It's a great and tough question, and to be totally honest I don't have a fully formed view on this. It does seem like a life lived on a farm with humans could have significantly less suffering than a live in the wild. If the animal is (i) not being used for some byproduct, e.g., being repeatedly inseminated for milk (ii) has enough volition, or freedom to roam, and reproduce in some (possibly controlled) manner, it seems like such a life could be quite good for an animal. There are probably many small family farms that keep animals for pleasure and not to raise for meat that practice this sort of ethical farming.

One argument against this sort of intervention comes from my experience living with our family dog (we've had him for five years). He is a calm and intelligent dog who I feel has had a good life, but I feel sometimes that it is a very restrictive one. He can't do whatever he wants, and is separated from other creatures like himself. My feeling is that his life was worth living, but there is an element of guilt when I think about how free he is, and once he passes away I don't think I will keep a pet in a future family I start.

It's very hard to say what these creatures who cannot speak up for themselves really want, and whether we should interfere with their lives to prevent suffering that's inherent in nature.

Do you have any thoughts on this? Please let me know if you have any books/resources to recommend. I'm planning to read Singer's Animal Liberation soon, which will probably discuss this question.