There's a difference between early and late abortions. If you have a late abortion, where the fetus might feel pain, then I think you should have a good reason. Because then you're inflicting pain. As you go through the third trimester, you need to have more serious reasons to end a pregnancy.
It was wrong to capture wild animals and confine them in captivity for people to go and gawk at them. And that's basically how zoos got started. But once you do that, and once you have animals that have been bred in captivity, you're really stuck with them in some sense. You can't return them to the wild.
Many European countries, as well as Australia, Canada, Israel, and New Zealand, have adopted legislation that creates a 'public lending right', where the government recognises that enabling hundreds of people to read a single copy of a book provides a public good, but that doing so is likely to reduce sales of the book.
I am not saying that factory farming is the same as the Holocaust or the slave trade, but it's clear that there is an immense amount of suffering in it, and just as we think that the Nazis were wrong to ignore the suffering of their victims, so we are wrong to ignore the sufferings of our victims.