Purebred Wagyu are a Western phenomena resulting from volume production requirements in the United States and Australia since the early 1990s. The crossbreed ‘grading up’ system from first outcross F1 through to F6 to achieve ‘purebred’ pedigree status is adopted from other Western breed society ‘breeding-up’ regimes targeting a specific pedigree status (EG: registered Boer goats in Australia can be bred up to full pedigree status over several generations using registered sires over non-Boer does at the first cross).
The system enables relatively rapid and inexpensive production of large breeding herds. It can also target the enhancement of traits perceived important in extensive pastoral systems (EG: maternal capabilities, tropical adaptation). Successful and consistent results within a herd are dependent on selection rigor (on the female side in particular). Given numerous outcross options, individual herd results might be expected to vary significantly. There is no Japanese equivalent to Australian purebred Wagyu herds.