So every bondman in his own hand bears the power to cancel his captivity.
I made the choice to be vegan because I will not eat (or wear, or use) anything that could have an emotional response to its death or captivity. I can well imagine what that must feel like for our non-human friends - the fear, the terror, the pain - and I will not cause such suffering to a fellow living being.
I can't mate in captivity.