I oppose racism, sexism, trans- and homophobia. And I oppose speciesism as well. It’s the same system: One group considers another group as less valuable and exploits, abuses or fights them.
You just draw the line at you own species.
Animals are innocent, vulnerable and easy to abuse because they don’t have a voice and don’t understand the situation we put them in. If they were human children or mentally disabled humans, we would protect them from harm because of who they are. Instead, we do the most horrible things to them, we take their freedom, their babies, their lifes. In factories, on an industrial scale. Because a pig is just a pig, right?

EDIT: Please reply, don’t just silently downvote. What’s your refutation?