Beef Cattle Breeding and Its Trend in Japan

다국어 초록 (Multilingual Abstract)

As beef cattle breeds we have Japanese Black, Japanese Brown Kumamoto and Kouchi, Japanese Shorthorn, Japanese Polled, Aberdeen Angus, Hereford and so on. The first five breeds are indigenous of Japan, though they had been crossed with some European breeds about hundred years ago, and called WAGYU. Beef is produced from the beef breeds, dairy breed, i.e., Holstein and their crossbred. Judging had been adopted as a means for improvement of the WAGYU cattle until recently. It had been believed that animals with good visual quality, that is, soft and elastic hides, fine and soft hair, gook born, fine bones in legs and clean-cut face, would produce high quality beef. However, performance and progeny testing programs for meat productivity were established and put to use as station system in 1968. The testing station was centralized only within prefecture. The results of the testing programs were not always successful. Then, the breeding scheme with field recording system for beef cattle was established recently so that dramatic responses for carcass traits are about to appear in some prefectures. The results obtained by the genome analysis have been considering to be introduced to marker-assisted selection, gene diagnosis for genetic diseases and so on. On the other hand, beef has been supplied increasingly from dairy herd since 1960's. At first, dairy bull calves were reared and fattened. Secondly dairy cows of genetically low performance have become top be crossed with WAGYU sire and the F₁ progeny were used as feeder cattle. Recently, the F₁ heifers are considering to be crossed with WAGYU bull again.