Wagyu (, Hepburn: wagyū, ) is not the name of a single cattle breed. Today, the term usually refers to four established Japanese breeds of beef cattle: the Japanese Black, Japanese Brown, Japanese Polled, and Japanese Shorthorn. Historically, it was also used for native Japanese cattle; the surviving Mishima and Kuchinoshima cattle populations are not included among the four modern breeds.
Beginning in the late nineteenth century, these breeds were developed from regional native cattle crossed with imported stock. The timing of crossbreeding and the imported breeds involved varied by breed and region. The resulting cattle were later established as distinct breeds through selection and closed breeding.
The Japanese Black accounts for more than 90% of Wagyu cattle raised in Japan and is the main source of the highly marbled beef commonly associated with Wagyu. Its beef has finely distributed intramuscular fat known as sashi, a high proportion of monounsaturated fatty acids, and a distinctive sweet aroma that develops during cooking. The other three breeds generally produce less heavily marbled beef. Regional names such as Kobe beef, Matsusaka beef, Ōmi beef, and Yonezawa beef refer to brands defined by geographical origin and production or quality standards, not to additional cattle breeds. In Japan, beef carcasses are graded separately for meat yield and meat quality.
In Japan, labeling guidelines introduced in 2007 recommend that the designation Wagyu be used only for beef from cattle documented as one of the four breeds or specified crosses between them and confirmed as having been born and raised in Japan. Beginning in the 1970s, cattle and genetic material exported from Japan formed the basis of Wagyu herds in the United States and Australia. Breed associations in both countries maintain their own herdbooks and DNA-based parentage-verification systems, registering cattle according to their documented pedigree and proportion of Wagyu ancestry.
Definition The word Wagyu literally means "Japanese cattle" and does not denote a single breed. Before the modern breeds were established, Japan had regional populations of native cattle. After the Meiji Restoration in 1868, most were crossed for several generations with imported breeds, mainly British and continental European cattle. Two uncrossed native populations, the Mishima and Kuchinoshima cattle, survive and are considered to have remained free from European genetic influence.
In modern Japanese breed and meat classifications, Wagyu usually means four breeds: the Japanese Black, Japanese Brown, Japanese Polled, and Japanese Shorthorn. Beginning in the late nineteenth century, these breeds developed from regional native cattle crossed with imported stock. The imported breeds used differed by breed and region. The resulting cattle were later established as distinct breeds through selection and closed breeding.
After bovine spongiform encephalopathy (BSE) was first confirmed in Japan in 2001, the Beef Traceability Law was enacted in 2003. The system assigns each animal a ten-digit identification number and records its birth and movements; it applies to all cattle in Japan, not only Wagyu. This system is also used to verify the labeling requirements introduced for Wagyu beef in 2007. Under guidelines issued by the Ministry of Agriculture, Forestry and Fisheries, the designation Wagyu is recommended only for beef from cattle documented as one of the four breeds or specified crosses between them and confirmed as having been born and raised in Japan. Breed identity is established through breed-registration records, while birthplace and rearing history are checked through the traceability system.
This Wagyu designation is narrower than the Japanese origin category "domestic beef" (, kokusan-gyū), which generally applies when the animal was raised in Japan for longer than in any other country. Domestic beef therefore includes qualifying Wagyu as well as beef from Western-derived dairy breeds such as Holstein and Jersey, and from crosses between dairy and beef cattle. Beef from these dairy breeds and dairy–Wagyu crosses may be sold as domestic beef but does not qualify as Wagyu.
Wagyu herds were also established outside Japan from cattle and genetic material exported beginning in the 1970s, particularly in the United States and Australia. Registered cattle in both countries include fullblood animals descended entirely from Japanese foundation stock as well as animals crossbred with other breeds. Breed associations maintain separate registers for these categories and use documented pedigrees, Wagyu ancestry percentages, and DNA parentage testing to determine registration. These are cattle-registration systems, whereas the Japanese guideline applies to the labeling of beef and also includes domestic birth and rearing requirements.
Origin
In 1927, fossils of an ancient wild species of cow, Hanaizumi Moriushi (Leptobison hanaizumiensis), dating from the Paleolithic period about 20,000 years ago, were discovered at the Hanaizumi Site in Ichinoseki City, Iwate Prefecture. The Hanaizumi Moriushi is a species similar to the bison and is said to be close to the steppe bison (Bison priscus) lineage. Fossil bones of Aurochs (Bos primigenius) have also been found in Ichinoseki City. Since Hokkaido and Honshu were land-locked with the Eurasian continent during the Ice Age, these animals came from the continent via Hokkaido.
In addition, projectile points made from polished wild cattle bones have been found at the same site, although in small quantities, suggesting that humans existed during this period and that Hanaizumi Moriushi and aurochs were hunted.
At the Ohama Site in Goto City, Nagasaki Prefecture, cattle teeth dating to the middle Yayoi period were excavated. Among them were also processed cattle molars. However, this excavation was controversial because it contradicted the statement in Chen Shou's Records of the Three Kingdoms (Wajinden) that there were no cattle or horses in Japan. Later, radiocarbon dating of the excavated cattle molars yielded a date of around 40 AD (±90 years).
However, some in the Japanese archaeological community remain skeptical about the presence of cattle in Japan during the Yayoi period, and there is a persistent view that they were brought to Japan from the Korean peninsula by the toraijin, a group of people who came to Japan in the mid-5th century during the Kofun period. At the Nango-Ōhigashi site in Gose City, Nara Prefecture, excavations revealed cow bones believed to date back to the 5th century. At the Funamiya Kofun Tumulus (late 5th century) in Asago City, Hyōgo Prefecture, pieces of a cow-shaped haniwa (clay figurine), believed to be the oldest in Japan, have been excavated. In addition, a cow-shaped haniwa was excavated from the Hashida No. 1 Tumulus in Tawaramoto Town, Shiki-gun, Nara Prefecture in the first half of the 6th century, and was designated as an Important Cultural Property of Japan in 1958.
On the other hand, recent genetic studies have shown that Wagyu and Korean cattle (Hanwoo and others) differ greatly in their genetic information. Livestock cattle are divided into two major lineages: northern lineage cattle (Bos taurus) and Indian lineage cattle (Bos indicus), and both Wagyu and Korean cattle belong to the northern lineage and do not contain Indian lineage such as Zebu cattle.
However, in terms of mitochondrial DNA haplogroups, haplogroup T4 (East Asian type) is predominant in the Wagyu (Japanese Black) at about 65%, while haplogroup T3 (European type) is predominant in Korean cattle at 66–83%.
T4 is a haplogroup unique to East Asia that is not observed in Near Eastern, European, and African cattle, and T3 is the predominant haplogroup in European cattle, but T3 is also predominant in Korean cattle. This means that the present breed of Korean cattle is not the main ancestor of the Wagyu.
In addition, haplogroup P has additionally been detected in about 46% of the Japanese Shorthorn. It has been detected in many extinct European aurochs, but has only been found in a total of three current livestock cattle—one Chinese and two Korean—out of several thousand individuals in the database.
The Japanese Shorthorn was created by crossing the Nanbu cattle bred in the former Nanbu Domain territory in northeastern Japan (present-day Iwate Prefecture) with Shorthorns and other breeds imported from the United States, but P has not been detected in Shorthorns and is thought to be derived from the Nanbu cattle.
Fossils of Hanaizumi Moriushi and Aurochs have been found in Iwate Prefecture, but it is unclear if the Nanbu cattle were related to these. Haplogroup P has also been found in Chinese and Korean cattle, but it is extremely rare compared to T4. Therefore, it is suggested that the ancestors of the Nanbu cattle have a different origin from the ancestors of the Japanese Black in western Japan, where T4 is abundant, and that there is no single ancestor of the Wagyu.
History Cattle were brought to Japan from the Korean Peninsula or China, but archaeological and genetic studies have proposed different dates for their arrival, ranging from around the turn of the era to the 5th century.
Nara period (710–794) In 675, due to the influence of Buddhism, Emperor Tenmu issued a decree banning meat eating, and eating cattle was officially prohibited in Japan. However, a study of human excrement excavated from the Heijo Palace site has revealed that Japanese people in the Nara period (710–794) continued to eat cattle even after the prohibition. In addition, the Yoro Code (757) stipulates that when a government-owned horse or ox dies, it should be dismembered and the skin, brain, horns, and gall bladder removed, and if there is calculus bovis (gallstones), it should be delivered to the state. The Yoro Code also includes provisions for the sale of the hides and meat of horses and cattle, and there were distribution channels throughout Japan for buying and selling these items during the Nara period.
Heian and Kamakura periods (794–1333)
During the Heian period (794 – 1185), the main use of cattle was for bullock carts. Cattle that excelled in this use were called sun-gyū (駿牛, swift bulls) and were regarded as excellent bulls. Owning such an excellent bull became a source of pride for the aristocrats of Japan at that time.
The "Pictorial Record of Swift Bulls" (駿牛絵詞) which is believed to have been written around 1279, is said to be the world's oldest specialized book on bulls. In the same book, the names of 52 bulls are listed as swift bulls. At the time, the cattle from Iki Island in present-day Nagasaki Prefecture had the highest reputation as swift bulls, but they were temporarily destroyed by the Mongolian army during the Mongolian invasion, which killed them and used them as food.
From the Kamakura period (1185–1333) to the Muromachi period (1336–1573), farming using cattle and horses became popular mainly in western Japan, contributing greatly to the development of agriculture. In a complaint by a farmer in 1423, describing the wrongdoing of a manor administrator, it mentions that the farmer owned cattle and used them for farming.
Edo period (1603–1867)
Until about the time of the Meiji Restoration in 1868, cattle were used only as draught animals, in agriculture, forestry, mining and transport, and as a source of fertilizer. Milk consumption was unknown, and – for cultural and religious reasons – meat was not eaten. Cattle were highly prized and valuable, too expensive for a poor farmer to buy.
Japan was effectively isolated from the rest of the world from 1635 until 1854; there was no possibility of the intromission of foreign genes to the cattle population during this time.