I suspect that even if you could leave your herd out in the snow all winter, a detailed analysis would determine that bringing them into the barn to keep them warmer and feeding them hay for the winter yields more milk per acre. That would, in turn, imply things like a lower carbon footprint and less damage to already stressed ecosystems.
It's kind of like burning wood to heat your house: It may be traditional, but that doesn't necessarily make it better. Realistically, the only reason all sorts of traditional practices were sustainable way back when was that the human population used to be a fraction of what it is now.
It's kind of like burning wood to heat your house: It may be traditional, but that doesn't necessarily make it better. Realistically, the only reason all sorts of traditional practices were sustainable way back when was that the human population used to be a fraction of what it is now.