Preheat oven to 350°F (175°C).

Combine cubed French bread and milk in a bowl.

Let the bread soak in milk until the milk is absorbed.

In a large bowl, gently mix ground beef, celery, grated carrot, grated onion, prepared horseradish, salt, and pepper.

Add the bread and milk mixture to the meat mixture and combine.

Shape the mixture into a loaf and place it in a shallow baking pan.

Bake in the preheated oven for 1 hour, or until the meatloaf is browned and cooked through.