The secret to keeping turkey from drying out or falling apart is to have the proper ratios of fats, breadcrumbs, eggs, and liquids or milk. This recipe incorporates all 4 in some way or another, so that the balls are perfectly moist and juicy, with no crumbling. If you make a substitution, try to substitute with something of similar nature or texture. For example, if you don’t have breadcrumbs, you can use crushed crackers instead.