Animal agriculture seems to me like one of those things that in 50 to 100 years people will look back on with bewilderment. "You mean you birthed whole animals, let them grow for two years, fed them all the while, just to kill them, chop up their remains, and ship that to people?" Plant based protein and maybe even more so cultured/clean meat (e.g. http://www.memphismeats.com/ ) seem likely to totally replace how we…
How long something has been around is often a good way to determine how much longer it will be around in the future. I'd be willing to bet that humans will stop driving cars much sooner than they stop farming. Humans have been practicing animal agriculture for a long time...
Might be some correlation there, but probably it's mostly unrelated. We did many things for a super-long time then stopped, because we found something better. For example, we used horses to get around for millennia.
We've done animal agriculture for a long time, but once something better comes around, we'll switch - and food technology is getting very close, and has other benefits too (helps against global warming, etc.).
But just like riding horses, eating animal products will never go away completely, of course.