The argument is drawing parallels between slavery (currently not socially acceptable) and treatment of animals as livestock (currently socially acceptable). You

The argument is drawing parallels between slavery (currently not socially acceptable) and treatment of animals as livestock (currently socially acceptable). You're basically responding to this argument by regurgitating what current status quo is. Stating "the status quo is the status quo" isn't an argument on why the status quo is justified. It's just a statement of fact.