Eating a largest possible animal means less amount of suffering per kg.
I think this is the right general trend but the details matter and make it probably not true. I think cow farming is probably more humane than elephant farming or whale farming would be.
Larger animals tend be more intelligent just because they have larger brains, so their sufferings will be more complex: they may understand their fate in advance. I think whales and elephants are close to this threshold.
An opposite logic may be valid: we should eat animals with smallest brains as their suffering will be less complex and also each of them is less individual and more like a copy of one another. Here we assume that suffering of two copies is less than of two different minds.
I think this is the right general trend but the details matter and make it probably not true. I think cow farming is probably more humane than elephant farming or whale farming would be.
Larger animals tend be more intelligent just because they have larger brains, so their sufferings will be more complex: they may understand their fate in advance. I think whales and elephants are close to this threshold.
An opposite logic may be valid: we should eat animals with smallest brains as their suffering will be less complex and also each of them is less individual and more like a copy of one another. Here we assume that suffering of two copies is less than of two different minds.