It's an interesting take on it, but I think that it ignores quite a lot of things:

• This article is terribly sourced. I'm willing to trust it a bit because the author seems well-qualified, but I can't be confident that the article is accurate.

• This article portrays cows grazing in really open fields, which is an inaccurate picture of how much beef is produced. The significant issue is factory farming, and this article does not address that. I have significantly less problem with feeding on animals that avoid feedlots. I wouldn't be too surprised if the ideal world included some degree of raising animals for food, for a variety of compelling reasons.

• I'm not worried at all about the death of nonhuman animals, but rather the suffering of nonhuman animals. This article seems to conflate the two.

• The normal grain argument is that even if the production of grain does damage, the grain still needs to be fed to the animals, so it's still a net benefit to consume as few animal products as possible. This article counters it by suggesting that cows eat special grains that humans cannot. Assuming that's accurate, if cows were not produced for consumption, all that inedible grain could be replaced with edible grain/vegetables.

• At best, this merits a cow-based diet -- we still should not consume chickens, fish, eggs, pigs, etc.

Overall, I still think anyone interested in preventing as much suffering as possible should reduce his or her animal product consumption as much as possible.