I think you perhaps read into what I said the opposite of what I was thinking when I wrote it. Please check again on the basis of what you know about me..
I'll clarify too: if we follow current economic systems but went the vegetarian route for the nation, there would be no mega beasts. There is no room in this economic system for animals which serve no monetary purpose, particular mega beasts which take up space which would then be required for cultivation. Do you understand my point now? You can't advocate a change to veganism for the nation without killing off millions of animals and destroying bloodlines in the process. It's why I mentioned shire horses; we've already had that mass extinction of some beautiful breeds of horses once they became economically irrelevant.
You cannot keep good lines of unique cows and pigs and insist that all arable land be turned over to cultivation and away from stock management. The work involved is too hard, and costly for it to be done purely on the basis of 'aren't the animals pretty'.
If we had a different system, on the other hand, we wouldn't be having this conversation, I suspect. If we had ethical small holdings across the board, I mean. But we don't. What we have would be described by the above if we somehow woke up to find 99% of the population vegan.