificial insemination. In the future the genetic variation between breeds will become increasingly important as the raw material for genetic improvement. 

K. K Kidd

Proceedings of the World Congress on Genetics Applied to Livestock Production, Volume 1, Madrid, Spain, 321–328, 1974