In a large mixing bowl, dissolve yeast in water. Add milk, sugar, egg, salt, and 3 cups flour. Stir until smooth. Stir in butter and remaining flour. Dough will be slightly sticky. Do not knead. Place in a large greased bowl. Cover and refrigerate overnight.
The next morning, punch down and divide in half. On a floured surface, roll each half into a 12-inch circle. Cut each circle into 12 pie-shaped wedges. Beginning at the wide end, roll up each wedge.
Place horns two inches apart, point-side down, on a greased baking sheet. Cover and let rise in a warm place until doubled, about one hour. Bake at 350° for 15 to 20 minutes or until golden brown. Brush rolls with remaining butter while still hot.