At first, I thought "what an absurd question!" But I'll assume you're really asking something else. If you take a frozen turkey, thaw it, drain it, and remove the giblets, of course it will weigh less than it did when it was frozen in the package. As you cook it, it will lose additional weight in both water and fat. So the cooked bird will weigh significantly less than the frozen package.
at 12:44 PM on Dec. 3, 2009