From this story on CNN:
When he's not too busy connecting people across the universe, Mark Zuckerberg is pursuing a new "personal challenge," as he calls it. "The only meat I'm eating is from animals I've killed myself," says the Facebook founder and CEO. It's an odd dietary direction for the 27-year-old Internet billionaire, but since he has taken to killing goats, pigs and chickens, "I'm eating a lot healthier foods. And I've learned a lot about sustainable farming and raising of animals," he says. "It's easy to take the food we eat for granted when we can eat good things every day." Zuckerberg's new goal came to light, not surprisingly, on Facebook. On May 4, Zuckerberg posted a note to the 847 friends on his private page: "I just killed a pig and a goat."
"...While Zuckerberg's new diet hasn't exactly gone viral in the way that, say, Facebook has, he says he's seen some people warming to it: "I was surprised by how many of my friends have interests in some of the areas I'm exploring in such diverse ways. Many are vegetarian, some enjoy hunting and some even farm. My girlfriend is my main partner in this, though, since we eat the most meals together." Zuckerberg's learning curve has been evolutionary: moving from sea creatures to land animals. His first kill was a lobster, which he boiled alive. He says it was a difficult kill, at least emotionally. He had an entirely new feeling once he took a bite: "The most interesting thing was how special it felt to eat it after having not eaten any seafood or meat in a while."