Preheat the oven to 350 degrees F (175 degrees C). Lightly grease a 9x13-inch baking dish.
Mix ground beef, ground turkey, Cheddar cheese, bread crumbs, zucchini, onions, bell pepper, egg, ranch mix, and Worcestershire sauce in a large bowl until well combined. Form mixture into a loaf and place in the middle of the prepared baking dish.
Stir ketchup and steak sauce together in a small bowl until well combined; pour over meatloaf.
Bake in the preheated oven until no longer pink in the center, about 1 hour. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).