Total Liberation means recognizing that all oppression is connected, and it means a commitment to resisting this oppression in all its forms.
Oppression happens when people believe that the universe exists for their use. They start to believe that everything else — the matter of the planet (which they call "natural resources"), other living beings, and other members of their own species — is naturally to be controlled, exploited, and devoured for their personal needs. The human beings of our current age have perfected a system of exploitation and oppression. They enslave and destroy all other species for their pleasure and comfort. They subjugate the members of their own species whose privilege does not match their own. Their entire civilization is structured around the use of all things as resources, and they have systems of morals and ethics that explain, excuse, and even govern these behaviors. The architects of the human system exploit and enslave nearly the entire world, and believe that this is the natural and right thing to do.
When human beings create such victims, they have a further nasty tendency to begin hating them. There is something inherent in the oppressive mentality that leads humans to hate animals, the rich to hate the poor, men to hate women, whites to hate people of color; the oppressor hates and blames his victims for their oppression.
Total Liberation represents an exit from this worldview. Because oppression is ingrained in human civilization of the current era, this must be an active project. It means constantly rejecting racism, sexism, homo- and transphobia, economic inequality, environmental destruction, and all forms of speciesism. If you are against murder, slavery, and exploitation — if you are a feminist, an anti-racist, an anarchist — if you believe in liberation — then you go vegan. Veganism means Total Liberation.