The Bond villain-esque revelation was made by Dorsey in a bizarre interview in Rolling Stone magazine.
Asked about his most memorable encounter with Zuckerberg, Dorsey said: “Well, there was a year when he was only eating what he was killing. He made goat for me for dinner. He killed the goat.”
He added: “He kills it with a laser gun and then the knife. Then they send it to the butcher.”
Asked by gobsmacked interviewer Brian Hiatt for more details, Dorsey went on: “A stun gun. They stun it, and then he knifed it. Then they send it to a butcher.
“Evidently in Palo Alto there’s a rule or regulation that you can have six livestock on any lot of land, so he had six goats at the time.”
The social media chief said: “I go, ‘We’re eating the goat you killed?’ He said, ‘Yeah.’ I said, ‘Have you eaten goat before?’
“He’s like, ‘Yeah, I love it.’ I’m like, ‘What else are we having?’ ‘Salad.’ I said, ‘Where is the goat?’ ‘It’s in the oven.’
“Then we waited for about 30 minutes. He’s like, ‘I think it’s done now.’ We go in the dining room. He puts the goat down. It was cold. That was memorable. I don’t know if it went back in the oven. I just ate my salad.”
Zuckerberg’s pledge to only eat meat from animals he killed himself was denounced in 2011 by animal rights organisations.
The charity Peta said on its website at the time: “Kinda makes you wonder if Zuckerberg is missing the empathy gene, huh?”