Cut bread into 1/2-in. slices. Place slices in a large bowl and add milk. Mix gently with a spoon to saturate with milk and let stand about 30 minutes. Stir occasionally.
Meanwhile, place a 6- to 8-qt. pot over high heat. Squeeze sausages from casings into pot. Discard casings. Cook meat, stirring often to crumble, until lightly browned, 10 to 15 minutes; discard fat. Add parsley, garlic, onion, and celery. Cook, stirring often, until vegetables are lightly browned, 5 to 8 minutes. Add chard and 1/2 cup water and cook, stirring often, until wilted, about 5 minutes.
With your hands, squeeze bread slices to break them into tiny pieces. Add cooked meat mixture, parmesan, basil, sage, and rosemary. Season with salt to taste.
Preheat oven to 325° or 350° (use temperature turkey requires; see Note below). Spoon stuffing into a shallow 3-qt. (9- by 13-in.) casserole. For moist stuffing, cover with foil; for crusty stuffing, do not cover. Bake until hot (at least 150° in center) or lightly browned, at least 30 minutes.
Make ahead: Up to 1 day ahead, make stuffing, put in casserole, cover, and chill. Allow about 1 hour to bake.
Note: For turkeys 10-13 lbs., oven/bbq temperature should be 350°; for turkeys 14 lbs. and over, oven/bbq temperature should be 325°.
Note: Nutritional analysis is per 3/4-cup serving.