The first African elephant calf conceived after artificial insemination has been born alive and well in Indianapolis Zoo, US.

Kubwa, the 24-year-old mother, was in labour for an hour and delivered a 90- kilogram (200-pound) female calf on Monday.

Keepers at the zoo cheered the successful end of a 22-month pregnancy. "The labour went extremely well and extremely fast," said Karen Burns, of the Indianapolis Zoological Society. "I think there's a lot of mothers out there who wish their labour was an hour."

The newborn has not yet been named but was described as "very strong" and was able to get up and walk within the first half-hour of its life.

The calf's first few days will be crucial as its bonds with its mother and the process of nursing begins.

Bonding crucial

"It's still too early to determine if she'll nurse. That's the next milestone for her and we're hopeful," said Ms Burns.

Being raised by its own parent, rather than zookeepers, is one very important factor in determining whether the calf will survive. The odds are not favourable.

Since 1985, there have been nine conceptions among elephants in captivity in North America. Four calves were lost in delivery, and only one of the remaining five survived past 11 months.

Kubwa is only the second elephant in the world to be artificially inseminated successfully - the first was an Asian elephant in Missouri. Another elephant in Indianapolis zoo, 18-year-old Ivory, has also been impregnated in the same way and is due to give birth on 29 August.

Debbie Olson, Director of Elephant Conservation and Science Programs at the Indianapolis Zoo, said the conception and successful birth of this elephant calf was extremely important to the long-term viability of African elephants in human care.

Artificial insemination

Nick Ellerton, curator at Knowsley Safari Park, England, told BBC News Online: "Artificial insemination is wonderful but there is no argument that the best thing is a bull elephant.

"However, there is a shortage of proven bulls and there are also problems managing bulls. Also, if there is a small genetic base, it is much easier to transport semen around the world's zoos, rather than the elephants themselves."

Mr Ellerton said both the male and female elephants have to be very well-trained for the artificial insemination procedure but he thought their welfare was not being compromised.

The artificial insemination technique used was perfected by the Institute for Zoo Biology and Wildlife Research (IZW) in Berlin, Germany, and was carried out in the Indianapolis elephants by Dr Thomas Hildebrandt and Frank Goeritz.