If you talk to a real vegan, their ethical argument will likely be “do not create animals in order to kill and eat them later”, period. Any discussion of the quality of life of the farm animal is rather secondary. This is your second argument, basically. The justification is not based on what the animals feel, or on their quality of life, but on what it means to be a moral human being, which is not a utilitarian approach at all. So, none of your utilitarian arguments are likely to have much effect on an ethical vegan. Note that rationalist utilitarian people here are not too far from that vegan, or at least that’s my conclusion from the comments to my post Wirehead Your Chickens.
If you talk to a real vegan, their ethical argument will likely be “do not create animals in order to kill and eat them later”, period. Any discussion of the quality of life of the farm animal is rather secondary. This is your second argument, basically. The justification is not based on what the animals feel, or on their quality of life, but on what it means to be a moral human being, which is not a utilitarian approach at all. So, none of your utilitarian arguments are likely to have much effect on an ethical vegan. Note that rationalist utilitarian people here are not too far from that vegan, or at least that’s my conclusion from the comments to my post Wirehead Your Chickens.