Sire referencing schemes were first introduced in Australian sheep breeds with the aim, as the name suggests, of referencing sires used In different flocks, where the flocks tended to be large and sires tended to be selected from within the flock. However, sire referencing schemes can provide additional benefits when flock or herd size is small, since In this situation sires at least must be purchased from outside from other breeders to avoid problems of inbreeding; sire reference schemes help ensure that superior stock from other breeders can be identified objectively.