The bloodlines within a breed can be very important reservoirs of genetic variation, and managing these within the overall breed is important to long-term breed survival.
(Sponenberg, Beranger, and Martin 2017)

Black and Tan English Shepherds
Old-fashioned Black and Tan English Shepherd Association
The bloodlines within a breed can be very important reservoirs of genetic variation, and managing these within the overall breed is important to long-term breed survival.
(Sponenberg, Beranger, and Martin 2017)