Euthanasia is intrinsic to the good work that many zoos do, and I understand the Copenhagen team's decision. Still, this is terrible PR for zoos, and will have repercussionsWARNING: video contains images some viewers may find distressing

My partner runs a zoo, and I am, in general, supportive of them – primarily because of their ability to engage and educate people, and also because of the work many of them do in conserving endangered species. It is important to understand, too, that euthanasia is part and parcel of animal husbandry, whether it be in a zoo, on a farm or with pets in the home. Euthanasia can be beneficial for an institution and for other animals: it can allow other individuals to get better care and attention – even survive.

So I would understand, in principle, Copenhagen zoo's decision to shoot a healthy young giraffe to avoid the problem of inbreeding. I could equally support its decision to feed the meat to the lions, and to let people see that. We are so detached from the cycle of life these days – many children have no idea where their food comes from – and giraffe are a part of lions' natural prey. I understand some people may find it gruesome or extreme, but I have no objection to this video being put online. People do not have to watch it, and I would defend its educational value. The same scene is happening now on the plains of Africa.

So sometimes euthanasia is necessary. The ethical considerations are the same whether it's a tiger, a rat, a terrapin. You can't, in general, breed animals in captivity to go back into the wild. So animals in captivity should be and are kept on contraceptives – although some zoos do argue that, for the benefit of the adults, some should go through the breeding process and raise offspring. We have to ask why was this animal born in the first place, if it was destined to be "unwanted".

The principal role of zoo animals, I feel, is as ambassadors for nature's wild masterpieces, as tools for education and public engagement, to teach people about the need for conservation and to motivate them to be concerned about the plight of animals in the wild. This animal surely could have played that role elsewhere.

This incident is probably the biggest PR disaster for zoos in recent memory. The belligerent arrogance of this particular zoo in the face of a worldwide campaign to save the animal will have global repercussions. People are polarised about zoos: they are either for or against. And the vast majority will not bother to find out why this happened; they will make a judgment. My partner will have to go to her zoo this morning and face a barrage of emails and a public outcry.

People will never even try to understand why this giraffe had to die when the Yorkshire Wildlife Park – even other zoos in Copenhagen – were offering to take it. This zoo will have its ethics committee; all zoos do. It took its decision and it has stuck by its guns. But by ploughing on regardless, it showed scant regard for the difficulties all zoos face in explaining their role and responsibilities to a sometimes sceptical public.

This zoo was, at least, transparent. When Longleat euthanased several lions recently, we only got to know about it because of a whistleblower. But zoos have enough PR problems as it is, and in this case a far better solution would have been to allow the giraffe to go to another zoo.