Actually, a substantial number of Transhumanists, and especially Abolitionist Transhumanists, are vegan or vegetarian. I myself am a strict vegetarian, and plan to eventually become a vegan. And yes, I am quite familiar with David Pearce; he's my friend on Transhumanists.org. His Hedonistic Imperative, an Abolitionist manifesto, is what led me to my philosophy. He's quite accessible, if you'd like to get to know him.