I suppose that to a person who a) is already eating beef burgers and b) is considering swapping the meat in their burger to chicken for environmental reasons, t

I suppose that to a person who a) is already eating beef burgers and b) is considering swapping the meat in their burger to chicken for environmental reasons, the value of the life of a cow and the life of a chicken are both functionally nil. Perhaps not "without value", but too difficult to quantify against each other to be meaningful when decision making.