Cows have 2 stomachs to derive nutrition from difficult-to-digest grasses. "Greens" are not all grasses.
http://michaelbluejay.com/veg/natural.html
"The meat-eating reader already has half a dozen objections to this before s/he's even read the rest of the article, and I will address those objections specifically, but first let me address them generally: It's human nature to want to feel that what we're doing is right, proper, and logical. When we're confronted with something that suggests that our current practices are not the best ones, it's uncomfortable. We can either consider that our choices may not have been the best ones, which is extremely disturbing, or we can reject that premise without truly considering it, so that we don't have to feel bad about our actions. That's the more comfortable approach. And we do this by searching our minds for any arguments we can for why the challenge must be wrong, to justify our current behavior. This practice is so common psychologists have a name for it: cognitive dissonance.
Think about that for a moment: Our feeling that our current actions are correct isn't based on our arguments. Rather, our actions come first and then we come up with the arguments to try to support those actions. If we were truly logical, we'd consider the evidence first and then decide the best course of action. But often we have it in reverse, because it's too difficult to accept that we might have been wrong.
Vegan bodybuilders shatter the myth that vegans are skinny and malnourished.
This is particularly true when it comes to vegetarianism. It's easy to identify because the anti-vegetarian arguments are usually so extreme, compared to other kinds of discourse. A person who would never normally suggest something so fantastic as the idea that plants can think and feel pain, will suddenly all but lunge for such an argument when they feel their meat-eating ways are being questioned, and they're looking for a way to justify it. It's human nature.
I used to be in the same position as most readers probably are now. Long ago my eating habits were challenged by a book I ran across in the library. I didn't want to consider it fairly, because I wanted to keep eating meat. I'd grown up eating it, and I liked it. And there was another reason: I'd grown up in a small farming community raising and killing chickens. Accepting the book's premise really meant that I'd have to admit that I might not have made the best choices. So I came up with various weak defenses to justify my behavior. But deep down I knew I was kidding myself, and practicing a form of intellectual cowardice. When I considered the arguments honestly, I stopped eating animals. There was really no other logical choice. That was 25 years ago and it was absolutely the best decision I ever made.
So I challenge you: stop trying to figure out ways that I "must" be wrong even before you've bothered to read the rest of this article. Instead, read it, and actually consider it rather than reflexively trying to come out with ways to dismiss it out of hand. You can certainly still disagree after you've considered all the evidence -- but not before."
I realize this is a lengthy article, not a blogger's set of easy-to-digest sound bites, but hopefully the angry omnivores here can take the time to read the entire article via the link above, as I've taken time to read and research the references you provided to me.
