No other breeds were involved. In fact, the breed was based on one (ONE!) hen and a rooster of the native land race that came from a closed flock with no "outside" blood (i.e., modern laying breeds). A highly controlled breeding program resulted in the modern varieties of the Jaer, the hobbyists breeding for both standard conformation (shows) and production, while the government gene bank focuses on production, vigor, etc. The large fowl varieties are thus truly a bird totally based on the original land race. The bantam variety, however, was developed using large-fowl Jaers, bantam Danish land race, and bantam OE.
