A controversial Danish zoo that was once labelled a "hideous institution" for feeding a healthy giraffe to lions has released a video on YouTube showing a giraffe giving birth as part of its breeding programme.

Copenhagen Zoo prompted global outrage in 2014 after the body of a giraffe was chopped up in front of school children before being fed to lions.

Officials ignored pleas from across the world, including Yorkshire Wildlife Park and 20-000 people signing an online petition, to save two-year-old Marius and went ahead and put down the animal with a bolt gun.

The zoo's scientific director Bengt Holst subsequently received death threats over the decision to kill it.

At the time the zoo said the killing was necessary as it had been told by the European Association of Zoos and Aquaria (EAZA) the giraffe had genes which were too similar to the rest of their giraffes and wanted to prevent inbreeding and protect future generations.

Sadly, the zoo then hit the headlines once again after it went on to euthanise two lions and their two cubs to make way for a new male. The animal's remains were planned to be used for research.

"Because of the pride of lions' natural structure and behaviour, the zoo has had to euthanise the two old lions and two young lions who were not old enough to fend for themselves," the zoo said.

But there was no public dissection of the animals since "not all our animals are dissected in front of an audience", it added at the time.

People look on as a veterinarian cuts apart the giraffe Marius after it was killed in Copenhagen Zoo February 9, 2014.
People look on as a veterinarian cuts apart the giraffe Marius after it was killed in Copenhagen Zoo 9 February, 2014. Reuters