Saute sausage and drain on paper towels. In large frying pan saute ground beef and drain. Combine sausage and cheese with ground beef and cook until cheese is melted. Add worcestershire sauce, oregano, salt, pepper, garlic powder and blend well. Spread on cocktail rye and sprinkle shredded Mozzarella on top. Bake at 350 degrees for 10 minutes. These can be made ahead and frozen. Bake for 12 minutes if frozen.