There are a few tricks that we use here to keep the turkey from being too dry. One, is to grate the onions. This helps release the onion juices and adds moisture to the turkey meat. The second trick is that we add milk, which adds a creamy liquid to keep the meatloaf from drying out. Finally, we also use Worcestershire sauce and ketchup in the meatloaf mixture itself, as well as in the glaze, to add both moisture and umami flavors to the meatloaf.