In Japan, skin tissue was taken from the ear of a cloned bull last April when the animal was four months old. Those cells were fused with an unfertilized egg that had been stripped of its nucleus and placed in the womb of a cow. The resulting bull calf weighed nearly 100 pounds at birth. The primary purpose of the Institute's project is to produce tasty beef. If there's a stud that's of the highest quality, we want that bull to be available more widely.
Cloning also reduces the amount of time needed for breeding.
The tissues of an animal as young as three months can be used for cloning, while cows do not mate naturally until they are about 14 months old. Cloned beef is already on sale in Japanese supermarkets, although the government's announcement last April that it had already allowed cloned beef to be sold unmarked for at least two years sparked a beef boycott nationwide.