I said they need it for an intended purpose which is for nurturing as well as adequate nutrition. They also don't need to be alive, but they certainly want to be. It's pretty disgusting that you're defending this.
you can't be certain about this: all of the research has failed to produce evidence sufficient to support the understanding of personal mortality in non-human animals. they don't want to be alive any more than they want to die, since they don't understand the choice.
They don't wish to die. This is very clear in their behaviour. They actively seek to avoid being killed, even though there's no escape for them. Many animal psychologists and slaughterhouse workers can verify this. They show fear and cower, try to escape, or even try to knock bolt guns away. They can smell blood of the animals that were killed before them, and they often see their dead bodies too. They moan desperately at the top of their lungs. They are sentient and highly intelligent animals. They know they're about to die and they exhibit a clear desire to live.
Even ignoring this, it's obviously in their best interests for them to be alive and not have their life taken away from them at a young age, just like it is for them to be with their mother and live a happy, healthy life, without harmful interference and exploitation by humans.
They don’t wish to die. This is very clear in their behaviour.
then it should be a simple matter to find an animal cognitive behaviorist to support this position. it's not, though, because behavior does not entail cognition.