Children watch as Marius, a male giraffe, is dissected at the Copenhagen Zoo in Denmark, Feb. 9, 2014. Rasmus Flindt Pedersen/AP

Saying it needed to prevent inbreeding, the Copenhagen Zoo killed a 2-year-old giraffe and fed its remains to lions as visitors watched, ignoring a petition signed by thousands and offers from other zoos and a private individual to save the animal. Neutering Marius was not an option, zoo officials said.

Marius, a healthy male, was put down Sunday using a bolt pistol, said zoo spokesman Tobias Stenbaek Bro. Visitors, including children, were invited to watch while the giraffe was then skinned and fed to the lions.

Marius’ plight triggered a wave of online protests and renewed debate about the conditions of zoo animals. Before he was killed, an online petition to save him received more than 20,000 signatures.

News of Marius’ killing Sunday sparked outrage and sadness among social-media users, many decrying the zoo’s decision.

But the public feeding of Marius’ remains to the lions was popular at Copenhagen Zoo. Stenbaek Bro said it allowed parents to decide whether their children should watch what the zoo regards as an important display of scientific knowledge about animals.

“I’m actually proud because I think we have given children a huge understanding of the anatomy of a giraffe that they wouldn’t have had from watching a giraffe in a photo,” Stenbaek Bro said in a telephone interview with The Associated Press.

He said the zoo, which has seven giraffes left, followed the recommendation of the European Association of Zoos and Aquaria (EAZA) to put down Marius because there already are a lot of giraffes with similar genes in the organization’s breeding program.

The Amsterdam-based EAZA has 347 members, including many large zoos in European capitals, and works to conserve global biodiversity.

Stenbaek Bro said that EAZA membership isn’t mandatory but that most responsible zoos are members of the organization.

He said his zoo had turned down offers from other ones to take Marius and an offer from a private individual who wanted to buy the giraffe for $680,000.

He said a significant element of EAZA membership is that the zoos don’t own the animals but govern them and therefore can’t sell them to any party outside the organization that doesn’t follow the same rules.

He also said it is important for the breeding programs to work.

Bengt Holst, the Copenhagen Zoo’s scientific director, said it turned down an offer from Yorkshire Wildlife Park in Britain, which is an EAZA member, because Marius’ older brother lives there and the park’s space could be better used by a “genetically more valuable giraffe.”

Yorkshire Wildlife Park said it called the zoo on Saturday with a last-minute offer to house Marius in a new giraffe house with room for an extra male. It said that it was saddened by the killing of Marius but that, “without knowing the full details, it would be inappropriate to comment further.”

The Copenhagen Zoo turned down an offer from a zoo in northern Sweden because it was not an EAZA member and didn’t want to comply with the same high standards, Holst said.

“I know the giraffe is a nice looking animal, but I don’t think there would have been such an outrage if it had been an antelope, and I don’t think anyone would have lifted an eyebrow if it was a pig,” he said.

The Copenhagen Zoo doesn’t give giraffes contraceptives or castrate them because that could have unwanted side effects on their internal organs and the zoo regards parental care as important, said Holst.

The EAZA said it supported the zoo’s decision to “humanely put the animal down and believes strongly in the need for genetic and demographic management within animals in human care.”

However, the organization Animal Rights Sweden said the case highlights what it believes zoos do to animals regularly.

“It is no secret that animals are killed when there is no longer space or if the animals don’t have genes that are interesting enough,” it said in a statement. “The only way to stop this is to not visit zoos.”

“When the cute animal babies that attract visitors grow up, they are not as interesting anymore,” said the organization.

Elisa Allen, spokeswoman for People for the Ethical Treatment of Animals in the U.K., said Marius’ case should serve as a wake-up call for anyone who “still harbors the illusion that zoos serve any purpose beyond incarcerating intelligent animals for profit.”

She said in a statement, “Giraffes rarely die of old age in captivity, and had Marius not been euthanized today, he would have lived out his short life as a living exhibit, stranded in a cold climate, thousands of miles away from his true home.”

The young giraffe’s slaughter comes amid other recent controversial killings of animals, including authorities’ culling of stray dogs in Sochi, Russia, before the Olympic Games there and the $350,000 auction in Texas of a permit to hunt a rhinoceros in order to raise funds for conservation.

Al Jazeera and The Associated Press

The young giraffe's killing comes amid other controversial killings of animals, including the culling of stray dogs before the Sochi Olympic games and the auctioning of a permit to kill a rhinocerous in order to raise funds for conservation.

The young giraffe's killing comes amid other controversial killings of animals, including the culling of stray dogs before the Sochi Olympic games and the auctioning of a permit to kill a rhinocerous in order to raise funds for conservation.