I agree meat and dairy are actually subsidized by various farm programs and other factors, but I'm not sure the figures here make sense.
For one thing, meat production uses almost 2/3 of agricultural land, either as pasture, or feedstock production. I think if you realistically accounted for habitat loss, etc, you'd arrive at a figure far above what the article claims.
On the other hand, you can't really blame the industry entirely for people's poor health, so lumping those costs into a 'subsidy' doesn't make sense.
And finally, I am not convinced by veganism. My family and I switched to a "much more vegetarian" diet over a year ago; at least half meals are meat-free, the rest with reduced meat or switched to less environmentally damaging meats (beef->chicken, etc).
It's worked well, but I'm reluctant to go even completely vegetarian, because of health concerns, especially for the kids, and certainly not vegan, until there is good proof otherwise.