Preservation breeding is an attempt by many animal breeders

Animal breeding

Animal breeding is a branch of animal science that addresses the evaluation of the genetic value of domestic livestock...

 to preserve bloodlines of animals, either of a rare breed, or of rare pedigrees within a breed. One purpose of preservation breeding is to protect genetic diversity

Genetic diversity

Genetic diversity, the level of biodiversity, refers to the total number of genetic characteristics in the genetic makeup of a species. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary....

within a species, another is to preserve valuable genetic traits that may not be popular or in fashion in the present, but may be of great value in the future.