To prepare dough, cook 1 2/3 cups milk in a heavy saucepan over medium-high heat to 180° or until tiny bubbles form around edge (do not boil). Remove from heat. Combine 2/3 cup oats, wheat germ, and cornmeal in a large bowl; stir in scalded milk. Cool until warm (100° to 110°).
Lightly spoon whole-wheat flour into dry measuring cups; level with a knife. Combine 1 1/2 cups wheat flour and yeast in a bowl, stirring with a whisk. Add flour mixture to milk mixture; stir well to combine. Add water and next 7 ingredients (through salt) to milk mixture; stir until well blended.
Lightly spoon all-purpose flour into dry measuring cups; level with a knife. Add 1/2 cup whole-wheat flour and 2 1/2 cups all purpose flour to milk mixture; stir until a soft dough forms. Turn dough out onto a floured surface; let rest 5 minutes. Knead dough until smooth and elastic (about 8 minutes); add enough of remaining flour, 1 tablespoon at a time, to prevent dough from sticking to hands (dough will feel tacky).
Place dough in a large bowl coated with cooking spray, turning to coat top. Cover and let rise in a warm place (85°), free from drafts, 1 hour or until doubled in size. (Press two fingers into dough. If indentation remains, dough has risen enough.) Punch dough down; cover and let rest 5 minutes. Divide in half. Working with one portion at a time (cover remaining dough to keep from drying), roll each portion into a 13- x 7-inch rectangle on a floured surface. Roll up each rectangle tightly, starting with a long edge, pressing firmly to eliminate air pockets; pinch seam and ends to seal. Place each roll, seam side down, in an 8- x 4-inch loaf pan coated with cooking spray. Cover and let rise 1 hour or until doubled in size. (Press two fingers into dough. If indentation remains, dough has risen enough.)
Preheat oven to 375°.
To prepare topping, combine 1 tablespoon milk and egg in a small bowl; brush over loaves. Combine flaxseed, poppy seeds, millet, and 1 teaspoon oats in a bowl; srinkle seed mixture over loaves.
Bake at 375º for 15 minutes. Reduce heat to 350º and bake 20 minutes or until loaves are browned on bottom and sounds hollow when tapped. Remove from pan; cool on wire racks.