Wouldn't work on me, I have close to a hatred toward dogs :-)

But I grew up in the countryside, I knew some cows and goats, heard the sad cry of the cows when you take their calves away. The reason why I eat very little beef and pork now but have less problems with chicken and fish is because I do feel different about them.

See I used to be more concerned about the ethics of animal exploitation as a kid than as an adult. (My experience was with free range animals though.) One of the questions I often came back at as a kid was "Do the animals understand what is happening? Why don't they try to escape?" It puzzled me that the cattle seemed to love their captors. Food was more primordial to them than freedom.

Then I realized some things: most humans would take such a deal. Security vs freedom. If I offered you to double your life expectancy (which is basically what wild vs farm animals experience), to feed and cure you, provide a more comfortable shelter than you could be able to get on your own, would you object to me eating your meat at a determined date?

I know I would refuse, I used to think most humans would but nowadays I am far less optimistic about that, and I am pretty certain that most animals would sign in.

I still think the whole system is unethical and an ideal world should not have it, so I do limit my meat consumption, I don't participate in the boohooing of vegans. I just don't see it as the highest priority ethical concern right now.

Always grateful for someone sharing their experience. I think by "knew" I meant live with, as one would live with a pet dog or a cat. I see them every day, I get to know their personality at a level that I understand when they're suffering, and how much they understand doesn't matter to me. I would feel devastated if someone were to take them away from me and unfeelingly exploit them. I'm not vegan, but I guess I'm boohooing participant.

But the ethical base-case is potentially that none of those cows, pigs, chickens or turkeys are ever born. Case by case we couldn't say, but statistically a lot of farm animals are going to be reliant on human logistics, organisation and protection to survive in the numbers that they do.

So the question might reasonably be 'are the conditions these animals face worse than never existing?'.

For a lot of them, the answer is most certainly yes, and if humans were in their positions, they'd say so too.

Then I think the natural follow-up experiment would be to imagine if a dog you know was born for dogfighting, and that you can be sure it will never escape. Would we rather it just not be born? If not, we just need to argue that being bred to dogfight is preferable to, or on-par with, being bred to be trapped in a cage and eaten.

I never understood that logic. I don't see why more animals (or humans) existing ought to be considered a good thing?

That isn't the core of the argument; the point is that there is no good outcome for most of those animals. The choice is exist, live and be slaughtered for food vs. never being born.

Not an enviable choice, but it confounds some of the simple ethical arguments for, eg, vegetarianism.

But I don't understand how it is relevant to what we should do?

Our goal is to minimize the amount of suffering we are responsible of. In that respect it is obviously better to not breed animals than to breed them and make them suffer.

I'm not sure your thought experiment is all that useful, because there are many people who feel that livestock are fundamentally different from their pets and your example is similar to "What if the wizard instead replaced every plant with a human? Is it unethical to eat plants then?"

True, but I rarely see people explicitly assert that. The more people have to explain an arbitrary distinction out loud, the less it makes sense in the culture.