Since 1955, the profile of the typical Japanese Wagyu cow/calf producer has changed from a small farmhouse operation averaging about 1.5 head per farm to an intensive medium size operation with about 35 breeders. A very large breeding herd would total about 120 females. In the same period, farm numbers declined 92% from 1,066,000 to 85,600.
With only about 1.4% of Japanese agricultural land under pasture (Longworth, 1981), cattle are raised intensively in sheds on rations of hay and grain, without any seasonal breeding pattern. Routine treatments include worming, clostridium vaccination and vitamin supplements.
Joining is overwhelmingly by artificial insemination. In parallel, in utero embryo production and transfer has been used extensively to increase the speed of herd genetic improvement, with an important objective being production of superior females for feeder production herds.
More recently, in vitro embryo technologies have enjoyed buoyant demand – due to the decline of Japanese Black Wagyu breeding female numbers (see graph below) and, particularly, insatiable demand for a narrow band of high performance Wagyu genetics.
IVF technology has been available for over 20 years and is mainly associated with human artificial reproduction. (For a plain English explanation see: Lewis . Or: Gordon, I., 2003. ‘Laboratory Production Of Cattle Embryos’, 2nd Edtn. CABI.)
Only the very high prices available to cattle producers enable IVF application in contemporary Japanese commercial programs. (Comparatively, current fullblood prices in Australia predicate that even in utero ET calves sold as feeders usually generate a loss for the producer.)
In Japanese IVF programs, unfertilised embryos are often collected from fullblood females at slaughter. These embryos can be registered (where the female bloodline is identified) or unregistered (female bloodline is unknown). The embryos are fertilized in glass (in vitro), and either frozen for later transfer or prepared for immediate transfer.
As a result of the use of sexed semen (widely used in Western dairy production), undamaged, sexed embryos are available for either freezing or transfer. Embryos are frequently transferred into dairy cattle, extending a FB breeder herd de facto and maximizing the value of production from dairy breeders.
Comparatively, embryo sexing in standard in utero embryo production programs results in damage that normally demands immediate fresh transfer after flushing/sexing.
Non registerable embryos are used mainly in feeder cattle production programs; registrable embryos in breeding cattle programs. As the price list below indicates, this technology is now mainstream in Japanese Wagyu breeding programs. Prices in JP Yen.
Price List of IVF Embryos at LIAJ
|Bull Name||Embryo Type|
|Non Registrable Embryo||Registrable Embryo|
Non Sex Identified
Non Sex Identified
Data Source: LIAJ
A potentially negative aspect of this narrow genetic focus in Japanese Wagyu breeding is loss of genetic diversity. A number of scientific commentators have now identified the resultant inbreeding as a potential threat to the future of the Japanese Black herd.