Tokyo, Oct 10 (IANS): The world's first cloned cow, named Kaga, has died due to natural causes aged 21 years and three months at the same research centre in Japan where it was born, government sources said on Thursday.

Kaga was born in July 1998 at the Ishikawa prefectural livestock research centre as part of a joint research project with Kinki University - now known as the Kindai University - using the same technology used to clone British sheep Dolly two years earlier, reports Efe news.

Twin cows Kaga and Noto were born as a result of Japanese research on bovine cloning, with the latter having died in May 2018.

Kaga, who died of old age (the normal lifespan of cows is 20-25 years), began to have problems standing up in September and was given nutritional supplements and an anti-inflammatory drip in its legs, officials of the research centre told local news agency Kyodo.

However, the cow could no longer stand in early October and was pronounced dead on Wednesday.

In 2006, a total of 14 cloned cows had been produced at the Ishikawa centre, but the research - originally aimed at improving the production of meat and milk - was scaled back after the distribution of cloned cow meat was restricted in the country in 2009.

The cloned cattle in Ishikawa have been kept to study the life expectancy among such animals.