Is Salisbury Steak made out of Chicken, Beef, And Pork?

I have this banquet brand tv dinner of Salisbury steak and some mashed potatoes but w/e but the problem is....next to the salisbury steak it says made with chicken,beef, and pork...I'm so confused right now, it's impossible to be made out of chicken and pork is what I thought...what the heck? Someone explain